This worm buried in the permafrost has awakened after 46,000 years of sleep

Such is the case of the worm, which was discovered “40 meters below the surface of the permafrost,” explains Vamshidhar. As the permafrost melted, scientists from the Laboratory of Permafrost Science in Pushchino, Russia, discovered this worm, which resembles a species of Panagrolimus or curl, known for its ability to maintain a state of cryptobiosis. During one permanent paleoenvironmental expedition to the coastal strip of the northeastern Arctic, approximately 300 different specimens were collected. Vamshidhar adds that the permafrost extraction processes are done in a way that “avoids any surface contamination”.

Permafrost samples stored under temperature and pressure conditions identical to the original were sent to a German laboratory. That’s when the researchers saw the nematodes rebound, thanks in particular to rehydration. The species remained frozen for 42,000 to 46,000 years. Because the verses cannot be dated [au carbone 14] Without killing them, Gad Vamshidhar adds, it is “the surrounding botanical elements that have been dated”.

By studying the genome of this young Pleistocene witness over a period of more than 100 generations, the researchers realized that it was in fact a new species. Panagrulimus collimensisNamed after the Siberian Kolyma River near which it was discovered.

The researchers then sought to gain a more precise understanding of the genome of these nematodes, in order to determine what enabled them to survive so long in permafrost. “We raised these worms in the lab and began isolating genomic DNA from their cells for sequencing.”

“With the help of Dr Philip Schaefer, we were able to confirm that this was indeed a new species by comparing its genome with that of a common type of nematode, Certain types are elegant explains Gad Vamshidhar. Chemical experiments made it possible to compare the two genomes in order to determine whether the two forms were “governed by the same cellular mechanisms”, which might explain their shared ability to enter a state of cryptobiosis.

The first observation is that the detected species have a peculiarity: they have a “triploid” genome. In other words, their cells are made up of triplets of chromosomes, not pairs.