The waters of the Mediterranean Sea have fleets of tiny translucent umbrellas, each about the size of a lentil. The tiny Turritopsis dohrnii wave and grasp with their pale tentacles, bringing plankton to their mouths as they drift in the glowing water.
Medusas, the mature adults, can turn back the clock and transform back into their youthful selves when their bodies are damaged. They transform into twiggy growths that attach to rocks or plants when they lose their limbs. The medusa buds off the polyp again. Old age doesn't kill T. dohrnii. They are, in fact, immortality.
In a paper published Monday in The Proceedings of the National Academy of Sciences, scientists looked at the jellyfish's genome and searched for the genes that control the process. By examining the genes active at different phases of the life cycle, the researchers were able to see how the rejuvenation of the jellyfish was orchestrated.
It can be hard to get enough T. dohrnii to look at their genomes. One scientist at Kyoto University in Japan has been able to maintain a colony in the lab for a long time. He has written and performed songs about his small subjects.
When it comes to living in an aquarium, the jellyfish are very picky, according to Maria Pascual-Torner. It's difficult to identify and sample them in the field because they're very small.
In order to get enough material for the new paper, Dr. Pascual-Torner and a colleague drove a camper van to a coast in Italy. They took them to the lab.
The researchers noticed that the jellyfish had extra copies of certain genes, which may be important for their survival. Many of the duplicated genes were found to protect and repair the jellyfish's DNA as it is often eroded with age.
The researchers put the jellyfish under stress by letting them eat. Scientists took snapshots of the genes they were using in each phase of the medusa's development. They took some jellyfish, froze them, and turned them into mush, which they used to make a record of which genes were active.
The scientists were interested in seeing a change in the use of genes associated with DNA storage. In adults, these genes were being used to make a lot of things. The genes became quieter as the animals began to descend back into polyps.
pluripotency is a cell's ability to grow into a variety of forms. They were quiet in the adult form but sprang into action when a Jellyfish broke its body down. When the process was over, the pluripotency genes came back to life.
According to Dr. Pascual-Torner, this suggests that during the transformation, genes that help cells to reset go into overdrive.
Maria Miglietta is a marine biology professor at Texas A&M University at Galveston who studies T. dohrnii. Her team discovered that genes related to protection and repair were involved in the rejuvenation of the Jellyfish.
Both sets of research suggest that when and how much the jellyfish's genes are expressed matters just as much as the genes themselves. There is a procedure for immortality, but there isn't a genes for it.
The researchers would like to understand more about this dance. Would the Jellyfish be able to start over if the storageProteins were changed to stay active? The rest of us can only move forward in time.
We are not likely to be able to use the process.
The goal of the team is not to find a formula for immortality. Humans andJellyfish are not the same. It isn't just about a single genes or complex. We found a mechanism that works together.
The question of whether any of these processes have a parallel in the human body is an open one. For the time being, this fountain of youth is just for the sea creature.