Diversity and ecological footprint of Global Ocean RNA viruses

Abstract

DNA viruses are increasingly recognized as influencing marine microbes and microbe-mediated biogeochemical cycling. However, little is known about global marine RNA virus diversity, ecology, and ecosystem roles. In this study, we uncover patterns and predictors of marine RNA virus community- and “species”-level diversity and contextualize their ecological impacts from pole to pole. Our analyses revealed four ecological zones, latitudinal and depth diversity patterns, and environmental correlates for RNA viruses. Our findings only partially parallel those of cosampled plankton and show unexpectedly high polar ecological interactions. The influence of RNA viruses on ecosystems appears to be large, as predicted hosts are ecologically important. Moreover, the occurrence of auxiliary metabolic genes indicates that RNA viruses cause reprogramming of diverse host metabolisms, including photosynthesis and carbon cycling, and that RNA virus abundances predict ocean carbon export.

Patterns and process in RNA viruses

Viruses are suspected to be lynchpins in ecosystem function, but so far we can only guess at their significance. DNA viruses are increasingly being recognized as significant components of biogeochemical cycling in the oceans. Dominguez-Huerta et al . explored global patterns of marine RNA virus occurrence by extracting virus sequences from Tara Ocean samples. Host prediction analysis identified predominantly protist and fungal hosts plus a few invertebrates. Like double-stranded DNA viruses and their hosts, RNA viruses showed marked depth limitation but little latitudinal change. Auxiliary metabolic genes in the RNA virome indicated that several eukaryote plankton processes are affected by viruses. A group of 11 RNA viruses that significantly influence ocean carbon flux were identified. —CA

Abstract

Community- and “species”-level analyses elucidate ecological impacts and roles of marine RNA viruses.