From the philosopher’s stone to Voldemort and his horcuxes, humans have long been fascinated with the concept of immortality. However, scientists have found that one pinky-nail-sized jellyfish species has the remarkable ability to live forever.
Turritopsis nutricula, which originated in the Caribbean, is biologically immortal; its mortality rate doesn’t increase with age, although it remains vulnerable to death through injury.
These jellyfishs’ immortality makes them an apt invasive species. T. nutricula are transported in the ballasts of ships and have been found in various corners of the world, including Spain, Florida, and Japan.
The secret to T. nutricula’s infinite life is a phenomenon called transdifferentiation. This is a process whereby sexually matured jellyfish revert back to their juvenile form through a conversion of their cell types. The embryonic stem cells of animals, including humans, are able to undergo a similar differentiation process during embryonic development and tissue repair. Pluripotent cells (starter cells that become other cell types) are turned into cells with specific functions by controlling which genes are on or off in that cell. What is unique about T. nutricula, is that already differentiated cells (cells that have a particular function, like brain or cardiac cells), have the ability to differentiate again, especially in times of environmental stress.
Transdifferentiation can be thought of an ongoing Benjamin Button complex, in which these jellyfish revert from their old state back to a juvenile one. The sexually matured stage—with its bell shaped body (known as the umbrella) and tentacles—is the most commonly known of the jellyfish’s multi-stage lifecycle. In their juvenile stage, the polyp, jellyfish are fairly stationary and live in colonies attached to the sea floor. In the transdifferentiation process, the umbrella inverts, and the tentacles are reabsorbed. The jellyfish then attaches to a suitable substrate, and the cells undergo transdifferentiation to form a new polyp colony.
Along with being an enigma of the natural world, T. nutricula provides many opportunities for diverse human medical applications, such as organ reproduction and potential cures for cancer. Much like the jellyfish’s life span, the possibilities are endless.