Isolation and molecular evolution of the selenocysteine tRNA (Cf TRSP) and RNase p RNA (Cf RPPH1) genes in the dog family, Canidae
Isolation and molecular evolution of the selenocysteine tRNA (Cf TRSP) and RNase p RNA (Cf RPPH1) genes in the dog family, Canidae
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DOI：
10.1093/molbev/msi022
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发表时间：
2005-02-01
影响因子：
10.7
通讯作者：
Wayne, RK
中科院分区：
文献类型：
--
作者：
Bardeleben, C;Moore, RL;Wayne, RK
为了鉴定快速进化的核序列，用于近缘物种的系统发育分析。我们从家犬（Canis familiaris）中分离了由RNA聚合酶III（pol III）转录的两个基因，硒代半胱氨酸tRNA基因（TRSP）和RNase P RNA（RPPH 1）基因。我们专注于由pol M转录的基因，因为它们的编码区很小（通常为100-300个碱基对[bp]），并且它们的基本启动子元件位于编码区上游几百个碱基对内。因此。我们预测编码区侧翼和启动子元件外部的区域将不受限制并将迅速进化。我们从23犬科动物和RPPH 1从12犬科动物扩增TRSP和分析这些基因的分子进化和它们的效用作为系统发育标记，以解决在犬科物种之间的关系。我们比较了基因侧翼区与核DNA的其他非编码区（内含子）和线粒体编码的COII基因的进化速率。TRSP从23犬科动物的比对显示，区域直接相邻的编码区显示高序列变异性。我们讨论这种模式的转录的功能机制。虽然侧翼区的进化速度并不比内含子快，但这两个基因都被发现是有用的系统发育标记。因为在侧翼区域发现了突触形态插入缺失。从TRSP和RPPH 1基因座生成的基因树与已发表的线粒体DNA系统发育基本一致，是第一个基于核序列的犬科系统发育。
In an effort to identify rapidly evolving nuclear sequences useful for phylogenetic analyses of closely related species. we isolated two genes transcribed by RNA polymerase III (pol III), the selenocysteine tRNA gene (TRSP) and an RNase P RNA (RPPH1) gene from the domestic dog (Canis familiaris). We focus on genes transcribed by pol M because their coding regions are small (generally 100-300 base pairs [bp]) and their essential promoter elements are located within a couple of hundred bps upstream of the coding region. Therefore. we predicted that regions flanking the coding region and outside of the promoter elements would be free of constraint and would evolve rapidly. We amplified TRSP from 23 canids and RPPH1 from 12 canids and analyzed the molecular evolution of these genes and their utility as phylogenetic markers for resolving relationships among species in Canidae. We compared the rate of evolution of the gene-flanking regions to other noncoding regions of nuclear DNA (introns) and to the mitochondrial encoded COII gene. Alignment of TRSP from 23 canids revealed that regions directly adjacent to the coding region display high sequence variability. We discuss this pattern in terms of functional mechanisms of transcription. Although the flanking regions evolve no faster than introns, both genes were found to be useful phylogenetic markers, in part. because of the synapomorphic indels found in the flanking regions. Gene trees generated from the TRSP and RPPH1 loci were generally in agreement with the published mtDNA phylogeny and are the first phylogeny of Canidae based on nuclear sequences.