Cloning Improvements

John K Clark (
Fri, 8 Aug 1997 09:32:39 -0700 (PDT)


Cows have a long gestation period, 10 months, but the Aug 8 New York Times
says 10 cows cloned from adult cows are on the verge of being born. The
Holstein cows were made by an American company in Wisconsin, ABS Global Inc.
Although no animal has been born yet it could just be a matter of days,
everybody seems healthy and apparently in cattle if you don't have a
miscarriage in the first 90 days the calf will probably be OK.

In the original sheep cloning only one try in 277 was successful, but ABS has
improved the procedure and has a much higher success rate, half the tries
resulted in an embryo and 80% of those made it past the critical 90 day mark.
The ABS improvement was in adding an extra step, they took the nucleus of a
cell from an animal they wanted to clone and placed it in an egg without a
nucleus and let it divide a few times, BUT then they removed one of those
cells and used it to clone the animal.

This should remove the fears, or hopes, of some that the original sheep
cloning was one in a million and they just got lucky, or that no other animal
would be as easy to clone as a sheep, or that a human would never be cloned
because the procedure was too inefficient.

John K Clark

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