Origin and evolution of the slime molds (Mycetozoa)
Origin and evolution of the slime molds (Mycetozoa)
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DOI：
10.1073/pnas.94.22.12007
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发表时间：
1997-10-28
影响因子：
11.1
通讯作者：
Doolittle, WF
中科院分区：
文献类型：
--
作者：
Baldauf, SL;Doolittle, WF
菌类包括细胞粘菌（盘基网柄菌）、无细胞粘菌（粘腹菌）和原生菌粘菌。然而，现有的分子数据对该类群的单系和系统发育位置存在分歧，核糖体RNA树显示粘胃粘菌和盘基网柄菌是不相关的早期分支谱系，但肌动蛋白和P-微管蛋白树将它们放在一起作为一个单一的连贯（单系）类群，与动物真菌分支密切相关。我们对来自每个分支的一个成员的延伸因子1 α基因进行了测序。霉菌纲，包括盘基网柄菌，其 cDNA 序列先前已获得。这些序列的系统发育分析有力地支持了单系真菌动物，其中粘胃和网柄菌彼此关系最密切。使用的所有系统发育方法也将这种连贯的真菌组合视为多细胞真核生物中出现的，暂时支持为与动物+真菌的关系比绿色植物更密切。根据我们的数据，现在有三种蛋白质始终支持单系真菌动物，并且至少有四种蛋白质将这些类群置于真核生物树的“王冠”内。我们建议针对这些问题更仔细地检查核糖体 RNA 数据，并且我们强调开发多个序列数据集的重要性。
The Mycetozoa include the cellular (dictyostelid), acellular (myxogastrid), and protostelid slime molds. However, available molecular data are in disagreement on both the monophyly and phylogenetic position of the group, Ribosomal RNA trees show the myxogastrid and dictyostelid slime molds as unrelated early branching lineages, but actin and P-tubulin trees place them together as a single coherent (monophyletic) group, closely related to the animal-fungal clade, We have sequenced the elongation factor-1 alpha genes from one member of each division of the Mycetozoa, including Dictyostelium discoideum, for which cDNA sequences were previously available. Phylogenetic analyses of these sequences strongly support a monophyletic Mycetozoa, with the myxogastrid and dictyostelid slime molds most closely related to each other, All phylogenetic methods used also place this coherent Mycetozoan assemblage as emerging among the multicellular eukaryotes, tentatively supported as more closely related to animals + fungi than are green plants. With our data there are now three proteins that consistently support a monophyletic Mycetozoa and at least four that place these taxa within the ''crown'' of the eukaryote tree. We suggest that ribosomal RNA data should be more closely examined with regard to these questions, and we emphasize the importance of developing multiple sequence data sets.