A kind of rare jellyfish Found in the eastern Pacific, pacific cladonema Although it is only about the size of a pinky fingernail, it can regrow a severed tentacle in just a few days. Jellyfish need their tentacles to hunt and obtain food, so keeping their tentacles intact is critical to their survival.What a jellyfish mold the necessary parts regenerate appendages It’s a mystery. Now, a research team based in Japan is beginning to understand the cellular processes these tiny jellyfish use to regenerate their limbs. Here are the findings: The study was published Dec. 21 in the journal PLOS Biology.
[Related: Even without brains, jellyfish learn from their mistakes.]
with salamander beetle-like insect Forms a mass of undifferentiated cells that have not yet developed into a specific cell type. These undifferentiated cells can develop into blastema cells, which are important for damage repair and appendage regrowth.
To look for signs of severe blastema in the jellyfish, the authors of this study cut tentacles from the jellyfish. pacific cladonema Jellyfish in the laboratory. Next, they studied the cells that were growing inside the jellyfish after the amputation. The team discovered that Jellyfish have stem-like proliferating cells It is actively growing and dividing, but has not yet transformed into a specific cell type. These cells appear at the site of injury and help the blastema.
“Importantly, these stem-like proliferating cells in the blastema are different from the resident stem cells localized in the tentacles,” said study co-author Yuichiro Nakajima, a cell biologist at the University of Tokyo. stated in a statement. “Repair-specific proliferating cells primarily contribute to the newly formed tentacle epithelium (thin outer layer).”
These stem-like cells, which reside near the jellyfish’s tentacles, are responsible for maintaining and repairing all the cells the jellyfish needs throughout its life. However, proliferating cells were only required to repair the missing appendage. Appears when a jellyfish is injured.
“The combination of resident stem cells and repair-specific proliferating cells enables rapid regeneration of functional tentacles within days,” Professor Nakajima said.
Bilateral and non-bilateral
According to the authors, this finding will help researchers better understand how blastoma formation differs between different animal groups with different developmental morphologies. For example, the salamander bilateral animals Expand two equal sides, left and right.jellyfish is considered non-bilateralHowever, despite their symmetrical differences, jellyfish and salamanders are both capable of regenerating limbs. Salamander limbs have stem cells that are restricted to the needs of specific cell types, and this process appears to work similarly to the repair-specific cells the researchers observed in jellyfish.
[Related: There’s no stopping this immortal jellyfish.]
“Given that repair-specific proliferating cells are similar to restricted stem cells in the limbs of bilateral salamanders, blastogenesis by repair-specific proliferating cells has been linked to complex organs and appendages during animal evolution. We can infer that this is a common feature that was independently acquired for the regeneration of the cells.” Sosuke Fujita, a cell biologist in Tokyo. stated in a statement.
It is still unclear where the repair-specific proliferating cells observed in blastema cells originate. The research tools currently available to investigate the origin of these cells are very limited in explaining their origin or discovering other stem-like cells. More research and new tools are needed to study genetics.
“It is essential to introduce genetic tools that allow tracing and intracellular manipulation of specific cell lineages. cladonema‘ said Nakajima. “Ultimately, understanding the mechanisms of blastoma formation in regenerating animals, including jellyfish, may help us identify cellular and molecular components that improve our own regenerative abilities.”