Marine Giant Viruses reveal their interplay with Eukaryotic Planktonic Communities in in Krossfjorden of Svalbard, Arctic.

Abstract

Giant viruses or Nucleocytoplasmic large DNA viruses are ubiquitous in the ocean and infect diverse eukaryotes. Characterizing ecological relationships between giant viruses and eukaryotes is critical to understanding the ecosystem. However, little is known about their diversity and relationships with eukaryotic hosts in the marine environments. To understand the interplay relationships between giant viruses and eukaryotic communities in the extreme conditions, we investigated the Giant viruses as well as planktonic eukaryotic communities using metagenomics at April and June 2018 in Krossfjorden ecosystem of Svalbard, Arctic Sea. In eukaryote communities, Gyrodinium sp. (Dinophyceae) and Aureococcus anophagefferens (Ochrophyta) were pre-dominant taxa. Our analyses reveal the community structures of Giant virus families correlate with specific eukaryotic lineages, including many photosynthetic groups. In particular, a higher proportion of Phycodnaviridae and Mimiviridae in Giant viruses appeared species in Chlorophyta and Dinophyceae communities. Giant virus communities are generally distinct between surface and bottom zones, but at some locations they exhibit a high similarity between the two depths. This vertical similarity correlates to surface eukaryotic biomass but not to physical mixing processes, which suggests a potential role of vertical transport in structuring bottom Giant virus communities.