Award: OCE-0961947

Ocean oxygen minimum zones are expanding, which is problematic as their microbial communities cause them to be sources of greenhouse gases. Viruses in many ecosystems impact microbial populations through mortality, gene transfer and metabolic reprogramming. This project focused on improving understanding of how viruses in oxygen minimum zones along the open ocean 'LineP' oceanographic transect in the Northeast Pacific Ocean interacted with their microbial hosts. Through this grant, the first large-scale viral metagenomic sequence dataset (32 viromes) was published in 2013 (Hurwitz & Sullivan 2013), with half of the viromes derived from LineP and the ocean viral communities studied here. This foundational dataset has already enabled several key advances in viral ecology including highlighting the abundance and ubiquity of SAR11 viruses (Zhao et al. 2013). As well comparative viromics studies helped determine what ocean processes drive viral communtiy structure (Hurwitz et al 2014), how viral communities adapt to different ocean environments (e.g., niche differentiation), and helped define what genes are shared by all Pacific Ocean viral communities (the core virome, Hurwitz, Brum & Sullivan 2014). The dataset also revealed that Pacific Ocean viruses use viral-encoded genes to directly modulate nearly every step of central carbon microbial metabolism (Hurwitz, Hallam & Sullivan 2013), and helped estimate the extent of the global virome which is now suggested to be 3 orders of magnitude smaller than previously thought (Ignacio-Espinoza et al 2013). Together, these findings establish the core gene sets that ocean viral communities need, as well as the ecological drivers of community niche differentiation in the pelagic Pacific Ocean and linking viral activity back to the core microbial metabolisms and ocean biogeochemical cycles of the North Pacific Ocean and associated OMZs. References cited: Hurwitz, B.H. & Sullivan, M.B. The Pacific Ocean Virome (POV): a marine viral metagenomic dataset and associated protein clusters for quantitative viral ecology. PLoS One 8, e57355 (2013). Hurwitz, B.H., Brum, J.R. & Sullivan, M.B. Depth stratified functional and taxonomic niche specialization in the æcoreÆ and æflexibleÆ Pacific Ocean Virome. ISME J in press (2014). Hurwitz, B.L., Westveld, A.H., Brum, J.R. & Sullivan, M.B. Modeling ecological drivers in marine viral communities using comparative metagenomics and network analyses. PNAS 111, 10714-10719 (2014). Hurwitz, B.L., Hallam, S.J. & Sullivan, M.B. Metabolic reprogramming by viruses in the sunlit and dark ocean. Genome Biol 14, R123 (2013). Ignacio-Espinoza, J.C., Solonenko, S.A. & Sullivan, M.B. The global virome: not as big as we thought? Curr Opin Virol 3, 566-571 (2013). Zhao, Y. et al. Abundant SAR11 viruses in the ocean. Nature 494, 357-360 (2013). Last Modified: 09/03/2014 Submitted by: Matthew Sullivan