Periodic Reporting for period 1 - PermAVirThaw (Ancient viruses in thawing permafrost: who are they and how do they impact present-day ecosystems?)
Reporting period: 2022-04-01 to 2024-03-31
Around 17% of the Earth’s terrestrial surface is composed of permafrost, characterized by frozen ground for at least two consecutive years. Humanity has left Pandora's freezer door open. With the poles warming 3-times faster than the rest of the world, permafrost is being rapidly lost, potentially releasing ancient microbes locked in frozen soil. Accumulated evidences show that microbes, including viruses, locked in ancient permafrost can stay viable over millennia. However, little is known about viruses that froze alongside many of these microbial communities, and their release due to permafrost thaw may directly affect the population dynamics of present-day hosts. To understand these impacts, we need to determine if and which viruses are archived in permafrost as well as which hosts they can infect. Viruses infecting plants and animals might pose major economic and human health threats whereas viruses infecting microbes can transform ecological systems on which we rely. Therefore, the overall aim of this project is to determine the persistence of viruses in arctic permafrost, as well as their capacity to infect present-day hosts and impact ecosystem functioning. Understanding the composition and ecological impacts of reservoirs of ancient viruses is of utmost urgency as permafrost thaws because of global climate change and previously frozen viruses are released into the environment.
This project has analysed over 500 metagenomes of ancient environmental DNA from arctic permafrost. The diversity of viruses as well as the virus-host dynamics as a response to climate change has also been explored. Viruses were confirmed to be archived in permafrost and evidence of their potential activity has also been detected.
This project successfully expanded the state of the art by delivering new methods to study arctic viromes and providing the first evidence about ancient viruses (>30 ka) archived in permafrost. Results obtained will be published in scientific journals, with potential impacts of changing how we currently understand arctic microbiome, and also improving our capacity to determine the consequences of climate change on permafrost-released microbes.