Early evolution of eukaryotes inferred by combined phylogeny of multiple genes

为了阐明真核生物的一个更高层次的遗传学推断真核生物树的一个根，进行了多基因的联合遗传学。为了这个目的，几个基因编码的胞质核糖体RNA和保守蛋白质被分离和测序的各种生物体属于stratifiles，alveolates，centrohelids，隐藻，红藻，和fornicates。包括获得的原始序列数据，产生具有不同分类单元采样和具有不同基因选择的各种数据集，并通过多基因的组合最大似然分析来分析这些数据集。到目前为止，已取得以下主要成果：1。不同的数据集分别获得了将双鞭毛体外群位置的质心定位于双鞭毛体的最优树和将变形虫和后鞭毛体分支之间的最优树，但这些位置没有得到统计学可信度的明确支持.没有得到明确的支持的单系性的chromalveolates包括隐芽植物，附着植物，层生植物，和alveolates。延伸因子1 α和延伸因子2的系统发育分析表明，短沟鞭水蚤和一种鞭毛虫与短沟鞭水蚤相似。brevis（NY0173）位于毛滴虫和滴虫分支之间，支持了先前基于SSUrRNA同源性的结果。

In order to elucidate a higher-order phylogeny of eukaryotes infer a root of the eukaryotic tree, combined phylogeny of multiple genes were carried out. For this purpose, several genes encoding cytosolic ribosomal RNAs and conservative proteins were isolated and sequenced from various organisms belonging to stramenopiles, alveolates, centrohelids, cryptomonads, rhodophytes, and fornicates. Including original sequence data obtained, various kinds of data sets with different taxon samplings and with different selections of genes were generated and these were analyzed by combined maximum likelihood analyses of the multiple genes. Until recently major outcomes listed below have been obtained:1. Optimal trees locating centrohelids at the outgroup position to bikont organisms and locating between the branches of amoebozoa and opisthokonts were independently obtained by different data sets, but these locations were not clearly supported with statistical confidence.2. No clear support was obtained for the monophyly of chromalveolates including cryptophytes, haptophytes, stramenopiles, and alveolates.3. Phylogenies of elongation factors 1 α and 2 demonstrated that Dysnectes brevis and a flagellate resemble to D. brevis (NY0173) were located between the branchings of trichomonads and diplomonads, supporting the previous results based on the SSUrRNA phylogeny.