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2005 National DNA Day Online Chatroom Transcript

This is an archive of the the National DNA Day Moderated Chat held April 25th, 2005. NHGRI Director Francis Collins and genomics experts from across the institute took questions from students, teachers and the general public on topics ranging from basic genomic research, to the genetic basis of disease, to ethical questions about genetic privacy.

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Information - Moderator Welcome to the online chat for DNA Day 2005! Experts from the National Human Genome Research Institute are here and ready to take your questions. The chatroom is open from 8 a.m. until 4 p.m. Eastern and we're going to try to answer as many of your questions as time allows. So, get busy and start sending them in! Joining us now are Vence Bonham, J.D. Chief of the Education and Community Involvement Branch and Associate Investigator in the Social Behavioral Research Branch; and Belen Hurle, Ph.D., Research Fellow, Genome Technology Branch and Science Educator, Education and Community Involvement Branch.

Are there any specific variations in the human genome that can be attributed to differences between the races? Will some of these variations help to develop individualized therapies?
     Vence Bonham, J.D.: No. Human Racial Groups are a social construct. How races are defined has changed over time. Human genetic variation exists across the world which often correlates with self identified race. However, there are no gene variants that are present in all individuals of one racial group and in no individuals of another group. Understanding an individual's ancestry is important for the development of individualized therapies and knowing a person's race or ethnicity may or may not tell us very little about that person's ancestry. Using the construct of race in describing human genetic variation is full of complexities.
St. Ignatius College Prep HS
How does methylation of DNA occur and what does it do to protect DNA from being cleaved?
     Belen Hurle, Ph.D.: Methyl group tags in the DNA of humans and other mammals play an important role in determining whether some genes are or are not expressed. Genes unnecessary for any given cell's function can be tagged with the methyl groups. Simpler organisms, such as many types of bacteria and the single-celled yeast, usually do not use methyl group tagged C's in regulating their genes. Some bacteria, but not all, use methyl group tagged A's (mA) for this purpose. However, most bacteria have specific patterns of mC and mA in their DNA as a signal that says "this is my DNA" and acts as part of an immunity mechanism that allows bacteria to destroy the DNA from infecting viruses without destroying their own DNA. In other words, the distinction between "foreign" and "self" DNA is made through a specific methylation of the bacterial DNA, which protects it from cleavage by the restriction enzymes. The viral DNA, which is not protected, is quickly degraded by the restriction enzymes carried by the bacteria.
Eddie Wang, Montgomery Blaire HS
Does every living thing have DNA?
     Belen Hurle, Ph.D.: Yes, every living thing -- plants, animals and even microorganisms -- has DNA. There are biological entities that do not rely on DNA, but they are pretty weird. Some viruses, for example, reproduce through RNA instead of DNA. And then there is an entity called a prion which does not appear to have any nucleic acid, but appears to cause some neurological disorders, including Alzheimer's dissease.
roberto ny
What happens on national DNA Day?
     Vence Bonham, J.D.: High school students and teachers across the country come together to celebrate our knowledge about the human genome. There are scientists that are going into high school classrooms across the country to share their knowledge about the human genome. We hope it encouages students to learn more about the human genome.
Should scientists/corporations have the right to patent genes? What impact does/will this have on genetic research?
     Vence Bonham, J.D.: The purpose of a patent is to provide an incentive (in the form of a time-limited monopoly) to encourage the commercializing of technological innovation. However, when someone patents a genetic sequence, he/she can exclude others from making, using, or selling any tests based on detection of the gene and/or particular mutations in the gene. Consequently, this makes the patent on a gene much more powerful and valuable than many other patents and can cause a limit in the sharing of research knowledge. The International Human Genome Project put its data in the public domain. All the sequence information acquired from the Human Genome Project was immediately deposited into databases that can be assessed on the World Wide Web.
St. Ignatius College Prep HS
Are there special enzymes that unwind/transcribe mitochondrial DNA, as compared to enzymes that help transcribe cellular DNA?
     Belen Hurle, Ph.D.: The mitochondrion is the energy producing organelle in the cell, and the only organelle in animal cells besides the nucleus that contains its own chromosome. Maintenance of mitochondrial function requires the replication and expression of the mitochondrial genome. Remarkably, not a single gene involved in mitochondrial molecular biology is encoded in the compact mitochondrial genome: all of the protein machinery for replication, transcription, and translation (and DNA repair functions) is encoded in the nucleus, and the relevant proteins must be imported into the mitochondrion.
Kiran Bhat, Montgomery Blaire HS
Do stem cells have the same genome as other cells?
     Belen Hurle, Ph.D.: Yes, stem cells have exactly the same genome as the other cells of the body from which they are derived. All cells in the body arise from a single cell, the fertilized egg. And then the fertilized egg changes into every other type of cell in the body. As most cells mature, they lose their ability to change into a different cell type. .Stem cells retain their ability to change into another type of cell. All cells of the body have exactly the same DNA, including the stem cells.
mohamed taha alahram egypt
Have there been certain genetic trends found in people of certain race and ethnic backgrounds?
     Vence Bonham, J.D.: Yes. There are a number of studies that show that certain allele frequencies are clustered in the indviduals of certain self-identified racial and ethnic backgrounds.
Erin, Maine
wat year was nucleic acid discovered?
     Larry Thompson: Friedrich Miescher, a chemist, isolated nuclein from the nucleus of pus cells in 1869. The substances were rich in phosphorus and nitrogen and came to be known as nucleic acid. And nucleic acid, of course, is the building block of DNA, the stuff of the genome.
Shanaenae, Sveeden
What are restriction enzymes and how are they used in genetic engineering?
     Belen Hurle, Ph.D.: Hello, Helena. Restriction enzymes are part of the immune system of bacteria. They recognize short sequences in the DNA of infecting phages and cut the DNA (DNA degradation). In genetic engineering they are used as "scissors" that allow researchers to chop big pieces of DNA in a controlled way for analysis and further manipulation.
Central HS, Helena AR
Is it possible that later on in the future we will be able to change the way our children look and act?
     Vence Bonham, J.D.: In the future it may be possible. The question is do we want to use technology to change the way our children look and act? What do you think?
Central HS, Helena AR
How close are we to cloning, do you think it will really happen?
     Belen Hurle, Ph.D.: Hello, how are you? the answer is, it depends on what organisim you are talking about. Sheeps and cats, for example, have been cloned already. In terms of humans, I think it is technically not possible yet. Most regulatory agencies in most countries around the world are concerned about the ethical implications and have legislation banning human cloning.
Central HS, Helena AR
How does mustard gas remove guanine from DNA?
     Belen Hurle, Ph.D.: Mustard gas is a very reactive intermediate and is particularly negative to cellular health as it has a strong tendency to bond to the guanine nitrogen in DNA strands. This leads to either immediate cellular death or, as recent research has found, cancer. Mustard gas is not very soluble in water but is very soluble in fat, contributing to its rapid absorption into the skin.
Clair Briggs, Montgomery Blaire HS
What should our class do for DNA day?
     Vence Bonham, J.D.: Watch the webcast and participate in the chat room. We want you to have fun as well as learn about the human genome.
Would you personally consider tweaking your own child's genome in order to create a better, healthier outcome?
     Vence Bonham, J.D.: Today you cannot tweak a person's genome. Gene therapy is an evolving technique used to treat inherited diseases. The medical procedure involves replacing, manipulating, or supplementing nonfunctional genes with healthy genes. Today the procedure is experimental and includes many risks. One example that is currently available is Preimplantation genetic diagnosis (PGD). PGD tests early-stage embryos produced through in vitro fertilization (IVF) for the presence of a variety of conditions. One cell is extracted from the embryo in its eight-cell stage and analyzed. Embryos free of certain conditions can be implanted in a woman's uterus and be allowed to develop into a child. We all have mutations in our genome and I would be hesitant to intervene. These are difficult personal and moral decisions for each person involved.
St. Ignatius College Prep HS
Are other forms of life possible without DNA?  (Assuming life has metabolic activity and reproduction)
     Belen Hurle, Ph.D.: Hi, Eric! How do you define forms of life? Some viruses have RNA as their only genetic material, but they are not free living organisms.
Eric, Newton North HS
If identical twins have the exact same DNA, then what accounts for their differences in intelligence, sexual orientation, etc.?
     Belen Hurle, Ph.D.: Every human is different from one another, even identical twins because we are all products of the interaction of our genes and the environment in which we live. Even before birth, the environment in which the twins develop is slightly different (Who was born first? Who gained more weight during pregnancy?). The environmental differences keep multiplying and accumulating from birth on, making it impossible to ever repeat a human being.
Rose Feinberg, Montgomery Blaire HS
Attn: Vence Bonham, What does J.D. stand for?
     Vence Bonham, J.D.: J.D. is a juris doctorate degree. It is a law degree. There is a need for professionals from different disciplinary backgrounds to be involved in genomic research. I conduct research on the social, ethical and legal implications of genomics.
Lisa, Ben Logan High School

Information - Moderator Joining us now is Larry Thompson, M.S., M.F.A., chief of the Communications and Public Liaison Branch.

