Zapata Felipe, Goetz Freya E, Smith Stephen A, Howison Mark, Siebert Stefan, Church Samuel H, Sanders Steven M, Ames Cheryl Lewis, McFadden Catherine S, France Scott C, Daly Marymegan, Collins Allen G, Haddock Steven H D, Dunn Casey W, Cartwright Paulyn
Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America.
Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, United States of America; Computing and Information Services, Brown University, Providence, Rhode Island, United States of America.
PLoS One. 2015 Oct 14;10(10):e0139068. doi: 10.1371/journal.pone.0139068. eCollection 2015.
Cnidaria, the sister group to Bilateria, is a highly diverse group of animals in terms of morphology, lifecycles, ecology, and development. How this diversity originated and evolved is not well understood because phylogenetic relationships among major cnidarian lineages are unclear, and recent studies present contrasting phylogenetic hypotheses. Here, we use transcriptome data from 15 newly-sequenced species in combination with 26 publicly available genomes and transcriptomes to assess phylogenetic relationships among major cnidarian lineages. Phylogenetic analyses using different partition schemes and models of molecular evolution, as well as topology tests for alternative phylogenetic relationships, support the monophyly of Medusozoa, Anthozoa, Octocorallia, Hydrozoa, and a clade consisting of Staurozoa, Cubozoa, and Scyphozoa. Support for the monophyly of Hexacorallia is weak due to the equivocal position of Ceriantharia. Taken together, these results further resolve deep cnidarian relationships, largely support traditional phylogenetic views on relationships, and provide a historical framework for studying the evolutionary processes involved in one of the most ancient animal radiations.
刺胞动物门是两侧对称动物的姐妹类群，在形态、生命周期、生态和发育方面是一个高度多样化的动物类群。由于主要刺胞动物谱系之间的系统发育关系尚不清楚，且近期研究提出了相互矛盾的系统发育假说，所以这种多样性是如何起源和演化的还不太清楚。在这里，我们将15个新测序物种的转录组数据与26个公开可用的基因组和转录组相结合，以评估主要刺胞动物谱系之间的系统发育关系。使用不同分区方案和分子进化模型的系统发育分析，以及对替代系统发育关系的拓扑测试，支持了钵水母纲、珊瑚纲、八放珊瑚亚纲、水螅纲以及由十字水母纲、立方水母纲和钵水母纲组成的一个进化枝的单系性。由于海葵目的位置不明确，对六放珊瑚亚纲单系性的支持较弱。综上所述，这些结果进一步解析了刺胞动物的深层关系，在很大程度上支持了关于关系的传统系统发育观点，并为研究最古老动物辐射之一所涉及的进化过程提供了一个历史框架。
