Log in Free trial  Ewe Again? Cloning from Adult DNA  Article
excerpt  Udderly amazing. Scientists have for the first time
used DNA from an adult mammal-specifically, genetic material
from cells in the mammary glands of a 6-year-old ewe-to create a
genetic duplicate. This clone, a healthy lamb named Dolly, was
born last July, Ian Wilmut of the Roslin Institute in Edinburgh,
Scotland, and his colleagues announce in the Feb. 27 Nature.
The spectacular feat builds upon cloning research dating back to
the early 1980s. At that time, scientists developed a procedure
called nuclear transfer that enables them to replace the DNA-
containing nucleus of an egg cell with a nucleus from another
cell. Researchers soon found that the altered egg could develop
into a clone of the animal that provided the nucleus-but only if
the nucleus came from a cell of a barely developed embryo.
Cloning attempts using nuclei from adult animals invariably
failed.  Last year, Wilmut and his coworkers described a
modified nuclear transfer me