An old giant virus discovered in 30,000 years frozen soil in Siberia – TF1

It has been dubbed “Mollivirus sibericum” because it is soft and it was found in Siberia . It is a new type of Virus giant, 30,000 years old, found in the permanently frozen ground (permafrost) in this region of the world and that researchers were able to wake up.

This discovery made by a Franco-Russian team shows that giant viruses “are not uncommon and are very diversified,” said Jean-Michel Claverie, one of the coordinators the study on the new virus published Monday in the Proceedings of the Academy of Science American (PNAS).

With Mollivirus, this brings to four the number of giant virus families identified since 2003, including two already found in permafrost, said Mr. Claverie, professor of medicine at the University Aix-Marseille and Genomic Information Laboratory Director and structural Marseille.

According to him, this must raise questions about the potential risk that some of these giant viruses wake up one day if men begin to stir too deep sub Soil arctic regions, in search of valuable minerals or oil.

Giant viruses, which have a diameter greater than 0.5 micron (0.5 thousandth of a millimeter) are easily visible with a simple optical microscope, unlike the other virus. It can easily be confused with bacteria. Researchers revive the laboratory by using amoebae (single-celled organism) as the host cells. They check before they are not pathogenic for man or mouse.

Last year, the team, which also includes Chantal Abergel of CNRS, had already managed to revive another type of giant viruses kept in the same sample of permafrost and appointed Pithovirus. The scientific world, which has long been thought that viruses were necessarily very small and composed only of a handful of genes, discovered in 2003 with a surprise first giant viruses, rich of a thousand genes and named “Mimivirus” (family of Megavirus). Another family of giant viruses, pandoravirus with 2,500 genes, was described in the journal Science in 2013.

“precautions” to take

“Mollivirus sibericum” found in permafrost (or permafrost) and taken by Russian teams in the extreme north-east Siberia, has more than 500 genes. It appears as an oblong shell from 0.6 microns long. To multiply, it needs of the host cell nucleus, which is not the case of Mimivirus or Pithovirus that merely the cell cytoplasm.

The analysis of the DNA contained in the permafrost sample confirmed the presence of intact genome Mollivirus although at an extremely low concentration. “Some still infectious viral particles may be sufficient, in the presence of susceptible host, the resurgence of potentially pathogenic viruses in Arctic regions increasingly coveted for their mineral and oil resources and whose accessibility and industrial exploitation are facilitated by climate change, “notes CNRS in a statement.

Global warming frees indeed increasingly polar sea ice, which provides access to Eastern Siberia and Northern by sea routes that did not exist. “If we are not careful and that these industrialized areas without taking precautions, you run the risk of waking up one day viruses such as smallpox once thought eradicated,” notes Mr. Claverie.