Viruses 15 thousand years old found in Tibetan glacier

Judging by the genetic code, these viruses can infect cells in conditions of extreme cold.

Viruses 15 thousand years old found in Tibetan glacier
Image: Private/ One of the ice samples taken at the Gulia Glacier

American scientists analyzed ice samples taken back in 2015 from the Gulia Glacier in western China. This ice was formed 15 thousand years ago at an altitude of more than 6,700 meters above sea level - and in it microbiologists found 33 viruses, 28 of which were previously unknown. The scientists report this in the journal Microbiome.

Microbiologists had to develop a unique way to study the frozen biomaterial so as not to damage the genetic code of viruses when trying to extract them from the ice. The analysis showed that only four samples have a genetic code that matches the scientific database of known viruses - they belong to the family of bacteriophages, which infect bacteria.

The remaining 28 viruses are unique and at the same time not related to each other. There are regions in their genetic code that allow them to infect cells at extremely low temperatures. Scientists speculate that these viruses lived in soils and plants, not in animals and humans.

The study of viruses and bacteria hidden by miles of ice has become a necessity in a changing climate. Because of global warming, glaciers are melting and can release many microorganisms that have been naturally isolated for thousands of years. Scientists are trying to understand what threat these viruses and bacteria may pose to the existing ecosystem.