Human evolutionary study on nucleotide sequence polymorphisms of a microsatellite in primates

人类微卫星D14S299(Wglc5)基因座具有可变重复序列(GGAT或GGAA)，日本人群中的核苷酸序列多态性已有报道。用与人类相同的引物对D14S299上的微卫星进行了扩增，它们来自19个非人类灵长类物种，分别代表3种猿类、8种东半球猴、6种新大陆猴和2种原猴。除原猴外，所有物种样品均可获得扩增产物。我们测定了3种灵长类动物(普通黑猩猩、白手长臂猿和灵巧长臂猿)和7种旧大陆猴(恒河猴、非洲绿猴、短尾猴、短尾猴、食蟹短尾猴、恒河猴和日本短尾猴)各等位基因的核苷酸序列。将序列数据与人类的序列数据进行比较。在卡特拉斯灵长类动物的所有等位基因中，人类的三个重复区域(GGAT或GGAA)是保守的。重复的GGAT单位在人类和普通黑猩猩中只重复两次，而在其他猫科灵长类动物中增加到3到11个。还观察到一些种或属特异的核苷酸替换和/或四核苷酸重复单位的插入/缺失。这些结果被总结并发表在《DNA多态》杂志上。在这一年，D14S299的同源序列是从另外三个类人猿物种(侏儒黑猩猩、大猩猩和猩猩)中测得的。在这些物种中也观察到了与卡他灵长类相同的形式可变重复。在人类谱系中发生了单核苷酸替换。这项研究表明，微卫星D14S299存在于猿类和东半球猴子中，而重复区域的共同结构在卡他灵长类动物中是保守的。我们现在正在尝试通过在给定的系统发育树上定位特定于科、属或种的分化来进行进化分析。

A microsatellite D14S299 (wglc5) locus, in human has the variable repeats (GGAT or GGAA), and the nucleotide sequence polymorphisms in the Japanese population has been already reported. PCR amplification of the microsatellite at the D14S299 orthologue was performed with the same primers as used in human from 19 non-human primate species representing 3 species of ape, 8 of old World monkey, 6 of New World monkey and 2 of prosimian. PCR products were obtained from all species samples except prosimian. We determined nucleotide sequences of each allele in primates including 3 ape species (common chimpanzee, white-handed and agile gibbons) and 7 old World monkey species (baboon, Africa green monkey, patas monkey, stump-tailed macaque, crab eating macaque, rhesus macaque and Japanese macaque). The sequence data were compared with those of human. Three repetitive regions (GGAT or GGAA) in human were conserved among all alleles of catarrhine primates examined. The number of repetitive GGAT unit, which repeated only twice in human and common chimpanzee, increased as 3 to 11 in other catarrihine primates. Some species-or genus-specific nucleotide substitutions and/or insertions/deletions of tetranucleotide repeat unit were also observed. These results were summarized and published in DNA Polymorphism. in this year, the D14S299 orthologue was sequenced from three more ape species (pygmy chimpanzee, gorilla and orangutan). Form variable repeats as same as catarrhine primates were also observed in those species. A single nucleotide substitution occurred in the human lineage. This research has revealed that the microsatellite D14S299 is present in apes and Old World monkeys, and the common structures of the repeat regions are conserved among catarrhide primates. We are now trying the evolutionary analysis by locating the family-, genus- or species-specific differentiations on a given phylogenetic tree.