title: Pole-to-pole biogeography of surface and deep marine bacterial communities.
abstract: The Antarctic and Arctic regions offer a unique opportunity to test factors shaping biogeography of marine microbial communities because these regions are geographically far apart, yet share similar selection pressures. Here, we report a comprehensive comparison of bacterioplankton diversity between polar oceans, using standardized methods for pyrosequencing the V6 region of the small subunit ribosomal (SSU) rRNA gene. Bacterial communities from lower latitude oceans were included, providing a global perspective. A clear difference between Southern and Arctic Ocean surface communities was evident, with 78% of operational taxonomic units (OTUs) unique to the Southern Ocean and 70% unique to the Arctic Ocean. Although polar ocean bacterial communities were more similar to each other than to lower latitude pelagic communities, analyses of depths, seasons, and coastal vs. open waters, the Southern and Arctic Ocean bacterioplankton communities consistently clustered separately from each other. Coastal surface Southern and Arctic Ocean communities were more dissimilar from their respective open ocean communities. In contrast, deep ocean communities differed less between poles and lower latitude deep waters and displayed different diversity patterns compared with the surface. In addition, estimated diversity (Chao1) for surface and deep communities did not correlate significantly with latitude or temperature. Our results suggest differences in environmental conditions at the poles and different selection mechanisms controlling surface and deep ocean community structure and diversity. Surface bacterioplankton may be subjected to more short-term, variable conditions, whereas deep communities appear to be structured by longer water-mass residence time and connectivity through ocean circulation.
authors.affiliation: Unité Mixte de Recherche 7621, Laboratoire d'Océanographie Microbienne, UMR 8222, University Pierre et Marie Curie 06, F-66650 Banyuls/mer, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Ghiglione
authors.forename: Pierre E
authors.initials: PE
authors.lastname: Galand
authors.forename: Thomas
authors.initials: T
authors.lastname: Pommier
authors.forename: Carlos
authors.initials: C
authors.lastname: Pedrós-Alió
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Maas
authors.forename: Kevin
authors.initials: K
authors.lastname: Bakker
authors.forename: Stefan
authors.initials: S
authors.lastname: Bertilson
authors.forename: David L
authors.initials: DL
authors.lastname: Kirchmanj
authors.forename: Connie
authors.initials: C
authors.lastname: Lovejoy
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Yager
authors.forename: Alison E
authors.initials: AE
authors.lastname: Murray
mesh_terms: D000864:Antarctic Regions; D001110:Arctic Regions; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005843:Geography; D008386:Marine Biology; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D014871:Water Microbiology
chemical_list: D012335:RNA, Ribosomal