How long have you been working on the genome project?
     Larry Thompson: Hi Melissa. The Human Genome Project began in October 1990. The first draft of the genome project was announced in June 2000 and the project was completed in April 2003, about two years earlier than expected. We are now done with the Human Genome Project and are moving on to many projects designed to help scientists and doctors understand the information contained in the genome's digital code. Ultimately, scientists want to identify all of the genes and other functional parts of the genome.
Melissa Frank, Benjamin Logan
Why is DNA not always double stranded?
     Belen Hurle, Ph.D.: Hi Saurov. You are our first person from India! When you separate the two strands of DNA you create two template strands that the cell machinery uses to produce two identical copies of the original molecule. You cannot achieve DNA replication withouth separating the strands first.
Saurov Mahanta, India
What would happen if half of your introns were removed?
     Belen Hurle, Ph.D.: Hello June, if an intron is not removed, it remains as part of the final RNA molecule. The translation of its sequence alters the sequence of the protein product, most often causing (a) frameshift with premature stop codons or (b) incorrect skipping of exon(s). In the scenario that you describe, many, many of your proteins would not be functional at all (very deadly condition).
June Hu, Montgomery Blaire HS
What role do you see genetic engineering playing in our everyday lives 10, 25, 50 years into the future?
     Bob Nussbaum, M.D.: Genetic engineering will provide us with new tools for diagnosing diseases and developing new treatments. It will also be used to grow replacement tissues in the laboratory to help repair damaged organs. Finally, I expect that we will be able to go in and change defective genetic information and correct it to prevent the disease from developing or progressing.
St. Ignatius College Prep
When was DNA Day originated, and who came up with it?
     Vence Bonham, J.D.: Congress declared April 25th 2003 as DNA Day to celebrate the completion of the human genome project and the 50th aniversary of the description of DNA.
Lindsey, Benjamin Logan High School
How do exonucleases repair DNA in replication
     Belen Hurle, Ph.D.: Hello Ravi, as you know, the main enzymatic activity of DNA polymerases is the 5' ----> 3' synthetic activity. It is possible (but rare) for DNA polymerases to incorporate an incorrect base during replication. Fortunately, these mismatched bases are recognized by the polymerase immediately due to the lack of Watson-Crick base-pairing. The mismatched base is then removed by the 3' ------> 5' exonuclease activity and the correct base inserted prior to progression of replication.
Ravi Umarji, Montgomery Blaire HS, Maryland
Do you see stems cells as the wave of the future?
     Bob Nussbaum, M.D.: Stem cells are important tools for developing replacment tissues and organs that have been damaged by disease or injury. I expect stem cells will be very important in helping to treat cancers, spinal cord injuries, and heart disease. All, importantly, by studying stem cells in culture, we can learn how normal stem cells in the body develop into the tissues of the body. The great hope is that we will develop drugs and other substances that will promote one's OWN stem cells to divide and develop and repair damaged tissues. So, I see stem cells as having both a BASIC research role, to help us understand how tissues develop, and an APPLIED role in giving us actual tools for repairing damaged tissues and organs.
St. Ignatius College Prep
What's your favorite chromosome?
     Eric Green, M.D., Ph.D.: For the Human Genome Project, my research laboratory was assigned chromosome 7. Our job was to develop an organized 'map' of this chromosome, which comprises 5% of the human genome. We then were involved in helping to get chromosome 7 sequenced. Our many person-years of effort certainly made chromosome 7 our 'local favorite'-- but in reality the entire human genome is so vast, so fascinating, and so important that it is impossible to really consider any part of your true favorite.
Chad, maine
What careers are there in this field?
     Kim Kaphingst, Sc.D.: This field has many different types of careers. You can be a genetic researcher or can do other types of research. I study how to communicate information about genetics to people. Other researchers study the ethical questions around genetics. Then other people educate the public about genetics.
Josh, Bellefonaine
What is the possibility of a human proteome project?
     Eric Green, M.D., Ph.D.: The Human Genome Project demonstrated that a large, focused effort could be mounted to tackle a 'comprehensive' goal-- like determining the entire sequence of the human genome. The notion of using a similar large, high-throughput project to determine the complete set of human proteins is certainly quite reasonable. Certainly, different methods and strategies would be required. Indeed, efforts to develop catalogs of all proteins in certain cells or certain tissues are ongoing. This emerging field is often called 'proteomics'.
St. Ignatius College Prep HS
Will genetic therapies, as they develop, be made (realistically) available to the public or will they be too expensive for most to afford?
     Bob Nussbaum, M.D.: This is an excellent and difficult question. If one looks at the history of many medical breakthroughs, treatments haved started out very expensive and then became cheaper as newer and better approaches have come along. For example, iron lungs were very expensive for treating people stricken with polio. Developing polio vaccines was expensive (and paid for primarily by private charitable donations through the March of Dimes, by the way) but is now so cheap that we are having trouble getting companies to make vaccines because their profitability is low. I do believe that in the future, a partnership between the government and private industry will work to make the fruits of genetic research available. However, this is a problem that all of society, not just scientists, not just geneticists, will have to deal with and solve. That's why it is SO IMPORTANT that everyone be aware of what is going on in genetics, not just a narrow group of specialized scientists, but policy makers and economists in the government. Every citizen of the world needs to have an accurate and thorough knowledge.
St. Ignatius College Prep High School
According to the DNA code, what organism is our closest relative?
     Eric Green, M.D., Ph.D.: The chimpanzee, whose genome was recently sequenced. At a DNA sequence level, we are 98.5% identifical to chimpanzees.
Billy Madison
How can twins DNA be exactly the same, yet be so different?
     Kim Kaphingst, Sc.D.: There are many things other than DNA that affect how people act. The environment in which you grow up and live in has a big effect on behavior. So, if twins have different groups of friends or are treated differently by other people, they can act very differently.
Jenna BLHS
how old are you people
     Larry Thompson: Hi. We have a roomful of about a dozen folks right now, reading and trying to answer all of your questions. And the age range is from the early 20s to the mid-50s. We have the institute's scientific director, one of the branch chiefs -- both are MDs doing research, among other staff. The range of people who work at the institute range from high school students on internships to very senior, tenure-track scientists with decades of experience.
steven woo, Warwick,RI
Is there current plans to study other animals' genomes?
     Eric Green, M.D., Ph.D.: Genome scientists around the world are actively sequencing the genomes of many other organisms, from bacteria to mammals. The genome sequences of mammals and other vertebrates will be particularly valuable for helping us determine the functional parts of the human genome. This field of 'comparative genomics' uses the evolutionary history recorded in each species' genome to reveal clues about what has and has not been retained in our genomes over millions of years of evolution. Such information provides powerful clues about what parts of our genome perform key functions, such as encoding for proteins or regulating when and/or where certain genes are switched on.
Kyle, PA
     Bob Nussbaum, M.D.: Every person has at least 1 in 1000 bases of DNA different from any other person. This variation in DNA can be of no significance OR can be responsible for differences in our appearance, tendency to various diseases, athletic abilities, personality traits, and many other aspects - but, of course, genes do NOT determine everything. Much of what we are and what diseases we suffer are the result of environmental influences, diet, upbringing, education, etc. Even though there is a complex give and take between genes and environment, we can make progress in finding genetic variation that affects our health and tendency to various diseeases. By finding these changes, we can help people by helpiong them change their "envionment" by letting them know what life style changes, behavior, diet, medications, would be particularly helpful to them or are of less importance than to someone else with different genetic variation.
St. Ignatius College Prep HS
As an upcoming college student I am preparing for a career in biology and genetics. What kind of training is required to become a genetic researcher or a genetic councilor?
     Kim Kaphingst, Sc.D.: A solid background in molecular biology will be important for both of those careers. You might think about biochemistry or biology as an undergraduate major. Working in a research lab is also great preparation. You might also take some psychology courses if you're interested in genetic counseling. Ask your advisor in college about summer internships that will give you practical experience and can help you decide what direction you would like your career to take.
Autumn Aul, Titusville High School
is spider man in any way possible?
     Eric Green, M.D., Ph.D.: Unlikely, in reality. The biology is a bit too complicated to really make a super-hero through a spider bite. BUT, the basic notion of introducing small amounts of new DNA into humans is possible and indeed is used to treat some diseases. This area is known as 'gene therapy.'
brittany price Ben logan
How do you actually see the genome?
     Kris Wetterstrand, M.S.: The genome is extremely small and can't be viewed with the naked eye. But since scientists have now determined the order of the chemical units in the human genome, you can go and see that data at a number of web sites including the Hit the 'submit' button for an example.
Olivia, Abingdon High School
Why is DNA so cool?
     Eric Green, M.D., Ph.D.: 4 letters. No upper case or lower case. No punctionation marks. No spaces. YET, it is responible for encoding all the information needed for all free-living organisms on Earth. What isn't cool about that???
I'm spanish, and I don't control english very good. May be somebody speaks spanish...Me podriais hablar acerca de los futuros projectos q teneis previstos sobre ADN?
     Belen Hurle, Ph.D.: Hola Fernando, El NHGRI tiene muchos proyectos en marcha: por ejemplo, tenemos un programa muy amplio de genetica comparativa en vertebrados y un programa llamado ENCODE que esta analizando el 1% del genoma humano con un detalle sin precedentes buscando todos los elementos que regulan al expresion de los genes comprendidos en ese 1%. Hay muchos mas programas: HapMap, el atlas del cancer quieres saber mas de estos y otros programas, porque no nos visitas en nuestra pagina web gracias por conectar desde Espana!
fernando, spain
What new developing modes of therapy and/or medicines do you find most exciting and most realistic?
     Bob Nussbaum, M.D.: 1. Medications that are designed to target very specific biochemical reactions involved in cancer (example: Gleevec, a treatment specific for a hard to treat form of leukemia) 2. learning how certain tissues in the body develop, by studying stem cells, so we can make these tissues and replace damaged one. Best example: can we remake the "islet cells" of the pancreas that make insulin and thereby cure diabetes. 3. We will find variations in DNA sequence that give a tendency to certain diseases, give people the chance to be tested for these variations, and thereby give them a personal, tailor-made set of medical suggestions to improve their health. Examples: Variations that cause high blood lipids and therefore heart disease can be found and appropriate dietary and medical treatments instituted. Variations that predispose to cancer of various kinds (like breast or colon cancer)can alert people to have more frequent screening tests or even institute preventive treatments.
St. Ignatius College Prep HS
How exactly was DNA discovered? What had to be done to find out the sequence?
     Kris Wetterstrand, M.S.: The structure of DNA was determined by James Watson and Francis Crick in 1953. Determining the human sequence was a project that lasted many years, involved hundreds od scientists in many countries and cost millions of dollars. It was a truly unique effort for biologists. The genome, which is large in terms of the number of chemical units had to be broken down into smaller pieces that could be manipulated in the lab and then put back together uses computers.
Whose DNA was used to sequence the human genome?
     Larry Thompson: The short answer is we don't know. And that was on purpose. The people who donated the DNA used in the Human Genome Project primarily came from Buffalo, N.Y., and were selected from a large pool of volunteers whose DNA was randomized and made anonymous. So, we don't know which individual's DNA was actually sequenced, but we know it is representative of all the DNA in the human genome because it was mapped back to all the chromosomes.
Dr. Reinhart's Class, Newtown Square, PA
What areas of genetic research would you advise interested students to keep a watchful eye on, to pursue in their studies? What would you tell them to concentrate on in college and what should they tell their parents they're planning on doing?
     Eric Green, M.D., Ph.D.: Future genome and genetic scientists would benefit from training in many different areas. Certainly computer science, biology, physics, and/of engineering would provide a strong foundation. Increasingly, we will need teams of talented scientists and clinicians, all bringing different expertise, to tackle the most vexing problems in genetics-- especially those aimed at improving human health. My advice is to gain a broad education, pursuing those areas that interest you most. I must admit that one area I wish I had more formal training in is computer science-- but then again, we were using punch cards when I was in college...
St. Ignatius College Prep HS
Can genes determine if someone is going to be a killer?
     Kim Kaphingst, Sc.D.: We do not have any clear evidence that genes determine whether somone will commit crimes like murder. Other things are likely to play an important role in determining a person's behavior. For example, we know the environment in which people grow up has a strong effect on people's behavior and whether they are more or less likely to commit a crime.
Central HS, Helena AR
Why are there such differing views among scientists that gene therapy or stem cells could cure Alzheimer's disease? How can these opposing views be tested safely?
     Bob Nussbaum, M.D.: We do not understand why Alzheimer's disease develops or how to stop it from progressing, so it is hard to prove that introducing nervous system stem cells could have a beneficial effect. We also do not know at this point how to get stem cells to develop into fully functioning nerve cells that make all the billions and billions of connections that are needed for normal brain function. I would say that what all scientists do agree on is that we need to know more, research more, and understand more before we can even make an educated guess as to how likely it is that stem cells could treat Alzheimer's. Testing needs to be done by growing cells in a Petri dish to test basic questions about how stem cells become nerve cells as well as testing treatments in animals who have been made to develop Alzheimer's disease, like mice and (ultimately) monkeys. I also expect that some very brave and altruistic people with the disease will volunteer to be tested once the culture experiments and animal experiments seem promising.
St. Ignatius College Prep HS
is human DNA more complex than all or any other organism's DNA
     Kris Wetterstrand, M.S.: Yes and no. The human genome is more complex than the genomes of bacteria or insects. However, many other animal's genomes. One way in which the human genome is more complex than insects, is that each gene makes mulitple proteins.
eric. benjamin logan high school
When you have sex is dna transfered in any way?
     Kris Wetterstrand, M.S.: Yes, in sexual reproduction, one copy of the genome, made up of DNA, comes from the mother and one from the father.
Dan Walser!!! Vets HS Warwick RI
How long will it be until we know the function of introns, and what do you predict their function will be?
     Eric Green, M.D., Ph.D.: EXCELLENT question. We are just starting to learn about possible functions for the sequences within introns. Previously, some thought introns did not necessarily contain functional sequences, but now we know that is not the case. For example, some introns contain 'switches' that influence when and where certain genes are turned on. There are certainly other important 'signals' within introns, which I predict we will discovery in the coming decade. The truth is that this represents an area of genomics that is NOT even described in the textbooks at your school yet. But stay tuned...
Garrett, Benjamin Logan High School, OH
Is protein folding a topic to be addressed by the HGP? How so?
     Belen Hurle, Ph.D.: Good morning Ezra Good question. It is relatively complicated to determine the three dimensional structure of a given protein, but once it is determined it is much easier to predict the structure of other family members. the HGP has helped to discover and classify in families many, many novel genes . We can do computer modelling of these new proteins using as a reference the one structure that has been experimentally resolved.
Ezra, Susquehanna Township HS, Harrisburg, PA
Is there any rhyme or reason to naming the four chemical bases?
     Kris Wetterstrand, M.S.: The four bases are adenine, thymine, guanine and cytosine, often represented as A, G, C and T. These names reflect the chemical structure of these bases.
Dr. Reinhart's Class, Newtown Square, PA
How do scientists search for genes associated with certain human behaviors, (eating disorders, addiction, depression, attention deficit disorders, autism)?
     Bob Nussbaum, M.D.: We first need to figure out how "genetic" a particular disease is. We often do this by comparing twins in which either only one twin has the disease or both. Next, remember that each person differs at approximately 1 in 1000 bases of their 6 billion bases of DNA. To find the genetic basis for such diseases, we either study families or populations in which some people have the disease and some do not. We then compare the sequence of DNA in affected versus unaffected people, looking for differences in sequence that are consistently found in affected versus unaffected people. This kind of study, called "gene mapping", requires skills of being able to make careful diagnoses and observations, highly sophisticated laboratory studies and computer-based statistical analyses.
St. Ignatius College Prep HS
Is there any part of your body that cannot be examined for DNA?
     Bob Nussbaum, M.D.: Your mature red blood cells and the cells of the lens of the eye do not have DNA - all the rest of the cells of the body contain DNA.
Kiran Belani, Montgomery Blair High School
how does DNA tie into a career in forensic toxicology ?
     Eric Green, M.D., Ph.D.: DNA studies are quite important in forensics and increasingly in toxicology. Certainly, someone considering a career in these areas will want to become quite facile in the world of DNA and genetics.
What made you so interested in science?
     Bob Nussbaum, M.D.: I was a trained doctor taking care of patients and became dissatisfied with the current state of knowledge in how to help my patients. I decided that only by becoming a research scientist could I push our level of knowledge higher rather than just applying what little we did know.
Central HS, Helena AR
What are somethings to expect as far as educating the public about genetics in the future?
     Kim Kaphingst, Sc.D.: This is an area in which NHGRI and others are doing a lot of work now. Researchers like me are studying how to help people learn about genetics. We also have educational programs for different groups to teach people information about genetics. You can find some of them at . This is an important topic and you're likely to see many more educational programs in the future.
Kate, Ben Logan
Can we see DNA.
     Kris Wetterstrand, M.S.: DNA itself is too small to be seen with the naked eye. You can see certain types of pictures of chromosomes. Since the human genome has been 'sequenced' you can easily access and 'see' the genome at website such as that supported by the National Center for Biotechnology Information Click on human on the right had side.
steven WOOD, Warwick RI
what is DNA?
     Kris Wetterstrand, M.S.: DNA is deoxyribonucleic acid. It is the chemical that makes up the human genome.
what is DNAs main job and why?
     Belen Hurle, Ph.D.: DNA is the molecule that stores the instructions to make you and every living organism. Is like your instruction manual that determines how tall you are, what is your eye color and so on.
billy bob warwick ri
We're 99.9% similar with each other. How can DNA change how we look with only .1% difference?
     Kris Wetterstrand, M.S.: THe human genome is 3 billion basses long. That give us 3 million differences at teh DNA level. That can lead to many differences in how we look.
How has awareness of various influences acting on the human genome, transposons, pseudogenes, repeat sequences, introns and intergenic DNA, epigenetic markers etc, influenced the direction of current genomic research?
     Eric Green, M.D., Ph.D.: Very good question. The things that you mention (e.g., epigenetic markers, transposons, repeats, and so forth) represent additional things that influence the functioning of DNA. Now that we have established the complete sequence of the human genome, attention is turning to how it encodes all of its information. Some of this is the primary sequence of its ~3 billion bases. But then there are other factors that play a role-- some of which you mention in your question. There are now ongoing efforts to study these areas in greater detail, with the goal of eventually unraveling all of the complexities of the human genome.
St. Ignatius College Prep HS
Could genetic technology be used to create super-athletes?
     Bob Nussbaum, M.D.: I hate to say this but it is always possible to misuse scientific knowledge. I believe science is based on a desire to udnerstand - how we choose to USE this information is not purely a scientific issue but is one for all of society, citizens, government, religious leaders, etc. to address. So, COULD it be used - the answer is YES. We already know of at least one protein in the body, myostatin, that limits muscle size. In mice who lack myostatin and in one child who had mutations in his myostatin gene described this year in a medical journal, muscles are big and strong. So, if we somehow blocked myostatin function, we could make people have bigger, stronger muscles. I could see this being used to help people with muscle wasting because of cancer or muscular dystrophies or multiple sclerosis. I would HATE to see this used to generate super athletes - but I must say, I am not a big fan of professional athletics and wish the huge salaries paid to them were paid to high school teachers instead.
Central HS, Helena AR
what's the difference between DNA and RNA?
     Kris Wetterstrand, M.S.: DNA and RNA are different at the chemical level. In the cell DNA carries the ultimate copy of genetic information and RNA takes that information to make proteins.
meghann warwick
What are the positive and negative social implications of genomic discoveries?
     Kim Kaphingst, Sc.D.: There are many positive social implications of genomic discoveries. These discoveries will allow us to learn ways to treat diseases more effectively and prevent diseases from developing so that we can improve the public's health. It is important to make sure that we protect people's privacy and prevent discrimination based on someone's genetic makeup to avoid some of the possible negative social implications.
Nate Stevens, Cape Elizabeth, ME
What is the Human Genome?
     Kris Wetterstrand, M.S.: Genome is a word used to refer to the entire collection of genetic information that each cell in an organism carries. So, the human genome is the genetic information that we carry in each of our cells. It includes our genes (units that make proteins) and lots of additional information.
GO DNA, Warwick RI
How would the various promoter sequences affect the genes of the human genome? Would they provide the same type of gene regulation the prokaryotic promoters do?
     Eric Green, M.D., Ph.D.: Promoters are sequences that act as 'switches' to turn genes on at specific times and in certain tissues or cells. Such regulatory control is critical for ensuring that the right genes are turned on (and the right proteins made) at appropriate times and places. Thus, promoters serve a critical role in orchestrating the expression and function of the ~25,000 human genes. Prokaryotic genomes have promoters as well, although they differ in a number of important ways. Because they are slightly simpler, at this point in time we actually know more about prokaryotic promoters than eukaryotic promoters. Hopefully, this will change in the coming years due to the ongoing work of genome scientists.
how did you find the double helix in DNA?
     Aideen McInerney, M.S.: Watson and Crick, working with coworkers, discovered the double-helical structure of DNA in 1953. This work involved studying light patterns emerging from DNA-- which provided key clues about its structure.
meghann warwick

Information - Moderator As you can see, we have with us now Eric Green, M.D., Ph.D., Scientific Director; Bob Nussbaum, M.D., Chief of the Genetic Disease Research Branch; and Kim Kaphingst, Sc.D., Investigator in the Social and Behavioral Research Branch; and Kris Wetterstrand, M.S., Program Analyst in the Division of Extramural Research.

How can genes program thoughts?  (i.e., instincts, such as sexual preferences, or how cats know how to pounce on a mouse, whereas dogs are born knowing different things)
     Bob Nussbaum, M.D.: Great question and I can't answer it. We know VERY VERY little about how much one's instincts are programmed, "hard-wired" as it were. For example, black labradors love to swim and fetch - shepherds won't fetch and don't like swimming but they know how to herd. Labs can't herd to save their lives. We know there MUST be genetic differences that have been bred into these two breeds to select for these behaviours. As for sexual preference, we really know next to nothing about how this is determined. We know a lot about how genes program our basic sexual development, the internal and external equipment as it were, but very little about the higher, more abstract aspects of sexual behavior and identity. There are some scientists who are trying to find genetic variations that predispose to homosexual and heterosexual preferences...but it is not clear how much genes really control this difference. That said, this does NOT mean that sexual preference must be learned. There are other inborn determining factors (such as exposures before birth while in the womb or in early infancy) that could affect this, independent of one's genetic makeup. This is a very "hot topic" these days, with a lot of religious and political leaders arguing about the extent to which sexual preference is "learned", a "choice", versus how much it is innate, inborn, and not something that one chooses, but is something that one is born with. I do not think genetics has an answer to this puzzle.
Eric, Newton North HS
How is dna tested?
     Bob Nussbaum, M.D.: We have methods for examining DNA in the laboratory and determing the exact sequence of the bases in any stretch of DNA. We can read the letters, A,C,G,T the same way you are R,E,A,D,I,N,G this message.
Nick Geneva High School
Are favorite foods or behaviors genetically determined?
     Kim Kaphingst, Sc.D.: Right now researchers are studying how much of different behaviors might be determined by genetics. It's important to remember, though, that other factors - like friends, family, and how you grow up - play important roles in determining behavior. Your food preferences might have some genetic component but might also be affected by other things such as your culture and the things your family eats.
Dr. Reinhart's Class, Newtown Square, PA
Since DNA is structured to prevent mutations or modifications, how does the study of DNA support the theory of evolution?
     Eric Green, M.D., Ph.D.: Actually, DNA is mutated all the time-- indeed, every time you go out in the sun. But we also have repair mechanisms that correct most (but not all) changes. Studying the genome sequences of different species (an area called 'comparative genomics') reveals what has and has not changed (mutated) over millions of years of evolution. As we sequence more animals' genomes, fundamental knowledge about evolution is becoming refined and advanced.
Joseph Dario from Montgomery Blair High School
What are the prospects for a career in the field of gene therapy research?
     Bob Nussbaum, M.D.: The field is wide open. We don't have dependable, safe ways of doing it, we don't know how to correct defects efficiently or effectively, how to deliver the therapeutic genes safely and efficiently, and that's just the beginning of the problems. So, for a smart, dedicated person interested in research and in treating sick people, the field "beckons". Hope you join in!
Brandon Field, Vermont
What kinds of genes does mitochondrial DNA contain? Could we survive without them?
     Eric Green, M.D., Ph.D.: Mitochondria have a several dozen genes, which have a number of different functions. We cannot survive without mitochondria. Indeed, mutations in mitochondrial genes are known to cause many different human diseases.
How many years of education do you need to go into this field?
     Kim Kaphingst, Sc.D.: It is likely that you will need a graduate degree - and probably a doctoral degree - to be a researcher in genetics. So after college, you'd probably spend about 5 years in a doctoral program. This doesn't mean you'll be in classes for all those years, though - actually doing research is an important part of a graduate program.
Billy Madison
In the future, will it be possible for HUMANS to transform into other animals via genetic engineering?
     Eric Green, M.D., Ph.D.: Unlikely. Minor changes to our genome-- maybe, such as with gene therapy. Major changes to transform us into other animals-- almost certainly not, biology is too complicated.
Booker T. Washington MS, Baltimore, MD
Have you used any PCR in your research? Just wondering because we have.
     Belen Hurle, Ph.D.: PCR is the basic instrument in any molecular biology lab, and it is rare the day that you don't use it. PCR is like a photocopy machine. It allows you to make many, many copies of any tiny amount of DNA that maybe was too small to be analyzed before amplification. It only takes a few hours to generate thousands of copies from just a handful of DNA molecules!
Lindsey, Benjamin Logan High School
What in your current research will be most important to future research?
     Eric Green, M.D., Ph.D.: Developing a catalog of all the functional sequences in the human genome. This will provide us the 'parts list' that will be a powerful resource for future genetics and genomics studies, including those aiming to establish how changes in our genome can cause human disease.
Booker T. Washington MS, Baltimore, MD
Why is it so difficult to locate disorders in genes now that the human DNA has been totally decoded?
     Bob Nussbaum, M.D.: Good question! We may KNOW the DNA sequence but it has by no means been decoded! There is lots of information in DNA (sequences that REGULATE how genes are read and how the proteins are made, for example) that we don't know how to read or what it means - we only know in a few cases how changing this DNA sequence can increase susceptibility to certain diseases. Many genetic diseases are the complicated result of genetic variation AND environmental influences. Teasing out the genetic contributions from the environmental factors is hard!! We can think of this problem as a "signal to noise" problem. For diseases inherited according to Mendel's basic laws, we can locate genes easily because the defective gene has such a big effect, the "signal" is huge compared to the "noise" caused by other genes and environments. For example, we located the genes for Duchenne muscular dystrophy and cystic fibrosis many years ago. For the more common diseases that are the result of complex interactions, such as diabetes, schizophrenia, various cancers, some forms of mental retardation, the effect of any one gene on the disease is limited and therefore it is hard to see its signal in the noise.
Reilly, Cape Elizabeth HS
How many people have the same DNA?
     Kris Wetterstrand, M.S.: Only monozygotic (identical) twins have exactly the same DNA. However, on average, people are 99.9% the same at the DNA level.
j d

Information - Moderator Joining us soon will be Jean McEwen, J.D., Ph.D., Program Director of the Ethical, Legal an d Social Implications Program and the International HapMap Project; and Heidi Parker, Ph.D., a postdoctoral researcher in the Cancer Genetics Branch. Heidi works with Elaine Ostrander to compare the dog genome to the human genome in an effort to answer questions about disease in both dogs and humans.

