On July 21, a study titled ‘Glacier ice archives nearly 15,000-year-old microbes and phages’ was published in the Journal Microbiome, in which a group of scientists claimed to have discovered ancient viruses frozen in two ice samples. These samples were taken from the Tibetan Plateau. Scientists said most of them were never seen before. In 2015, the scientists collected samples from ice cores that started freezing at least 14,400 years ago.
In a statement, Zhi-Ping Zhong, lead author and researcher at the Ohio State University Byrd Polar and Climate Research Center, said, “These glaciers were formed gradually, and along with dust and gases, many, many viruses were also deposited in that ice. The glaciers in western China are not well-studied, and our goal is to use this information to reflect on past environments. And viruses are a part of those environments.”
The preprint format of the paper was published in Biorxiv in January 2020. At that time, Zhong had said, “We establish ultra-clean microbial and viral sampling procedures and apply them to two ice cores from the Guliya ice cap to study these archived communities.”
During the research, the scientists found genetic codes for 33 viruses. Four of them belonged to virus families that typically infect bacteria. 28 of them were novel that means there were never identified before. The scientists believe that these viruses came from the soil or plants instead of animals or humans. As they were frozen in ice, roughly half of them managed to survive.
Matthew Sullivan, co-author of the study and director of Ohio State’s Center of Microbiome Science, said, “These are viruses that would have thrived in extreme environments. These viruses have signatures of genes that help them infect cells in cold environments – just surreal genetic signatures for how a virus is able to survive in extreme conditions.”
He further added that the technology they used to study the viruses and microbes inside ice would help develop technology to study similar genetic sequences in other extreme environments such as Mars.
Lonnie Thompson, Senior author of the study, said that this discovery would help the researchers to understand how viruses in the glaciers respond to climate change. He said, “We know very little about viruses and microbes in these extreme environments and what is actually there.” While emphasizing the importance of such researchers, he said, “The documentation and understanding of that are extremely important. How do bacteria and viruses respond to climate change? What happens when we go from an ice age to a warm period like we’re in now?”