A strange animal believed to be immortal due to its regenerative ability has been the subject of a recent study. Researchers have finally discovered why Hydractinia symbiolongicarpus can extend its life for as long as possible.
Hydractinia Has Special Stem Cells to Regenerate
A microscopic invertebrate called Hydractinia symbiolongicarpus, which dwells on crab shells and is normally completely resistant to aging has been discovered to exploit internal aging to develop a completely new body, Newsweek reported.
Charles Rotimi, co-author of the paper and director of the Intramural Research Program at the National Human Genome Research Institute (NHGRI), a division of the National Institutes of Health, said in a statement that studies like this that investigate the biology of unusual organisms show both how universal many biological processes are and how much we still don't know about their roles, relationships, and evolution. Such discoveries have a significant chance of offering fresh perspectives on human biology.
They discovered that Hydractinia had unique stem cells enabling it to regenerate its tissues. More specialized cells, such as heart or muscle tissue, cannot differentiate from these stem cells into any body cell.
In contrast to humans, who can only use stem cells while in the womb, animals like Hydractinia may use stem cells throughout their lives, giving them the ability to produce new body parts. While Hydractinia stores its stem cells in the lower half of its body, the researchers discovered that when they removed its mouth, the mouth regenerated a brand-new body, demonstrating that the animal could produce fresh stem cells.
The publication's authors searched the Hydractinia genome for genes associated with aging or "senescence" --the slowing of cell repair and the aging of the body and its systems --to understand how these stem cells are stimulated to create.
The researchers discovered that one of the three senescence-related genes in Hydractinia had been "turned on" in cells close to the mouth cut. The animal could not regenerate when this gene was removed from the genome, showing that senescence is required to produce fresh stem cells.
Senescence has the exact opposite effect on humans and many other species.
According to Andy Baxevanis, research co-author and senior scientist at NHGRI, most studies on senescence are concerned with chronic inflammation, cancer, and age-related disorders. Senescent cells typically remain senescent in humans, producing persistent inflammation and accelerating cellular aging in nearby cells.
We can learn about how senescence can be advantageous from creatures like Hydractinia and broaden our understanding of aging and healing.
Other Immortal Animals
In a previous report from Science Times, animals like jellyfish and salamanders can also elongate their lives. The immortal jellyfish, or Turritopsis dohrnii, is reportedly among those creatures with what seems to be an endless lifespan.
The immortal jellyfish can survive harsh environments because they have a "reset button" that enables them to revert to an earlier development stage when injured or threatened, per the American Museum of Natural History.
Salamanders and axolotls can also regenerate their lost limbs when injured. These animals also exhibited regeneration abilities. Additionally, planarian flatworms can split themselves and rebuild their whole bodies from both halves, producing two new worms.
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