How long do you think it will take to be able to save lives by fixing the DNA?
     Bob Nussbaum, M.D.: There have already been more than a dozen children with severe inherited immune defects that have been cured by gene therapy in which a defective gene was replaced. Unfortunately, three of these childen developed leukemia because the replacement gene got stuck into the middle of a gene that regulated the growth of the white blood cells that developed into leukemia. So, the therapy has been very succesful in over 10 children but three suffered a complication, one of whom died, the other two are in remission after treatment for their leukemias.
Fernando de Andres, Spain
Why are gorrillas so close to humans and why are they so cool?
     Eric Green, M.D., Ph.D.: The sequence of our genome differs from that of the gorilla by only a few percent-- we are incredibly closely related to these remarkably cool creatures. I had the chance to visit the San Diego Zoo two weeks ago, and was given a behind-the-scenes tour of their gorilla exhibit. These animals have a very sophisticated way of communicating (through non-verbal means). Watching them for even a short period of time reveals numerous similarities with humans. Similarly, they suffer from many of the diseases as humans.
lloyd banks and da whole g-unit click
Do medicines actually correct a misspelling in the genome, or do they simply aid to the affects of the diseases through another method?
     Bob Nussbaum, M.D.: Medicines so far do NOT correct the misspellings. They affect biochemical and functional changes "downstream" from the gene itself.
eric from ben logan high school
Is there an evil gene?
     Kim Kaphingst, Sc.D.: We don't think there is an "evil" gene. Behaviors that might be thought of as "evil," like committing violent crimes, are more likely to be determined by their environment, which means the way people grow up and influences from peers and family.
Mark Nardelli Newton, MA
What is an interesting unknown fact about DNA?
     Eric Green, M.D., Ph.D.: A fact that is now 'known' but a surprise that emerged a few years ago... The human genome does not even have TWICE the number of genes as the fruit fly genome--- yet seemingly we are more than twice as complex. Go figure!
Karli, Benjamin Logan High School
How would they go in and change the sequence of DNA so diabilitating diseases weren't present in the human fetus?
     Bob Nussbaum, M.D.: We do not know how to do this efficiently and effectively yet. There are methods for replacing defective information in cells being grown in Petri dishes but it is very inefficient and only works in 1 in a few thousands to a few millions of cells. We can also inject a normal gene to replace a defective one but it does not "home in" to the actual defective gene and cut it out and replace it with a normal copy.
Megan, Benjamin Logan
Does our DNA change as we age because of viruses we might acquire in our lifetime?
     Bob Nussbaum, M.D.: DNA does change as we age but not primarily due to viruses. DNA is a chemical and it suffers "wear and tear" from toxic chemicals. Also, as the cell copies its DNA, there is a basic level of "typographical error" that occurs, so DNA can accumulate typos.
Frannie, Waubonsie hs in Aurora, IL
What is a plasmid?
     Kris Wetterstrand, M.S.: A plasmid is a structure in cells consisting of DNA that can exist and replicate independently of the chromosomes.
Danno Cox, Ohio
How long is DNA viable for identification or experimentation in any sort of preserved state like cryogenic freezing or the like?
     Bob Nussbaum, M.D.: VERY long time. we have cells that have been frozen away 40 years ago that have been brought out of deep freeze and can grow on Petri dishes in culture. If the DNA is actually purified and stored in solution, we don't know how long DNA could be preserved. A scientist called Svente Paabo isolated DNA from the teeth and bones of a Neandertal man. There was also that caveman found frozen in the Alps from whom I suspect DNA could be successfully isolated.
Dr. Reinhart's Class, Newtown Square, PA
How does the cell distinguish between the exons and introns in the DNA when creating mRNA?
     Eric Green, M.D., Ph.D.: The process of forming the final mRNA molecule is called 'splicing'. Embedded within the DNA sequence are signals that tell the splicing machinery where to cut out introns, leaving behind the exons. While we know quite a bit about these signals, we have much more to learn-- especially since the same gene can lead to multiple different forms of mRNA. What are the signals that determine which forms are made at different times and in different cells? These are the kind of questions being addressed now in genomics. We hope to establish a complete catalog of such signals in the human genome.
Kiran Belani, Montgomery Blair High School
When I have a child when I get older, will my child recieve most of my "husband's" traits?
     Bob Nussbaum, M.D.: Every child gets half of his genetic info from his Mom, half from his Dad. Which half of his Dad's genes and which half of his Mom's gene the child inherits is entirely up to chance, 50-50, like flipping a coin. So, will the child receive most of your husband's traits? No, each child will get half of his genetic info from his Dad, but the relationship between information and traits is unpredictable. NOT all traits are strictly genetic and some are the result of combinations of various genes - if you get some of these genes but not others from a parent, will you also have the trait? or not? Tough question and we don't have an answer.

Information - Moderator Joining us now is Donna Krasnewich, M.D., Ph.D., Deputy Clinical Director and Investigator in the Medical Genetics Branch. And just a reminder, this is a moderated chat so you can NOT chat among yourselves, only with the experts. Thanks!

if twins have the exact same DNA, if one is a suspect in a murder case how could you determine which one comitted the crime using genetics?
     Jean McEwen, J.D., Ph.D.: The law enforcement officials investigating the case would need to look at all the evidence together - the DNA is just one piece of evidence. So they would try to find additional evidence, beyond just the DNA, that tied one of the twins to the crime, or establish that the other twin had an alibi (i.e., was somewhere else at the time and could not have committed the crime). In the end, the DNA would be just one piece of evidence in the case that the court or the jury would consider. To my knowledge, there has not yet been a case in the U.S. involving a dispute over which of two twins committed a crime, where the DNA evidence showed that it could have been either of them.
pAT pAT, Ben Logan HS
How can the chihuahua belong to the same species as the great dane?
     Heidi Parker, Ph.D.: The domestic dog, Canis familiaris, is a single species that diverged from the Gray Wolf somewhere between 15,000 and 50,000 years ago. All of the breeds that we see today are the result of specialized breeding programs developed by humans to create animals that fit a specific need. Even though dogs like the Great Dane and Chihuahua look very different today, their ancestors came from the same family.
Kyle Dancause, Cape Elizabeth Maine
How might RNA's antisense abilities support the hypothesis that RNA was the original hereditary material?
     Eric Green, M.D., Ph.D.: A very sophisticated question. The more we learn about RNA and the ways it can confer function, we gain clues about how RNA may have played a central role in early life forms. You raise an interesting question about some newly discovered ways that antisense RNA controls the expression of genes. What were the evolutionary origins of antisense RNA? Perhaps this points to an earlier role where RNA played a more central role in biological function, perhaps even predating DNA's role.
St. Ignatius College Prep HS
Is any one chromosome more susceptable to mutation than the others in human beings?
     Bob Nussbaum, M.D.: Over what time frame? From generation to generation, no, mutation is pretty much the same across all chromosomes. Over evolutionary time, hundreds of MILLIONS of years, the Y chromosome seems to be changing more rapidly by losing information that is going to other chromosomes. Also, the ~16,500 basepairs of mitochondrial DNA has a higher overall mutation rate than the 46 chromosomes in the nucleus.
Dr. Reinhart's Class, Newtown Square, PA
Has a human been cloned yet? Our clas is wondering what the latest news is? Thanks.
     Eric Green, M.D., Ph.D.: No human has ever been cloned, at least as far we know. There are certainly no plans at the NIH to clone a human. This topic is often discussed in a casual way-- in reality cloning a human would be technically difficult and likely quite dangerous. There are many biological aspects to this process that we do not yet understand.
Ms. DeVito
Is there a hypothesis theorizing if chloroplasts were once their own separate cells and how they became part of plant cells?
     Belen Hurle, Ph.D.: Endosymbiosis is a symbiotic relationship between two organisms in which one of the organisms lives inside the other.Almost all biologists believe that this phenomenon explains where mitochondria and chloroplasts came from. In the early stages od life, not all organisms developed the ability to perform photosynthesis, or to convert to aerobic cellular respiration. Many of those that didn't make these alterations themselves went into partnership with other organisms that did. If an anaerobic cell could engulf an aerobic one (without digesting it), it could get the benefit of the ATP overflow from its captive partner. Given a couple of billion years to get used to each other, the inside, aerobic partner became so specialized for aerobic cellular respiration that it lost almost all of the basic life skills, depending upon the external host cell to support it. Voila mitochondrion. If you tell the same story, but substitute "photosynthesis" for "aerobic cellular respiration," you have a recipe for the invention of chloroplasts.
Jisung Kim, Montgomery Blair High School
My dog Bear looks different then his brother Colby? Why does this occur and do genetic mutations on the #22 chromosome cause this?
     Heidi Parker, Ph.D.: Your dogs look different because they each have a unique pattern of genes and mutations that affect appearance. Even though they both got their looks from their parents, they received a different mixture of features which gives them their own individual look. Mutations that cause these differences can be found on any or all of the dog chromosomes included but not limited to chromosome 22.
What is gene therapy?
     Donna Krasnewich, M.D., Ph.D.: Gene therapy is a way to treat some genetic disorders which currently is being done in a research setting. An example may be the best way to explain how it works. Some children/adults have alterations in their DNA that makes their white blood cells ineffective in fighting off infections in their body (ie. severe combined immunodeficiency disease). Gene therapy for this disorder would be to remove some of the precursor white blood cells (the "mother" cells) from the bone marrow of the affected child. Then these cells are taken to a very sterile laboratory and the cells are incubated with the corrected gene that these cells are missing. Some of these precursor cells "take up" the gene and actually integrate it into their genome. It is then replicated like the cell's own DNA. Then these cells are taken from the sterile laboratory and given back to the patient by an intravenous transfusion. Hopefully, these mother cells will produce "corrected" cells that will move into the blood stream and help that person fight off infection. Remember, gene therapy does not work, at this time, for all diseases because the gene must be able to get into cells where it is needed. Some organs are harder to move corrected genes into, ie the brain. Researchers are working on strategies to widen the spectrum of diseases that will be helped by gene therapy.
Billy Madison
Is it true that, in the future, everyone will have to get an DNA test when they are first born?
     Jean McEwen, J.D., Ph.D.: Already today, virtually every baby born in a hospital in the U.S. gets blood drawn through a heel stick. This blood is then tested for a variety of inherited childhood disorders (such as PKU, or phenylketonuria). This testing, called newborn screening, is mandatory in most states in the country. In most states, the blood spots from these tests are saved onto cards, which are stored for many years, and in some cases indefinitely. So, the blood spots on these cards could theoretically be looked at in the future, if somebody wanted to do DNA testing. Of course, most states have laws that limit who has access to these cards and what they can be used for. But some privacy advocates are worried that these laws are not strong enough.
Candice Josphinum High School
what is genetics
     Heidi Parker, Ph.D.: Genetics is the study of genes. Although these days geneticists do not limit themselves only to genes but study all regions of the chromosome, and sometimes elements that interact with chromosomes, that can be inherited.
Alexis Rensselaer
What possible restrictions on health care and insurance will we see in the near future as a consequence to DNA mapping?
     Jean McEwen, J.D., Ph.D.: Nobody really knows for sure. There have already been some reported cases of people being denied health insurance (or charged really high rates for insurance) because they have a gene that predisposes them to get a certain disease. Some people worry that this kind of "genetic discrimination" will happen more and more in the future, as more and more genetic tests become available. Some states have passed laws that limit the extent to which insurance companies can take genetic information into account in issuing insurance policies. However, these laws vary a lot from state to state. So a lot of people think that federal legislation is needed in this area. So far, however, no federal legislation has been enacted that prohibits genetic discrimination in insurance.
Jared Barnes, Ben Logan
Could paralysis be caused by some misspelling of DNA?
     Donna Krasnewich, M.D., Ph.D.: There is DNA that codes for each and every part and function of our body. So, there are genes that code for the way all of the nerves and muscles that work together to help us move. Paralysis is the inability for a person to move their muscles/parts when they want to. They may have a problem with the way their brain is sending the signal, the nerves that take that signal to the muscle or the way the muscle moves in response to the nerve impulse. There are many genes that code for these parts and an alteration in one of them may lead to "paralysis" of difficulty moving a part of their body. Sometimes a child has a problem moving their body when they are born. This is called a congenital problem. Sometimes people have paralysis come on when they are older. This was always coded into their DNA but the onset of their problems were not programmed to start until they were older. Many physicians will be able to help answer more specific questions.
Karla - Benjamin Logan HS
Are twins identical genetically?
     Belen Hurle, Ph.D.: There are two kinds of twins: identical twins and fraternal twins. If the mother produces 2 eggs during the same cycle instead of one egg only, and both egges are fertilized, you have fraternal twins. Fraternal twins are not any more similar than normal sibilings. Identical twins happen when a fertilized egg splits in half during the early stages of embryo development. Identical twins are identical at the genetic level.
boby dumb
How similar are the dog and human genome (to what degree)?
     Heidi Parker, Ph.D.: The genetic content of the dog and human genomes match at approximately 70-75% over all. Regions that are translated into proteins are typically greater than 90% identical.
Sarina Taylor

Information - Moderator Joining us now is Colleen McBride, Ph.D., Chief of the Social and Behavioral Research Branch. Her research involves developing new ways to promote changes in people's behavior in ways that will lower their risk of developing certain diseases.

I'm currently researching Asperger Syndrome for a genetic disorder and I was wondering if there was a chromosome mutation causing it.
     Donna Krasnewich, M.D., Ph.D.: As you know there is alot of work currently being done to understand why children have Asperger Syndrome. You also know that there are hypothsized causes including genetics changes, environmental triggers and combinations of genes and environment. There is a very nice review of the topic of autism including asperger syndrome with the genetics causes listed on This is very useful resource written by experts to explain some genetic disorders.
Eli, Cape Elizabeth, Maine
why do older dogs tend to develope moles and sometimes even tumors?
     Heidi Parker, Ph.D.: Tumors are groups of cells that are growing without the usual cellular controls often due to aquired mutations within the cells. Every time a cell divides it has the opportunity to acquire a mutation. As with humans, dogs are more likely to develop tumors as they age. The older the dog, the more time it has had to build up mutations that lead to tumor formation and sometimes cancer.
Sarina Taylor, New Jersey
Do you think cloning humans will ever be legal in the United States?
     Jean McEwen, J.D., Ph.D.: Maybe, but probably not for a very, very long time - if ever. Right now, human reproductive cloning just has not been demonstrated to be possible. Even if it became possible, there would be very serious physical safety risks associated with human reproductive cloning, so it would be extremely dangerous to attempt. For this reason, and because of the very serious ethical issues raised by human reproductive cloning, this practice will almost certainly not be allowed under the law for a very long time, if ever.
Lesley Greenville, AL
how different is my dog and my chromosomes
     Heidi Parker, Ph.D.: You have 22 pairs of chromosomes and an X and Y chromosome. Your dog has 39 pairs of chromosomes if it is a girl or 38 pairs and an X and Y if it is a boy.
billy bob, fort deposit
I feel that some of the genetic technologies are beneficial, but we as people are getting a little outrageous. I feel that some of these decisions should be made only for medical attention. We are playing with people's lives. Do you think there is a need for god?
     Colleen McBride, Ph.D.: You raise an important concern and one that our Institute has made a priority. Indeed, in applying genomic discovery the social impact of these developments should be taken into consideration. For that reason, we have an active program of research and advisement in the ethical, social and legal implications of application of genetic technologies.
Central HS, Helena AR
what organism has the most chromosomes?
     Belen Hurle, Ph.D.: I don't know which organism has the record, but is probably a plant. Angiosperm plants have polyploid genomes which means that the whole genome is in multiple copies. I will give you some examples: humans have 46 chromosomes (2n, diploid genome); sugar cane has 80 chromosomes (8n) ; species of coffee plant with 22, 44, 66, and 88 chromosomes are known (2n, 4n, 6n and 8n respectively).
Sarina Taylor, Ridgewood HS
How can someone who has never met their parents trace back their DNA to find out who their parents are?
     Donna Krasnewich, M.D., Ph.D.: For many this is a topic that can be very emotional, bringing out both happy and sad feelings. The technical answer is that there are DNA tests that will verify that a person is a parent if that parent's blood is available to compare. However, currently there is not a databank of DNA from every person (remember all of our DNA is different and individual) so a match may not be available leaving the person asking the question without an answer. There are people who are experts in answering these questions for an individual, they are called geneticists/genetic counselors, usually they are at medical centers in many cities. They may be help a person sort through the options available, the cost and the emotional issues surrounding this question.
Candice Josephinum High School
Could you please explain ELSI?
     Jean McEwen, J.D., Ph.D.: NHGRI allocates 5% of its total budget for genomic research to the support of research on the ethical, legal, and social implications (ELSI) of that research. The idea is to try to anticipate and address some of the major ethical, legal, and social implications raised by this type of research before problems arise (e.g., issues about privacy, genetic discrimination, how genetic information will be used in health care, intellectual property issues, etc.) For more information on ELSI, please visit: .
Why do some scientists call centromeres the "black holes" of chromosomes and what is their function?
     Heidi Parker, Ph.D.: Centromeres are the sites on the chromosomes where the cell division apparatus attatch in order to pull the two matching chromosomes apart when the cell divides. The region is difficult to sequence through because of its physical structure and the presence of repetitive DNA sequence. There are no active genes known to be in the centromere region of the chromosomes which may lead to discriptions such as the "black hole"
Elezar ,Hyderabad, india
What are some the future projects that will branch off of the HGP?
     Larry Thompson: Sequencing the human genome was just the first step of this amazing journey to understand all the parts that make up the human body. The HGP is rapdily leading to identifying all the genes in the body, as well as the regulatory pathways that tell genes when to turn on and how to interact with other genes. The National Human Genome Research Institute has launched a number of sophsiticated studies to help interpret the genome, including the International HapMap Project, which is designed to detect and understand the common variation in the human genome; the ENCODE project, which is designed to detect every kind of information and control mechanism in the genome; the chemical genomics program, which is identifying small molecules and creating a screening program to probe gene function and understand the biological networks, and which may also lead to the development of new medications. There are many other initiatives, such as those in nanotechnology, a project to make strains of mice in which individual genes are knocked out, so the genes function can be studied, and a series of ongoing studies to understand the ethical, social and legal implications of all this new knowledge.
Annie, BLHS
What tests did you do to find out DNA is six feet long?
     Larry Thompson: That's a great question, because it certainly is hard to imagine how something that long can be packed into a cell so small that you can't even see it. The genome length is estimated to be six feet long by physically measuring the molecules that make up a nucleotide and then adding up the estimated amount of DNA in each individual chromosome. So, while it is very long, a strand of DNA is extremely thin -- way thinner than hair.
Jason Machamer, Susquehanna Township
Would it ever be possible for a doctor to literally change someone's DNA in order to cure genetic diseases?
     Donna Krasnewich, M.D., Ph.D.: Gene therapy is the way to do this. Currently, gene therapy is in the research phase and scientists and physicians are working hard to find ways to integrate genes into DNA that work better. This may either just help make someone feel better or cure the disease. There is alot more work to do on this front.
Sarina Taylor
How can pet owners prevent their dogs from having cancer?
     Heidi Parker, Ph.D.: Cancer in dogs is similar to cancer in humans. You can prevent your dogs exposure to possible cancer causing agents like smoke or pesticides but if your dog has inherited the predisposition to cancer there are no preventative methods known to stop it. The best thing to do is to try to catch the cancer early so that the dog can get proper treatment and improve their chance of survival.
Sydnie Hill, Tulsa, OK
Are any breeds of dogs more similar as far as DNA to humans then other breeds?
     Heidi Parker, Ph.D.: No, all the breeds are more similar to each other than they are to any other species.
Sarina Taylor
Are there genes for violent behavior?
     Colleen McBride, Ph.D.: At this time, there is no gene to explain violent behavior and it is unlikely that any single gene will explain such a complex behavior. Scientists agree that unraveling the factors that explain behaviors such as aggression and hostility will be a very complicated undertaking because it will involve the combination of multiple genes and environmental influences. The research is ongoing.
Mark Nardelli's class, Newton, MA
Would you spend the money to save your own child's umbilical cord stem cells as a future insurance policy?
     Don Hadley, M.S., C.G.C.: This is a sensitive question for many people. It is clear that stem cells from cord blood have the potential to be very helpful in some clinical situations...certainly this is a field that will advance in the coming years.
St. Ignatius College Prep HS
why does that kid keep asking about his dog?
     Larry Thompson: I suspect we are getting a lot of dog questions because some students are watching the multimedia webcast in which our cancer branch chief Elaine Ostrander, Ph.D., discusses her genomic research with dogs. If you are interested in learning about Dr. Ostrander's dog research, you can see the webcast at
Katie, Chicago
We've just read about Alu repeats, a major class of SINEs. Our information states that each repeat is about 300 bases long and comprise about 2 - 3% of the genome & are increasing. Do you know what they do yet? At what rate are they increasing? How will that impact our genome?
     Belen Hurle, Ph.D.: Our genome is littered with all kinds of repetitive elements, and Alu repeats are one family of many. These elements have the capacity of replicate themselves and integrate in different places of the genome.Per se they don't add or substract any function to our genomes. In an indirect way, they are thought to increase the number of non-important targets of mutagenic agents, in other words they "dilute" the number of mutations that could impact important genes. They also promote genome plasticity and speciation during evolution , because they promote non-homologus recombination and genomic rearrangements. On the dark side, they can cause genome inestability and chromosome fragility with the result of human genomic syndromes (a piece of cromosome gets deleted or moved to a wrong location of the genome).
Schumm's Genetics Class
Is it possible to steal peoples DNA?
     Jean McEwen, J.D., Ph.D.: Yes, theoretically, all you would need to do is to obtain a strand of that person's hair, some saliva (e.g., from a cigarette butt), or some scrapings from their fingernails. But, of course, just having the strand of hair, the saliva, or the fingernail scrapings would not automatically tell you anything about that person's DNA; in order to find out the information encoded in their DNA, you would need to subject the person's sample to DNA analysis This would require specialized knowledge and laboratory equipment.
Ted Bundy from Berlington Vermont

Information - Moderator Joining us now is John Hodges, M.S., a Scientific Program Analyst in the Division of Extramural Research. He is working with the Knockout Mouse Project and the Minority Action Plan.

i remeber reading about a family who had their older dog cloned so they could still have that dog after it passed away. Would these clones just look the same or would they have the same personality as well?
     Heidi Parker, Ph.D.: While there are some aspects of behavior that may be genetically controlled, personality is probably due more to the environment that the dog was brough up in. Since the field is extremely new, there have not been any studies to compare clone personalities to the originals.
Sarina Taylor
Are their any chemicals that can alter your DNA?
     Donna Krasnewich, M.D., Ph.D.: There are chemicals called mutagens or teratogens that may change the physical nature of the DNA. Remember that much of the time these chemicals work in a random manner, this means that it may not affect a gene that makes a change in the physical appearance of any individual.
Eduardo Caroacheo
Why did you choose April 25 as DNA Day?
     Colleen McBride, Ph.D.: April 25 is an important day for the National Human Genome Research Institute. It was the day that the final sequence of the human genome was published. Additionally, April was the month in 1953 during which Watson and Crick first described the structure of DNA.
Dr. Reinhart's Class, Newtown Square, PA

Information - Moderator Joining us now is Don Hadley, M.S., C.G.C.. He's an Investigator in the Social and Behavioral Research Branch.

