How the Turritopsis dohrnii jellyfish escapes death and rejuvenates

Scientists are studying how the small, transparent jellyfish species known as Turritopsis dohrnii can reverse its life cycle and rejuvenate by transforming its cells back into a stem cell-like state when under severe stress.

It is quite difficult to kill the small, transparent jellyfish species called Turritopsis dohrnii. Marine biologist Maria Miglietta from Texas A&M University's Galveston campus has cut them, boiled them, starved them, added excessive amounts of salt to their tanks, and placed them in fresh water; yet, the creatures managed to escape death every time. When under severe stress, they stop moving and sink to the bottom of the tank, shedding their adult jellyfish appearance and transforming into cell clusters. Within one to three days, a polyp—one of the early stages of the life cycle—forms from this cell cluster, and the polyp grows to create a colony from which new adult jellyfish will emerge. Miglietta states that a colony capable of producing hundreds of new jellyfish can be obtained from a single jellyfish that does not die, and that each new jellyfish that emerges can undergo the same rejuvenation process.

Scientists are investigating the genetic and molecular processes that allow the Turritopsis dohrnii species to escape death, aiming to understand whether similar processes could be triggered in humans by unlocking these secrets. Michael Koldobskiy, a pediatric oncologist at Johns Hopkins University, states that these mechanisms could be used in the field of regenerative biology to reverse age-related deterioration, but that application for human health is still a very distant goal. The mechanism behind this rejuvenation ability was first noticed in 1992 by an Italian scientist. Biologist Stefano Piraino from the University of Salento discovered that some tissues in the adult stage revert to a stem cell-like state through a process called transdifferentiation.