Sea squirts could hold the secret to human immortality

Sea squirts might not look like much...they're simple, hermaphroditic creatures that barely even have a brain. But they have a particular knack for activating the enzyme telomerase, which protects DNA from degradation. That unexpected talent could help fight human aging.

Although these simple organisms only live about six months to a year, the basic mechanisms that go into maintaining their bodies are the same ones used by other marine animals with extremely long lifespans - most notably, there are deep-sea corals who live for tens of thousands of years that function in much the same way.

Excitingly, although the sea squirt may seem incredibly different from us humans - and, to be fair, they mostly are - their basic genetic structure is surprisingly similar to that of humans. That makes their secrets of health and (relatively) extended life potentially useful to us.

That's why Helen Nilsson Sköld, a marine ecologist at Sweden's University of Gothenburg is studying them. She hopes to better understand just how these life-extending mechanisms work, and ultimately determine how they might be helpful to humans. She explains:

"Animals that clone themselves, in which part of an individual's body is passes on to the next generations, have particularly interesting conditions related to remaining in good health to persist. This makes it useful to study these animals in order to understand mechanisms of aging in humans. My research has shown that sea squirts rejuvenate themselves by activating the enzyme telomerase, and in this way extending their chromosomes and protecting their DNA. They also have a special ability to discard 'junk' from their cells. Older parts of the animal are quite simply broken down, and are then partially recycled when new and healthy parts grow out from the adult bodies."

There's something of a time factor with this research. The very same mechanisms that can create exceptionally long life - particular asexual reproduction - also creates dangerously low levels of genetic diversity, making those species far more vulnerable to sudden environmental changes. That means they're under particular threat from climate change, and it's for the best if we can figure out their secrets sooner rather than later.

Via the University of Gothenburg. Original paper in Biogerontology. Image via National Geographic.