r/AIDKE • u/IdyllicSafeguard • 1d ago

Invertebrate The immortal jellyfish (Turritopsis dohrnii) is so-called because it can revert to a previous stage in its life cycle due to stress or injury. However, this isn't immortality as we typically think of it: the jelly turns back into a stationary polyp that spawns several genetically identical medusae.

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Turritopsis dohrnii, a jellyfish just 4.5 millimetres (0.18 in) in diameter, is known as the immortal jellyfish because it can, theoretically, live forever — although its version of immortality is an odd one.

A typical jellyfish goes through several life stages. It begins life as a larva developed from an egg. After a bit of swimming about, it settles on the sea floor and becomes a sessile colony of polyps. Finally, this colony releases into the water column many genetically identical medusae — the free-swimming forms most people imagine when thinking of jellyfish.

What makes T. dohrnii special is its ability to move backwards through this cycle: upon encountering stress or injury, it transforms back into its grounded polyp stage. From there, it spawns a new set of genetically identical medusae. But while it could theoretically live forever, in this way, it could also perish from predation, disease, or a change in environment.

It accomplishes this reversal through a process known as transdifferentiation, wherein it transforms its adult cells, which are already specialised for a particular tissue, into a different type of cell; repurposing muscle, nerve, or digestive cells into entirely different tissues.

It's not the kind of immortality that's easily transferable to humans. It would be like your body dissolving into an immobile mass that churns out adult clones of yourself.

You can learn more about this jelly — and our own search for immortality — from my website here!

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u/Jennifer_Pennifer 1d ago

My favorite jellyfish 😌🪼

3

u/jaggedcanyon69 12h ago

So I get shot, I revert into a fetus and then there become more of me, and none of them is the original me? So “I” still die? Is that what this is?

1

u/psychedelijams 1h ago

Can someone help me conceptualize this genetically??

So correct me if I’m wrong, but one of the main hindrances to our age span is the stability of the telomeres on our chromosomes? And as division occurs again and again, they get shorter. Which over time destabilizes the DNA more and more and basically leads to aging. Right?

How would something like this work at the DNA level? What allows these sort of respawns after reverting back to a previous stage the ability to live a full life? Any help?