Data from: Phylogenomic analyses of Echinodermata support the sister groups of Asterozoa and Echinozoa

Echinoderms (sea urchins, sea stars, brittle stars, sea lilies and sea cucumbers) are a group of diverse organisms, second in number within deuterostome species to only the chordates. Echinoderms serve as excellent model systems for developmental biology due to their diverse developmental mechanisms, tractable laboratory use, and close phylogenetic distance to chordates. In addition, echinoderms are very well represented in the fossil record, including some larval features, making echinoderms a valuable system for studying evolutionary development. The internal relationships of Echinodermata have not been consistently supported across phylogenetic analyses, however, and this has hindered the study of other aspects of their biology. In order to test echinoderm phylogenetic relationships, we sequenced 23 de novo transcriptomes from all five clades of echinoderms. Using multiple phylogenetic methods at a variety of sampling depths we have constructed a well-supported phylogenetic tree of Echinodermata, including support for the sister groups of Asterozoa (sea stars and brittle stars) and Echinozoa (sea urchins and sea cucumbers). These results will help inform developmental and evolutionary studies specifically in echinoderms and deuterostomes in general.

棘皮动物（Echinoderms）包含海胆、海星、海蛇尾、海百合与海参五大类群，是一类多样性极高的生物类群，在后口动物（deuterostome）物种中，其物种丰富度仅次于脊索动物（chordates）。棘皮动物因具备多样的发育机制、易于实验室操作与培养的特性，且与脊索动物的系统发育亲缘关系较近，故而成为发育生物学研究的优质模型系统。此外，棘皮动物在化石记录中留存极为丰富，甚至保留了多种幼虫形态特征，使其成为进化发育生物学研究的宝贵实验体系。然而，此前的多项系统发育分析始终未能对棘皮动物门的内部演化关系达成一致支持，这一问题阻碍了该类群其他生物学方向的研究进展。为验证棘皮动物的系统发育关系，我们对来自棘皮动物全部5个演化支的23个从头转录组（de novo transcriptomes）进行了测序。通过采用多种系统发育分析方法，并设置不同的采样深度，我们成功构建了获得高置信度支持的棘皮动物门系统发育树，其中明确支持海星总纲（Asterozoa，包含海星与海蛇尾）与海胆总纲（Echinozoa，包含海胆与海参）互为姊妹群的演化关系。本研究结果将为棘皮动物乃至后口动物的发育与进化生物学研究提供关键的理论参考。