Turritopsis dohrnii, widely known as the immortal jellyfish, possesses a unique biological superpower known as cellular transdifferentiation. When exposed to severe environmental stress, physical trauma, or old age, this tiny hydrozoan bypasses normal biological mortality. Instead of dying, the adult medusa absorbs its tentacles, settles onto the ocean floor, and transforms back into a juvenile polyp colony.
This process relies on transdifferentiation, a rare cellular mechanism where fully specialized somatic cells, such as striated muscle or exumbrellar epidermal cells, reset their identity without first returning to a fully pluripotent stem cell state. During this metamorphosis, specialized muscle cells lose their structural organization, alter their gene expression profiles, and re-differentiate into entirely new tissue types needed for polyp survival, such as digestive endoderm or stolon tissues. This developmental reversal can theoretically be repeated indefinitely, making T.
dohrnii biologically immortal under ideal conditions. Researchers studying this process hope to unlock insights into regenerative medicine, stem cell reprogramming, and cellular aging in higher organisms.