Superworms resurrected after 46,000 years in Siberian ice: here’s their secret in DNA

John

By John

They are resurrected after being trapped for46,000 years in the Siberian ice: are the “super worms” belonging to a hitherto unknown species, brought back from their dormant state. The analysis of their DNA has revealed the secret which allowed them to survive for so long, in a kind of lethargy called cryptobiosis.

The genes that make it possible are also found in the worm most studied by geneticists, Caenorhabditis elegans. The discovery, published in the journal Plos Genetics, is the result of research coordinated by theRussian Academy of Sciences and extends the longest cryptobiosis ever reported by tens of thousands of years and could also allow for the development of better conservation strategies for the most vulnerable organisms.

“What molecular and metabolic pathways these organisms use and for how long they are able to suspend vital functions is not yet fully understood,” comments Vamshidhar Gade of ETH Zurich and co-author of the study, at the time ‘Max Planck Institute for Genetics and Molecular and Cell Biology in Dresden.

The little sleeping worms had been dug out of the frozen ground in 2018but the present study led by Anastasia Shatilovich made it possible to precisely date the frozen deposits in which they were located, about 40 meters below the surface: since the late Pleistocene, between 45,839 and 47,769 years ago, they have never thawed.

Laboratory research has shown that, when subjected to mild dehydration, both the well-known C. elegans and the new species called Panagrolaimus kolymaensis (in honor of the arctic river Kolyma, in whose region the samples were found) increase the production of a sugar called trehalose, which probably helps them survive drying and freezing.

The study authors also tested the survival abilities of the two species, finding that dehydrating before freezing helps these worms prepare for cryptobiosis, improving their chances of surviving even extreme temperatures. For example, when C. elegans larvae were subjected to this treatment, they survived 480 days at -80 degrees without any problems. “Our results demonstrate that C. elegans can also remain viable for much longer periods than documented so far,” say Max Planck’s Gade and Teymuras Kurzhchalia, another of the study’s authors.