Evolution of the salmonid mitochondrial control region.
Evolution of the salmonid mitochondrial control region.
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DOI：
10.1016/1055-7903(92)90014-8
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发表时间：
1992-09
影响因子：
4.1
通讯作者：
Andrew M. Shedlock;Jay D. Parker;David A. Crispin;Theodore W. Pietsch;G. C. Burmer
中科院分区：
文献类型：
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作者：
Andrew M. Shedlock;Jay D. Parker;David A. Crispin;Theodore W. Pietsch;G. C. Burmer
为了探索鲑科线粒体DNA控制区（D-loop）的进化性质及其在系统发育推断中的应用，对所有8种溯河太平洋鲑鱼（genusOncorhynchus）、大西洋鲑鱼（Salmo salar）和北极灰鲑（Thymallus arcticus）的整个控制区进行了测序。比对结果表明，这些原始硬骨鱼保留了先前在其他脊椎动物中报道的普遍保守的序列元素。结果揭示了核苷酸替换、插入和缺失的显著非随机分布，这表明鲑鱼d环的部分可能受到差异选择约束，并且这些鱼类的大多数控制区可能以与其mtDNA基因组其余部分相似的速度进化。对9kb的鲑鱼序列数据进行了极大似然分析和Fitch简约分析，得到了具有相同拓扑结构的进化树。这些结果与先前对有限数量的鲑鱼分类群的分子研究以及对鲑鱼进化的更全面，经典的分析是一致的。基于mtDNA控制区的分子钟假设，这些数据的预测也与化石证据一致，化石证据表明，oncorhynchus物种可能与上新世中期一样古老，因此可能在大约500万或600万年前产生了现存的太平洋鲑鱼。
To explore the evolutionary nature of the salmonid mitochondrial DNA (mtDNA) control region (D-loop) and its utility for inferring phylogenies, the entire region was sequenced from all eight species of anadromous Pacific salmon, genusOncorhynchus, the Atlantic salmon,Salmo salar, and the Arctic grayling,Thymallus arcticus. A comparison of aligned sequences demonstrates that the generally conserved sequence elements that have been previously reported for other vertebrates are maintained in these primitive teleost fishes. Results reveal a significantly nonrandom distribution of nucleotide substitutions, insertions, and deletions that suggests that portions of the salmonid D-loop may be under differential selective constraints and that most of the control region of these fishes may evolve at a rate similar to that of the remainder of their mtDNA genomes. Maximum likelihood and Fitch parsimony analyses of 9 kb of aligned salmonid sequence data give evolutionary trees of identical topology. These results are consistent with previous molecular studies of a limited number of salmonid taxa and with more comprehensive, classical analyses of salmonid evolution. Predictions from these data, based on a molecular clock assumption for the mtDNA control region, are also consistent with fossil evidence that suggests that species ofOncorhynchuscould be as old as the Middle Pliocene and would have thus given rise to the extant Pacific salmon prior to about 5 or 6 million years ago.