Surface microlayer-mediated virome dissemination in the Central Arctic

Area of Science:

• Environmental microbiology
• Virology
• Polar science

Background:

• Aquatic viruses are crucial in regulating microbial communities, especially in polar regions.
• Limited accessibility hinders understanding of viral diversity, adaptations, and host interactions in polar aquatic ecosystems.
• Viruses face challenges like scarce hosts and harsh conditions in polar environments.

Purpose of the Study:

• To investigate viral diversity, abundance, adaptations, and host interactions in Arctic aquatic ecosystems.
• To fill knowledge gaps regarding viruses in the Central Arctic and Northern Greenland.
• To explore viral strategies for survival in extreme, host-limited environments.

Main Methods:

• Sample collection from melt ponds and open water in the Central Arctic during the Synoptic Arctic Survey 2021.
• Size-fractioned filtration, genome-resolved metagenomics, and cultivation-based investigations.
• Analysis of viruses from the surface microlayer (SML) and deeper water (~60 cm depth).

Main Results:

• Melt ponds exhibited lower prokaryotic and viral diversity compared to open water.
• Viral communities included bacteriophages, with 17.2% encoding auxiliary metabolic genes (AMGs) for cryoprotection.
• Active prophages were induced from Arctic SML strains, and SML viral abundance correlated with broader distribution.
• Prophages were frequently associated with surface microlayer genomes.

Conclusions:

• Viruses utilize sophisticated strategies to survive in extreme, host-limited Arctic conditions.
• The air-sea interface acts as a significant platform for viral dispersal in the Central Arctic.
• Findings enhance understanding of viral roles in polar aquatic ecosystems.