They seem to be very simple beings. However, these creatures are more complex than previously believed. Jellyfish regenerate their tentacles, and even complex organs. Researchers from the University of Tokyo studied its regeneration mechanism. It has similarities with that of salamanders.
At first glance, jellyfish are not all that remarkable creatures. They are gelatinous blobs without brains, hearts or blood. They often depend on ocean currents. But they are one of the most successful animal groups on the planet.
The secret of cells
One of the keys to its success is its tentacles, long tendrils that entangle its prey. They are injected with paralyzing toxins that allow them to be digested calmly. If jellyfish lose those tentacles, they can grow them back in a very short time.
Researchers from the University of Tokyo and biologist Sosuke Fujita studied the jellyfish Cladonema pacificum. It is known that animals with the capacity for regeneration have a group of cells called a blastema. Jellyfish develop this from tissues called proliferative repair-specific cells. They are very similar to stem cells. They can become whatever their guest needs.
The researchers removed the tentacles to analyze the regeneration process. They euthanized and dissected the animals, using different dyes to mark the different cells. It turned out that jellyfish stem cells are constantly in and around their tentacles. They can become any type of cell the body needs. But specific proliferative repair cells only appear when the animal is injured.
Relative salamanders
The researchers were surprised to find a similar repair mechanism in jellyfish and salamanders. Their last common ancestor lived hundreds of millions of years ago. This could indicate convergent evolution. In this, very different organisms independently develop similar traits.
How did jellyfish come to have proliferative cells specific for repair? Knowing this is the next objective of scientists. «Jellyfish regenerate their tentacles. We want to understand the mechanisms of blastema formation in regenerative animals. “It can help us identify cellular and molecular components that improve our own regenerative capabilities,” they concluded.
