Tuesday, 01 August 2023 15:44:22
Grahame Jackson posted a new submission ‘Scientists Revive 46,000-Year-Old Nematodes From Siberian Permafrost’
Scientists Revive 46,000-Year-Old Nematodes From Siberian Permafrost
By MAX PLANCK INSTITUTE OF MOLECULAR CELL BIOLOGY AND GENETICS (MPI-CBG) JULY 30, 2023
Scientists discovered ancient nematodes in the Siberian Permafrost, one of which was identified as a previously undescribed species, Panagrolaimus kolymaensis. The nematodes demonstrated similar survival mechanisms to the model nematode Caenorhabditis elegans. The research indicates that nematodes have developed ways to preserve life over geological time periods, potentially informing conservation strategies in the face of global warming. Credit: Alexei V. Tchesunov and Anastasia Shatilovich / Institute of Physicochemical and Biological Problems in Soil Science RAS
An international research team shows that a newly discovered nematode species from the Pleistocene share a molecular toolkit for survival with the nematode Caenorhabditis elegans.
Some organisms, such as tardigrades, rotifers, and nematodes, can survive harsh conditions by entering a dormant state known as “cryptobiosis.” In 2018, researchers from the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia found two roundworms (nematode) species in the Siberian Permafrost. Radiocarbon dating indicated that the nematode individuals have remained in cryptobiosis since the late Pleistocene, about 46,000 years ago.
Researchers from the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, the Center for Systems Biology Dresden (CSBD), and the Institute of Zoology at the University of Cologne, all located in Germany, used genome sequencing, assembly, and phylogenetic analysis and found that the permafrost nematode belongs to a previously undescribed species, Panagrolaimus kolymaensis. They showed that the biochemical mechanisms employed by Panagrolaimus kolymaensis to survive desiccation and freezing under laboratory conditions are similar to those of a life-cycle stage in the important biological model Caenorhabditis elegant.
P. kolymaensis, female. Scanning electron picture. Credit: Alexei V. Tchesunov and Anastasia Shatilovich / Institute of Physicochemical and Biological Problems in Soil Science RAS
Revival and Initial Investigation of the Nematodes
When Anastasia Shatilovich at the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia revived two frozen individual nematodes from a fossilized burrow in silt deposits in the Siberian permafrost, she and her colleagues were beyond excited. After thawing the worms in the lab, a radiocarbon analysis of plant material from the burrow revealed that these frozen deposits, 40 meters below the surface, had not thawed since the late Pleistocene, between 45,839 and 47,769 years ago.
At the same time, the research group of Teymuras Kurzchalia at the MPI-CBG (Teymuras Kurzchalia is now retired) was already addressing the question of how larval stages of the nematode Caenorhabditis elegans survive extreme conditions. When the team heard about the permafrost nematodes, they immediately reached out for a collaboration with Anastasia Shatilovich.
Collaboration and Further Research
Vamshidhar Gade, a doctoral student at that time in the research group of Teymuras Kurzchalia, started to work with the permafrost nematodes. “What molecular and metabolic pathways these cryptobiotic organisms use and how long they would be able to suspend life are not fully understood,” he says. Vamshidhar is now working at the ETH in Zurich, Switzerland.