应用15个STRs揭示广西4个少数民族的遗传关系

为研究广西仫佬、毛南、苗和瑶族的15个短串联重复序列（STR）基因座的遗传多态性,探讨这4个民族群体的遗传差异和进化关系。通过PCR-STR及测序仪,检测了广西4个民族766例无关个体的15个STR位点基因频率的分布并比较各民族间的差异,计算遗传学参数、遗传距离和构建系统进化树。结果显示：仫佬、毛南、苗和瑶族的15个STR位点分别共检出135,134,148,145种等位基因和424,432,445,436种基因型;各民族的平均Ho〉0.7,累积DP,EPP和PIC均在0.99999以上;毛南族和苗族,瑶族和其他民族间在多数位点的基因频率分布上存在显著差异,而仫佬族和毛南族或苗族间在多数位点上不存在差异;4个民族在进化树上被分为两组,仫佬族和毛南族聚成一组,苗族和瑶族聚成另一组。说明广西仫佬、毛南、苗和瑶族的15个STR基因座具有高度的遗传多态性,实用价值较高,是一组可用于人类群体遗传学、法医学个体识别和亲子鉴定等研究的有力工具;4个民族STR的遗传差异性和遗传关系与他们的语言文化和民族历史基本一致。

Genetic Relationships Among Four Minorities in Guangxi Revealed by Analysis of 15 STRs

The aim of this study is to investigate the genetic diversity in 15 STRs (short tandem repeats) loci of four minorities in Guangxi Province and to probe into the genetic variation and relationships among these ethnic groups. Allele frequencies of 15 STR loci were collected from 766 unrelated Mulao, Maonan, Miao, and Yao ethnic individuals by PCR-STR and sequencing, and their allele-frequency distribution were compared with each other. The genetic parameters and genetic distances were calculated, and the phylogenetic tree was constructed. Based on the results from this study, 135, 134, 148, and 145 alleles and 424, 432, 445, and 436 genotypes for 15 STR loci were observed in the Mulao, Maonan, Miao, and Yao minorities, respectively. The average heterozygosity of all ethnic groups analyzed was above 0.7;the cumulative power of discrimination (DP), the probabilities of paternity exclusion (EPP), and the polymorphic information content (PIC) were greater than 0.99999. Comparison of the allele-frequency distribution indicated that there were significant differences at most loci between Maonan vs. Miao, Yao vs. other groups, but no distinct differences between Mulao vs. Maonan, and Mulao vs. Miao minorities. The NJ tree based on the genetic distance showed that the four minorities were separated into two groups. Mulao and Maonan were clustered into one group, whereas Miao and Yao into the other. Our results revealed that 15 STR loci of the four minorities possessed high genetic diversities. Therefore, the combination of these 15 STRs is a powerful tool for forensic individual identification and paternity investigation, as well as anthropologic and genetic researches. The genetic variation and relationships among the 4 populations revealed by 15 STRs are basically consistent with their linguistic culture and ethical history.