西藏藏族群体15个短串联重复序列位点的遗传多态性研究

目的获得15个短串联重复（Short tandem repeat，STR）基因座在西藏藏族人群中的基因型及等位片段频率分布，获得相应位点的群体遗传学数据。方法126份EDTA抗凝血样采自西藏藏族地区无血缘关系的藏族个体。Chelex法提取DNA，PCR复合扩增，自动基因分析仪电泳收集电泳结果数据，基因扫描分析软件计算扩增产物片段相对大小，基因分型软件进行样本基因型分型。结果全部样本的每个STR基因座都获得了清晰的基因型分型结果。15个STR基因座的杂合度介于0.627-0.897之间。累计非父排除率和累计个人识别机率为0.999999527和〉0.999999999。结论经一次扩增电泳可获得15个STR基因座的基因型分型结果，累计非父排除率和累计个人识别机率较高，适用于法医学亲权鉴定和个人识别。

Study of genetic polymorphism of fifteen short tandem repeat loci in Tibetan ethnic group of Chinese population

Objective To acquire the population genetic data of fifteen short tandem repeat （STR） loci in Tibetan ethnic group of Chinese population. Methods A total of 126 EDTA -blood specimens were collected from the unrelated individuals in Tibetan ethnic group of Chinese population. The DNA samples were extracted with Chelex method and amplified by multiplex PCR technique. The PCR products were analyzed by an automatic genetic analyzer; the relative fragment＇s lengths of PCR products were calculated by genescan analysis software and afterward genotyped by genotype software. Results Fifteen STR loci of each sample showed a successful result of genotyping. The heterozygosities of the fifteen STR loci in Tibetan ethnic group were found to be 0. 627-0. 897; the combined exclusion probability and discrimination power for the fifteen STR loci in Tibetan ethnic group were determined to be 0. 999999527 and above 0. 999999999 respectively. Conclusion The distinct genotype of fifteen STR loci and the sex of sample could be unveiled just through PCR and electrophoresis once, and a higher measured value could be obtained for both the combined discrimination power and the exclusion probability. The fifteen STR loci can meet the needs of the parentage testing and personal identification in forensic medicine.