Clones and aging

John K Clark (
Sun, 11 Jan 1998 13:15:56 -0800 (PST)


On Sun, 11 Jan 1998 Harvey Newstrom <> Wrote:

>My prediction for clones is that Dolly and other current clones
>will succumb to rapid aging and die of old age at roughly the
>same time as their parent. DNA has telomeres on the end of them
>that act as null-genes. The ends of the DNA get lost through
>copying. More and more of the telomeres are lost through repeated
>copying, until finally real genetic information gets lost.

The theory that telomeres are the clock that tells a cell when to age and die
may have some truth in it, but the idea has not aged very well in the last few
months. However it doesn't really matter because whatever the aging clock is
cloning must have reset it, at least to some degree. Dolly came from an adult
cell and in the normal course of events this cell would only be able to
reproduce a few more times, but Dolly must have exceeded this limit many
times over, and done it when she and was still growing in the womb with her
cells reproducing at a frantic rate.

She looks perfectly healthy but we won't know for sure if the clock was fully
reset until we watch her for several more years and see how she ages. It will
also be interesting to observe her offspring. My bet is that she is normal
in every way, time will tell.

John K Clark

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