A new study led by the University of Oviedo in Spain has unlocked the genetic code of the “immortal jellyfish,” an animal capable of repeatedly reverting into a juvenile state after sexual reproduction. The experts hope that better understanding the factors leading to this creature’s unique longevity could offer new perspectives on human aging.
Although many species of jellyfish have some capacity to reverse aging and revert to a larval state, most of them lose this ability once they reach sexual maturity. However, Turritopsis dohrnii appears to be the only known species able to repeatedly revert back into a larval stage even after sexual reproduction. According to the experts, the immortal jellyfish uses this “superpower” to avoid predators, allowing it to revert to a cyst which turns into a polyp attached to the seafloor when threaten by other animals. Once the threat is gone, the creature starts to mature once again.
To better understand what makes T. dohrnii special, the scientists sequenced its genome and compared it to that of Turritopsis rubra, a close genetic relative which lacks the capacity to rejuvenate after reaching sexual maturity. The analysis revealed that T. dohrnii had twice as many copies of the genes associated with DNA repair and protection, which helps producing greater amounts of protective and repairing proteins. Moreover, this jellyfish also had unique mutations which stunted cell division and prevented telomeres (chromosomes’ protective “caps”) from deteriorating.
“Our results suggest that gene amplification and point variants unique of T. dohrnii could affect its replicative efficiency, as well as DNA repair and telomere maintenance activity, which may be pivotal processes for cell rejuvenation and proliferation,” the study authors explained.
“In addition, expansions and sequence variations of genes associated with DNA repair, mitochondrial dysfunction and intercellular communication could increase its capacity to maintain redox environment and reduce cellular damage during stress events.”
These findings could inspire developments in regenerative medicine and provide insights into age-related diseases such as cancer or neurodegeneration. However, as Monty Graham, a jellyfish expert and director of the Florida Institute of Oceanography put it, “we can’t look at it as, hey, we are going to harvest these jellyfish and turn them into a skin cream.” Instead, exploring such gene variants in T. dhornii and other animals – including humans – could shed more light on the nature of aging, and help scientists slowly build an arsenal to combat its most unwanted effects.
The study is published in the journal Proceedings of the National Academy of Sciences.