Back in 1988, scientists learned about the existence of tiny immortal jellyfish Turritopsis dohrnii (although they were previously erroneously classified as Turritopsis nutricula). Representatives of this species are very small (about 5 mm in diameter) and are considered the only animals on Earth that can live forever. And Spanish biologists from the University of Oviedo decided to find outHow do jellyfish do it?
It is important to note that despite their name, T. dorhnii is still not immortal in the traditional sense. We are talking about biological immortality: that is, their risk of death does not increase with age, since they are able to turn into a polyp at any stage of development and live through all the cycles of development anew. In this case, the genetically new individual will be a complete clone of the previous one.
The mechanism is activated by injury, hunger or adverse conditions. It is as if an adult could turn back into an embryo due to lack of food and go through the stages of birth, maturation and puberty again – and so cycle after cycle if necessary. However, from external causes, these jellyfish can die at any moment, like other organisms.
To find out the reason for this superpower, scientists compared the DNA of T. dorhnii and other jellyfish. The analysis showed that more than a thousand genes can help the jellyfish reverse aging: they are somehow associated with aging and DNA repair.
But only one of them provides two aspects that have not been observed in other jellyfish. It turns off the conversion of DNA to RNA or protein, and also turns on pluripotency (the ability of a stem cell to replace any other that the body needs).
Although this gene is absent in other jellyfish, it is not limited to one. With a high probability, several genes working in conjunction are responsible for the immortality of T. dorhnii.
Scientists believe that if they can better understand these mechanisms and the interaction of genes, then in the future such developments can be used to extend the life of people. This will not help us live forever, but it may well slow down the aging of the human body.