SAGE KE Bulletin Board

Why does reproduction rejuvenate an organism?

9 July 2002

Laura L. Mays Hoopes

I am very interested in your question, and in fact have an NSF grant at present that is partially concerned with an approach to it using yeast. In yeast, the telomere argument does not work at all, since telomere shortening does not occur.

With regard to your three possibilities, I believe that you are assuming no aging of gametes under the heading "protection", but in human aging,age-related egg atresia does seem to occur. I would suspect that there is strong selection for protection, whether or not it is relevant to the resetting, though. The selection is a good model, but is a healthy 15 year old equivalent to a 0 year old? Is just selection for survival enough? Dilution is an interesting idea, and would go along with some evidence indicating that the yeast aging process is driven by some cytoplasmic factor. Personally, though, I believe that there is an active resetting process of some kind, and I hypothesize that it involves chromatin in some way. So, I would argue that you need a fourth category. Laura L. Mays Hoopes

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