Molecular evolution of intergenic DNA in higher primates: pattern of DNA changes, molecular clock, and evolution of repetitive sequences.
Molecular evolution of intergenic DNA in higher primates: pattern of DNA changes, molecular clock, and evolution of repetitive sequences.
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高等灵长类动物基因间 DNA 的分子进化：DNA 变化模式、分子钟和重复序列的进化。
DOI：
10.1093/oxfordjournals.molbev.a040479
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发表时间：
1988
影响因子：
10.7
通讯作者：
Reneke,J
中科院分区：
文献类型：
--
作者：
Maeda,N;Wu,CI;Bliska,J;Reneke,J
从大猩猩、猩猩、恒河猴和蜘蛛猴中克隆了位于β-珠蛋白基因簇中的β-珠蛋白和δ-珠蛋白基因之间的3.1 kb基因间DNA片段，并测定了每个片段的核苷酸序列。构建了这四个序列的同源性，以及先前发表的来自人类的两个等位基因序列和来自黑猩猩的一个等位基因序列，并分析了该区域突变的积累。碱基替换的位点在该区域内不是均匀分布的：两个Alu重复序列累积了0.21 ± 0.02个替换/位点，在片段的其余部分中累积了0.15 ± 0.008个替换/位点。如果相邻位点是独立的，那么在相邻位点发生替换比预期的更频繁。当排除祖先-CG-二核苷酸位点时，观察到的过量消失。序列的系统发育关系表明，人类序列与黑猩猩序列共享最近的共同祖先。数据还显示，类人猿在这部分基因组中积累的突变比恒河猴少。在灵长类进化过程中，该区域12种核苷酸替换的相对累积速率在DNA链中是不对称的。根据这些积累速率，推断3.1-kb片段3'端附近的一段简单序列的起源是在一条链上包含50% T和50% C的序列。在3.1 kb区域中的两个方向相反的Alu序列在新世界猴与其他谱系分化之前插入到它们现在的位置。我们的分析表明，蜘蛛猴的两个Alu重复序列的核苷酸序列是出乎意料的相似，彼此和推导的祖先序列的Alu重复。这些数据表明，蜘蛛猴Alu重复序列之间存在某种类型的重组事件，但这不是简单的基因转换。
A 3.1-kb intergenic DNA fragment located between the psi beta-globin and delta-globin genes in the beta-globin gene cluster was cloned from gorilla, orangutan, rhesus monkey, and spider monkey, and the nucleotide sequence of each fragment was determined. The phylogeny of these four sequences, together with two previously published allelic sequences from humans and one from chimpanzee, was constructed, and the accumulation of mutations in the region was analyzed. The sites of base substitutions are not evenly distributed within the region: two Alu repeats have accumulated 0.21 + 0.02 substitutions/site with 0.15 + 0.008 substitutions/site in the remainder of the fragment. The occurrence of substitutions at neighboring sites is more frequent than would be expected if they were independent. The observed excesses disappear when ancestral -CG- dinucleotide sites are excluded. The phylogenetic relationships of the sequences indicate that the human sequence shares a most recent coancestor with the chimpanzee sequence. The data also show that great apes have accumulated fewer mutations in this part of the genome than has the rhesus monkey. The relative rates of accumulation of 12 kinds of nucleotide substitution in the region during primate evolution are asymmetric in the DNA strands. From these rates of accumulation, the origin of a simple stretch of sequence near the 3' end of the 3.1-kb fragment was deduced to be a sequence comprising 50% T and 50% C on one strand. The two oppositely oriented Alu sequences in the 3.1-kb region were inserted at their present positions before the divergence of the New-World monkeys from other lineages. Our analysis shows that the nucleotide sequences of the two Alu repeats in spider monkey are unexpectedly similar both to each other and to the deduced ancestral sequence of Alu repeats. The data suggest that there has been some type of recombinational event between the spider monkey Alu repeats but that it was not a simple gene conversion.