Biogeography and diversity of Collodaria (Radiolaria) in the global ocean
Biogeography and diversity of Collodaria (Radiolaria) in the global ocean
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DOI：
10.1038/ismej.2017.12
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发表时间：
2017-06-01
期刊：
影响因子：
11
通讯作者：
Not, Fabrice
中科院分区：
文献类型：
--
作者：
Biard, Tristan;Bigeard, Estelle;Not, Fabrice
胶团藻是异养海洋原生生物，以数百个细胞组成的大型群体或大型单细胞存在。到目前为止，所有描述的物种都将细胞内微藻作为光共生体。虽然最近的环境多样性调查的基础上的分子方法表明，他们一贯高的贡献，浮游生物群落和他们的世界范围内的发生，我们的了解，他们的多样性和地理仍然非常有限。在这里，我们估计了18 S核糖体DNA（rDNA）基因拷贝每个cololdarian细胞的孤立（5770 +/- 1960小亚基（SSU）rDNA拷贝）和殖民标本（37 474 +/- 17 799 SSU rDNA拷贝，为每个单独的细胞在一个殖民地）使用单标本定量PCR。然后，我们调查了透光带内的胶衣的环境多样性，通过元条码调查从塔拉海洋考察，发现两个胶衣家庭Collosphaeridae和Sphaerozoidae贡献最大的胶衣多样性，包括大多是世界性的类群。虽然在每个生物地球化学生物群系内的生物地理模式是均匀的，我们观察到，沿海生物群系的多样性始终低于海洋生物群系，并占主导地位的Sphaerozoidae，而Collosphaeridae占主导地位的开放海洋。与六个环境变量的显着关系表明，胶棉多样性的影响，海洋省份的营养状况，并增加对贫营养区。
Collodaria are heterotrophic marine protists that exist either as large colonies composed of hundreds of cells or as large solitary cells. All described species so far harbour intracellular microalgae as photosymbionts. Although recent environmental diversity surveys based on molecular methods demonstrated their consistently high contribution to planktonic communities and their worldwide occurrence, our understanding of their diversity and biogeography is still very limited. Here we estimated the 18S ribosomal DNA (rDNA) gene copies per collodarian cell for solitary (5770 +/- 1960 small subunit (SSU) rDNA copies) and colonial specimens (37 474 +/- 17 799 SSU rDNA copies, for each individual cell within a colony) using single-specimen quantitative PCR. We then investigated the environmental diversity of Collodaria within the photic zone through the metabarcoding survey from the Tara Oceans expedition and found that the two collodarian families Collosphaeridae and Sphaerozoidae contributed the most to the collodarian diversity and encompassed mostly cosmopolitan taxa. Although the biogeographical patterns were homogeneous within each biogeochemical biome considered, we observed that coastal biomes were consistently less diverse than oceanic biomes and were dominated by the Sphaerozoidae while the Collosphaeridae were dominant in the open oceans. The significant relationships with six environmental variables suggest that collodarian diversity is influenced by the trophic status of oceanic provinces and increased towards more oligotrophic regions.