Tom Mahoney wrote:
> Another more logical explanation is that impaired immune response,
> degenerative temporomandibular joint disease, hyperinflation of the
> lungs, or any of the other numerous causes of death in mice including
> tumors could occur before any detrimental effect on life span would
> be seen from loss of fibroblasts.
These (except the last) aren't other explanations at all: they are the
same explanation applied to different cell types. The conclusion of our
discussion -- that, if telomere loss drives aging, then SOME telomeres in
SOME cell type or other must be maintained/restored during embryogenesis
without telomerase but be lost during life -- stands. This can be tested
in whichever cell type one chooses; there are only 250 or so to look at,
of which most divide very rarely if at all so are not candidates anyway.
Your final suggestion (regarding tumours) is different -- very different.
It bears no relation to the idea that telomere LOSS drives aging, unless
you suggest that telomere loss is tumorigenic. If you mean that, then
this is in the same category as above.
Aubrey de Grey