Thread

1. rotbart · 1791018164 · focus · HN ↗

   The strongest evidence we have of the reversibility of epigenetic aging, as well as its limitations -- are embryos which undergo an epigenetic reset.

   After fertilisation, the embryo strips the father's DNA of its age-linked chemical tags and swaps its packaging, destroys his mitochondria, rebuilds telomeres, and clears damaged proteins, though it can't undo the DNA mutations sperm gather as men age.

   (those that result in an non viable embryo result in miscarriage.)

   1. jijijijij · 1791030973 · focus · HN ↗

      Embryogenesis is an early fail-fast process. The vast majority of mutations and instabilities are caught through developmental checkpoints. Every living human passed a ruthless selection process in the womb.

      So part of the magic of that aging reversal is simply abandoning what doesn't stick. You can't do that to a grown human, obviously.

      1. lostmsu · 1791050882 · focus · HN ↗

         It is not that ruthless though, is it? Because it is limited by the number of egg cells.

         1. jijijijij · 1791055040 · focus · HN ↗

            Given the fact the large majority of embryos die early after conception, I would call it quite ruthless. And of course, there is intense gamete selection beforehand too.

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