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

人类的微卫星D14 S299（wglc 5）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被报道。对D14 S299直向同源基因的微卫星进行PCR扩增，所用引物与来自19种非人灵长类动物的引物相同，所述19种非人灵长类动物代表3种猿、8种旧世界猴、6种新世界猴和2种原猴。PCR产物从除原猴外的所有物种样品中获得。我们测定了3种猿类（普通黑猩猩、白掌长臂猿和敏捷长臂猿）和7种旧世界猴（狒狒、非洲绿色猴、猕猴、短尾猕猴、食蟹猕猴、恒河猴和日本猕猴）的每个等位基因的核苷酸序列。并与人的序列进行比较。人类的三个重复区（GGAT或GGAA）在所检测的卡他鼻灵长类的所有等位基因中是保守的。在人类和黑猩猩中仅重复两次的重复GGAT单位的数目在其它灵长类动物中增加到3 ~ 11个。还观察到一些种或属特异性的核苷酸替换和/或四核苷酸重复单元的插入/缺失。这些结果被总结并发表在DNA多态性。今年，D14 S299的直系同源基因从另外三种猿类（侏儒黑猩猩、大猩猩和猩猩）中测序出来。在这些物种中也观察到与卡他鼻灵长类相同的形状可变重复序列。在人类谱系中发生了单核苷酸取代。这项研究表明，微卫星D14 S299存在于猿和旧世界猴中，并且重复区域的共同结构在卡他灵长类中是保守的。我们现在正在尝试通过在给定的系统发育树上定位科、属或种的特异性差异来进行进化分析。

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.