Does every mammal have the same DNA?
     Heidi Parker, Ph.D.: Every mammal has the same set of basic genes needed to live and replicate. They do not have the exact same DNA and the genes tend to be rearranged and the seqeunces slightly different. This accounts for the differences seen between the species.
Bobby Jo, Greenbo, AL
If you know the sequence of DNA of a gene that causes a disease, how does that help in the creation of a treatment for the disease?
     Donna Krasnewich, M.D., Ph.D.: You are asking an excellant questions that is the basis of work in many labs. First, once you know the sequence of DNA then you have to find out what protein the DNA codes for. Then one has to learn how that protein functions, which will help to explain why a dysfunction of that protein causes disease. Now you have narrowed down where to focus the therapy which can either be a biochemical intervention or perhaps an interaction with some physiologic process. There are also currently some innovative work being done on strategies to design a therapy that DNA or RNA interacts directly with other genetic material to change the disease course. This is very new and still in the laboratory phase.
Ben Henig, Susquehanna Township High School
Is there any current research pertaining to a bacteria genome and antibiotic/antimicrobial resistance?
     Belen Hurle, Ph.D.: Yes a lot. Many bacteria strands that cause serious disease, such as tuberculosis, have develop resistance to antibiotic treatments which is a serious medical concern. Other researchers study the genomes of bacteria that do not cause disease, such as the normal flora in our gut, or our mouth.

Information - Moderator And we have one more expert joining us now. Jean Jenkins, R.N., Ph.D., is a Senior Clinical Advisor in the Office of the Director.

so far what's happened in the knockout mouse project?
     John Hodges, M.S.: The Knockout Mouse Project (KOMP) is still in the planning stages. At the end of March NIH held a workshop which solicited advice from the larger scientific research comunity about how to go forward with the project. The NIH KOMP working group is now evaluating the recommendations from the meeting and articulating a funding plan to get the project going.
Randi, Benjamin Logan High School
How important to the medical field is protein folding?
     Belen Hurle, Ph.D.: Very important. Many point mutations alter the normal folding of a protein imparing its physiological function and causing lethal or very serious conditions. Sometimes, just learning about the folding of an unknown protein gives important clues on its function (is it a pore-like protein? does it look like a channel or a transporter? is it soluble?) .
Erin A, Susquehanna Township HS, Harrisburg, PA
If we inherit mitochondria from our mother, shouldn't we have the same metabolism as our mother?
     Donna Krasnewich, M.D., Ph.D.: Metabolism is controlled by many factors within our body besides our mitochondria. Specifically within cells there are other metabolic pathways including how we break down fats and sugars or how we respond to glucose in our bodies. The number of variables that may influence our physiologic metabolism is large and many genes, both from our mother and father influence that metabolism.
Wawasee High School
How do genes create complex shapes? (Such as bones or the circulatory system)
     Heidi Parker, Ph.D.: Typically a gene is a sequence of DNA that is translated into a protein. These protiens then have various roles in the cell that can establish the cell type during the early stages of development. The types of genes that are expressed, the amount of protien produced and the timing of the protien production creates specific cell types such as a bone cell or blood cell.
Eric, Newton North HS
When do you expect the Genome project to be complete?
     Larry Thompson: The Human Genome Project was officially launched in October 1990, and it was expected to take 15 years. The first draft of the human genome was announced in June 2000 and the final human genome sequence was placed in the public databases in April 2003, at which point the Human Genome Project was completed. Genome studies continue, however, to understand all the information contained in the genome sequence.
Selitta, Rockingham NC, but live High Point at T.Wingte Andrews High !Go Red and Richmond Raiders!
Does DNA affect ear wax color?
     Donna Krasnewich, M.D., Ph.D.: There is a specific disease called alkaptonuria which can affect a person by giving them dark urine, cartilage and even darkened ear wax. Alkaptonuria is a metabolic disease that changes the way an individual uses specific amino acids and creates a buildup of a certain chemical which is black in color. People with alkaptonuria also may have significant joint problems. If someone has very dark ear wax I would suggest that they see their physician to be evaluated.
Emily Bean, Queensbury, NY
Do you ever get tired of working in a lab with things that are smaller then you can see without a microscope?
     Belen Hurle, Ph.D.: Not really. It is like peaking through a window to other worlds. I think that astronomers looking through a telescope feel the same kind of excitement. The most frustrating part of research is that it requires a lot of patience. Sometimes you go for a long period of time without discovering anything relevant and you feel miserable, sometimes you make several exciting discoveries in a row and you feel very good about yourself.
Zeba Race, Newton, MA
When diagnosing behavioral "disorders" isn't it somewhat misleading to call these disease? How much of a continuum exists in terms of the severity of behavioral disorders?
     Colleen McBride, Ph.D.: Yes, I would agree that in many cases referring to variation in behavior as disorders or diseases might not be appropriate. In many genetically influenced characteristics there is a continuum or degree of expression that influences the "severity" of the phenotype. What we classify as a behavioral disorder also is influenced by what society defines as normal behavior, that in turn can be changed by social forces. So your point demonstrates the complexity of this issue!
Ryan Gustafson, Chicago
Is there genetic information in tumors?
     Donna Krasnewich, M.D., Ph.D.: Tumors, which are the solid form of cancer, have DNA within the cells that compose them. This DNA has changes in it that cause the cells within the tumor to grow without stopping when they touch another cell. This uncontrollable growth causes solid tumors.
Sadako Yeol, Japan
Is it ever possible for two people or organisms unrelated, to have to same dna coinccedentally?
     Heidi Parker, Ph.D.: Statistically it is impossible. That would require two random people to match 3 billion bases with 4 possibilities at each base.
Sarina Taylor, Ridgewood HS
Can scientists use DNA to bring back the dinosaurs?
     Larry Thompson: Your question, of course, was the thesis of the book and film, Jurassic Park. While anything is possible, scientists are far from being able to technically do in reality what the film-makers could do on the silver screen. However, scientists have isolated DNA from extinct animals. California scientists isolated genes in the early 1980s from a quagga, an extint animal that looks like a cross between a horse and zebra. The genes came from a small clump of dried muscle tissue found in a museum display with a quagga in it. Still, it's hard to imagine that a dinosaur could be brought back to life because DNA extracted from these ancient samples tends to be broken up pretty badly and are unlikely to be functional.
Regine, Chicago
Why is DNA damaged by ultraviolet rays?
     John Hodges, M.S.: UV Radiation damages DNA through a variety of different mechanisms: 1) UVA raditation generates Reactive Oxygen Species (ROS), or free radicals, which react with and damage DNA. 2) 8-Oxoguanine, which also results from exposure to UV radiation, leads to GC --> AT transitions by mispairing with adenine. 3) UV radiation also produces thymidine dimers and single strand breaks. Tymidine dimers result when there are two adjacent "Ts" in the DNA sequence which become joined with a covalent bond.
Charlitta,High point NC
Is being albino caused from a mutation? if so why does this mutation seemingly occur so often?
     Donna Krasnewich, M.D., Ph.D.: Albinism is lack of pigmentary material in the cells where it belongs. Pigmentary material has color. There are many different conditions where either the pigmentary material isn't made correctly or isn't put in the right place in the cell so that the cells collectively do not have pigment....thus the individuals are albino. Albino individuals occur in many species, I suspect because of the same mechanisms I mentioned above. It is interesting that you think they are common, the numbers show that they may be as rare as 1 in 40000 to 1 in 60000 individuals. Thanks for your questions.
Sarina Taylor, Ridgewood HS
Are their any ways to prevent genetic diseases before a baby is born?
     Jean Jenkins, R.N., Ph.D.: That's a really good question. Prevention is not always on the minds of persons considering having children! A good first step to thinking if a couple is at risk of having a child with a genetic disease is to go back to family history. Talk with relatives about any history of problems of genetic conditions in the family. Ethnicity is also important to consider as some conditions occur more frequently with certain ethnic origins. Such factors may indicate the potential for higher risk factors that may be inherited in the family or affect pregnancy. If there are concerns raised, there are genetic counselors who can help assess the risk further and discuss implications for the pregnancy. Personal characterisitics also influence the health of the baby - for instance, women who are older have a higher risk of having a child with Downs syndrome. So consideration of age, medications, and environmental exposures are all important to consider when thinking about having a healthy child. Healthy lifestyles are also important for prevention - such as adequate folic acid intake, and no smoking or alchohol during pregnancy. For the future, gene therapy as an option for intervention in utero is being considered. Clinical studies will be needed to determine the effectiveness and safety of correcting a genetic disease in utero.
Sarina Taylor, New Jersey
Is there a genetic path to finding a cure for AIDS?
     Donna Krasnewich, M.D., Ph.D.: This is a very important and complex question. There are alot of people working on understanding why some people are more resistant to contracting the clinical symptoms of AIDS dispite exposure to the virus. There are many labs working on genetic strategies from a variety of angles to design new therapeutic strategies.
Booker T. Washington MS, Baltimore, MD
What is the Knockout Mouse Project and the Minority Plan?
     John Hodges, M.S.: The Knockout Mouse Project (KOMP) is a Trans NIH project to generate a comprehensive catalog of null mutations in ES cells for every gene in the mouse genome. These would be made readily available to all researchers at a low cost. The Minority Action Plan is a NHGRI specific initiative which requires grantees to insitute programs aimed at recruiting underrepresented minority students into academic careers in the genomic sciences.
Ashley, T Wingate Andrews
Why do mature red blood cells and the cells of the lense of the eye not have DNA?
     Belen Hurle, Ph.D.: Because they are highly specialized cells. Red blood start out with a nucleus, like other cells, but when they fill up with hemoglobin the nucleus is squished smaller and smaller until it disappears. With no nucleus, red blood cells are fragile and live only about 120 days. In your body, about 2 million red blood cells die per second! But your bone marrow produces new ones just as fast. The lens fibers are highly elongated, thin, flattened structures without nuclei and other organelles. They are filled with proteins - crystallins
Caitlin, Chicago
Does DNA affect the size of your body and how?
     Heidi Parker, Ph.D.: Yes, there are genes that effect the speed at which you grow, the length of time that your body continues to grow (and when it tops growning), the density of bones, the size of your head etc. Some of these genes work together. These are often called quantitative genes and the effects can be added together to give variations in size. There are also mutations in genes that cause extremes of size in rare cases.
Andrea Hyatt- Campbell....4ever & always
Is being a midget hereditary?
     Donna Krasnewich, M.D., Ph.D.: First, the word midget is not the right clinical word for individuals who have short stature, the correct word is dwarfism. There are many genetic causes of dwarfism with the most common being achondroplasia which is inherited in a dominant pattern from one parent or the other. This gene is called FGFR3.
Jordan Hawley, Tulsa, OK
If I was interested in studying Biology in college, and possibly become a biologist, what might be the best way to experience the field, hands on, as a high school student?
     Belen Hurle, Ph.D.: Hi Mary Kate, I see that you are in Columbia MD. I ENCOURAGE you to apply to a summer research program at the NIH or any university around here. You will spend 8 to 10 weeks in a laboratory, working on your own research project and learning about what other researchers in the lab do. It is a great way to find out if you really like research and it also will look very good in your college application. For research opportunities at the NHGRI check out
Mary Kate Franchetti, Columbia MD
Is the cheek Swab test a possibility or merely hypothetical?
     Jean Jenkins, R.N., Ph.D.: Use of a cheek swab for genetic testing is already being used as a genetic testing methodology. As with any genetic testing, quality control of the laboratory processing the sample is important to consider. The main concern with genetic testing is that individuals are informed about the risks and benefits of what the test result information wil provide. Sometimes use of cheek swab testing bypasses such genetic counseling.
justin, high point nc
Is it possible to take apart DNA and rearrange it to form a different gene?
     John Hodges, M.S.: The short answer is, 'yes'. This can happen on a couple of different levels. Meiotic recombination occurs in Meiosis and is responsible for generating a significant portion of the genetic diversity that fules evolution. Essentially, large pieces of sister chromosomes swap places and this sometimes leads to the combination of new genetic elements creating a new gene or changing expression levels of that gene. It is also possible to manipulate genes and other pieces of DNA in the laboratory. Researchers, using a host of different enzymes and other technologies, can isolate different pieces of DNA, change them, and piece them back to together again. This is called molecular biology.
Amy Tai, Newton MA
How do scientists go about searching for genes associated with certain human behaviors? Do these behavioral genetics studies hold any water with the molecular biologists? Would you consider these really separate disiplines or are they examples of any serious research efforts with an intergrated approach?
     Don Hadley, M.S., C.G.C.: Identifying genes asociated with human behavior utilize the same basic approaches as those used for identifying more medically focused diseases such as Huntington disease or Cystic Fibrosis. Therefore, the approaches used are not questioned. Behavioral conditions challenge scientists to begin to develop approaches that are able to consider the contributions of more than one gene as well as contributions from the enviroment. From that standpoint, molecular biologists are watching the efforts of those studying human behavior closely since they are beginning to be asked to address common medical conditions that have "complex" (both genetic and environmental) causes. In summary, I see them as complementary approaches that will mutually benefit each other.
St. Ignatius College Prep
How does reverse transcriptase work? Why is it necessary in cells?
     Heidi Parker, Ph.D.: Reverse transcriptase creates DNA from RNA. It is not a component of a cell, but comes from RNA viruses that use it in order to create DNA so that they can transcribe their own viral protiens after they enter a cell.
Matt Morrone - Harrisburg

Information - Moderator Joining us now is Vivian Ota Wang, Ph.D., Program Director in the Ethical, Legal and Social Implications Program.

Is there DNA present in your body after you die?
     John Hodges, M.S.: Yes, DNA exists in our cells after we die.
JT, T Wingate Andrews
How does one create a genetic map?
     Belen Hurle, Ph.D.: It depends: if it is a physical map, normally you start creating a restriction map, that is chopping the original DNA in a controlled way into pieces with the help of a collection of restriction enzymes . Then you put together the DNA fragments like pieces of a puzzle. If it is a genetic map, say in mouse, it involves crossing mice from two mouse strains and following up how a collection of genetic markers that span your region of interest segregate in the offspring.
Charlotte Ahearn, Baltimore Maryland
Is RNA generated during transcription from the DNA, or is there a molecule already present that receives the copy of the DNA and thus becomes mRNA?
     Heidi Parker, Ph.D.: RNA is generated during transcription from individual nucleotides available in the nucleus. Transcriptional proteins take the nucleotides and connect them together in a particular sequence matching the DNA sequence that is being read.
Peter O'Hagan, wellesley ON
Can you trace Autism or other mental illnesses within family bloodlines?
     Jean Jenkins, R.N., Ph.D.: There is a lot of research ongoing to try and determine the genetic contribution to mental illnesses, such as schizophrenia and bipolar disease. Families with a higher incidence of such illnesses have been key to such research. But with this complex disease, there is probably no single gene responsible. Ongoing research is determining genes and other factors that contribute to a higher incidence. For more specifics on progress being made with autism one site that may be useful is and visit the research page describing the genomics initiative Another site to visit for genetic information visit Thanks!
TJ High Point, NC
Does the two parts of a DNA helix always go in a specific direction? (a start and a finish, spinning in a clockwise or counterclockwise pattern?)
     John Hodges, M.S.: Yes, DNA is a polar macromolecule. Each strand of the double helix is composed of chemical subunits which can be thought of as having a head and a tail, these are called 5' and 3' ends. By convention, when a research reads a DNA sequence the top strand runs in the 5' --> 3' direction while the bottom strand runs in the opposite orientation, 3' --> 5'. This configuration is called, 'antiparallel'. There are also a few basic kinds of DNA helices: A, B, and Z DNA. The most common, B-DNA, which is the form present in our chromosomes, is a right handed double helix 2nm in diameter. It also has 10 bp per turn of the helix with a twist of 36 degrees per base pair.  
Jonny Pistachio, Florida
Are identical twins DNA still identical when they are 90 years old, 40, 20, 10?
     Belen Hurle, Ph.D.: At the genetic level, they start off as identical but they can accumulate mutations in a different way: say one of them works in a nuclear plant and the other doesn't. As individuals, they are never identical from the very beginning -say one of them put more weight on during pregnancy - and they are exposed to different environments, friends, teachers, lifestyle, and so on.
M Chaney, FL
Do you work in collaboration with scientists from other fields?
     Heidi Parker, Ph.D.: Yes, almost all of our work is done in collaboration with other scientists. By enlisting the talents of people with a variety of specialties you get a unique view of your subject and come up with a creative way of addressing it.
Zeba Race, Newton, MA

Information - Moderator Joining us now is Holly Peay, M.S., C.G.C., Associate Director of the Genetic Counseling Training Program. She works with psychiatric genetic counseling.

