The making of a branching annelid: an analysis of complete mitochondrial genome and ribosomal data of Ramisyllis multicaudata
The making of a branching annelid: an analysis of complete mitochondrial genome and ribosomal data of Ramisyllis multicaudata
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DOI：
10.1038/srep12072
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发表时间：
2015-07-17
影响因子：
4.6
通讯作者：
Bleidorn, Christoph
中科院分区：
文献类型：
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作者：
Teresa Aguado, M.;Glasby, Christopher J.;Bleidorn, Christoph
多尾小枝藻是环节动物亚纲(环节动物纲，多尾类)的一员，具有显著的分枝体计划。利用下一代测序方法，对多尾轮虫和锥虫的完整线粒体基因组进行了测定。并进行了测序和分析，这是来自Syllidae的第一批。这两个序列中的基因序列不遵循Errantia中假设的基本模式的顺序。利用核18S和线粒体16S和cox1基因的系统发育分析方法，对多尾轮虫的系统发育关系进行了研究。多尾小枝藻是锥虫一个分支的姊妹群。两个属Ramisyllis和Trypanobia与Parahaplosyllis、Trypanosyllis、Eurysyllis和Xenosyllis位于一个长的分枝分支中。长分支的原因是18S rRNA基因的突变速度加快。利用系统发育骨架，我们提出了一种情景，在这种情景中，在大多数海鞘类中发生的胚胎后片段的添加，它们巨大的繁殖模式的多样性，以及它们再生丢失部分的能力，结合在一起，为发展一种新的分支体模式提供了进化基础，正如在Ramisyllis中实现的那样。
Ramisyllis multicaudata is a member of Syllidae (Annelida, Errantia, Phyllodocida) with a remarkable branching body plan. Using a next-generation sequencing approach, the complete mitochondrial genomes of R. multicaudata and Trypanobia sp. are sequenced and analysed, representing the first ones from Syllidae. The gene order in these two syllids does not follow the order proposed as the putative ground pattern in Errantia. The phylogenetic relationships of R. multicaudata are discerned using a phylogenetic approach with the nuclear 18S and the mitochondrial 16S and cox1 genes. Ramisyllis multicaudata is the sister group of a clade containing Trypanobia species. Both genera, Ramisyllis and Trypanobia, together with Parahaplosyllis, Trypanosyllis, Eurysyllis, and Xenosyllis are located in a long branched clade. The long branches are explained by an accelerated mutational rate in the 18S rRNA gene. Using a phylogenetic backbone, we propose a scenario in which the postembryonic addition of segments that occurs in most syllids, their huge diversity of reproductive modes, and their ability to regenerate lost parts, in combination, have provided an evolutionary basis to develop a new branching body pattern as realised in Ramisyllis.