Department of Zoology, University of Oxford, Tinbergen Building, Oxford OX13PS, United Kingdom.
Mol Phylogenet Evol. 2012 Apr;63(1):208-12. doi: 10.1016/j.ympev.2011.12.010. Epub 2011 Dec 16.
Gastrotricha is a species-rich phylum of microscopical animals that contains two main orders, Chaetonotida and Macrodasyida. Gastrotrichs are important members of the aquatic environment and significant players in the study of animal evolution. In spite of their ecological and evolutionary importance, their internal relationships are not yet well understood. We have produced new sequences for the 18S rDNA gene to improve both the quality and quantity of taxon sampling for the gastrotrichs. Our phylogeny recovers the monophyly of the two main Gastrotricha clades, in contrast to recent studies with similar sampling, but in agreement with morphology based analyses. However, our topology is not able to resolve the first branches of the macrodasyidans or settle the position of the puzzling Neodasys, a controversial genus classified as a chaetonotidan on morphological grounds but placed within macrodasyidans by molecular studies. This analysis is the most exhaustive molecular phylogeny of the phylum to date, and significantly increases our knowledge of gastrotrich evolution.
环节动物门是一个物种丰富的微小动物门，包含两个主要目，Chaetonotida 和 Macrodasyida。环节动物门是水生环境中的重要成员，也是动物进化研究中的重要角色。尽管它们具有生态和进化意义，但它们的内部关系尚未得到很好的理解。我们已经为 18S rDNA 基因生成了新的序列，以提高环节动物门的分类采样质量和数量。我们的系统发育恢复了两个主要的环节动物类群的单系性，这与最近具有类似采样的研究相反，但与基于形态的分析一致。然而，我们的拓扑结构无法解决macroda syidans 的第一个分支，也无法确定令人困惑的 Neodasys 的位置，该属在形态学上被归类为 chaetonotidan，但分子研究将其置于 macroda syidans 中。这一分析是迄今为止该门最详尽的分子系统发育分析，大大增加了我们对环节动物进化的认识。
