Thread: Immortal Jellyfish

Jellyfish that never dies? I sort of understand from this site but not completely can you explain it better?

http://www.scientificentertainment.c...al_animal.html

Pretty cool.

It is not the only potentially immortal thing, of course. And I have to say potentially, since there are numerous things that can kill individuals. Just not old age.

Lots of bacteria and protists reproduce primarily by binary fission - simply splitting in half. They are also potentially immortal. There is even a line of immortal human cells - taken from a woman who had cervical cancer. The cancer cells have now been growing in cell culture for more than 50 years after the woman who donated them has died.

According to the article, the jellyfish is potentially immortal since its cells are able to change type. This means cells that are physiologically older can revert to a type that is physiologically younger. Thus it can perpetually rejuvenate itself - make itself younger. Of course, that does not protect it from predators or disease. So it is only potentially immortal. My guess is that, in reality, and on average, these jellyfish do not survive for more than a season or two.

Even if it does revert back to its immature state, the DNA will still accumulate damage that will eventually do it in. Transdifferentiation may change gene regulation but it doesn't give it a whole new, fresh set of DNA.

Alex

That may be true. The article did not cover DNA damage. However, it does not have to be true. There are many organisms with DNA repair mechanisms way better than in humans.

what about the telomeres? like AlexP said wouldnt fresh dna be needed

Well telomerases are fairly common, the common inhibition of telomerase expression likely protects against uncontrolled growth, but even humans express telomerase during gamete production.

Edit: I'd be surprised if there are any animals that lack telomerase completely.