Some of us spend our lives trying to extend it, or at least chasing our youth so as not to be thrown away too quickly in the elephant cemetery. In the axolotl, an atypical amphibian known for the smile it seems to constantly display, this problem does not exist: never beyond the larval stage, it resembles a large baby until its death.
The apparent eternal youth of axolotls does not stop at their appearance: these salamanders, mainly present in Central America, and whose existence is threatened, do not experience – or hardly any – physical decline or illness. During their existence, which lasts twenty-one years on average, they have the ability to regenerate their limbs, their tail and even some of their organs, which allows them to remain relatively new, even at an advanced age.
This phenomenon of stagnation in the larval state, well known to scientists, is called neoteny. It has already been the subject of numerous studies by biologists fascinated by the ability of these animals to defy aging. The last of them, relayed by National Geographichighlights a hitherto little-known element: in reality, the axolotl body simply stops aging from the age of 4. More precisely, it is their epigenetic clock that is stopped.
The clock master
The epigenetic clock allows us to estimate an animal’s age based on how events in its life, such as stress or diet, turn its genes on or off. For example, an individual who has suffered numerous traumas may have an epigenetic age much greater than their chronological age. But in the axolotl, no problem, since after four years, its epigenetic age suddenly finds itself frozen until the end of its days.
These results could be another step in the long quest to discover effective anti-aging therapies for humans. Not only is this goal popular, it is lucrative: the anti-aging market, currently valued at almost €37 billion, is expected to increase in value by 50% by 2032.
A better understanding of axolotl genetics could inspire drugs to regenerate cells, muscles or perhaps even limbs. “This is a big step forward in the field of aging and regeneration”says James Godwin, an immunologist at the MDI biological laboratory in the state of Maine, who was not involved in the new study.
At this point, why the axolotls’ epigenetic clock stops at age 4 is still very mysterious, as is their ability to renew their tissues throughout their lives and the fact that their regenerated limbs are considerably younger than those of the rest of their body. “If we discover how the axolotl is able to stop its clock”concludes Maximina Yun, biologist at the German University of Dresden, “We may be able to recreate this in other organisms.”
Source: www.slate.fr
