| |


Contact David Kroll


Pharma & Healthcare 4,826 views

Why GMO Food Opponents Shouldn't Freak Out About Cauliflower Virus DNA

English: cauliflower

Cauliflower (Photo credit: Wikipedia)




1. The viral DNA would have to survive digestion.








Pass me another plate.



Post Your Comment

Please or sign up to comment.


  • Mae Wan Ho has been claiming for years that the CaMV promoter is dangerous for years, despite all evidence to the contrary. I will respond point by point.

    1. People who work with HeLa cells understand that they are a very odd cell line, and conclusions about human cell biology have to be taken with a huge grain of salt if they are observed in these cells. That being said, the argument that the CaMV promoter could be active in humans is a non-issue because it is engineered into plant cells, and not people. If gene promoters that were active in people are an issue for food plants, then what about all the other tens of thousands of promoters in the plants we eat? It’s a non-issue.

    2. Ho is somewhat right that you can’t compare the active virus with a fragment of one of its genes. It stands to reason that the active virus, which when it is infecting plants will be present in both a naked and encapsulated form, should be a greater risk (if at all) than a fragment of one of its genes. And in order to have any biological activity, if the gene fragment is somehow turned into a protein it would have to get into our own cells, and it does not have the capability to do that. Ho s incorrect that people generally do not eat virus-infected produce. Plant virus infections can go undetected, and indeed, surveys of produce find that the presence of live CaMV infections can be 15% in many different vegetables, and 20% in broccoli, for instance. Here is a link to one such survey: http://www.ica.csic.es/index.php/es/def/pdf9?modelo=publicacion
    This one was done in Spain, so other regions may vary in terms of prevalence. So yes, people eat active, functional CaMV viral proteins and DNA, and when they do, it is at high levels.

    3. This is rubbish. If there are other promoters involved, they do not affect the tendency of the gene itself to fragment and move around the genome. Again, any other promoters there might be would affect its expression in plants, not in humans, because they are engineered into plants.

    4. The claim about HIV is similarly way out there. Following the links to Ho’s claims on the ISIS site, the “link” she proposes between the two is the claim that if the CaMV promoter was tied to transcription factors in human cells, that it could somehow increase the expression of HIV and other genes based on a similarity in how they are activated. My advice is don’t drop the AIDS bomb unless you can back it up.

    5. This is an incorrect usage of this citation, and a misrepresentation of its results. The Zhang paper is available here: http://www.nature.com/cr/journal/v22/n1/full/cr2011158a.html.
    This paper has been widely cited by anti-GE individuals as evidence of danger from GE crops, when it in fact suggests interesting facts about the foods we already eat. They found that micro RNAs, (miRNA) present in rice could suppress the expression of human genes. They spiked their samples with extra miRNAs so they could observe this effect, so it may not reflect actual effects of eating rice. It was also a single paper finding this effect, which may not be found by other researchers. That being said, it is a fascinating paper. But Ho completely misuses it. Her claim is that the viral gene fragment and/or promoter will get into human cells and make bad things happen. But that is a DNA-meditated function. It has to be incorporated into our DNA to even begin to be an issue, and even then it would only be the rare cell that could possibly have that happen. The effect of the Zhang paper was not to activate genes through affecting DNA, but to suppress genes through an RNA-mediated process called RNA silencing. It’s completely different!

    So in summation, Mae Wan Ho’s claims are off-base, and do not stem from an understanding of the relevant biology. To hear this come from “a scientist on the roster of experts on the Cartagena Protocol” makes me very worried about the future international regulation of GE organisms.

  • Seems to me that the issue at large is that these “foods” are not rigorously INDEPENDENTLY tested by FDA, USDA, or any other independently operated and funded lab. All testing is done by the corporation that dreams up these novel seeds, and that testing only generally shows what MONSANTO or their ilk want us to see/read so these novel seeds can be sold to farmers and consumed by the unwary US consumer. If these “foods” are safe and reliably nutritious, then labeling them as GMO will only show everyone that indeed the GMO is safe. Personally, my family and I avoid purchasing GMOs by carefully reading and understanding product labels and have become educated from where all our food comes from, and a laboratory is not a place I want to eat from. It is sad to note that the Biotech Industry is completely reliant on consumer ignorance and by their dubious means of trying to show how GMOs are safe without allowing for independent surveys, investigations, or testing….