What is the structural feature that allows DNA to self-replicate?
     John Hodges, M.S.: DNA doesn''t "self-replicate" but depends on proteins in the nucleus to do this. DNA is a double stranded linear molecule. The two strands in the DNA double helix are templates of each other. There are four basic molecules that compose the larger macromolecule - A, G, T, C - and these behave chemically in certain ways: ''A'' pairs with ''T'' and ''G'' pairs with ''C''. So, in a strand of DNA with the top sequence reading A - T - T - C - G - G, the bottom strand would read T - A - A - G - C - C. During DNA replication the two strands separate and the proteins that replcate DNA can read one strand to produce a partner pairing strand by using the base pair rule above. You can try this by writing on a sheet a paper a string of random letters composed of As, Gs, Ts, and Cs. Once you''ve done this, fill in the bottom strand using the base pair rule - A pairs with T, G pairs with C. Then separate and copy these two sequences on different parts of your sheet of paper and repeat this process. You should find that you can repeat this as many times as you want, always faithfully replicating the DNA helix.
Lita, High Point NC! GO RED RAIDERS!!!!!!!
What academic path would advise a student who is interested in genetic counseling to take in college?
     Don Hadley, M.S., C.G.C.: Since the practice of genenetic counseling requires knowledge from multiple areas, I would encourage you to take a broad collection of courses that include both the basic sciences (biology, biochemistry, genetics, etc.) as well as social sciences (psychology, sociology, anthropology, etc.). A more detailed answer to your question can be found through the internet through the National Society of Genetic Counselors' website ( You should also know that genetic counselors typically have a Masters degree (graduate degree) from one of the approximately 30 genetic counseling programs in the United States. The NSGC website ( will direct you to those programs' websites. Each program will also give you an answer about pathways to genetic counseling. Good luck.
Maria Makris, St. Paul's School for Girls
Is depression hereditary?
     Holly Peay, M.S., C.G.C.: Depression is what we call a multifactorial disorder, meaning that both genetic and environmental factors play a role. Researchers are beginning to identify the genes and environmental factors involved in depression. It is extremely complicated, though. In some families we think that there are strong genetic factors, while in other families there are weak genetic factors and strong environmental factors. To make matters more complicated, there is not one "depression gene"- there are likely to be many genes that increase risk to depression by modifying how one interacts with one's environment. So the answer to your question is that yes, depression is partly hereditary, but the environment is important as well.
Erik, Chicago

Information - Moderator We are back up and running after a brief technical problem. Thank you for your patience! Please start asking questions again.

Can your DNA predetermine whether you will have musical talent or not?
     Vivian Ota Wang, Ph.D.: Although many people believe that DNA can predetermine whether a person will have musical talent, musical talent is much more complicated than just someone's DNA. Besides someone's genetic makeup, his or her environment, motivation to practice, etc also contributes to someone's potential musical ability.
Jenny, NY
What kinds of DNA are there?
     Nate Sutter, Ph.D.: Great question! Although the rules in biology are often defined by exceptions to them, DNA is one of the great constants. DNA is used by bacteria, worms, flies, trees, algae, mice, monkeys, and humans to store and transmit information. This is done with the familiar 'A', 'C', 'G', and 'T' bases we know about. What makes us different from trees and worms is the particular order of the bases along the chromosomes. So while every DNA molecule has similar chemical properties, the particular sequence in a tree will be different from a human.
lazara geneva ny
Do co-joined twins have the exact same DNA? If not, how do they differ?
     Belen Hurle, Ph.D.: if they are co-joined because they are the result of one embryo that partially split during development, the answer is yes. If they are co-joined because two independent embryos got fused together during development, the answer is no.
Mrs. Talley's Nashville High Biology
Are there certain regions or cultures that do or do not support this type of research more than others?
     Vivian Ota Wang, Ph.D.: This is an interesting question that many people ask. In part, what each person understands what genetic research is (and Isn''t) will influence whether they support genetic and genomic research. Because of this, at some level, in all cultures and regions there are people who support and not support genetic research. This can seem confusing at times since you may hear different opinions from people of the same culture. The bottom line is there is probably no one answer for a particular cultural group. I would encourage you to ask your question to many types of people from different cultures to explore the various ways they see genetic may be pleasantly surprised by their responses.
Jackie from Baltimore, Maryland
In order for DNA to be transcribed, RNA polymerase typically combines with a series of protein promoters, allowing it to latch on to a gene sequence. How are the promoters themselves transcribed?
     Nate Sutter, Ph.D.: RNA polymerase is itself a protein. All proteins are produced when DNA is transcribed into RNA, as you mention, and RNA is translated into protein. Some of these proteins, called transcription associated factors, help to "promote" the transcription process. The proteins working to transcribe a gene at any given time were previously translated. In other words, there is a pool of protein machines that at any given point are being lost yet also being replenished by freshly translated proteins. The cell can't ever stop working!
Trieneke, Canada
Do genetics have anything to do with the type of people we fall in love with?
     Vivian Ota Wang, Ph.D.: Although many people may wish that DNA can help one easily find the "love of one's life," it's never really that easy since a person's choices are a complicated combination of personal preferences, opportunity, one's personality, environement, etc.and not solely based on genetics.
Since twin studies form the basis of research on behavioral genetics - would it be worthwhile looking at twins for differences in numbers of repeat sequences, epigenetic markers, etc. that may lead to underlying factors of behavioral 'disorders'and a better understanding of the so-called "alternative genome?"
     Holly Peay, M.S., C.G.C.: Yes, these sorts of twin studies could be useful to researchers. Unfortunately, this is difficult in practice. The first issue in behavioral genetics is defining the behavior we are trying to evaluate, which can be extremely challenging. The second issue is that the types of studies you are describing have not been used extensively for complex disorders like human behaviors, and we have both technical and learning curve issues. (Complex traits- also called multifactorial traits- such as human behaviors involve more than one gene, and often are highly effected by the person's environment.) Some such studies have been done, for example several studies have evaluated trinucleotide repeats in bipolar disorder. As we learn more about the complicated way our genetic material works, we will increasingly be able to evaluate non-traditional ways of passing on behavioral traits.
Dobrov - St. Ignatius College Prep
Are there ways to screen for Tay Sachs Disease?
     Holly Peay, M.S., C.G.C.: Yes, there are genetic tests that allow us to determine who is at risk to have a child with Tay Sachs disease. Tay Sachs is a recessive condition, meaning that both parents have to carry a change in the gene to have an affected child. A blood test can be used to determine if a person is a carrier. If both parents are found to be carriers, there is a 25% chance that the child would be affected. If a child was exhibiting signs of Tay Sachs, the same genetic test could be used to diagnose the disorder. If you are interested in more information about genetic testing for Tay Sachs, please ask your health care provider.
Kevin, Chicago
After you look in a microscope for a long time, does everything around you look strange?
     Belen Hurle, Ph.D.: Sometimes I get a headache if I work too long on the computer or the microscope , but only because it puts a lot of stress on your eyes.

Information - Moderator Right now, we have with us Nate Sutter, Ph.D., a postdoctoral researcher in the Cancer Genetics Branch. He works with Elaine Ostrander comparing the dog genome to the human genome in an effort to answer questions about disease in both dogs and humans.

I want to be a genetic counselor. What classes should I take in high school, what will my typical work day look like, how much money will I make to start, how much post high school education do I need?
     Holly Peay, M.S., C.G.C.: It is important to take biology, chemistry, and advanced math to prepare for the classes required in college. Most genetic counseling programs require college-level biology, chemistry, organic chemistry, biochemistry, human genetics, biostatistics, and psychology classes. Your typical day depends on what sort of genetic counseling you do. Genetic counselors work in hospitals seeing prenatal, pediatric, cancer, and adult patients; in research settings; in policy and advocacy; in education; for biotech and pharmaceutical firms; and in other roles as well. You can learn more about genetic counseling at Included in that website is an annual report of genetic counselors that has information about salary.
Wawasee, IN
Are you guys being provided with good food for this occasion?
     Larry Thompson: Hmmm, it must have been just before lunch for you to ask this questions. :-) But the fact is, yes, we are being provided food. The team of scientists visiting the chat room need to be fueled, just like anyone else. And since tax money cannot be used to fund food for federal employees, the executive committee of the National Human Genome Research Institute reached into their own pocket to donate the money that purchased our snacks and something to drink. Thanks for asking.
Dan Loganberry, Chicago

Information - Moderator Joining us shortly will be Sara Hull, Ph.D. She is Director of Bioethics Core in the Social and Behavioral Research Branch.

WHat kinds of activities concerning genes can I do with my class.
     Vence Bonham, J.D.: There are many activities you can participate in for DNA Day, all of which are described at These include educational materials for students, videos and webcasts to view with classes, and information about inviting speakers to your class (The Mentor Network). Also, take a look at the Educational Resources page at There are other, more general activities around genetics listed as well.
Mrs.Veronica Cheatham
I know DNA is small, but how small?
     Nate Sutter, Ph.D.: DNA is both miniscule and enormous. The double helix strand is only about 34 angstroms wide, which is 0.0000000034 meters wide. However, a lot of DNA gets tightly packed into every cell in our bodies---if stretched out end to end it would be 2 meters long! DNA is a remarkably good way to store a huge amount of information in a tiny space.
Cherylyn, Ohio
To what extent is homosexuality related to genetics factors?
     Vivian Ota Wang, Ph.D.: This is a complicated question that is often asked and debated. At this point in time, the research findings are unclear. Since this area of research is in its infancy, the very limited number of studies both support and contradict to what degree genetics and homosexuality are related or not. As more research is conducted in this area, we will be able to better understand the genetic and environmental factors related to your question.
Paul, Denver
Why is it some kids dont have the same eye, or hair color as either of their parents?
     Holly Peay, M.S., C.G.C.: Say your parents have brown eyes. Depending on the eye color of their parents (your grandparents), you may either have brown eyes or blue eyes. The same is true for hair color. Your hair and eye color is not just dependent on your parents' coloring, but actually depends as well on the eye and hair color of your ancestors.
Sarah Kloss Greendale High School

Information - Moderator Joining us is Aideen McInerney, M.S., a genetic counselor in the Inborn Errors and Cell Biology Section of the Genetic Disease Research Branch

Is panic disorder hereditary?
     Holly Peay, M.S., C.G.C.: Panic disorder is another disorder that seems to have both genetic and environmental factors. This makes sense in panic disorder because environmental influences tend to lead to panic symptoms, but environmental factors likely play a role way before the individual ever experiences any panic symptoms. So yes, there are hereditary factors involved in panic disorder, but there are also environmental factors that are important.
Jacob Metzger, Cape Elizabeth High

Information - Moderator Joining us now is Sarah Anzick, Ph.D., a research scientist in the Cancer Genetics Branch.

I am doing a biology project and I cant seem to find an organism that belongs to the Phylum Porifera. Can you please tell me a good organism that I can get a lot of research from?
     Nate Sutter, Ph.D.: The common name for the poriferans is the sponges. You'll find lots about them on the web but I wouldn't recommend trying to collect actual organisms, they are difficult to collect without damaging them and difficult to care for long term. Good luck with your research!
Brian, New Jersey
How does Spectral Karyotyping work if there are millions of DNA sequences....?
     Sarah Anzick, Ph.D.: Spectral Karyotyping is a technique in which each of the chromosomes are sorted into separate tubes and then are fluorescently labeled with a different color. Sequences that are shared between the chromosomes are blocked so the chromosome specific sequences stay labeled with the chromosome specific color.
Charlotte Ahearn, Baltimore Maryland
Do you think scientists should have the right to patent genes? W hat impact would no patents have on the genetic research front?
     Sara Hull, Ph.D.: This is a very complicated issue, as you are probably aware. On the one hand, patents are intended to encourage innovation, allowing scientists to gain financial compensation for their efforts. This is the American way. On the other hand, many feel that biological things (genes, mice, etc.) are not inventions that can be patented -- they are things that occur in nature. Another concern is that patenting could inhibit sharing of sequences and information that might lead to more research that could benefit the public. I believe that patents can be helpful to the extent that they encourage the development of products that are beneficial to the public, but think the line should be drawn when they start to decrease benefits to the public. You can take a look at Vence Bonham's response on this topic from earlier in the day for more detail. Your question about the impact of banning patents on gene sequences is a very good one. I do not know the answer, but I could guess that it might lead to less innovation in the short term -- particularly in the private sector -- but that the playing field would level out in the long run.
Dan Noonan, IL
Why have Cat genome experiments just started?
     Nate Sutter, Ph.D.: Biologists decided to focus first on those genomes that could provide the most information about humans and their diseases. That meant sequencing the human genome and the genomes of the most commonly used 'model' organisms first: fruit fly, worm, yeast. You may like to know that the dog genome has just recently been completed. I'm personally thrilled by that, since our lab works to understand human and dog inherited diseases by studying the dog genome. Eventually the genomes of many different organisms will be completed. Comparing many different genomes is a powerful way to discover the functional features of genomes.
Linda, East Middle School
Is being overweight something that is carried through generations in DNA, or could an obese couple produce an average sized child?
     Holly Peay, M.S., C.G.C.: In a small number of families there are one ormore genes that cause individuals to be obese, and it is very difficult for them to maintain a normal weight. In those families we tend to see many individuals in several generations who are obese, but even in these families there are about equal nnumbers of individuals who are of normal weight. In the VAST majority of families, however, obesity is caused by both genetic and environmental factors, and through the use of exercise, diet, and sometimes medications, individuals who have an increased risk for obesity may obtain and maintain a normal weight. So yes, in most cases an obese couple can and will produce a normal-sized child, and in fact if there is diet and exercise modification children are unlikely to become obese.
Allyson Ridge, Cape Elizabeth ME
How does a disease like Tay Sachs continue in a hereditary line if it kills everyone who gets it?
     Aideen McInerney, M.S.: This is a really good question! We have two copies of each gene and we inherit one from our mother and the other from our father. Some of these genes don't work properly. In the case of Tay Sachs disease the affected person inherits both copies of the Tay Sachs gene which don't work properly. This is what is called a recessive condition (need two faulty copies of the gene to cause a disease). The parents are "carriers". Carriers are unaffected and unaware that they carry an abnormal gene because their other copy compensates. Therefore, although this is a terminal disease in affected people, it doesn't cause any health problems in carriers, who go on to have their own children and pass on the gene.
Kevin, Chicago

Information - Moderator A number of students have been asking "What is DNA." That question already has been asked. Please use the find function to search the chat window for the answer.

