Genome-scale evidence of the nematode-arthropod clade.
Genome-scale evidence of the nematode-arthropod clade.
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DOI：
10.1186/gb-2005-6-5-r41
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发表时间：
2005
期刊：
影响因子：
12.3
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中科院分区：
文献类型：
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迄今为止进行的最广泛的系统发育分析，包括 11 个完整基因组，在体腔动物-蜕皮动物进化问题的开放式辩论中支持了蜕皮动物假说。腔皮动物是否形成一个单一的分支（体腔动物），或者所有蜕皮外骨骼的动物（例如腔皮节肢动物和拟腔皮动物线虫）是否形成一个独特的分支（蜕皮动物），这是动物系统学中最令人费解的问题，也是进化生物学中一个主要的开放性主题。先前旨在解决该问题的单基因和基因组规模分析产生了矛盾的结果。在这里，我们提出了第一个基因组规模的系统发育证据，有力地支持了蜕皮动物假说。通过迄今为止最广泛的系统发育分析，对 11 个真核物种的完整基因组进行了分析，以找到源自 18 条人类染色体的同源序列。数据集的系统发育分析显示，线虫和节肢动物序列之间对相等进化速率的调整增加，导致从支持体腔动物到支持蜕皮动物的逐渐变化。当秀丽隐杆线虫的快速进化序列被删除时，拓扑之间的转变就会发生。当脊索动物、线虫和节肢动物序列被限制以适应相同的进化速率时，蜕皮动物拓扑在统计上被接受，而体腔动物被拒绝。节肢动物和线虫单系类群的可靠性在数据集中被明确接受，其中长分支吸引效应的痕迹被消除。这是第一个强烈支持“蜕皮进化枝”假说的系统发育学证据。
The most extensive phylogenetic analysis carried out to date, including 11 complete genomes, is shown to support the Ecdysozoa hypothesis in the open-ended debate of the Coelomata-Ecdysozoa evolutionary problem. The issue of whether coelomates form a single clade, the Coelomata, or whether all animals that moult an exoskeleton (such as the coelomate arthropods and the pseudocoelomate nematodes) form a distinct clade, the Ecdysozoa, is the most puzzling issue in animal systematics and a major open-ended subject in evolutionary biology. Previous single-gene and genome-scale analyses designed to resolve the issue have produced contradictory results. Here we present the first genome-scale phylogenetic evidence that strongly supports the Ecdysozoa hypothesis. Through the most extensive phylogenetic analysis carried out to date, the complete genomes of 11 eukaryotic species have been analyzed in order to find homologous sequences derived from 18 human chromosomes. Phylogenetic analysis of datasets showing an increased adjustment to equal evolutionary rates between nematode and arthropod sequences produced a gradual change from support for Coelomata to support for Ecdysozoa. Transition between topologies occurred when fast-evolving sequences of Caenorhabditis elegans were removed. When chordate, nematode and arthropod sequences were constrained to fit equal evolutionary rates, the Ecdysozoa topology was statistically accepted whereas Coelomata was rejected. The reliability of a monophyletic group clustering arthropods and nematodes was unequivocally accepted in datasets where traces of the long-branch attraction effect were removed. This is the first phylogenomic evidence to strongly support the 'moulting clade' hypothesis.