2个新Y-STR基因座的序列分析和在广东汉族群体中的多态性研究

分析了Y染色体2个新STR基因座DYS522和DYS527的序列结构及其在151例广东汉族男性无关个体中的遗传多态性。结果显示, DYS522基因座为单拷贝, 核心序列gata, 观察到重复数目为9~13次。DYS527基因座有双拷贝, 每一个拷贝的序列结构有6个稳定的重复序列和2个数目变异的重复序列, 如(GGAA)₃…(GGAA)₂…(GGAA)₂…(GGAA)₃…(GGAA)₄…(GGAA)₃…(GAAA)_m(GGAA)_n。在广东汉族男性群体中观察到2个数目变异的核心序列重复总数目(m+n)为18~26次。还发现1个稀有的拷贝“15.3”。在广东汉族男性群体中, 2个基因座所组成的单倍型有63种, 出现最多的单倍型为11/21-22, 频率为0.0728, 仅出现1次的单倍型有29种, 频率为0.0066。本系统单倍型多样性(HD)为0.9780, 个体识别力(DP)达0.9715。在38对父子遗传中未发现DYS522和DYS527基因座发生变异。这2个Y-STR具有种属差异, 能够区分“男人”和“非人”雄性动物。因此, DYS522和DYS527基因座具有高度的多态性, 适用于法医学实践和人类进化的研究。

Sequence Analysis of DYS522 and DYS527 Loci and Their Genetic Polymorphism Among Guangdong Han Population

Analyzed the sequence characteristics and the genetic polymorphism of two new Y-STR loci: DYS522 and DYS527, in 151 unrelated Han males in the Guangdong Province. The results show that the DYS522 locus consists of repeats of a core sequence (GATA), with the number of repeats ranging between 9 and 13. The DYS527 locus contains two copies of a sequence motif. This motif has the following modular structure: (GGAA)3...(GGAA)2...(GGAA)2...(GGAA)3...(GGAA)4...(GGAA)3...(GAAA)m(GGAA)n, where the value of (m + n) ranges between 18 and 26 among different individuals. A rare copy with 15.3 (m+n) repeats was found. Altogether, 63 different haplotypes of these two loci were identified. Of these, 29 occurred only once, with a frequency of 0.0066, and the most common haplotype occurred at a frequency of 0.0728. This system has a haplotype diversity (HD) of 0.9780, and a discriminating power (DP) of 0.9715. The analysis of 38 father/son pairs has detected no mutation event at the DYS522 and DYS527 loci within any pair. It is found that these two loci are specific to the human species. These results indicate the DYS522/DYS527 loci to be highly polymorphic and useful genetic markers in forensic science and human evolution studies.