The Immortal Jellyfish
Searching for the key to immortality
For thousands of years, mankind has been searching for various ways to prolong life, with a single goal in mind: immortality. Various legends have surfaced throughout the ages concerning this topic: the Chinese Peaches of Immortality, the Golden Apples of Norse Mythology, and the Holy Grail. However, these are only a fraction of the myths from the world’s thousands of various cultures. The search continues in the modern age of medicine and technology, but scientists may have found the key to immortality in one of the most primitive of animal species: the jellyfish.
Originally discovered in the late nineteenth century in the Mediterranean sea, Turritopsis dohrnii is the only known organism to be able to “reset” itself, earning it the nickname of the “Immortal Jellyfish”. At first glance, Turritopsis doesn’t seem very different from other jellyfish species. Like all jellyfish, Turritopsis hatches as a planula (larva) from a fertilized egg. The cilia-covered planula then attaches to the seafloor and develops into a column of polyps, which after maturation are released one by one into the ocean, where they become genetically identical medusae.
Measured at around 4.5 mm when fully grown, Turritopsis dohrnii are bell shaped, transparent (through which its characteristic red stomach can be seen), and can have up to ninety tentacles lining the edges of the bell. However, what makes this species unique from all others is its ability to reverse its developmental process in response to physical damage and environmental stress, allowing the medusa to once again become a polyp colony — which then develop once more into medusae.
Known as cellular transdifferentiation, this process gives Turritopsis dohrnii the ultimate survival skill. This cellular mechanism operates during its process of rejuvenation, allowing its already specialized cells to become entirely different types of specialized cells (a process similar to that undertaken by human stem cells), forming an efficient way to recycle cells as well as to produce genetically identical copies of itself. As far as current research shows, Turritopsis dohrnii can live indefinitely, as long as it is not consumed by other organisms, starved, or killed through other such means. Because of cellular transdifferentiation, Turritopsis dohrnii has been known to have an extraordinary ability to survive, even allowing it to “hitchhike” on boats and spread into the various waters of the world, including the coasts of Japan, Panama, and Florida — thousands of miles away from its Mediterranean home.
While Turritopsis dohrnii’s ability to age in reverse does have potential in stem cell research and could potentially help scientists find a way to replace cells that have been damaged, not much research has yet been done in this field. The process of aging in reverse remains a mystery as there are very few hydroid experts, and Turritopsis is notoriously difficult to culture in a laboratory environment. Professor Shin Kubota of Kyoto University’s Seto Marine Biology Laboratory is currently the only scientist that maintains a culture of and conducts extensive studies on this species of jellyfish. Whereas most marine biologists hesitate to make claims concerning Turritopsis’ potential for human medicine, its regenerative ability is undeniable, and Professor Kubota believes that understanding the jellyfish can lead to significant discoveries and advancement in the treatment of injury and cancer.
As to how much the jellyfish can help us, only time will tell.
