4ndrewl a day ago

I first became aware of these thanks to the Octonauts. Thanks Captain Barnacle! https://youtu.be/ZiLWrw-1GM8

kreco 21 hours ago

Not an expert but I'm wondering why this jellyfish does not age.

Usually, at some point in time, cells cannot replicate correctly due to telomere shrinking.

Are jellyfishes not subject to any of this?

  • throwup238 20 hours ago

    Part of this species' transdifferentiation process in the cyst stage is increased expression of various DNA repair mechanisms include telomerase [1].

    > Transcripts associated with telomere organization and maintenance, DNA integration, repair, and damage response were among those that showed high expression in the cyst relative to medusa and polyp.

    [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC8480191/

  • fallingfrog 19 hours ago

    If the epigenetic drift theory of aging is correct, it's because when the jellyfish becomes a polyp again its epigenome is reset to factory defaults, erasing the effects of aging.

    According to this theory, the reason the epigenome accumulates damage is because while the dna strand is static through the life of the organism, and therefore has all sorts of error correction mechanisms, the epigenome changes on a per-cell level as the organism grows according to hormonal signals and so on. That's how a nerve cell and a muscle cell can have the same dna strand but act almost as if they are from totally different species. Therefore it has to be flexible and can't be error checked in the same robust way. So aging is a consequence of multicellular life cycles.

    • bn-l 18 hours ago

      Hmm so you go back to being a baby and can remember nothing?

      • rowanG077 9 hours ago

        Well this is a jellyfish. It's probably hard to test if it can remember anything. Besides memories aren't stored in epigenetics as far as we know.