How are the names for genes created?
     Belen Hurle, Ph.D.: The HUGO Nomenclature Committee ( provides guidelines for giving unique and meaningful names to every human gene . The researcher proposes a name and the committe approves or reccomends another name. On a fun note, researchers working with Drosophila, C. elegans, and zebrafish, for some reason, get to assign specially creative names, specially if there is a known mutant. Consider this: "what's up?" is the real name of a fish mutation that affects the sense of balance of the zebrafish mutants.
Chari Harris
Why is Biology so important in middle school?
     Sarah Harding, M.P.H: It's important to understand the basis of any subject, so learning Biology at the Middle School stage gives you the chance to master the fundamentals before moving ahead to the more complicated topics. The great thing about Biology is that many of the applications and processes overlap one another, so understanding the basics can lead to a whole lot of fun and interesting topics. For example, with genetics, without a good understanding of DNA, it would be difficult to understand the more complicated applications like gene therapy or sequencing.
Brian Hogan New Jersey
where is the DNA in your body?
     Nate Sutter, Ph.D.: Almost every cell in your body contains a full copy of your unique DNA. This means that a forensic biologist can collect a small sample of cells from a crime scene, examine the DNA and determine if that DNA matches another sample (taken from a suspect, for example).
Haruhara Haruko, Bernalillo High School
Can our DNA predispose us to skin cancer, or is this entirely based on the environment?
     Holly Peay, M.S., C.G.C.: Yes, DNA can predispose us to skin cancer, though the relative effects of genes and environment can vary. For example, there are many genetic syndromes that include increased risk for skin cancer. In those syndromes DNA plays a large role in skin cancer. In most cases, however, environment plays a larger role than genetics in skin cancer, though there certainly are families in which individuals are predisposed to skin cancer. If you have a close relative with skin cancer it is even more important that you avoid excessive sun exposure and have your skin evaluated.
Billy Idol
Do you think our society will ever become like the movie GATTACA?
     Sara Hull, Ph.D.: Yes and no. I think we will have increasing abilities to predict future illness through genetic testing. However, the role of environment on disease will always be complicated, such that I don't ever think we can be 100% sure of what diseases a person will eventually have at the time they are born. It would be a mistake to ever make the kind of predictions that the movie portrays about a person's future, and it would be a shame to limit a person's future choices about career/relationships/etc. based on such predictions. The movie also raises some important questions about enhancement (e.g., the piano player with extra fingers) that we need to think hard about -- is this a good direction for technology to take us? It's good that you are viewing movies like this thoughtfully and thinking hard about what the future should look like. Also, the ELSI (Ethical, Legal, and Social Implications) program of the NIH-funded human genome project was created to help us think about these issues as genetic technology emerges, rather than after the fact. All of these things make me believe that we face a very different future than the one shown in the movie.
Erica BGHS
Why is this dna day?
     Sarah Harding, M.P.H: DNA Day began as a celebration of the completion of the Human Genome Project, which was an international effort to sequence all 3 billion base pairs in the human genome. The complete sequence was published on April 25, 2003, and the first annual DNA Day was celebrated. In addition, back in April of 1953, Watson and Crick first described the structure of DNA. DNA Day also commemorates this.
Eric kelley pountly vt
GeA broadcast of 'Dateline' explained a recent breakthrough in gene therapy regarding Alzheimer's disease. A study concluded that by using a patient's own skin cells, they can be cultured and turned into human growth factors that once implanted into the patient's brain will slow the progession of memory loss and confusion. How else can gene therapy be used to help patients with Alzheimer's? Are there solutions that are likely to develop from the information from the human genome project?
     Aideen McInerney, M.S.: This is a complicated question with a less than simple answer! One of the main problems with gene therapy is getting the cells with the corrected gene to the right location. For diseases which affect the blood it is relatively easy to get bone marrow cells etc. However, for diseases which affect the brain, it is harder to get the corrected cells to the affected area. I do think that gene/cell therapy will be used in Alzheimer's disease in the future but it is not clear yet when that might happen. Without a doubt, better understanding our genes and what happens when they don't work properly will give us great insight into how we can better treat diseases in the future. In the case of Alzheimer's disease, it is likely that we will be able to use genetic tests to identify people at increased risk and these people in turn will be started on medications to help reduce their risk of Alzheimer's disease.
Cassandra, Buffalo Grove High School in Illinois
In the next decade or two, I see DNA testing becoming a major national controversy. Do you think our government will ban it?
     Sara Hull, Ph.D.: I don't think so. Genetic testing in various forms has been around for many years already and has proven to be beneficial to at least some people. As more tests become available, the government's role will probably be to develop guidelines on the ethical use of genetic testing technology. In addition, many of us are interested in doing research on the ways in which genetic testing can be most beneficial to the public's health. Government regulation can help limit who can order genetic testing (like a physician or other health care provider), but it is very unlikely that an outright ban would occur.
Ron Mexico, Cape Elizabeth, ME
How fast does DNA replicate?
     Belen Hurle, Ph.D.: Great question, Michelle. Bacteria can replicate about 100,000 bases per minute. Eukaryotic DNA polymerases are slower than bacterial DNA polymerases and can replicate about 500 - 5,000 bases per minute. To make up for the slower replication, eukaryotes have more origins of replication.
Michelle Zellmer Greendale, WI
Recent studies have shown that there could be a possible link between depression and the mutation of the gene 5-HTT. How valid do you think this research is?
     Holly Peay, M.S., C.G.C.: It is unclear at this point what the link is between depression and 5-HTT, if there is one. Some studies have found a correlation between variants in this gene and depression, while others have not. This non-replication is not uncommon in research on multifactorial disorders, and it does not necessarily mean that the research was not valid. Stay tuned for more information!
Erik Murray, Chicago
Where will the human genome research be in 50 years and how will it impact us?
     Sarah Anzick, Ph.D.: It is difficult to project 50 years from now but we will probably know how all of our genes function and how small variations in the human genome influence our overall health. In 50 years, genome research will help to create a more "personalized" approach to predicting disease susceptibility and response to treatment.
garrett , plano texas
What is a karyotype?
     Belen Hurle, Ph.D.: A karyotype is the chromosomal complement of an individual, including the number of chromosomes and any abnormalities. The term is also used to refer to a photograph of an individual's chromosomes.
Gabe rodriguez from Bernalillo High
In all of the videos that we've watched in class there are many machines that have "de-coded' DNA. What exactly do the machines do? What process do they go through?
     Nate Sutter, Ph.D.: To determine the sequence of a DNA molecule we first need lots and lots of copies of that molecule, which we obtain by growing bacteria carrying the DNA sequence or by doing the polymerase chain reaction. Next, we set up a special kind of DNA synthesis reaction in a test tube. The reaction takes one strand of DNA and builds the second strand. Sometimes, the reaction stops at the first base, sometimes at the second base, or third, fourth, etc. When the reaction stops on an 'A' base it 'tags' the strand with a molecule that fluoresces a certain color. When the reaction ends on 'C' it gets another color, and 'G' and 'T' get unique colors too. When the reaction is finished, this set of "dideoxy-terminated" DNA strands are run on the sequencing machine. The machine electrophoreses the molecules through a gel matrix and separates them by size. A laser reads the colors as they come out the other end and a computer translates the colors into DNA bases.
Emily, Benjamin Logan High School
What are some of the ethical issues you face as a scientist?
     Sara Hull, Ph.D.: The kinds of ethical issues that I am most familiar with on a day-to-day basis have to do with the use of human subjects in research. For example, we have to evaluate whether the benefits of the research are likely to outweigh the possible risks of harm that we expose subjects to in the research. Also, it is very important to get informed consent from each person who becomes involved in our research. If we collect blood or other specimens from research subjects, we have to make sure we tell people that we may do research on these samples in the future since it can be stored for many years. Another important issue is that we have to be very careful to protect the privacy of the people who participate in our studies.
Bilal,high point nc
Is metabolism hereditary?
     Holly Peay, M.S., C.G.C.: Metabolism has strong genetic factors. Even a genetically healthy metabolism, however, can be overwhelmed by negative environmental factors, such as excessive consumption of unhealthy foods or not eating necessary vitamins, or by not having adequate exercise. There are a set of genetic disorders called metabolic disorders. In this class of disorders, genetic mutations affect how the metabolism works, and individuals with these disorders can have bad effects even with a good, healthy diet. In some cases we can treat these metablic disorders, while in others we cannot.
Kristy McFaul, Greendale, WI
What sort of work is actually being done with the DNA sequences (specific projects, etc.)?
     Nate Sutter, Ph.D.: I'll give you an example from our own lab. Heidi went to dog shows and collected cheek cell samples from several thousand purebred dogs. She then extracted each dog's DNA and analyzed 100 genetic markers for the dogs. Markers are places where the DNA is different in one chromosome or individual compared to another. Using a set of markers like this, one can determine which chromosomes are more similar to one another. Heidi then determined how dog breeds are genetically related to each other using this information. For example, we now know that the Bernese Mountain Dog breed, which suffers from a very common and devastating cancer, is closely related to the Greater Swiss Mountain Dog breed. We may be able to use these two breeds together to help us map the genetic basis of this terrible cancer.
Dana Riker, Cape Elizabeth, Maine
What is messenger RNA?
     Sarah Anzick, Ph.D.: As the name implies, messenger RNA (mRNA) is the instructional part of a gene. The introns (or non-coding regions) of the gene are spliced out from the exons to generate the template that is used for protein synthesis. In the lab, mRNA can be isolated from the total RNA using a special oligo d(T) primer and it represents approximately 1-3% of the total RNA.
Scott Campbell, Bethesda, Maryland
Is hypochondria genetically caused?
     Holly Peay, M.S., C.G.C.: To my knowledge, there have been no studies documenting a genetic component to hypochondriasis. This does not mean that there IS no genetic portion to the cause of the disorder, but rather that adequate research has not been done.
Mote, Nashville High
With our knowledge of DNA, will it someday be possible to elminate diseases altogether? Can we use this knowledge to prevent people from getting viruses and infections too?
     Aideen McInerney, M.S.: Wow! The short answer is "No". Knowledge about genes and their function will help hopefully help us to treat diseases which are purely genetically determined e.g. Cystic Fibrosis, Tay-Sachs etc. This knowledge should also help us to treat conditions which are partly genetic and partly environmental e.g. heart disease etc. This will happen by using genetic discoveries to develop better and custom medications which will hopefully minimize the symptoms rather than cure the condition. New viruses and infections will always occur and though genetic discoveries might aid in developing vaccines or treatments, it is unlikely we will be able to prevent them from occuring in the first place.
Why is it so hard to find out what certain genes do?
     Belen Hurle, Ph.D.: Finding a gene's function is a lot like detective's work: you depend on finding reliable clues and being able to interprete them. I will give you some examples of good clues: there is another member of the same gene family described in the literature already; the protein that the gene encodes has a recognizable protein domain taht makes obvious the function; when you express the protein artificially in a cell in the laboratory the cell function changes in a way that you can measure. If there is absolutely no clue, it can get really complicated and frustratrating.
Matt Yantanakasol from Cape Elizabeth High School
As a scientist are you too busy to have a lot of time for yourself or for your family?
     Don Hadley, M.S., C.G.C.: Like any professional career, one challenge we face is making sure that we don't let our jobs take all of our time; no matter how interesting or important or job becomes. A person has to learn to manage the work load so that the family doesn't get put aside. Professionals of all kinds need to learn how to protect themselves from becoming 'burnt out". This can happen if a person doesn't take time off and enjoy other parts of life. A balance is needed and can happen even in the most exciting and demanding careers. My job is the greatest, but so are my family and my hobbies. A balance between all three is ncessary to make me the best professional that I can be.

Information - Moderator Joining us now is Phyllis Frosst, Ph.D., Science Policy Analyst in the Policy and Program Analysis Branch.

How often does DNA split and make copies of eachother?
     Belen Hurle, Ph.D.: Usually DNA replication is associated to mitosis and cell division. So the answer is, it depends on what cell we are talking about: E coli bacteria divide every 30 min. Cancer cells also divide very fast. Some other cell types divide very slowly or never. The less specialized the cell is, the faster it divides.
Matt Mohoney/Troy Mrkvicka Greendale Wisconsin
What exaclty is Down syndrome and can it be prevented?
     Aideen McInerney, M.S.: Most people have 46 chromosomes or 23 pairs. They inherit one copy of each chromosome from each parent i.e. 23 chromosomes in the sperm and 23 in the egg. People with Down Syndrome have an extra chromosome. This occurs because they inherit an extra chromosome from one parent, usually their mother. This can occur at any age but as women get older, their eggs are less effective at packaging their chromosomes and there is an increasing chance that an egg will have too many or two few chromosomes. This occurs randomly and cannot be prevented. Having children at a younger age reduces the chance of this occuring but it can happen at any age.
How would the Human Genome Project benefit adopted people?
     Sara Hull, Ph.D.: The problem that many adopted people face is that they don't know anything about their family health history. The Human Genome Project itself cannot fix this problem directly, at least in the short term. Regulations that provide adoptees with access to their biological parents' medical information need to be reformed to fix that problem. The reason why many feel this information is important is because it helps people understand their risks of disease and sometimes helps them make decisions about their health care. A few years down the road, it is likely that technology that emerges from the Human Genome Project will help predict risk for common and even some rare diseases in the absence of family history information. This would be a benefit for adopted people and anyone without complete family history information.
Alexandria-Crawfordsville, Indiana
What current legislation is there to protect an individual against genetic discrimination in the workplace, insurance, etc.
     Phyllis Frosst, Ph.D.: Unfortunately, there is currently no federal legislation to protect individuals against discrimination in the workplace, although these bills have passed in the US Senate, they continue to have lukewarm sucess in the US House of Representatives and have not been passed. Several states have legislation to protect individuals against genetic descrimination, but Americans in many US states are still without this important protection.
Has there been any advancement in the use of vectors in gene therapy? i had heard there were significant problems with vector use.
     Phyllis Frosst, Ph.D.: Hi Kristine, the good news is that the field of Gene Therapy is steadily evolving and improving. New viral vectors are currently being used (mostly in cells and in animal models) that have less of the components of the original virus and more of the genetic information that is being delivered. Much more technically advanced. An important thing to understand about gene therapy trials in people, is that the protocols are approved after much evaluation and analysis, so usually, the vectors that are being used in human trials are several years beind the current cutting edge technology.
kristine babick, cape elizabeth, ME
The final gene count for humans, though still not known precisely, is lower than initially assumed. What are the prevailing theories as to why this might be so?
     Phyllis Frosst, Ph.D.: Good question Danny. Approximately 74% or more of human genes express more than one splice isoform through the alternate splicing mechanism.Some isoforms are only expressed in a particular tissue or developmental point, suggesting different functions for splice isoforms of the same gene .
Danny Hoffman, Mississauga ON
In your opinion, what should I focus on as a middle school teacher to best help my students understand the future implications of the human genome project?
     Sarah Harding, M.P.H: Alongside teaching the fundamentals of genetic research and applications, it is important for students to learn how to ask questions about the implications of that research. Specifically, students can learn about the implications of the Human Genome Project by looking at ELSI (Ethical, Legal and Social Implications) of genetics. But there isn't necessarily one way to understand all of the implications of the Human Genome Project. Instead, skills of critical thinking can allow students to consider the implications for themselves, as the implications of research may very from person to person, or from individuals to society.
Shannon Hudson, Crawfordsville, Indiana

Information - Moderator Joining us now is Francis S. Collins, M.D., Ph.D., Director of the National Human Genome Research Institute and the leader of the now-completed Human Genome Project.

