Here's the secret to how 'immortal' hydras regrow severed heads
By Mindy Weisberger published about 6 hours ago
For hydras, there's more than one way to get a head.
Hydras can regenerate lost body parts — even their heads. (Image credit: Choksawatdikorn/Science Photo Library/Getty Images)
Tiny aquatic animals called hydras can regrow lost heads, and scientists now have a clearer idea of how these freshwater invertebrates do it.
A hydra's body is fairly simple: It's a tubelike cylinder tipped with a grasping footlike appendage at one end and a tentacle-ringed mouth at the other. But hydras possess the remarkable ability to regrow bits of their bodies that have been amputated; under the right circumstances, an entirely new animal can grow from a detached chunk of tissue.
In lab experiments, hydras have demonstrated that they can renew their own cells indefinitely, which means that these animals are biologically immortal. But while prior research has identified some aspects of hydra regeneration, researchers have been searching for answers about how the hydra genome directs its cells to grow a brand-new head.
Now, scientists have not only mapped hydras' instructions for head-growing; they've also shown that gene activity during the growth of a replacement head diverges from the genetic instructions that shape head growth in a new hydra when it buds — or emerges directly from a parent's body during asexual reproduction.
More:
https://www.livescience.com/how-hydras-regrow-heads-map?utm_source=notification
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Epigenetics hold the secret to the hydra's death-defying abilities.
Tibi Puiu by Tibi Puiu December 10, 2021 in Biology, News Reading Time: 4 mins read
A tiny immortal hydra. Credit: Creative Commons.
Hydras, tiny aquatic animals, are some of the most intriguing creatures in the animal kingdom. For one, they’re virtually immortal. Because their stem cells have the capacity for unlimited self-renewal, unless the hydra is eaten or physically destroyed by an external force, it could theoretically live forever. It does know death from old age.
Even when its head is severed, the hydra will grow one back — its will to live is truly unmatched. Now, researchers in California have found their secret, and it’s all in their genes. Or rather, in how they’re regulated, known as ‘epigenetics’.
Hydras, which are related to corals, sea wasps, and jellyfish, are asexual, meaning they can reproduce on their own without the need for a mate. Instead, they reproduce by growing buds on the surface of their bodies, miniature clones of the original individuals that simply break away once they are mature. Research has found that animals that reproduce later on and less frequently tend to live longer. Hydras, however, begin to reproduce almost immediately after they form.
In 2012, researchers at the Zoological Institute of Kiel University found that the key to the hydra’s longevity is the FoxO gene, which was previously linked with aging in humans. The researchers found that FoxO plays a fundamental role in the maintenance of stem cells.
More:
https://www.zmescience.com/science/news-science/how-immortal-hydras-regenerate-severed-heads/