  • David Kroll David Kroll, Contributor 2 years ago

    Bill, indeed, just as with drugs, medical devices, and diagnostics, the FDA does not test products. The costs of such studies are to be incurred by the companies wishing to market these products. If you think that the FDA or USDA should be testing these foods and products, write to your legislators to provide more funds and personnel to these agencies to conduct the tests. Regulatory agencies can only do what they are legislated to do, but such mandates must be adequately funded.

    If you have a philosophical objection to GMO foods, by all means buy GMO-free foods from your stores.

  • Robert Wager Robert Wager 2 years ago

    Bill it would appear you are unaware that all testing for GM crops are dictated by OECD, WHO approved testing protocols. The company doing the tests has zero say on what tests, how many tests, what controls, how many controls what duration etc. All these parameters are determined by internationally agreed upon standards.

    If you feel the testing is insufficient, may I ask you what test(s) not already done, would you like to see and why?

  • Is the purpose of this article appears to rescue Jon Entine from his howlingly bad coverage of this issue, of which conflating Joe Cummins and Ronnie Cummmins ( who are two separate people) into the purveyor of a grand anti-virus conspiracy was only the icing on the cake?
    Your article pretty much comprehensively also misses the point.
    The issue at stake is that the protein potentially produced by Gene VI is the likely problem, not the DNA itself.
    Production of this protein will not be driven by the CaMV 35S promoter (since it overlaps it), a separate one would be needed and this that was why the details of each construct and rearrangement are important. Each GMO insertion event will present a different risk. This is all detailed at Independent Science News and it is highly recommended that your readers go to the source.
    The point by the way of unrealistic ‘heroic’ experiments (which actually those you refer to are not) is in general to drive the detection of rare events in small populations to get a handle on what really occurs at lower doses in much large real populations. Overdosing animals in this way has a very logical rationale (which you as a former toxicologist ought to know) but it is a commonplace for industry PR flacks to foment this misunderstanding (and attack experiments as ‘unrealistic’) since much of toxicology uses this methodology. Its quite clever really, and thoroughly wicked.

  • David Kroll David Kroll, Contributor 2 years ago

    I disagree with your characterization of the argument I presented here. Coating DNA with optimized gene transfer lipids is unrealistic in the context of eating foods harboring this construct.

    As for my apparent misunderstanding of the objection (I’ve seen objections elsewhere that are concerned about the promoter), how would you presume that the Gene VI protein is made in human cells? To do this, you’d need a recombination event that inserts the Gene VI coding sequence under control of a host promoter.

    I’m not so much trying to rescue Jon Entine as I am trying to stress that studies are required in the context of a consumer eating foods with CaMV sequences.

  • Lise Lise 2 years ago

    The point is that it is up to the companies to show that Gene IV protein is NOT made in human cells and up to EFSA to ensure they’ve checked out this scenario. They are not supposed to presume that the Gene IV protein is NOT made in human cells, yet apparently they have completely failed to address this question. You say that “studies are required in the context of a consumer eating foods with CaMV sequences” but which studies have been performed to assess this scenario?

  • David Kroll David Kroll, Contributor 2 years ago

    Lise, I think we actually agree on this point. I’m much more familiar with the regulation of drugs, diagnostics, and medical devices by the FDA but I’m aware that several U.S. agencies have jurisdiction over agricultural biotechnology products. Companies will generally do studies that satisfy the requirements of regulatory authorities (and sometimes their internal concerns about safety that are not required by regulators).

    At present, I don’t believe that the study we’re speaking about is required by regulators. I’d agree that assumptions should not be made about safety. On the other hand, perhaps regulators have already addressed these concerns with originating companies or have used the logic I did in the article about the low likelihood of these genetic elements to have adverse effects in humans.

    And, as I said above, I’m perfectly fine with specific human tests being required of companies.

  • Jonathan Latham is the original source for the misrepresentations of the CaMV Gene IV paper. For instance, they used bioinformatics to determine that the gene fragment had no similarity to any known proteins with toxicity to humans, yet, Latham claims that the gene is a “likely problem.”

  • Here is a complete list of GMO foods commonly found on our grocery shelves. Print it out, share it, and put them back on the shelves. Seek the healthy alternatives that are out there