Scientists have discovered dozens of ancient virus species in two 15,000-year-old ice samples taken from the Tibetan plateau in China, many of which are still unknown to science.

The study was published in the journal Microbiome, RIA Novosti reported.

In 2015, American biologists at Ohio State University analyzed ice nuclei taken from the Gulia Glacier in western China and found the genetic codes of 33 previously identified viruses, 28 of which are unlike any modern virus.

Glaciers store a great deal of information about the history of the Earth because they "take" dust particles, traces of gas, microbes and plant matter from the environment. By studying the ice nuclei obtained as a result of the excavation of glaciers, scientists are gaining information about the climate, the composition of the atmosphere, and what biological species existed at different times in history.

"These glaciers have formed gradually, and along with dust particles and gases, there are also a lot of viruses," he said. Glaciers in western China have not been well studied, and our goal is to use this information to reflect the environment of the past. Viruses are also part of this environment, ”the press release quoted Zhi-Ping Zhong, a leading author of the article and a microbiologist at the Center for Polar and Climate Research and the Microbiome Research Center at Ohio State University.

According to scientists, at least half of the viruses found came back to life after the ice melted. This is very important information, because the glaciers of Tibet are shrinking every year, and as they melt, ancient viruses appear.

"These are viruses that can thrive in extreme conditions," he said. They have gene signatures that help them infect cells when they are very cold, ”said Dr. Matthew Sullivan, another participant in the study, a professor of microbiology at Ohio State University and director of the Microbiome Research Center.

To "read" these signatures, the authors have developed a new method of ultra-pure ice sterilization, which allows to study the genetic material of microbes and viruses in ice without contamination, because infection with modern microbes is a serious problem for such research.

"Perhaps this method will help us find genetic sequences in other experimental glacial conditions, such as Mars, the Moon or closer to us - in the Atacama Desert," says Sullivan.