Unité Mixte de Recherche 7621, Laboratoire d'Océanographie Microbienne, UMR 8222, University Pierre et Marie Curie 06, F-66650 Banyuls/mer, France.
Proc Natl Acad Sci U S A. 2012 Oct 23;109(43):17633-8. doi: 10.1073/pnas.1208160109. Epub 2012 Oct 8.
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.
南极和北极地区为测试塑造海洋微生物群落生物地理学的因素提供了独特的机会，因为这些地区在地理位置上相距遥远，但却面临着相似的选择压力。在这里，我们使用小亚基核糖体 (SSU) rRNA 基因 V6 区的焦磷酸测序标准化方法，对极地海洋的浮游细菌多样性进行了全面比较。报告还纳入了低纬度海洋的细菌群落，提供了全球视角。南大洋和北冰洋表层海洋群落之间存在明显差异，78%的操作分类单元（OTU）是南大洋特有的，70%的 OTU 是北冰洋特有的。尽管极地海洋细菌群落彼此之间比低纬度浮游群落更相似，但对深度、季节以及沿海和开阔水域的分析表明，南大洋和北冰洋的浮游细菌群落始终彼此分离。与各自的开阔海洋群落相比，南大洋和北冰洋沿海表层海洋群落之间的差异更大。相比之下，极地和低纬度深层海水之间的深层海洋群落差异较小，与表层相比，其多样性模式也不同。此外，表层和深层群落的估计多样性（Chao1）与纬度或温度没有显著相关性。我们的结果表明，两极的环境条件存在差异，控制表层和深层海洋群落结构和多样性的选择机制也不同。表层浮游细菌可能更容易受到短期、多变的环境条件的影响，而深层群落的结构似乎是由更长的水团停留时间和通过海洋环流形成的连通性决定的。
