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

• Main Authors: Anastasia Shatilovich, Vamshidhar R. Gade, Martin Pippel, Tarja T. Hoffmeyer, Alexei V. Tchesunov, Lewis Stevens, Sylke Winkler, Graham M. Hughes, Sofia Traikov, Michael Hiller, Elizaveta Rivkina, Philipp H. Schiffer, Eugene W Myers, Teymuras V. Kurzchalia
• Format: Other/Unknown Material
• Language: English
• Published: Zenodo 2022
• Subjects: Cryptobiosis; permafrost nematodes; permafrost
• Online Access: https://doi.org/10.5281/zenodo.6590382

Some organisms in nature have developed the ability to enter a state of suspended metabolism called cryptobiosis 1 when environmental conditions are unfavorable. This state-transition requires the execution of complex genetic and biochemical programs 1 , 2 , 3 , that enables the organism to survive for prolonged periods. Recently, nematode individualshave been reanimated from Siberian permafrost after remaining in cryptobiosis. Preliminary analysis indicates that these nematodes belong to the genera Panagrolaimus and Plectus 4 . 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 n. sp . Comparative genome analysis revealed that the molecular toolkit for cryptobiosis in Panagrolaimus n. sp. 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.