湖南土家族群体X染色体10个STR位点的遗传多态性及法医学应用价值评估

对198名湖南土家族健康无关个体抽取静脉血, 提取DNA, 经PCR扩增, 变性聚丙烯酰胺凝胶电泳, 银染进行等位基因分型; 软件SPSS13.0计算各位点基因型频率和等位基因频率, 进行Hardy-Weinberg平衡检验, 并检验基因分布差异有无统计学意义; Fstat软件计算基因多态性及固定指数; Powerstats软件计算各种法医学应用指标。在湖南土家族群体中, 共检出65个等位基因, 频率分布在0.0048～0.6170之间; 10个X-STR位点中DXS6789、DXS6799、HPRTB位点的多态性和分化程度较低; DXS7133、DXS7423位点的法医学应用价值较低; 位点比较中, 湖南土家族群体与德国、意大利群体的差异最明显。DXS6804、DXS7132、DXS7130、DXS8378、DXS6789、DXS6799、DXS7424、HPRTB等8个位点在湖南土家族群体的个体识别和女孩的亲权鉴定中有应用价值, 对疾病相关研究有实际意义; 差异性检验结果揭示高加索人种与蒙古人种间存在着较大的差异性。

Genetic polymorphisms of ten X chromosome STR loci in Hunan Tujia population and their forensic evaluation

Genomic DNA was extracted from whole blood of 198 unrelated health individuals of Tujia ethnic group from south China's Hunan Province. Genotyping and detection of PCR products were carried out on denaturing polycrylamide gel electrophoresis followed by silver staining. Allele frequencies and genotype frequencies were computed. Deviation from Hardy-Weinberg equilibrium and differences of gene distribution were examined by SPSS 13.0. Fixation index, genetic polymorphism and indices of forensic application were calculated using Fstat and Powerstats, respectively. The results revealed that the frequencies of 65 alleles were distributed from 0.0048 to 0.6170. Among the ten X-STR loci, DXS6789, DXS6799 and HPRTB presented lower diversity and differentiation, while DXS7133 and DXS7423 showed lower value in forensic application. Results of multiple comparisons by loci showed that difference between German, Italian and Tujia population were the most dominant, and it suggested that great genetic differences did exist between Caucasian and Mongo-lian. In conclusion, DXS6804, DXS7132, DXS7130, DXS8378, DXS6789, DXS6799, DXS7424 and HPRTB had a good value in forensic identification, paternity testing of female and disease related study for Tujia population.