CNRS, UMR 7144 & Université Pierre et Marie Curie, Station Biologique de Roscoff, Equipe EPPO - Evolution du Plancton et PaléoOcéans, Place Georges Teissier, 29682 Roscoff, France.
Protist. 2012 May;163(3):435-50. doi: 10.1016/j.protis.2011.10.002. Epub 2011 Dec 8.
Acantharia are ubiquitous and abundant rhizarian protists in the world ocean. The skeleton made of strontium sulphate and the fact that certain harbour microalgal endosymbionts make them key planktonic players for the ecology of marine ecosystems. Based on morphological criteria, the current taxonomy of Acantharia was established by W.T. Schewiakoff in 1926, since when no major revision has been undertaken. Here, we established the first comprehensive molecular phylogeny from single morphologically-identified acantharian cells, isolated from various oceans. Our phylogenetic analyses based on 78 18S rDNA and 107 partial 28S rDNA revealed the existence of 6 main clades, sub-divided into 13 sub-clades. The polyphyletic nature of acantharian families and genera demonstrates the need for revision of the current taxonomy. This molecular phylogeny, which highlights the taxonomic relevance of specific morphological criteria, such as the presence of a shell and the organisation of the central junction, provides a robust phylogenetic framework for future taxonomic emendation. Finally, mapping all the existing environmental sequences available to date from different marine ecosystems onto our reference phylogeny unveiled another 3 clades and improved the understanding of the biogeography and ecology of Acantharia.
短角原生动物是全球海洋中无处不在且丰富的放射虫原生动物。它们的骨骼由硫酸锶构成，而且某些港湾微藻内共生体的存在，使它们成为海洋生态系统生态学中的关键浮游生物。根据形态学标准，1926 年 W.T. Schewiakoff 建立了短角原生动物的现行分类，自那时以来，一直没有进行重大修订。在这里，我们从各种海洋中分离出的形态学鉴定的单个短角原生动物细胞中建立了第一个全面的分子系统发育。我们基于 78 个 18S rDNA 和 107 个部分 28S rDNA 的系统发育分析揭示了 6 个主要分支的存在，分为 13 个亚分支。短角原生动物科和属的多系性表明需要对现行分类进行修订。这种分子系统发育突出了特定形态学标准（如外壳的存在和中央连接的组织）的分类相关性，为未来的分类修正提供了一个稳健的系统发育框架。最后，将迄今为止从不同海洋生态系统获得的所有现有环境序列映射到我们的参考系统发育树上，揭示了另外 3 个分支，并提高了对短角原生动物生物地理学和生态学的理解。
