高变异Y染色体短串联重复片段检验体系的建立及对北方汉族群体调查

Establishment of High Mutation Y-Chromosome Short Tandem Repeat Multiplex Amplification System and Investigation on Han Nationality in Northern China

【目的】建立一套五色荧光复合扩增体系,并调查中国北方汉族遗传多态性和父子家系突变情况。【方法】根据文献筛查出在中国某一群体中突变率为高变异和快速变异的Y-STR基因座,建立一套五色荧光Y-STR复合扩增体系,计算在500个北方汉族无关男性个体中的基因多样性,观察每个样本的Y-STR单倍型,并对中国北方汉族500个父子对进行检测,统计父子间的突变情况。【结果】成功构建了包含21个Y-STR基因座复合扩增检验体系,在北方汉族群体中基因多态性在0.4023~0.9904之间,500个无关个体中未发现有相同的单倍型。在500个父子对中观察到21个Y-STR基因座共发生134次突变,其中突变率最高的基因座是DYF399S1,为7.40×10^(-2);在DYS612、DYS547、DYS627、DYS526b、DYS576、DYS630、DYS449、DYF404S1、DYS390、DYS570和DYS518基因座上突变率≥1.00×10^(-2)。此外,DYS626、DYS458和DYS439基因座突变率≥4.00×10^(-3)。有97个父子家系出现1个基因座突变,16个家系同时出现2个基因座突变,仅有1个家系同时出现3个基因座突变,家系突变的概率为0.268。其中127次为一步突变,7次为两步突变,符合逐步突变模式。【结论】高变异Y-STR基因座能够有效区分具有父系亲缘关系的男性个体,可作为联合DNA索引系统(combined DNA index system,CODIS)常染色体和常规低突变Y-STR系统基因座的补充。

【Objective】To establish a five-color fluorescence Y-chromosome short tandem repeats(Y-STRs)multiplex amplification system and investigate the genetic polymorphisms and paternal family mutations in the Chinese Northern Han population.【Methods】A total of twenty-one highly and rapidly mutating Y-STR loci were selected according to previous studies to establish a five-color fluorescence Y-STR multiplex amplification system.Genetic diversity and mutation rate were analyzed in 500 unrelated male individuals or 500 paternal(father and son)pairs separately in the Chinese Northern Han population.【Results】A multiplex amplification system containing 21 Y-STR loci was successfully established.The genetic diversity of each Y-STR ranged from 0.4023 to 0.9904,and no identical haplotypes were found in the 500 unrelated individuals.The mutation rate was 0.268,and one hundred and thirty-four mutations were observed in the 21 Y-STR loci among the 500 paternal pairs,of which the highest mutation rate was 7.40×10^(-2) at DYF399S1.The mutation rate of the loci,including DYS612,DYS547,DYS627,DYS526b,DYS576,DYS630,DYS449,DYF404S1,DYS390,DYS570 and DYS518,was≥1.00×10^(-2).Further,the mutation rate of DYS626,DYS458 and DYS439 loci was≥4.00×10^(-3).A total of ninety-seven father and son pairs were one locus mutation,sixteen pairs had two loci mutations,and only one pair had three loci mutations at the same time.A total of one hundred and twenty-seven cases were one-step mutations and seven cases were two-step mutations,which were consistent with the stepwise mutation pattern.【Conclusion】The rapidly mutating Y-STRs could effectively distinguish male individuals with paternal kinship and could be used as a complement to the Combined DNA Index System(CODIS)autosomal STRs and general Y-STRs.