The DNA of the tardigrade reveals the secrets of an animal almost immortal

rukanoga/epictura

Published the 02.08.2017 at 07h38

A A

Keywords :

tardigradeséquençageADNgénétique

Too strong, the tardigrade. This microscopic animal does not leave to surprise. It is that he is endowed with extraordinary capabilities : it is able to withstand without flinching at extreme temperatures – from 0 to 150 °C – but also in the vacuum of space and pressures are particularly high (several thousand atmospheres). It has also been sent into space, where it is income intact. Irradiated with X-rays at doses that would kill most species on the planet, “the water bear” (her nickname) survives quietly. This is probably the animal most resistant in the world.

When it appears at the end, deprived of water, dried for three decades, he has actually not said its last word : it revives at the first drop of rain. Of course, under the microscope, it is not included in the catalogue of the species most cute, but this species quasi-immortal would envy all of the kingdom alive, with his ability to adapt out of the ordinary.

Protein magic

But how does he do it ? Plagued by curiosity, perhaps mixed with jealousy, a team of researchers has begun to unravel the functioning of the tardigrade. The objective was to explain its extreme resistance to drought. The sequencing of the DNA that they have undertaken on the two species has spoken. The results of this analysis were published in the journal PLOS Biology.

According to the researchers, the conditions of extreme drought, in consequence, to activate some genes from the tardigrade, which produce proteins. These act as a biomatériel : they allow to replace the water missing in the cells of the animal. Once moisture is again available, the cells become saturated and the proteins dissolve.

Scientists believe that these results may have interesting implications for the human. Indeed, by synthesizing the protein, it would be possible to preserve vaccines without refrigeration, and transport them around the world, for example.

A mysterious origin

The genomic sequencing of the tardigrade is only in its infancy, but it opens up very many prospects. In effect, by isolating the genes involved in its different forms of resistance, the applications could be many and unprecedented.

Still a question remains unresolved : where does the tardigrade ? It is present everywhere on the planet, but no one can explain why nature has provided this animal adaptation, well in excess of those required for the terrestrial environment. Some supputent : the water bear come from space. Fossils of this animal have been found, dating back to the cambrian explosion (sudden appearance of species of multicellular, there are more than 500 million years ago). One thing is for sure : the tardigrade, we will bury all…