Scientists have distinguished a species of jellyfish who are essentially "biologically immortal" after analyzing their DNA and studying what it is that makes them live forever. A recent study determined that the jellyfish, Turritopsis dohrnii, has figured out a way to get around death, which begs the question of how?
According to scientists, this "is the only species able to rejuvenate repeatedly after sexual reproduction, becoming biologically immortal." With this information, scientists are curious if their DNA holds the magic behind living eternally - but that may be jumping a few too many steps forward. Every being of the T. dohrnii species is an identical clone that starts life as a polyp and then develops into a medusa, which is pretty standard. So what makes them stand out?
The T. dohrnii species becomes a "cyst" that turns back into a polyp and restarts from the beginning when the matured medusa gets sick, injured, or just ages. So, instead of dying, the animal is able to replicate and create more clones, and the cycle just continues on and on and on. Scientists are calling it the "life cycle reversal," comparing it to a person who is old and reverts back to a fetus or a chicken to an egg. The scientists behind this study at the University of Oveidas in Spain explain how they were able to solve the eternal mystery by comparing the DNA of the T. dohrnii to another very close relative of the jellyfish species that is incapable of immortality.
In the published study, researchers compared "genes involved in aging and DNA repair, together with the transcriptome [mRNA] analysis of life cycle reversal (LCR) of T. dohrnii," which has now "provided new insights into the molecular mechanisms underlying Turritopsis plasticity, which may contribute to the immortal phenotype of T. dohrnii." So basically, explaining that the T. dohrnii species has a more "effective replicative mechanism(s) and repair systems." In addition to the replicative mechanisms and repair systems, the immortal jellyfish species were found with more genes controlling DNA repair, which also contributes to the longevity of the medusa.