Revised small subunit rRNA analysis provides further evidence that foraminifera are related to Cercozoa
Revised small subunit rRNA analysis provides further evidence that foraminifera are related to Cercozoa
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DOI：
10.1007/s00239-003-0015-2
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发表时间：
2003-01-01
影响因子：
3.9
通讯作者：
Pawlowski, J
中科院分区：
文献类型：
--
作者：
Berney, C;Pawlowski, J
有越来越多的证据表明，核糖体DNA为基础的真核生物的染色体发生的一般形状是强烈偏见的长枝吸引现象，导致一个人为的基础集群的群体，可能是高度衍生。在这些类群中，有孔虫类特别令人感兴趣，因为它们在核糖体树中的系统发育位置与它们在化石记录中的寒武纪外观形成对比。最近的一项基于肌动蛋白的真核生物系统发生学研究提出，有孔虫可能与尾藻密切相关，因此，有孔虫可能是真核生物之冠中的分支。在这里，我们重新分析了小亚基核糖体RNA基因（SSU rDNA）的同源性，删除所有的长分支谱系，可以人为地吸引有孔虫序列的树的基础。我们的分析表明，有孔虫分支与海洋有壳丝状Gromia oviformis一起作为姐妹群的Cercozoa，与肌动蛋白的发生一致。我们的研究证实了实用的SSU rDNA作为一个系统发育标记的megaevolutionary的历史，提供的文物，由于在核糖体基因的替代率的异质性被规避。
There is accumulating evidence that the general shape of the ribosomal DNA-based phylogeny of Eukaryotes is strongly biased by the long-branch attraction phenomenon, leading to an artifactual basal clustering of groups that are probably highly derived. Among these groups, Foraminifera are of particular interest, because their deep phylogenetic position in ribosomal trees contrasts with their Cambrian appearance in the fossil record. A recent actin-based phylogeny of Eukaryotes has proposed that Foraminifera might be closely related to Cercozoa and, thus, branch among the so-called crown of Eukaryotes. Here, we reanalyze the small-subunit ribosomal RNA gene (SSU rDNA) phylogeny by removing all long-branching lineages that could artifactually attract foraminiferan sequences to the base of the tree. Our analyses reveal that Foraminifera branch together with the marine testate filosean Gromia oviformis as a sister group to Cercozoa,,in agreement with actin phylogeny. Our study confirms the utility of SSU rDNA as a phylogenetic marker of megaevolutionary history, provided that the artifacts due to the heterogeneity of substitution rates in ribosomal genes are circumvented.