Ancient viruses discovered in an ice core from Tibet

Researchers from Ohio State working on the Tibetan plateau in China made an interesting discovery in two ice core samples the team obtained. They discovered viruses that were 15,000 years old in two of the samples that have never been seen before. Those viruses survived because they remained frozen for thousands of years.

Study findings were published recently that required the team to create a new, ultra-clean method of analyzing microbes and viruses in ice without contaminating it. The glaciers formed gradually, and along with dust and gases, significant amounts of viruses were deposited into the ice. Glaciers in China aren't well studied, and the researchers say their goal was to use information from their study to reflect past environments.

The ice cores were collected in 2015 from the Guliya ice cap in western China. They were collected at high altitudes, with their origination located 22,000 feet above sea level. The cores contain ice accumulated year after year, trapping whatever was floating in the atmosphere around them as they froze. Scientists note that the layers create a timeline of sorts that can be used to understand more about climate change, microbes, viruses, and gases across history.

Ice cores obtained by the team were determined to be nearly 15,000 years old using a combination of traditional and new techniques for dating. Genetic code for 33 viruses were found in the ice, and while four of them had been previously identified, 28 of them are new. Interestingly, about half of those viruses survived when they were frozen because of the ice, not despite it.

Study co-author Matthew Sullivan said the viruses would've thrived in extreme environments and have signatures of genes that help infect cells in cold environments. Researchers on the project believe their technique developed to decontaminate the cores and study microbes and viruses in the ice could help study genetic sequences in other extreme icy environments such as the moon, Mars, or other locations on Earth. They believe the viruses likely originated with soil or plants rather than animals or humans.