Hervé Moreau, Isabel Ferrera, Hugo Sarmento, Emilie Villar, Camille Clerissi, Nigel Grimsley, Julie Poulain, Jean-Michel Claverie, Silvia G. Acinas, Patrick Wincker, Karoline Faust, Stephane Pesant, Pascal Hingamp, Colomban de Vargas, Fabrice Not, Jeroen Raes, Eric Karsenti, Lucie Subirana, Peer Bork, Hiroyuki Ogata, Shinichi Sunagawa, Olivier Jaillon, Stefanie Kandels-Lewis, Gipsi Lima-Mendez, Yves Desdevises, Information génomique et structurale (IGS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Biologie intégrative des organismes marins (BIOM), Observatoire océanologique de Banyuls (OOB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Marine Biology and Oceanography, Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona] (ICM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut de Génomique d'Evry (IG), Institut de Biologie François JACOB (JACOB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Department of Structural Biology, Vrije Universiteit Brussel (VUB), Department of Applied Biological Sciences (DBIT), European Molecular Biology Laboratory, Dept Biol Struct, Res Grp Bioinformat & Eco Syst Biol, VIB, Dept Appl Biol Sci, Microbiol Unit, Evolution des Protistes et Ecosystèmes Pélagiques (EPEP), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff [Roscoff] (SBR), European Molecular Biology Laboratory [Heidelberg] (EMBL), Diversité et Interactions au sein du Plancton Océanique (DIPO), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Education academy of computational life sciences, Tokyo Institute of Technology [Tokyo] (TITECH), CNRS, EMBL, [PROMETHEUS/ANR-09GENM-031], [TARA-GIRUS/ANR-09-PCS-GENM-218], Genoscope/CEA, Stazione Zoologica Anton Dohrn, UNIMIB, ANR, [POSEIDON/ANR-09-BLAN-0348], [BIOMARKS/ANR-08-BDVA-003], Department of Marine Biology and Oceanography [Barcelone], Université Paris-Saclay-Institut de Biologie François JACOB (JACOB), UCL - SST/LIBST - Louvain Institute of Biomolecular Science and Technology, and Department of Bio-engineering Sciences
Pascal Hingamp ... et al. -- 18 pages, 7 figures, 3 tables, Nucleo-cytoplasmic large DNA viruses (NCLDVs) constitute a group of eukaryotic viruses that can have crucial ecological roles in the sea by accelerating the turnover of their unicellular hosts or by causing diseases in animals. To better characterize the diversity, abundance and biogeography of marine NCLDVs, we analyzed 17 metagenomes derived from microbial samples (0.2–1.6 μm size range) collected during the Tara Oceans Expedition. The sample set includes ecosystems under-represented in previous studies, such as the Arabian Sea oxygen minimum zone (OMZ) and Indian Ocean lagoons. By combining computationally derived relative abundance and direct prokaryote cell counts, the abundance of NCLDVs was found to be in the order of 104–105 genomes ml−1 for the samples from the photic zone and 102–103 genomes ml−1 for the OMZ. The Megaviridae and Phycodnaviridae dominated the NCLDV populations in the metagenomes, although most of the reads classified in these families showed large divergence from known viral genomes. Our taxon co-occurrence analysis revealed a potential association between viruses of the Megaviridae family and eukaryotes related to oomycetes. In support of this predicted association, we identified six cases of lateral gene transfer between Megaviridae and oomycetes. Our results suggest that marine NCLDVs probably outnumber eukaryotic organisms in the photic layer (per given water mass) and that metagenomic sequence analyses promise to shed new light on the biodiversity of marine viruses and their interactions with potential hosts, We thank the coordinators and members of the Tara Oceans consortium (http://www.embl.de/tara-oceans/start/) for organizing sampling and data analysis. We thank the commitment of the following people and sponsors who made this singular expedition possible: CNRS, EMBL, Genoscope/CEA, VIB, Stazione Zoologica Anton Dohrn, UNIMIB, ANR (projects POSEIDON/ANR-09-BLAN-0348, BIOMARKS/ANR-08-BDVA-003, PROMETHEUS/ANR-09-GENM-031, and TARA-GIRUS/ANR-09-PCS-GENM-218), EU FP7 (MicroB3/No.287589), FWO, BIO5, Biosphere 2, agne`s b., the Veolia Environment Foundation, Region Bretagne, World Courier, Illumina, Cap L’Orient, the EDF Foundation EDF Diversiterre, FRB, the Prince Albert II de Monaco Foundation, Etienne Bourgois, the Tara schooner and its captain and crew. CC benefited from a doctoral fellowship from the AXA Research Fund. Tara Oceans would not exist without the continuous support of the participating 23 institutes (see http://oceans.taraexpeditions.org). This article is contribution number 0003 of the Tara Oceans Expedition 2009–2012