The ring of life provides evidence for a genome fusion origin of eukaryotes
The ring of life provides evidence for a genome fusion origin of eukaryotes
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DOI：
10.1038/nature02848
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发表时间：
2004-09-09
期刊：
影响因子：
64.8
通讯作者：
Lake, JA
中科院分区：
文献类型：
--
作者：
Rivera, MC;Lake, JA
基因组保存着地球生命进化的记录。但基因组融合和水平基因转移似乎已经充分掩盖了基因序列记录，因此很难重建生命的系统发育树。在这里，我们使用来自代表性原核生物和真核生物的完整基因组数据以及一种新的基因组分析方法来确定树的总体轮廓，该方法使得重建古代基因组融合和系统发育树成为可能。我们的分析表明，真核生物基因组是两种不同原核生物基因组融合的结果，因此在连接原核生物和真核生物的最深层次上，生命之树实际上是一个生命环。一种融合伙伴从古老的光合作用分支深处分支出来，另一种则与古菌原核生物有关。真细菌生物体要么是变形菌，要么是包括蓝藻门和变形菌门的较大光合进化枝的成员。
Genomes hold within them the record of the evolution of life on Earth. But genome fusions and horizontal gene transfer seem to have obscured sufficiently the gene sequence record such that it is difficult to reconstruct the phylogenetic tree of life. Here we determine the general outline of the tree using complete genome data from representative prokaryotes and eukaryotes and a new genome analysis method that makes it possible to reconstruct ancient genome fusions and phylogenetic trees. Our analyses indicate that the eukaryotic genome resulted from a fusion of two diverse prokaryotic genomes, and therefore at the deepest levels linking prokaryotes and eukaryotes, the tree of life is actually a ring of life. One fusion partner branches from deep within an ancient photosynthetic clade, and the other is related to the archaeal prokaryotes. The eubacterial organism is either a proteobacterium, or a member of a larger photosynthetic clade that includes the Cyanobacteria and the Proteobacteria.