John Cherwonogrodzky jcherwon at
Wed Mar 12 12:45:25 EST 1997

Dear Colleagues:
     A few weeks ago I read a good summary on the aging process. One of the 
points raised in the article was the observation of telomere shortening. As a 
cell divides, the telomere ends of the chromosomes shorten. Hence tissue 
cultures using cells taken from a fetus will last 30-40 divisions, tissue 
cultures taken from a mature animal will last 20--30 divisions. My questions 
- Does this occur in all tissues, or are sperm and egg chromosomes spared 
telomere shortening (otherwise the fetus would have an extremely short 
- Do fetus or cancer cells have a method for telomere repair and lengthening?
- Given that "Dolly" was a clone of an udder cell from a 6 year old sheep, 
would one expect that Dolly will have a lifespan shortened by 6 years or one 
that is as long as her "mother"?
    Take care...John 

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