Telomeres and stuff

From: John Clark (
Date: Sun Apr 30 2000 - 14:56:58 MDT

In the April 28 issue of "Science" ,the one about the improvement
in cloning technology, I found the following two paragraphs, they
seem important to me, I'd like somebody to tell me why I'm wrong.

 " Another sign that the cloning process had somehow turned back
   the clock on the animals' cells came when the team cultured
   fibroblasts, a type of connective tissue cell, from the calves' ears.
   The cells expressed high levels of a gene called EPC-1, which is
   typically found at high levels in young cells and may be involved in
   cell division and proliferation."

An imperial result independent of telomeres that seems to indicate
the cells really are more youthful, or rather act more youthfully.

 "In a related experiment, the team cloned five calf fetuses from adult cells
  kept in culture until senescence. They removed the fetuses at 6 weeks
  of gestation so they could compare their cells with those of normal fetal
  calves. The clones' cells divided an average of 93 times compared to
  only 61 for cells from normal calves. If this increased life-span extends
  to the whole animal, Lanes says, there is "a real possibility" that cloned
  animals might live as much as 50% longer than their normal counterparts
  --up to 180 to 200 years in the case of humans--an idea, he says, that
  "is going to raise an eyebrow or two.""

That's even more direct evidence. I grant you it still doesn't prove the entire animal
will live longer but it does give considerable weight to that idea; and a increase
from 61 to 93 divisions is not small and is not theoretical, it's a concrete
experimental result. I know Robert Bradbury has expressed some contempt for
this work but I confess I just don't understand why. Perhaps the effect was caused
because the telomeres got longer, perhaps it was caused by something else, but
whatever the reason the result if true is pretty damn interesting. And I happen to think
it probably is true, I mean It's not like the report came out of The National Enquirer,
"Science along with "Nature" are the two most respected science journals in the world.

        John K Clark


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