title: RNA viruses as major contributors to Antarctic virioplankton.
abstract: Early work on marine algal viruses focused exclusively on those having DNA genomes, but recent studies suggest that RNA viruses, especially those with positive-sense, single-stranded RNA (+ssRNA) genomes, are abundant in tropical and temperate coastal seawater. To test whether this was also true of polar waters, we estimated the relative abundances of RNA and DNA viruses using a mass ratio approach and conducted shotgun metagenomics on purified viral samples collected from a coastal site near Palmer Station, Antarctica on six occasions throughout a summer phytoplankton bloom (November-March). Our data suggest that RNA viruses contributed up to 65% of the total virioplankton (8-65%), and that, as observed previously in warmer waters, the majority of RNA viruses in these Antarctic RNA virus metagenomes had +ssRNA genomes most closely related to viruses in the order Picornavirales. Assembly of the metagenomic reads resulted in five novel, nearly complete genomes, three of which had features similar to diatom-infecting viruses. Our data are consistent with the hypothesis that RNA viruses influence diatom bloom dynamics in Antarctic waters.
authors.affiliation: Department of Oceanography, Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, HI, 96822, USA.
authors.forename: Jaclyn A
authors.initials: JA
authors.lastname: Miranda
authors.affiliation: Department of Oceanography, Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, HI, 96822, USA.
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Culley
authors.affiliation: Department of Oceanography, Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, HI, 96822, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Schvarcz
authors.affiliation: Department of Oceanography, Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, HI, 96822, USA.
authors.forename: Grieg F
authors.initials: GF
authors.lastname: Steward
mesh_terms: D000864:Antarctic Regions; D017377:Diatoms / Q000821:virology; D016679:Genome, Viral; D056186:Metagenomics; D010802:Phylogeny; D010839:Phytoplankton / Q000821:virology*; D012328:RNA Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012623:Seawater / Q000821:virology