RNA Viruses Linked to Eukaryotic Hosts in Thawed Permafrost

Area of Science:

• Environmental microbiology
• Virology
• Climate change science

Background:

• Arctic permafrost is thawing due to global warming, with unknown impacts on microbial communities and viruses.
• While DNA viruses in permafrost are studied, RNA viruses remain largely uncharacterized.
• Understanding viral dynamics in thawing permafrost is crucial for Arctic ecosystem health and global biosecurity.

Purpose of the Study:

• To characterize the composition and diversity of RNA viruses in thawed Arctic permafrost.
• To investigate the potential hosts and ecological roles of these RNA viruses.
• To assess the presence of potential pathogenic RNA viruses in thawing permafrost.

Main Methods:

• Incubation of permafrost samples at 4°C for 97 days to simulate thaw conditions.
• Metatranscriptomic sequencing to identify and assemble RNA viral sequences.
• Bioinformatic analysis to determine viral community composition, host associations, and functional genes.

Main Results:

• A diverse RNA viral community was detected, including double-stranded RNA viruses (Reoviridae, Hypoviridae) and single-stranded RNA viruses (Rhabdoviridae, Leviviridae).
• Detected RNA viruses primarily targeted eukaryotic hosts such as fungi, Metazoa, and Viridiplantae.
• Sequences of potential plant and human pathogens were identified, and viral community structure correlated with predicted host populations.
• Auxiliary metabolic genes involved in carbon utilization were found in some RNA viral sequences, suggesting a role in carbon cycling.

Conclusions:

• Thawing Arctic permafrost harbors a novel and distinct RNA viral community, primarily infecting eukaryotes.
• RNA viruses are linked to eukaryotic host dynamics and may influence carbon cycling in thawing permafrost.
• The presence of potential pathogens highlights the importance of monitoring Arctic environments for emerging viral threats.