Ancient Worms Revived After 46,000 Years
By: Brayden Yin
As melting permafrost has unveiled hidden life frozen thousands of years ago, the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia made a discovery that female roundworms were thawed from a 46,000-year slumber and revived. Now, scientists want to know how these two nematode worms survived such a long time in stasis.
In 2018, Anastasia Shatilovich, from the RAS Institute, uncovered a fossilized gopher burrow from beneath 130 feet of permafrost. Inside, they found two female nematodes that had been frozen in permafrost. They were revived by just placing the worms in water. Radiocarbon dating showed that the specimens were frozen in the Arctic soil between 45,839 and 47,769 years ago, during the late Pleistocene era. After they were revived, the specimens reproduced several generations in the sterile environment of the lab, then died.
The species Panagrolaimus kolymaensis has a certain gene that allows the worm to enter cryptobiosis, in which the worms can resist extremely low temperatures by transitioning into a dormant state. A contemporary nematode, the species Caenorhabditis elegans, can also enter cryptobiosis. Teymuras Kurzchalia, a professor emeritus at the institute where the study was conducted, said that many nematodes can achieve cryptobiosis, but kolymaensis is the only species know to have sustained dormancy for thousands of years. The study also revealed that the worms cannot survive without a certain sugar called trehalose, which the specimens had while in stasis, but lost the ability to produce it when they died days later. Without the presence of this sugar, the specimen dies.
“The major take-home message or summary of this discovery is that it is, in principle, possible to stop life for more or less an indefinite time and then restart it,” Kurzchalia says.
There are no practical uses for a deep understanding of cryptobiosis, but Dr. Kurzchalia added that it could one day be engineered by humans.