灵长类动物的线粒体DNA序列:节奏和方式进化。
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布朗WM普拉格EM,王,威尔逊AC
灵长类动物的线粒体DNA序列:节奏和方式进化。
J摩尔另一个星球。1982;18 (4):225 - 39。
- PubMed ID
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6284948 (在PubMed]
- 文摘
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我们克隆和测序一段从人类线粒体DNA,黑猩猩,大猩猩,猩猩和长臂猿。这段是896 bp的长度,包含了三个基因转移rna和部分两个蛋白质,和在所有5灵长类动物同源。5序列之间相差基地替换在283个职位和一个碱基对的缺失。序列物种间差异的范围从9 19%,同意估计乳沟地图比较,从而确认mtDNA进化的速度在灵长类动物核DNA的5到10倍。最引人注目的新发现摆脱这些比较是转换大大超过颠换。百分之九十二的差异最密切相关的物种(人类、黑猩猩和大猩猩)转换。对物种分化较长的时候,观察到的转换比例下降,直到在灵长类动物和非灵长类之间的比较,它到达45的值。时间依赖性可能是由于删除的记录转换由多个核苷酸替换的站点。这一发现说明了选择的重要性密切相关的物种进化过程的分析。卓越的倾向过渡mtDNA进化需要正确的修正方程多个替换在同一站点。 With revised equations, we calculated the incidence of silent and replacement substitutions in the two protein-coding genes. The silent substitution rate is 4 to 6 times higher than the replacement rate, indicating strong functional constraints at replacement sites. Moreover, the silent rate for these two genes is about 10% per million years, a value 10 times higher than the silent rate for the nuclear genes studied so far. In addition, the mean substitution rate in the three mitochondrial tRNA genes is at least 100 times higher than in nuclear tRNA genes. Finally, genealogical analysis of the sequence differences supports the view that the human lineage branched off only slightly before the gorilla and chimpanzee lineages diverged and strengthens the hypothesis that humans are more related to gorillas and chimpanzees than is the orangutan.