Natures wonders: immortal jellyfish (Introduction)

by David Turell , Wednesday, September 14, 2022, 20:42 (799 days ago) @ David Turell

Changes living forms:

https://www.nytimes.com/2022/09/06/science/immortal-jellyfish-gene-protein.html?unlocke...

"Fleets of tiny translucent umbrellas, each about the size of a lentil, waft through the waters of the Mediterranean Sea. These miniature jellyfish, known as Turritopsis dohrnii, wave and grasp with their pale tentacles, bringing plankton to their mouths like many other jellyfish species adrift in the glowing water.

"But they have a secret that sets them apart from the average sea creature: When their bodies are damaged, the mature adults, known as medusas, can turn back the clock and transform back into their youthful selves. They shed their limbs, become a drifting blob and morph into polyps, twiggy growths that attach to rocks or plants. Gradually, the medusa buds off the polyp once again, rejuvenated. While a predator or an injury can kill T. dohrnii, old age does not. They are, effectively, immortal.

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"When they and their colleagues sequenced the creatures’ genomes, the researchers noticed that the jellyfish had extra copies of certain genes, a sign that these might be important for the creatures’ survival. The researchers found many of the duplicated genes among them, including some that protect and repair the jellyfish’s DNA, as DNA is often eroded with age in animals.

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"As the jellyfish transformed, the scientists were interested to see a marked change in the use of genes linked to DNA storage. In adults, these genes were active or expressed at a high level — that is, they were being used frequently to make proteins. But as the animals began their descent back into polyps, the genes became quieter, with their proteins reaching their lowest levels in the floating ball form.

"Genes related to pluripotency, or a cell’s ability to grow into a variety of fully developed forms, did the opposite. They were quiet in the adult form but leaped into action as a jellyfish broke its body down and started to build it back up. The pluripotency genes then returned to dormancy when the process was complete.

"What this suggests, Dr. Pascual-Torner said, is that DNA that’s normally in storage is brought out during the transformation, and genes that coax cells to reset go into overdrive.

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"Her team saw that genes related to DNA repair and protection were involved in the jellyfish’s rejuvenation.

Both sets of research suggest when and how much the jellyfish’s genes are expressed matters just as much as the genes themselves in giving an old body new life. In other words, there is no gene for immortality, but there is certainly a procedure for it."

Comment: Just a fascinating study. No one is meant to live forever, but thess guys have a trick. dhs will ask why these exist. They fit into their ecosystem.