Who has never dreamed of pressing the pause button while the years go by? The British weekly New Scientist The question is asked and an animal capable of doing so is found: the axolotl. (Ambystoma mexicanum), already known for its exceptional ability to regenerate an amputated limb.
According to work available on the bioRxiv preprint platform, this amphibian from the salamander family stops aging at the age of 4, that is, after the first third of its life.
To reach this conclusion, Maximina Yun and Steve Horvath, and their colleagues at the Universities of Dresden in Germany and Cambridge in England, studied the methylation of DNA in axolotls. As they age, chemical markers (methyl groups) are grafted onto the DNA molecule. This is the case for mammals and frogs. And the age of these animals is correlated with what biologists call the “DNA methylation profile.”
Counteracting aging
It was by studying the axolotls that researchers noticed that after four years it became stable and no longer underwent any changes. Steve Horvath, whose words are reported by New Scientistmarvels at it:
“It’s a strange phenomenon that I haven’t seen in any other species.”
It is not clear exactly how DNA methylation contributes to aging. However, it is known that it plays a role in the specialization of cells during development. However, as New Scientist, “When axolotls regrow an amputated limb, their cells must despecialise”.
In order to regenerate, axolotls can therefore rely on weakly methylated DNA. And Maximina Yun puts forward an attractive hypothesis: “Animals capable of regenerating throughout their lives would retain a certain flexibility of development which would counteract the aging process.”
The axolotl is a subject of study that has not revealed all its secrets. “Even the cause of their death remains a mystery.”summary New Scientist.
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