Japanese researchers discovered how jellyfish can repair their tentacles after damage within a maximum of 72 hours. Scientists hope that studying the regenerative function of animals will help learn more about the potential possibilities of tissue regeneration in humans in the future.

When many people hear the word “regeneration” they immediately think of lizards with their infamous regrowing tails. In fact, many living organisms, from deciduous trees to humans whose upper skin layers such as hair and nails are constantly renewed, have the ability to renew their own tissues.

Both our bone tissue (because bones grow after fractures) and the liver (up to 85 percent) have the ability to regenerate; However, the recovery of this organ after damage is not due to an increase in the number of cells, but due to an increase in their size.

Just as mammalian ungulates have wool or horns, birds periodically shed their feathers and grow new ones. However, repairing entire organs “from scratch” is a gift that very few lucky people have. These include not only lizards, salamanders and insects, but also humorous ones: jellyfish, coral polyps and sea anemones.

The regeneration of functional tissues in various animals depends on their ability to form the so-called blastema, a group of undifferentiated cells that not only heal injuries but also “grow” new organs.

Researchers from the University of Tokyo (Japan) studied one such jellyfish, Cladonema pacificum. This tiny creature, about the size of a small fingernail, can regenerate damaged tentacles in record time, in just two to three days. How does he do this? Biologists were looking for the answer to this question, and when they found it, they published the results of their research in the journal PLOS Biology.

Scientists have discovered stem-like proliferative cells growing in jellyfish that actively divide but do not divide into specific cell types. They are stem-like proliferative cells that appear at the site of damage and form a blastema. They also differ from resident stem cells, which are localized in the tentacles. Such cells are also involved in the healing process, but mostly only in the formation of the epithelium (the thin outer layer of the already formed tentacle).

It is interesting that stem-like proliferative cells, like the resident stem cells mentioned above, are not always present in the body of the jellyfish, but appear only at the time of damage. Scientists have not yet been able to determine the source of the appearance of such cells. Researchers hope that uncovering the exact mechanism of tissue regeneration in standing individuals will shed light on the possibility of “turning on” these processes in humans as well.