Immortal hydra reveals how telomerase defies cellular aging

The common hydra, a millimeter-scale organism, possesses a cellular strategy that defies universal aging mechanisms. Researchers characterized telomerase in this apparently immortal species and found sustained expression of the catalytic subunit hyTERT in its somatic tissues—extraordinary, since human telomerase remains inactive in most somatic cells. Telomeres, repeated sequences at chromosome ends that shorten with each cell replication, act as a clock condemning cells to death when too short. The hydra circumvents this trap by maintaining telomerase in high-proliferation regions even during regeneration and asexual budding. Although the hydra is a primitive invertebrate—essentially a bundle of stem cells capable of regenerating any body part—its telomere maintenance mechanisms pose a crucial question for longevity medicine: which cellular principles from this organism could translate into therapies that slow telomere shortening in human aging tissues?