In reply to Mr. G. Morley, I'd be surprised if the mitochondria play
an important role in the ageing process. My work with yeast (i'm
afraid i work at the unglamorous end of the ageing field) implies
that mitochondrial damage has very little effect on cellular
senescence.
Cheers
Gordon Barker
Another possibility is that the aging process is linked
to the number of normal mitochondria the individual possess
per cell..... the nucleus of the adult cell was transplanted
into the denucleated egg of another sheep - the mitochondria
of which should all be fully functioning.