Caloric Restriction preserves replicative potential.....

ufotruth at ufotruth at
Sun Jan 17 15:52:47 EST 1999

>The problem is with your "of course".  Replicative capacity of mouse
>cells in vitro is a lot less than that of human cells, even though their
>telomeres are a lot longer (for Mus musculus) or about the same as ours
>(for Mus spretus).  Similarly, cells from telomerase knockout maintain
>their relicative capacity from one generation to the next despite loss
>of telomere length.  It's certainly possible that this curious uniformity
Hmm... That is interesting. So do you mean that if you have lets say
five generations of telomerase knock-out mice, that with each
generation the telomere lengths of their organs, or lets just say
their skin for an example, gets shorter and shorter? But at the same
time their replicative capacity stays the same?

>of replicative capacity in Mus, irrespective of telomere length, is due
>to all Mus species having the same *minimum* telomere length -- i.e. Mus
>musculus has a bigger variation -- but there is no evidence whatever
>that this minimum telomere length is short enough to trigger replicative
>senescence: thus, rather more likely on present evidence is that mouse
>cells suffer replicative senescence by a mechanism not based on their
>telomere length at all.

Hmm.. I wonder if the cells of mice have *ever* been immortalized in
in-vitro by a telomerase gene? If they have then that would show that
their senescense and aging is not regulated by their telomere lengths.
Do you know if this has ever been tried or not? I am going to have to
do some searching on medline to try and find some information on this.

If we could discover what mechanism causes their cells to age and
senesce then perhaps we could search for a similar mechanism in human
cells, even though it may not be the primary one at work. 

I really appreciate all the information. You are a kind and helpful
person and I really appreciate you. Thanks for responding to my post.

Best Regards,
>Aubrey de Grey

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