What is a genome? I dont understand it.
     Sarah Anzick, Ph.D.: A genome is simply a term that refers to the entire DNA content that makes up an organism. For example, the human genome is composed of 3 billion DNA bases (A,C,G,T) that are packaged into 23 pairs of chromosomes.
Kaneisha E. Chicago,il
How does the Human Genome Project benefit Genetic Counselors?
     Don Hadley, M.S., C.G.C.: One of the greatest challenges genetic counselors face is having enough information to answer questions that people and their families ask. The human genome project helps provide greater resources to address these questions. Having been a genetic counselor for 24 years, I've seen an amazing amount of information about genetics unfold in a way that provides answers to many families. Another ten years of genomic research holds tremendous promise to address even more questions. Although experience has taught us that sometimes new answers can create new questions and new challenges for the families and people we hope to help.
Kenzie- Crawfordsville, Indiana
What made you want to get into genetics?
     Francis S. Collins, M.D., Ph.D.: I first got interested in science in high school, but it was chemistry and physics that appealed to me the most -- they were so elegant and principle based. I thought biology was a bit messy. But later on I discovered DNA, RNA, protein, and the genetic code -- and realized that Life Makes Sense! And the part that made the most sense was genetics. I don't like memorizing stuff -- and genetics is all about principles.
what is the best way to get hands on field work while in high school to prepare for a future career in biology
     Vence Bonham, J.D.: A good way of obtaining "hands on experience" is to obtain a volunteer or paid internship with a researcher at a university or college near your home who is conducting research of interest to you. You may want to go to National Institutes of Health (NIH) database called CRISP see website: to find scientist funded by NIH near you. NIH also has many programs for high school and college students to expose them to biomedical research. Talk to your teacher about opportunties in your community.
anna new mexico
How did you get to be the head of the Human Genome Project?
     Francis S. Collins, M.D., Ph.D.: When Jim Watson stepped down as the first leader of the project (in 1992), the NIH mounted a search for a new leader. I was leading a genome center at the University of Michigan at that point. As a physician, I was particularly interested in the medical applications. When the dust all settled on the search process, I was invited to take on the job. I said no! I didn't think of myself as a federal employee. But after a few months I decided I was missing out on something historic, so I said yes after all. I've never regretted that decision!
hannah, Crawfordsville Indiana
How are diseases formed on the strands of DNA?
     Phyllis Frosst, Ph.D.: Greg - There are lots of ways for DNA to become mutated and to result in a disease. These include DNA damage, like from radiation or from the sun (think about skin cancer), or from environmental chemicals. Most often genetic diseases are as a result of problems that occur during cell division, when DNA divides during mitosis. This is a way for small positive changes to occur (that's how evolution works) and also for deleterious changes that can result in the occurance of disease.
Greg Hansen Greendale Wisconsin
How do evolutionists explain different numbers of chromosomes in different organisms if all organisms originated from a single organism?
     Belen Hurle, Ph.D.: Sometimes the whole genome of an organism gets duplicated once or several times, it is called polyploid. I will give you some examples: humans have 46 chromosomes (2n), it is called diploid genome); sugar cane has 80 chromosomes (8n) ; species of coffee plant with 22, 44, 66, and 88 chromosomes are known (2n, 4n, 6n and 8n respectively). Sometimes, only one gene family expands in a particular organism.
Steve - aurora - illinois
What has been learned from the knockout mouse program?
     Francis S. Collins, M.D., Ph.D.: About 2500 mouse genes have been "knocked out" (i.e. inactivated in the mouse germline) -- and we have learned a lot about biology as a result. As an example, a knock out of the mouse cystic fibrosis gene creates a pretty good animal model of the disease, and allows testing of new drugs without putting people at risk. But we are impatient to see more mouse knockouts generated -- and so there is a new project getting underway to do this.
Blake CEHS
With regards to Tim's questions, my Scholars were confused because in their research of the NIH website, they found a reading that said there is the HIPAA legislation to protect us from genetic discrimination in insurance and that 31 states had passed legislation to protect individuals in the workplace. They were wondering if the legislation is lacking in any real consequences for discrimination. Thanks!
     Phyllis Frosst, Ph.D.: HIPAA protects people in group insurance primarily, and not those with individual health insurance. And HIPAA is federal legislation (which is great) but state-by-state legislation protects individuals.
Booker T. Washington MS, Baltimore, MD
How much does a genome weigh?
     Geoff Spencer: According to our leader, Francis Collins, a genome weighs 6.7 picograms per cell.
Gene benlogan
What is your favorite gene and why?
     Francis S. Collins, M.D., Ph.D.: I'm afraid that I am rather fickle and capricious person when it comes to choosing favorites -- my favorite gene is usually the one that I'm working on that day. Today it would be the lamin A gene, mutations in which cause progeria, a dramatic form of premature aging. My lab identified the genetic cause, and we are now working on a treatment. And work done by a medical student in the lab over the last two weeks looks very promising!
I have a sister and a brother who were diagnosed with Multiple Sclerosis within one year of each other. Are we close to identifying a gene for Multiple Sclerosis?
     Aideen McInerney, M.S.: There are a lot of researchers doing work on the genetic and environmental causes of MS. I think we are very close to identifying genes which play a role MS. For more information visit the NINDS website on MS disorders/multiple_sclerosis.htm.
Lori Abbott from Arlington Heights, IL
With "over-the-counter" DNA testing becoming more available, is NIH currently supporting any additional anti-discrimination legislation?
     Phyllis Frosst, Ph.D.: NIH, as the federal governement, is prohibited from lobbying congress who make the laws. However, that does not prevent the NIH from expressing opinions and educating the public (and congress, when they ask) about genetic discrimination and about "over the counter" testing.
Amy Trigonoplos, Bethesda, Maryland
what is the weirdest thing you've ever seen while studying genes?
     Francis S. Collins, M.D., Ph.D.: There's a lot of weird stuff out there. Perhaps the weirdest recent discovery is just how few in number are the genes in the human genome -- only about 25,000. When you consider that fruitflies have 13,000 genes, and roundworms have 19,000 genes, and a mustard plant has 25,000 genes, it's a wonder that we get by.
kris ferguson, greenville, alabama
What made you want to have DNA day?
     Vence Bonham, J.D.: DNA Day provides an opportunity for students and teachers to celebrate our knowledge of the human genome. We hope that you will learn something new and have an exciting conversation in your classroom.
meghann Seamans
How is it possible to use barely any remains of blood to figure out who a person is?
     Belen Hurle, Ph.D.: You can use a PCR (Polymerase Chain Reaction) machine to amplify that tiny amount of DNA to a sizeable amount of genetic material. PCR is sometimes called the molecular photocopy machine
Angela, Greendale, WI
Do you think that the Human Genome Project will be beneficial to our society?
     Francis S. Collins, M.D., Ph.D.: You won't be surprised to hear my answer is YES!! The HGP will provide information about health and disease that will revolutionize medicine -- by allowing better ability to predict who is at risk for what, as well as providing the kind of information that will make it possible to develop treatments for cancer, diabetes, heart disease, mental illness, and a host of other conditions. Hang on to your hat!
Michelle Buffalo Grove High School
Where does your funding come from?
     Phyllis Frosst, Ph.D.: TJ - Funding for NIH (and NHGRI) comes from congress, who fund all agencies including defense and NASA and all the others. Funding comes through a process called "appropriations" where the congressional committees divide their chunk of money among the various federal agencies.
Can your DNA un-mutate?
     Sarah Anzick, Ph.D.: Once a mutation is fixed into the genome, it cannot really 'un-mutate.' However, we do acquire numerous mutations in our DNA due to environmental exposures, such as UV radiation (sunlight), but fortunately this damage gets repaired through vast repair mechanisms that are able to detect and fix the damage on the DNA.
Magda & Allen, NC
     Francis S. Collins, M.D., Ph.D.: This was indeed a big surprise! But clearly we humans are still pretty complex organisms -- how do we get by with just 25,000 genes? After all, a mustard plant has the same number. But recent data suggests that humans do a lot with these genes -- the average gene makes 3 proteins, and further modifications of those proteins adds additional complexity.
Danny Hoffman, Mississauga ON
What gene afflicts people with Parkinson's disease?
     Aideen McInerney, M.S.: Parkinson's disease is not usually inherited in families. However, there are some families in which many people are affected with the condition. Studying these families has enabled us to discover five genes so far and five other locations in the genome in which other genes are located. The five genes found to date are alpha-synuclein, parkin, DJ-1, Pink-1 and LRRK2. We are currently doing more research on these genes in order to better understand what they do and what happens when they don't work properly.
Hustle & Bustle Cape Elizabeth, ME
Do you think insurance companies should be able to request someone's genetic information before accepting someone as a customer?
     Vence Bonham, J.D.: What type of insurance? Health insurance, life insurance, disability insurance? It is important that everyone has access to health insurance and should not be discriminated against because of their genetic information.
Dakota Smoll and Rogge Merriman Crawfordsville IN
How are siRNA's being used in gene therapy? What is the future of using viruses as vectors of genetic manipulation in gene therapy?
     Phyllis Frosst, Ph.D.: Mike - Traditional gene therapy delivers a missing gene or a functional copy of a defective gene that makes no protein. siRNA offers the ability to reduce the production of a defective gene, a completely new trick! Viruses, are incredibly good a doing what they do best, deliver DNA into cells, they've had hundreds of years to get this good, and we've only just started. Of course, we have to understand how viruses work, and how cells react to the viruses, so it takes a lot of work to make sure we really get it. They definitely have a future.
Mike, Chicago
What is a picogram?
     Phyllis Frosst, Ph.D.: Hi Amy - nice to hear from you. A picogram is 1 times ten to the negative 12th of a gram. or one million millionth of a gram.
Amy, Bethesda
Is it possible that someone who is subjected to genetic testing could in any way injured or disabled because of the genetic tests?
     Don Hadley, M.S., C.G.C.: Genetic testing is not likely to harm any one physically since the testing is done on a small blood sample or cells from a cheek swap. However, we do worry that there could be psychological or social "harms" if a person isn't given appropriate information or counseling prior to the testing to help them understand the potential implications of testing. Furthermore, many families are worried about insurance companies or employers discriminating against them if the results of genetic testing are made available to them. Might insurance companies charge persons more (higher premiums) if they are found to have have genetic changes that increase their risks for diseases or health problems? How does knowing your risk for diseases effect how you feel about your future, getting married, having children? Research is being done to help us understand the range of reactions and concerns relating to genetic testing, however, we don't yet have all the answers. We need more professionals from many backgrounds to help answer these challenging questions as they arise. Come join us!
Rogge Merriman, Indiana
What race has the most problems with DNA?
     Francis S. Collins, M.D., Ph.D.: The connection between "race" and genetics is one of the most complicated and controversial aspects of genetic research. One of the problems is that people use the word "race" in multiple different contexts. In the sense that race has a connection to ancestral geographic origins, there is a weak genetic connection to self-identified race -- but it is good to keep in mind that we are all 99.9% identical at the DNA level, regardless of the color of our skin. Groups that are particularly concerned about genetic research are generally those that have bad experiences in the past with medical research, or for whom health care resources are limited by current social systems. In the U.S., American Indians and African Americans have been particularly concerned about how genetic research might be used in discriminatory ways. The Human Genome Project has an Ethical, Legal, and Social Implications that has placed a significant focus on this issue of race and genetics, and is supporting a wide of research and public education.
Why do some genetic traits seem to skip generations?
     Belen Hurle, Ph.D.: Some diseases are inherited in a "dominant" fashion, having the mutation on only one of your two chromosomes gives you the disease. Others are inherited in a "recessive" fashion, you need two copies of the mutation in order to have the disease. People with one copy of a recessive mutation are called "carriers" of the disease and can pass it on to their children without having it themselves, assuming that the other parent also has a recessive mutation to donate to the chid.
Jessie Wisconsin
What do you know about the Huntington's Disease gene?
     Aideen McInerney, M.S.: We have two copies of every gene. Sometimes one of these genes don't work properly. Usually the normal copy of the gene compensates. In the case of Huntington's disease the abnormal copy "dominates" the normal copy and causes disease. This is called a dominant condition. The gene is located on chromosome 4p and encodes for a protein called huntingtin. In part of the gene, there are three DNA bases which are repeated a number of times. These are called trinucleotide repeats. People with 11-34 repeats have a normal copy of the gene and have no problems where people with 40 or more repeats will develop the disease. The function of the HD gene is not currently known.
eric totheroh crawfordsville, IN
Do believe what you are doing (maniuplating the human body/DNA) is morally correct? Why?
     Francis S. Collins, M.D., Ph.D.: Your question is a good one. But to answer it, it's important to know what the genome project's goals really are. We are not manipulating human DNA is a way that can be passed on to the next generation -- that is considered unacceptable at the present time on ethical and safety grounds. What we are trying to do is identify the causes of disease by studying the DNA of affected individuals. Those discoveries then lead us to ideas about treatment -- but those don't usually involve manipulating the DNA, they involve compensating for the problem with diet, exercise, or drugs. In rare instances, researchers are trying to treat disease with gene therapy, where the gene itself is the drug -- this has shown benefit, for instance, for hemophilia. But that is actually less of a "manipulation" than organ transplantation, so most ethicists agree that gene therapy is acceptable (as long as it doesn't get passed to that person's children).
Franklin J. Johannes Jr., Texas
How do cancer cells differ from regular cells?
     Sarah Anzick, Ph.D.: There are a number of differences that distinguish a cancer cell from a normal cell. At the genetic level, cancer cells acquire mutations in genes that are critical for maintaining control over cell division. Two specific types of genes that are altered in cancer cells are tumor suppressors and oncogenes. When mutated or overexpressed (too many copies), these critical genes no longer maintain control over the cell cycle, which leads to increased cell proliferation and decreased death.
Are humans still evolving?
     Sarah Anzick, Ph.D.: Absolutely! Evolution happens all the time, to any orgamism that has DNA. It just happens very slowly, over a long time, so it's hard to observe it in humans in our lifetime. For organisms that reproduce very quickly like unicellular organisms and bacteria, you can actually watch evolution in action in a test tube!
Ken/Taylor Greendale, WI, USA
Assuming you believe in evolution and many other scientific theories, do you hold any sort of religious faith?
     Francis S. Collins, M.D., Ph.D.: Yes, I am a committed Christian. I don't find any conflict between what I know as a rigorous scientist studying the genome, and what I know as a person of faith. For more information about the harmony of evolution and faith, pick up a copy of "Coming to Peace with Science" by Darrel Falk (Intervarsity).
Corey McGregor, Ohio
What are the chances for getting cancer if a a their parents acquire cancer during their middle age?
     Aideen McInerney, M.S.: This is a hard question. It depends on the type of cancer and the age of onset. It also depends on whether or not there is any more family history. The following are some general guidelines -Certain cancers are more likely to be inherited than others. -An earlier age of onset, the more likely that genes play a stronger role - The more people affected with the same or related cancers, the more likely that this is an inherited cancer. If you are concerned about your risk, go to to identify a genetic counselor in your area.
Elezar India
How signficant is the environment in the expression of certain characteristics? Can we regulate the expression by adapting our behaviors or will genetics always prevail?
     Don Hadley, M.S., C.G.C.: Certainly, our genetic makeup is important, but it does not have to prevail! We already know of several inherited conditions, in which changing diets, behavior or having health routine health screening can lessen the chances that the person will develop disease. As we learn more, the number of conditions that we can prevent or at least reduce the chances of it occuring will grow. The human genome project and newer efforts now underway are beginning to address ways to reduce risk whether through medication, genetic therapies, or altering behavior.
Alaina Susquehanna Twp. HS
     Francis S. Collins, M.D., Ph.D.: Sorry to disappoint you, but there will be no perfect kid. I'm hoping that in the future we will have the ability to prevent and treat diseases, but the subject of "enhancement" is much murkier. Who would decide what is an improvement? And given that genes are not predetermining (just predisposing) for things like intelligence, athletic ability, and personality, even the most finely designed genome might give rise to a kid who smoked dope and failed math. We'll get closer to perfect kids from caring families and good education than we'll ever get from genetics.
How are teachers involved in the human genome project??
     Sarah Harding, M.P.H: Teachers haven't been directly involved with the research side of the Human Genome project, but are certainly now part of the dissemination of information and education of students around the Human Genome Project and it applications. In addition, teachers can help to excite students about career options in genetics, to ensure the field is full of a diverse group of individuals.
michelle crawfordsville IN
What happens if DNA is exposed to radiation?
     Phyllis Frosst, Ph.D.: After exposure to radiation, DNA becomes damaged and the enzymes that read and translate the DNA code can become confused and make mistakes and the function of the cell can degerate, for example in cancer. Fortunately, if the damage is limited (like we get from the sun everyday) our cells have specialized machinery to fix DNA damage. It's pretty cool.
Zurc Nairb of Greendale
Do animals pass down the same genetic information like humans do?
     Phyllis Frosst, Ph.D.: Yes! Animal parents pass their genes onto their puupies and kittesn and kids just like humans.
Erica Greendale
Is it possible for a mother to have more than two identical offspring? (One egg dividing 4 or more times and each producing a baby?)
     Aideen McInerney, M.S.: That's an interesting question! Theoretically that is possible but I have never heard of it happening.
Jazmine Manns
In the future, can all diseases be avoided?
     Aideen McInerney, M.S.: This question has been answered. Please look for query 711.
New genetic technology has advanced science on all fronts, including weapons technology. What new concerns do genetics bring to the world of biological warfare?
     Francis S. Collins, M.D., Ph.D.: Hi Kevin, there are legitimate concerns about the ways in which biotechnology in the wrong hands might allow the development of even more dangerous bioterrorism organisms. Could a diabolical microbiologist engineer a smallpox virus that would evade the current vaccine, or make a toxin that was even more dangerous than the natural virus? Fortunately, this kind of manipulation requires a high level of sophistication, and there are a lot more "good guys" working on these issues than there are "bad guys". Still, this is an area of considerable current concern, and new safeguards are being put in place to be sure that technology that could be misused in this way is not readily available to bioterrorists.
Kevin, Chicago
how does evolution tie in to genomes
     Phyllis Frosst, Ph.D.: Evolution acts by the accumulation of small changes in an individual's DNA, or genome, over time, that are passed on through multiple generations over an extended period of time.
What is your opinion on the Genetic Information Nondiscrimination Act of 2005, also called S.306?
     Francis S. Collins, M.D., Ph.D.: This is a well-crafted bill that would provide much-needed protection against genetic discrimination in health insurance and the workplace. Its passage by a vote of 98-0 in the U.S. Senate reflects the bipartisan support for this legislation. President Bush has indicated he would sign it. It is hoped that the U.S. House of Representatives will soon take up the bill, and bring it to the floor for a vote. Without this kind of protection, many people will be afraid to take advantage of potentially life-saving genetic information.
Charlotte Ahearn, Baltimore Maryland
Do identical twins have the exact same DNA structure??
     Don Hadley, M.S., C.G.C.: Identical twins share the exact same DNA at the time of conception. However, changes can occur after conception which can make their DNA differ. Likewise, even though their DNA starts out the same, exposures to the "environment" (harsh chemicals, for example) can change their risks for diseases to occur. So in the end, even identical twins can have minor differences in their DNA.
Michelle -- Indiana
is the ability to move only ONE eyebrow genetic?
     Phyllis Frosst, Ph.D.: In as much as some people are able to and some people cannot, I bet it is. But I think that some people might be able to learn how to move a single eyebrow, if they really worked at it, so I don't think it's a yes or no for any one individual.
If one letter in a pair is wrong, can that really mess up a child mentally and physcially?
     Aideen McInerney, M.S.: Some genes play an important role in every cell and when these genes are not working properly they can have devastating effects on the entire body.
Tierra D. Chicago
how many genomes are in one cell?
     Belen Hurle, Ph.D.: One nuclear genome and hundreds of mitochondrial genomes (several mitochondrial genomes per mitochondria). Some organisms, like angyosperm plants, have polyploid genomes in their nucleus. In other words, the whole nuclear genome has undergone one or more rounds of duplication.
Gene benlogan
What do you think about evolution?
     Francis S. Collins, M.D., Ph.D.: Theodore Dobzhansky said that nothing in biology makes sense except in the context of evolution. At the level of studying the genome, his statement makes a lot of sense -- as the relatedness of the human genome sequence to that of many other organisms provides compelling for a single origin of life on Earth. But one of my own personal concerns is the current battle between evolutionists and people of faith. I count myself as part of both of those camps, and I find no conflict between these worldviews. If God chose to use the mechanism of evolution to create, who are we to say that wasn't the way we would have done it?
Allen & Magda
Are there many career opportunities in the genetics field? Other than being a genetic counselor, what else is there? Are there many jobs, besides a lab technician, for someone who just has just a bachlor's degree?
     Sarah Harding, M.P.H: The genetics field has a lot of opportunities for different types of careers, and not all of them require advanced degrees. People have careers combining genetics with other disciplines such as law, education, sociology, art, and writing. One of the great things about genetics is the diverse options. For more specific information about careers in genetics, visit
Rachel East High School
Is asthma hereditary?
     Aideen McInerney, M.S.: Asthma is what we call a multifactorial disorder. This means that genes and environment play a role in causing the condition. Therefore, a person can inherit a predisposition to developing asthma but it is likely that other genes and environmental factors will also be involved in determining whether that person actually develops asthma.
Sarah; Greenville, Alabama
I am a graduate student interning at Ben Logan HS and our science department stresses biotechnology, where the students have the opportunity to do trransformations, PCR and other procedures that many students do not get to do until College. We have a number of students do independent research in various aspect of genetics, such as antibiotic resistance. What universities would you recommend to these students and where would you refer them for scholarship information? Thanks!
     Sarah Anzick, Ph.D.: NIH has several training programs that provide opportunities for students to gain research experience. The Summer Internship Program is a 8-12 week long training program in which students work side-by-side with leading scientists, and the postbac Intramural Research Training Award (IRTA) is a one year training program. Information and applications for the various training programs can be found on the NIH-wide Web site at,
Cyndi Shepard, Ben Logan HS
How close are researchers to curing diabetes and do you think it will be the result of gene therapy?
     Francis S. Collins, M.D., Ph.D.: There are two types of diabetes, type 1 and type 2. They are actually quite different diseases, but they have in common a problem with insulin and glucose, and a host of complications including cardiovascular and kidney disease. Genetic studies are closing in on the hereditary contributions to both, which may provide critical clues to the development of new treatments. For Type 1 diabetes, much excitement surrounds the use of transplants and stem cell research. Gene therapy may play a role, but my own suspicion is that other approaches will work first -- and we all hope that will be soon!!
Dr. Montana
Can you explain the cell cycles that DNA goes through?
     Phyllis Frosst, Ph.D.: Hi Jodi and Chelsea - As each cell goes through a cycle to divide into two cells, it must make an exact duplicate of its DNA, by a process called "replication". So, each cell carefully copies its DNA into two copies, and then these form into 2 full sets of chromosomes. These are pulled in opposite directions and get enclosed into two new "daughter" cells.
Jodi and Chelsey
I am an exchange student from Kenya. How does the DNA of people in the United States differ from those in Kenya?
     Vence Bonham, J.D.: There is human genetic variation from individuals across the globe. There is more variation among individuals from the continent of Africa than other parts of the world. The United States is a melting pot of individuals from many different geographic areas of the world so people from the United States have genetic variation too.
Why are some babies born with a birth defect?
     Don Hadley, M.S., C.G.C.: That is a very tough question. There are many different reasons why some babies are born with birth defects. Sometimes, we can explain what caused the birth defect, but we can't answer why that change occurred. Sometimes it may result from a "new mutation", as a result of an exposure that occurred during the pregnancy or as a result of an inherited condition. Whenever it happens it is hard for the family to adjust to having a baby with a birth defect. They might benefit from talking to genetics professionals to help address these questions and address their concerns about the future.
Veda and Keecha
Do you know any songs about DNA, if so, how does it go?
     Francis S. Collins, M.D., Ph.D.: Oh yes!! I like to write such songs. Here's one, to the tune of "You Really Got a Hold on Me" (Beatles). "Mendel had all his wrinkled peas, and Darwin had all his finches beaks, but Oh, Oh, Oh, we really got you now, you can't stop us now, we really got the code on you." (It goes on.)
Jenny Cohen, MA
We viewed the movie Lorenzo's Oil and became interested in ALD. What new developments are there with myelin restoration? Are there any genetic engineering possibilities?
     Aideen McInerney, M.S.: Wow, that is an interesting question! There are a lot of exciting animal studies on regenerating neurological cells but there are no human studies as of now. I am not aware of any gene therapy possibilities at the moment. The greatest hope in the foreseeable future probably lies in using genetic discoveries to develop new or better drug treatments which could halt or slow the progression of the disease.
Mable Orndorff, Charlie E. Albuquerque Academy
Are emotional characteristics genetically inherited?
     Don Hadley, M.S., C.G.C.: We can't answer that question just yet, but we suspect that at least parts of our emotional reactions may be influenced by our genetic make-up. Certainly, other factors influence our emotions including the many of experiences throughout life.

Information - Moderator Francis Collins, the NHGRI director, has now left the chat room.

