Evolution of Patchily Distributed Proteins Shared between Eukaryotes and Prokaryotes: Dictyostelium as a Case Study
Evolution of Patchily Distributed Proteins Shared between Eukaryotes and Prokaryotes: Dictyostelium as a Case Study
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DOI：
10.1159/000324505
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发表时间：
2011-01-01
影响因子：
1.2
通讯作者：
Andersson, Jan O.
中科院分区：
文献类型：
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作者：
Andersson, Jan O.
蛋白质家族通常在生命树中呈斑块状分布;它们存在于亲缘关系较远的生物体中，但在亲缘关系较近的谱系中却不存在。这可能是编码它们的生物体的祖先之间的横向基因转移的结果，或者是缺乏它们的谱系中的损失。在这里，一个新的方法来研究原核生物和真核生物之间共享的斑块状分布的蛋白质的进化。在细胞黏菌盘状网柄菌和有限数量的其他谱系（包括至少一种原核生物）的基因组中编码的蛋白质被鉴定。49个这样的斑块状分布的蛋白质家族的系统发育分布的分析表明，与生物体的同源性冲突; 25个与远亲的阿米巴鞭毛虫奈格尔虫（挖洞）共享，而只有两个是在更密切相关的内阿米巴。大多数蛋白质家族在系统发育分析中显示出意想不到的拓扑结构;真核生物在85%的树中是多系的。这些观察结果表明，基因转移是斑块状分布的蛋白质分布在所有生命领域的一个重要机制。为了更好地理解真核生物基因的起源和进化以及真核生物的多样化过程，需要对这种可交换基因片段进行进一步的研究。版权所有（C）2011 S. Karger AG，巴塞尔
Protein families are often patchily distributed in the tree of life; they are present in distantly related organisms, but absent in more closely related lineages. This could either be the result of lateral gene transfer between ancestors of organisms that encode them, or losses in the lineages that lack them. Here a novel approach is developed to study the evolution of patchily distributed proteins shared between prokaryotes and eukaryotes. Proteins encoded in the genome of cellular slime mold Dictyostelium discoideum and a restricted number of other lineages, including at least one prokaryote, were identified. Analyses of the phylogenetic distribution of 49 such patchily distributed protein families showed conflicts with organismal phylogenies; 25 are shared with the distantly related amoeboflagellate Naegleria (Excavata), whereas only two are present in the more closely related Entamoeba. Most protein families show unexpected topologies in phylogenetic analyses; eukaryotes are polyphyletic in 85% of the trees. These observations suggest that gene transfers have been an important mechanism for the distribution of patchily distributed proteins across all domains of life. Further studies of this exchangeable gene fraction are needed for a better understanding of the origin and evolution of eukaryotic genes and the diversification process of eukaryotes. Copyright (C) 2011 S. Karger AG, Basel