MOLECULAR PHYLOGENETIC ANALYSIS OF ACTIN GENIC REGIONS FROM ACHLYA-BISEXUALIS (OOMYCOTA) AND COSTARIA-COSTATA (CHROMOPHYTA)
MOLECULAR PHYLOGENETIC ANALYSIS OF ACTIN GENIC REGIONS FROM ACHLYA-BISEXUALIS (OOMYCOTA) AND COSTARIA-COSTATA (CHROMOPHYTA)
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DOI：
10.1007/bf02102805
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发表时间：
1991-12-01
影响因子：
3.9
通讯作者：
SOGIN, ML
中科院分区：
文献类型：
--
作者：
BHATTACHARYA, D;STICKEL, SK;SOGIN, ML
从异形鞭毛原生生物Achlya两性(Omycota)和Costaria costata(Chromophyta)中分离并鉴定了肌动蛋白产生区。限制性内切酶和克隆实验表明，这些基因以单拷贝形式存在，序列测定表明中肋骨条藻肌动蛋白基因区域存在两个内含子。利用距离矩阵和最大简约度方法对肌动蛋白基因区域进行系统发育分析，通过核糖体DNA(RDNA)序列比较和生殖细胞超微结构的比较，证实了两性艾美耳虫和中肋甲的紧密进化关系。高等真菌、绿色植物和动物被视为单系类群；然而，无法确定这些类群的确切分枝顺序。通过比较rRNA推断的系统发育框架被用来评估不同真核生物肌动蛋白基因区域的进化速度。肌动蛋白基因区域的核苷酸替换率在不同的谱系中不一致。比较肌动蛋白和rDNA序列差异的比率表明，高等真菌和开花植物中肌动蛋白基因区域的进化速度分别是其rDNA序列的2.0倍和5.3倍。相反，动物肌动蛋白的进化速度大约是它们的rDNA序列的五分之一。
Actin genic regions were isolated and characterized from the heterokont-flagellated protists, Achlya bisexualis (Oomycota) and Costaria costata (Chromophyta). Restriction enzyme and cloning experiments suggested that the genes are present in a single copy and sequence determinations revealed the existence of two introns in the C. costata actin genic region. Phylogenetic analyses of actin genic regions using distance matrix and maximum parsimony methods confirmed the close evolutionary relationship of A. bisexualis and C costata suggested by ribosomal DNA (rDNA) sequence comparisons and reproductive cell ultrastructure. The higher fungi, green plants, and animals were seen as monophyletic groups; however, a precise order of branching for these assemblages could not be determined. Phylogenetic frameworks inferred from comparisons of rRNAs were used to assess rates of evolution in actin genic regions of diverse eukaryotes. Actin genic regions had nonuniform rates of nucleotide substitution in different lineages. Comparison of rates of actin and rDNA sequence divergence indicated that actin genic regions evolve 2.0 and 5.3 times faster in higher fungi and flowering plants, respectively, than their rDNA sequences. Conversely, animal actins evolve at approximately one-fifth the rate of their rDNA sequences.