A novel nematode species from the Siberian permafrost shares adaptive mechanisms for cryptobiotic survival with C. elegans dauer larva

• Published in: PLOS Genetics
• Main Authors: Shatilovich, Anastasia, Gade, Vamshidhar R., Pippel, Martin, Hoffmeyer, Tarja T., Tchesunov, Alexei V., Stevens, Lewis, Winkler, Sylke, Hughes, Graham M., Traikov, Sofia, Hiller, Michael, Rivkina, Elizaveta, Schiffer, Philipp H., Myers, Eugene W., Kurzchalia, Teymuras V.
• Other Authors: Copenhaver, Gregory P., Russian Foundation for Basic Research, Volkswagen Foundation, Deutsche Forschungsgemeinschaft, University College Dublin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2023
• Subjects: permafrost
• Online Access: http://dx.doi.org/10.1371/journal.pgen.1010798; https://dx.plos.org/10.1371/journal.pgen.1010798

Some organisms in nature have developed the ability to enter a state of suspended metabolism called cryptobiosis when environmental conditions are unfavorable. This state-transition requires execution of a combination of genetic and biochemical pathways that enable the organism to survive for prolonged periods. Recently, nematode individuals have been reanimated from Siberian permafrost after remaining in cryptobiosis. Preliminary analysis indicates that these nematodes belong to the genera Panagrolaimus and Plectus . Here, we present precise radiocarbon dating indicating that the Panagrolaimus individuals have remained in cryptobiosis since the late Pleistocene (~46,000 years). Phylogenetic inference based on our genome assembly and a detailed morphological analysis demonstrate that they belong to an undescribed species, which we named Panagrolaimus kolymaensis . Comparative genome analysis revealed that the molecular toolkit for cryptobiosis in P . kolymaensis and in C . elegans is partly orthologous. We show that biochemical mechanisms employed by these two species to survive desiccation and freezing under laboratory conditions are similar. Our experimental evidence also reveals that C . elegans dauer larvae can remain viable for longer periods in suspended animation than previously reported. Altogether, our findings demonstrate that nematodes evolved mechanisms potentially allowing them to suspend life over geological time scales.