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
are:
- Does this occur in all tissues, or are sperm and egg chromosomes spared
telomere shortening (otherwise the fetus would have an extremely short
lifespan)
- 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
