A remarkable biological discovery has been made. 15,000-year-old viruses have been isolated in Tibetan glacier ice. It is extremely rare for viruses to be preserved in this manner. What is of scientific curiosity is where most of the viruses were previously unknown to humans.
The discovery was made by researchers from Ohio State University, who think the preservation is due to the viruses having remained frozen for the duration of their in the Tibetan region of China. The location was Guliya, a region that resembles a “polar” ice cap surrounded by vertical 30 to 40 meter ice walls and an internal temperature at the core of minus 21 degrees Celsius.
In examining the 15,000 year-old ice, the scientists unearthed the genetic codes for 33 viruses. Four of those viruses were known, but the majority were novel as shown from a careful analysis of the viral gene sets and comparing these with viral libraries worldwide (the identification and discovery of viruses using next-generation sequencing technology is a fast-developing area). The viruses possess the signatures of genes that aid them in infecting cells in cold environments.
Other viruses, not as old, have been isolated from inhospitable environments such as: Arctic sea ice and ancient permafrost brine (cryopeg), soils, lakes, deserts, air, cryoconite, and the Greenland ice sheet.
The viruses appear to be those associated with soil and plants, rather than of the types associated with animals.
The research was also important for the techniques developed to capture the viruses(“a first window into viral communities and functions in ancient glacier environments”, as the researchers put it). The fragility of the viruses and extreme cold required the use of a newly invented, ultra-clean method of analyzing microbes and viruses in ice without contaminating it.
The technology could be used to search for genetic sequences in other extreme icy environments, such as Mars, the Moon, or even within other extreme environments on Earth, like the Atacama Desert (driest nonpolar desert in the world, a region formed of stony terrain, salt lakes, sand, and felsic lava that flows towards the Andes).
In addition the discovery of ancient viruses can also offer clues about the changing climate at the genetic level, and for comparisons to be made with the current process of global heating, a process unequivocally the result of human actions.
The report into the find appears in the journal Microbiome, with the paper titled “Glacier ice archives nearly 15,000-year-old microbes and phages.”
