Yes: he is immortal. It is, despite having no heart and no brain. It is called ‘Turritopsis dohrnii’. It is a transparent jellyfish barely seven millimeters long. It lives in Mediterranean waters. It is the only immortal species on Earth
After the reproductive stage, living beings usually grow old and die. But this jellyfish can reverse its life cycle and rejuvenate. As if a chicken has the ability to become an egg again. It’s an amazing ability.
Eternal life
Now they investigate it to find how to delay the biological clock. Carlos López-Otín’s group at the University of Oviedo does it. Its genes were compared with those of other jellyfish to isolate those that give it its special characteristic.
This work “does not pursue a dream of human immortality that some people announce”. What they seek is to understand the keys and limits of cellular plasticity. And the reason why some organisms are able to travel back in time. “We are looking for answers to the many diseases associated with aging that overwhelm us today,” they explain.
Working with this animal model was not easy. Maria Pascual is an expert in marine ecology. She traveled to southern Italy in search of the elusive jellyfish. Other specimens were caught in Balearic waters, near the island of Mallorca, and some others came from northern Japan.
Difficult search
The work was arduous. Such a small species was not found on the coast. It was necessary to learn to differentiate its polyps from other similar species. “In the Gijón aquarium, culture conditions with extreme safety and care measures were established. They were essential to progress in the project and decipher its genome.”
The only immortal species on Earth was compared with its sister (‘T. rubra’). No very visible differences were found, until a more human-like look was put beyond the computer algorithms. The changes are subtle. But they explain why just one of these species is a reprogramming laboratory in itself. And how it can change to live forever.