What is the genetic difference between a rat and a mouse?
     Phyllis Frosst, Ph.D.: At approximately 2.75 billion base pairs, the rat genome is slightly larger than mouse genome, which is 2.6 billion base pairs. The rat genome contains about the same number of genes as the mouse genome though. Interstingly, rats possess some genes not found in the mouse, including genes involved in immunity, the production of pheromones (chemicals involved in sexual attraction), the breakdown of proteins and the detection and detoxification of chemicals.
Booker T. Washington MS, Baltimore, MD
What is the procedure for finding out if you have a genetic disorder?
     Don Hadley, M.S., C.G.C.: The first step is to talk with your doctor or nurse about your concerns. The doctor can help identify a medical genetics team that can address your questions. If the doctor doesn't know of a genetics team, you can find one by going to the National Society of Genetic COunselors website ( to find the closest genetics professionals in your area. The team will ask questions about your health and your families. They might perform tests or examinations, if they feel it is appropriate. Sometimes genetic testing might be considered, but only if you feel that you want to know and it has the potential to help.
Beauregard Jackson, alabama
If my mom had twins will it skip me?
     Aideen McInerney, M.S.: Sometime there are multiple sets of twins in a family. These can be identical or non-identical and are usually inherited along the maternal line. People inherit a increased predisposition to having twins i.e. there is an increased chance of having twins. Therfore your Mom may/or may not have passed on an increased predisposition to you but you may or may not have twins. Your children could also inherit this predisposition from you. Twins can therefore "skip" generations. It is also worth mentioning that twins can occur randomly and are not always familial.
me benlogan
What do you think the non-protein coding regions of DNA do?
     Phyllis Frosst, Ph.D.: Well, some of them are the regions that regulate DNA, some regions make centromeres (the "middles" of the chromosomes", some encode very small RNAs called "microRNAs". some are probably important for maintaining the structures of DNA in chromosomes and some do things that we don't know yet! But we're learning about them in a project called ENCODE that you can read about on our website.
Noah Beit-Aharon
What is the highest number of chromosomes ever found in a human?
     Aideen McInerney, M.S.: To the best of my knowledge 49, XXXXX is the largest number of chromosomes reported in a live human being.
I am a student at LBW and I am researching the genome project.I am trying to "livin" it up. Do You have any suggestions.
     Geoff Spencer: Hello. I would recommend you visit our education kit, "Exploring Our Molecular Selves," where you can download films and other interactive multimedia tools. See
Jay Nicole Harris Pouncey
I am always looking for good cute songs to teach my students. I've made up three of my own, but the Beatles one has me curious. How would I get a copy of it in its entirety?
     Belen Hurle, Ph.D.: Have you ever wonder how segments of DNA would sound like if its sequence was transposed into music? Several scientists-musicians-artists have done just that and composed some interesting pieces. Check out this random selection of websites, sample audio clips, or news articles about the sounds of DNA at
Wawasee, IN
how do the DNA chips detect things as small as dna and show them in visable light?
     Sarah Anzick, Ph.D.: It's all in the magic of lasers! First, lets make sure you understand DNA chips. DNA chips are produced by placing individual gene sequences onto glass microscope slides. The technology has advanced such that we are now able to place ALL the genes in the human genome onto a single slide. The experimental sample RNA is reverse transcribed, labeled with fluorescent nucleotides, and applied to the DNA chip for hybridization onto the genes. The slide is then put into a scanner where a laser excites the fluorescent dyes on the sample, and light is emitted. The scanner then reads the light from each gene and records it as an intensity value, which is what we see as DNA.
DL ben logan
How long did you go to school to become a scientist?
     Phyllis Frosst, Ph.D.: Well, I spent 4 years in College studying towards an undergraduate degree, and then 5 years doing reseach and classes towards a Ph.D. I was then a Postdoctoral Research Fellow for 2 years and then I joined NHGRI. If I had wanted to be a professor at a universty I probably would have done 4-6 years of postdoctoral work. But really, I was a scientist as soon as I started working at the lab bench in graduate school in my first year. I thought of experiments to do, I did them, and I analyzed my research. Right from the start, I was discovering things that I was the first person on the planet to know.
Jay and Fay
Are tendencies to get addicted to drugs and alcohol inherited?
     Don Hadley, M.S., C.G.C.: We believe that in some cases the tendency for addiction can be influenced by our genetic make-up. Research studies are just beginning to provide some answers about this. But it is clear that there are other factors, pressures that life presents (loss of a loved one, experiencing a disease,etc.) can also influence the tendancy towards addictive behaviors.
Maygen, GHS
Why am I shorter than my parents ?
     Aideen McInerney, M.S.: There are lots of genes which affect height. We have two copies of each gene. Imagine that there is one main gene which affects height. If a mother has a "tall" and a "short" version of the gene. The tall gene might outweigh the short gene and then that person would be tall. This might happen with the Dad and the Mom. However, the child could inherit both copies of the "short" version of gene and therefore be shorter than their parents.
Meg Bugni
Are all of the genes of humans discovered?
     Phyllis Frosst, Ph.D.: You know, the last little bit of any project is the most challenging. We know almost all of the genes in the genome, enough to know that there are about 24000 of them.
Kyleen- Baltimore Maryland
How many different scientists worked on the Human Genome Project?
     Geoff Spencer: Hi Annie. Great question. Over 1,000 scientists from 6 different countries worked on sequencing the human genome during a 13 year period.
Annie, Benjamin Logan High School
What are the possibilities that a person who has been cured of Leukemia might pass this disease on to his offspring?
     Don Hadley, M.S., C.G.C.: Good question. In most cases, leukemia is not inherited. In other words, most of the time, if a person gets leukemia, it is not because they inherited a gene from their parent that caused it. Likewise, if a person has leukemia, it is not likely that they will pass anything along to their children which would cause they to have leukemia. Only in a small percentage of times, it may have a genetic conponent that might increase the chances that a child could also develop the disease.
Marva Blades, Carver Middle School, Tulsa
Is evolution in your genes and not survival of the fittest?
     Phyllis Frosst, Ph.D.: Well, the answer is that it's both. Let me give you an example. Say you're a hunter in the forest, and your eyesight is bad. Out of 100 members of your tribe, you may be the most likely to get eaten by a bear, because you'll never see it coming or maybe you'll run into a tree trying to get away. The genetic source of this is that your genes control how good your vision is, in many ways. So evolution acts on the traits that make one person the "fittest" but what underlies that is their genes. As more people with bad genes are eliminated from the population, by being eaten by bears, the population evolves to have better eyesight.
Hi I'm Helga Shabnan.
Is sickle cell disease preventable?
     Vence Bonham, J.D.: Sickle cell disease causes symptoms that can be treated. With good treatment individuals can lead a normal life. There are some tests that can be done when planning a family which might reduce the chances of having a child with the disease. You can use preimplantation genetic diagnosis (PGD) which tests early-stage embryos produced through in vitro fertilization (IVF) for the presence of a variety of conditions. One cell is extracted from the embryo in its eight-cell stage and analyzed. Embryos free of conditions can be implanted in a woman's uterus and allowed to develop into a child. PGD has been used to prevent sickle cell disease. A decision could be made not to implant the embryo with the mutation that causes sickle cell disease.
David Dajnowski
Does DNA control everything in your boby and if so wouldnt it even control your emotions to a point?
     Aideen McInerney, M.S.: DNA doesn't control everything in your body. The environment plays a very important role also. Your emotions are affected by your psychological well-being, hormones and a large number of environmental factors. While genes play a role, they definitely are not the only factors which affect emotions.
D Larsen Benjamin Logan High School
How do viruses store information in RNA?
     Phyllis Frosst, Ph.D.: If you know the central "dogma" of biology: DNA ->RNA->Proteins, then a virus that has RNA and not DNA can still have the information to code for proteins. Mostly viruses that have an RNA genome, code for a protein called "reverse transcriptase" that is able to turn RNA into DNA inside the cell. Actually, HIV works this way.
Kaytee, Greenville, AL
What is PKU?
     Don Hadley, M.S., C.G.C.: PKU stands for Phenylketonuria which is a autosomal recessive disorder that affects the way a baby/child uses phenylalanine in the foods they eat. It is a condition that is tested for at birth and if found, the child is put on a special diet that keeps foods with the harmful substance out of their diet. If the person goes off the diet, they will develop a gradual worsening in their thinking abilities progressing to mental retardation.
David Science and Tech
Can twins have diffrent fathers?
     Don Hadley, M.S., C.G.C.: It is possible for non-identical twins to have different fathers. Identical twins, however, can NOT have different fathers.
jay and Fay

Information - Moderator Eric Green, M.D., Ph.D., the Scientific Director of the National Human Genome Research Institute is back in the chat room.

In 1994, Walter J. Gehring of the University of Basel, Switzerland, conducted an experiment in which he replaced the gene in a fruitfly that coded for eyes (the Eyeless gene) with that of a rat. Much to everyone's surprise, the fruitfly grew fruitfly eyes - not rat eyes. Could you please explain how this is possible?
     Laura Lyman Rodriguez, Ph.D.: While I am not familiar with this specific experiment, I understand that the Eyeless gene is homologous between fruit flies and mice, meaning that there is a large amount of similarity between the DNA codes in the two species. It is possible that if a sufficient degree of similarity (or homology) exists between the genes in the two species, one may be able to at least partially substitute for the other. A fruit fly eye would be expected to develop in this case (versus a rat eye), because the substituted Eyeless gene would interact with and direct the activity of other fruit fly genes in the experimental organismm.
Trieneke, Canada
What is a hemaphropodite?
     Aideen McInerney, M.S.: Usually, a woman has two X chromosome and men has an X and a Y. A hermaphrodite is a person whose appears to be a woman but has an X and a Y or a man who has two X chromosomes. Some people who have hermanphroditism have some cells which are XX and others that are XY.
Veda and Keecha
What causes a resesive gene to overpower a dominat gene?
     Phyllis Frosst, Ph.D.: A recessive gene is so-called because it takes 2 copies (one on each chromosome) in order to cause a disease. A dominant gene requires only one copy of the mutant chromosome in order to cause a disease.
Will parents be able to choose their childrens' genes?
     Joy Boyer: Yes, however should parents be able to choose their childrens' genes? This is an important social and ethical question as a society we must consider as these technologies become available. In addition, this is a lot of decision power to give to parents; who's to say their kids would want the genes picked for them? What do you think?
Kris V, Greendale
Assuming that you are a conjoined twin, and you share a same organ, would you have the same DNA or would they be separated? If so, how is it they don't alwys look the same?
     Don Hadley, M.S., C.G.C.: Cojoined twins are identical twins that did not completely separate, therefore, they share their DNA. However, a persons appearance is affected by other factors beside genetics and, therefore, identical twins may have physical differences that result from non-genetic factors such as mechanical pressures inside the mother's womb.
Allie Brianna Austin Indiana!
can your grandparents have the same dna as you
     Phyllis Frosst, Ph.D.: Some of your DNA can be the same as your grandparents, technically as much as 1/4. In reality, every time 2 people's DNA combines to make a child, alterations happen in the DNA that makes small changes or rearrangements.
danielle, ala
Do pigs have similar dna as humans?
     Eric Green, M.D., Ph.D.: All free-living organisms have the same fundamental DNA structure -- made up of 4 chemicals, abbreviated G, A, T, and C. Remarkably, the order of these chemicals (the DNA sequence) in the genomes of all mammals is remarkably similar. For example, across the ~3 billion chemical bases comprising the human genome, more than half are identical between humans and pigs (and dogs and mice and rats and cats and so forth). Go figure!
caleb shields
Are humans still evolving?
     Eric Green, M.D., Ph.D.: Yes. Evolution is a slow process, but it is constant.
Nnamob Evets Greendale
Do you think that in the future we'll be able to make artificial body parts such as hearts, livers, etc. for people to live on?
     Phyllis Frosst, Ph.D.: I like to think that we'll understand how organs form so well, that we'll be able to generate them from many kinds of cells. On a parallel track, look at how far we've come with artifical hearts? I think the future holds a lot of promise.
Just wanted to wish everyone a Happy DNA Day 2005!
     Larry Thompson: Thank you, Amanda. Everyone in the DNA Day chat room just when "Ahhhhhh ...." when I read this question out loud. We've been having a good time doing this and we hope you all have enjoyed it as well.
Amanda, California
Do you belive that moderen science will ever be able to allow you to choose your baby's DNA before they are born?
     Aideen McInerney, M.S.: Sarina Taylor asked a similar question and Jean Jenkins answered it. Use "Ctrl + F" to find her question.
sTepHAniE Ohio
Why do some people have six fingers instead of five?
     Eric Green, M.D., Ph.D.: There are some genetic disorders where the defect relates to skeletal development. This can result in the formation of too many fingers (or toes). Amazingly, this can be caused by a single 'typographical' change in one base of our ~3 billion base genome.
Eric and Andy Greendale WI
what is the major factor for cancer?
     Don Hadley, M.S., C.G.C.: Cancer results from a combination of genetic factors, environmental exposures and, well let's say, fate or timing of the exposure. By saying cancer has a genetic component, I don't mean that cancer is inherited. In fact, most cancer is not inherited but happens as a result of genetic changes in a single cell that are the result of environmental exposures. In a small percent of people who have cancer (5-10%), the cancer is inherited and people within those families have a higher chance of developing cancer during their lifetime.
Jennifer, high point nc
We would like to know how 3 codons turn into proteins?
     Phyllis Frosst, Ph.D.: Well, with a possibilty of 4 bases in combinations of three, you get a matrix that, with some redundancy, yields 21 amino acids and a couple of stop coding, which seems to be all that evolution needed to make complex organisms like us. In practice, three bases correspond to a tRNA - a molecule which has the ability to recognize a triplet of DNA on one end, and carry an amino acid (the building blocks of proteins) on the other. Enzymes join the amino acids together into a chain, and Voila! Proteins.
Kelley from Wi

Information - Moderator Joy Boyer, the Senior Program Analyst for the Ethical, Legal and Social Implications Research Program, has just entered the chat room.

How is DNA research helpful in disease prevention?
     Eric Green, M.D., Ph.D.: Some genetic changes predispose an individual to a particular disease. For example, some forms of colon or breast cancer are caused by specific changes in our DNA. If we know an individual has such a genetic change, we could monitor that person more closely for the development of cancer-- aiming to catch the cancer at an earlier and more treatable stage. This is one area of promise for using genetics to prevent disease.
Increasingly children are being diagnosed with forms of ADD. What is the genetic basis for this disease? Can its source be traced to any specific part of the genome?
     Don Hadley, M.S., C.G.C.: Great question. Scientists are currently undertaking efforts to identify the genetic basis that results in a person having ADD or ADHD. One NHGRI lab is leading the charge to identify the genetic bases of ADD/ADHD in collaboration with other labs at the NIH. Go to the NHGRI website (www.genome. gov) and type in "ADHD" in the search window. You'll find lots of info.
Ryan Gustafson, St. Ignatius College Prep, Chicago
How much RNA is there compared to the amount of DNA in a cell?
     Phyllis Frosst, Ph.D.: DNA is about 3% of the cell weight and RNA is 25% of the cell weight.
Michele D Greendale HS
How do you respond to criticisms of the Human Genome Project that it is associated with genetic determinism and cost a great deal of money that could have been better spent on public health?
     Laura Lyman Rodriguez, Ph.D.: The Human Genome Project does not promote the concept that genes, or genetic information generally, are the ONLY factors influencing ones health or potential to develop any particular disorder. In fact, for many diseases, especially common disorders such as cardiovascular disease or type 2 diabetes, it is the interaction of one's genetic information with environmental factors and lifestyle choices that result in specific risks for disease. Therefore, by dramatically enhancing scientits ability to identify which genes are involved in any particular disorder, the Human Genome Project will facilitate public health research in the long run by helping to target studies into how particluar environmental factors contribute to disease development or progression in certain genetic backgrounds.
St. Ignatius College Prep HS
With many advances in RNA research, the focus seems to be moving from DNA to RNA. Since we have not fully pursued DNA research yet, do you think that the scientific community is moving from one new topic to another too quickly without finishing older endeavors?
     Phyllis Frosst, Ph.D.: Science really moves in parallel tracks. At any one time, many different areas of research are being pursued, that's how progress happens and advances are made.
Dan, St. Ignatius HS
I have a friend who once told me he had two fused chromosomes. Is this a possibility, and he seemed normal, but can this cause defects?
     Eric Green, M.D., Ph.D.: On rare occasions, individuals harbor 'variant' chromosomes-- containing deletions, rearrangements, and other structural changes. In some cases, these can be formed by the inadvertent fusion of two chromosomes. The consequence of such a change can be innocent (no defect) or disease-associated. It depends on whether such a fusion disrupts functional sequences in our genome.
Is Prune Belly Syndrome considered genetic?
     Aideen McInerney, M.S.: Some genetic abnormalities are inherited while other genetic abnormalities occur for the first time in us. Prune Belly syndrome usually occured for the first time in the affected person. It usually does not recur in families. Therefore, PBS is genetic but not inherited
Cassie Gentry
What does DNA look like?
     Phyllis Frosst, Ph.D.: Well, there are a bunch of experiments that you can try in class or at home where you can isolate DNA using common household products. If it's in a liquid, like from an isolation from a strawberry, DNA is a white stringy sticky substance. When it's dried out, it's mmore of a white powder.
Kristi, Massachusetts
What is the liklihood of having easy access to stem cell therapy for treatment of heart disease?
     Don Hadley, M.S., C.G.C.: Tremendous interest in conducting stem cell research exists. The ease of obtaining stem cell therapy will depend in part on the success of the research, however, it will also depend on the social and political interest in furthering the research in this area. Stem cell research for heart disease is being conducted at research labs throughout the country.
St. Ignatius College Prep
How does one find his/her genetic heritage? I have seen people in India who have very fair skin and blue/green eyes as seen in europe and there are people who are very dark just like those from Africa. Centuries ago, we know that, people have travelled from different countries to India. Is there any database where public can find how they can trace their genes to see possibly their heritage? Which genes are considered in this process?
     Vence Bonham, J.D.: There are companies that state they can use a variety of genetic markers to assist you in finding out about your genetic heritage. However, they cannot give you specific information about your heritage. There is geographic variation across the globe. However, individuals from different parts of the world may have similar skin color and hair texture. Many factors including environmental and genetic factors influence how people look.
Mayee, Virginia
what are the chances the i will get high blood pressure if my mom has high blood pressure.
     Aideen McInerney, M.S.: Blood pressure is a multifactorial condition. This means that it is affected by both genetic and environmental factors e.g. diet, exercise etc. If there is a strong family history on your mother's side of high blood pressure then you could inherit a predisposition to develop high blood pressure. However, environmental factors would also affect your risk. Speak to your doctor in order to monitor your blood pressure and discuss what you can do to modify your risks.
lucy xiong milwaukee, wi
Does spongebob have DNA?
     Eric Green, M.D., Ph.D.: Who lives in a pineapple under the sea? Absorbent and yellow and porous is he. etc. Yes, Spongebob (like all living creatures) has DNA with the same fundamental structure as humans. Now, his squarepants probably do not contain DNA, though.
Don Hadley: What is the most intresting thing you have studied?
     Don Hadley, M.S., C.G.C.: After being involved in the field of genetic counseling for 24 years, I find that the most interesting case is always the next one to come. I have been privileged to have families share so many of their expereiences with me that it is impossible to pick just one or even a few. Each family, each person teaches me something new and helps me appreciate the incredible resilience of the human spirit.
Jay and Fay
Are there more genomes than the human mapped out?
     Geoff Spencer: Yes. Among those that have been done are the mouse, the rat, the chicken, the roundworm, the fruitfly, the chimpanzee, the dog, 2 pufferfish, dozens of microbes, a zebrafish, several fungi, the cow...that's about it.
Robb, Wisconsin
What's the relationship between the number of chromosomes found in various species? We noticed that corn has 20 chromsosmes, yet a chicken only has 18 chromsomes? What determines the number of chromosomes that an organism has? thanks!
     Belen Hurle, Ph.D.: Mammals have around 40 chromosomes. The range of chromosomes in vertebrates varies. You can read question 307 for additional information
Elizabeth Petersen, Ladue Middle School
What are the implications of the findings of the HGP, that we only have 20,000 genes? Where do our traits come from?
     Phyllis Frosst, Ph.D.: 20 000 is actually, quite a lot of genes. Our complexity, compared for example to the mustard weed that has more genes, is that we do a lot more with the genes we have. We splice their exons (the coding portions) together to mix and match into different proteins, and we do a lot of modifications on proteins with phosphates, methylation, glycosylation and many other kinds of modifications to make lots more proteins than we have genes.
Stephanie from Oakland
is it really possible for there to be someone else in the world to look just like you?
     Aideen McInerney, M.S.: Obviously an identical twin would look just like you. The likelihood that an unrelated person looking like you is small and just like you is very very unlikely
Jasmine from Andrews High

Information - Moderator The DNA Day Chat Room is closed and we are no longer taking any questions. Thanks to all the teachers and students across the nation who participated in this entertaining and educational experience. We may post a few additional answers to questions already received and a transcript of all the questions and answers will be posted on this site. Happy DNA Day 2005.

How have we found all the genes without knowing their functions and/or purpose?
     Laura Lyman Rodriguez, Ph.D.: The knowledge that has been generated through the Human Genome Project, and other molecular genetic research studies, has identified specific types of sequence patterns characteristic of genes. This information has been used to create sophisticated computer programs that have helped scientists to search through the raw DNA code of the Human Genome Project and identified candidate gene sequences for further analysis.
George, Curious
How close in years are they to finding a cure for diabetes?
     Don Hadley, M.S., C.G.C.: Hummmmm, that's a great question. Unfortunately, there is no precise answer. Many, many people are working on understanding enough about the various forms of diabetes in an effort to develop effective treatments. WHether it will be 5 years or 10 years, we can not say for sure, but ut will happen.
Dorelle Ohio

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Posted: April 25, 2005