RE: clones might not age faster after all

From: Ramez Naam (ramezn@Exchange.Microsoft.com)
Date: Sat Feb 12 2000 - 19:38:15 MST


What this article indicates is that later-generation cells had more success
(in this experiment) in the very initial stages of cloning.

That doesn't in any way address the concern that the telomeres of the
resulting clones are as short as the telomeres of the cloned cell, and thus
that they will reach senescence earlier.

Not that this will necessarily have a visible effect. I think it's in your
book _The Last Mortal Generation_, Damien, where a description of ageing in
an experiment with telomerase knockout mice is given. The mice breed
successfully for 5 or 6 generations with normal life spans (though
progressively shorter telomeres and lower birth weights) and then reach
sterility.

If telomere length is not the first bottleneck for ageing in a species, one
would expect that a clone might live a normal or near-normal lifespan. And
its offspring (unless it were a telomerase knockout like the experimental
animals above) would have full length telomeres and age normally.

In any case, it looks easy enough to replace the telomeres on chromosomes
before implantation into an egg that I don't expect telomere length to be
much of a barrier to cloning.

From: Damien Broderick [mailto:d.broderick@english.unimelb.edu.au]
> http://www.newscientist.com/nsplus/insight/clone/clonesmaynot.html



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