Screening And Typing Of High Informative Y-SNP Loci In East China Han Population

Objective To screen out Y-SNP loci with high information content in East China Han population,a Y-SNP typing method was established by combining multiplex PCR,mass spectrometry and microsequencing techniques,which could provide a typing platform for the identification of special genetic relationships.At the same time,the applicability of microsequencing method in detecting mixed DNA samples of men and women was discussed.And accumulating the genetic data of Y-SNP population in China.Material Under the principle of informed consent,343 blood samples of unrelated males of East China Han population and 23 pairs of Y-STR mutant paternal blood samples were collected,stored at 4? for reserve.Male DNA standard samples 9948 and 2800 M were used as positive control.Mixed samples in the experiment were made of male DNA standard 9948 and female DNA standard 9947 A.Methods According to Y-SNP information in Y-chromosome phylogenetic tree and bioinformatics database(NCBI),71 Y-SNP loci with polymorphism in East Asian population were selected for typing by multiplex PCR and mass spectrometry.Nearly 30 loci with moderate and high information content were screened out from these loci.Multiplex PCR and microsequencing-based SNPshot typing techniques were established for Y-SNP typing of homologous paternal individuals(biological fathers and sons,brothers,uncles and grandchildren,etc.)and their genetic stability was analyzed.In addition,in order to evaluate the possibility of using this method to test rape cases,Y-SNP typing of mixed DNA samples of men and women(mixed in proportion of 1:1,1:4,1:9 and 1:19)was carried out to investigate whether the results of male component typing were interfered by female substances.Results Population genetic data of 71 Y-SNP loci were obtained.Statistical analysis showed that 18 loci were highly informative in East China Han male population(GD?0.3),32 loci with moderate information(0.2?GD<0.3).In order to promote this application of technical means in various forensic biology laboratories,29 Y-SNP loci were finally selected,and multiplex PCR technology and SNPshot typing technology based on microsequencing principle were established.All the 29 loci(rs9785908?rs9786247?rs2267801?rs17269816?rs17276358?rs9786707?rs2032678?rs11096432?rs2032674?rs13447354?rs17276345?rs17842387?rs16980363?rs17269928?rs2032665?rs9306848?rs4589047?rs16980610?rs16980641?rs2075640?rs9306845?rs9786502?rs16980601?rs17174528?rs16980426?rs17316592?rs11096433?rs52812045?rs2075181)showed high polymorphism(GD?0.2),A total of 64 haplotypes were detected.For Y-STR mutation cases(father and son,brother,uncle and nephew,grandson,etc.),multiplex PCR amplification and SNPshot analysis were used to detect 29 Y-SNP loci,The results of typing were consistent,proved the genetic stability of SNP loci.With regard to mixed samples of men and women,the classification of male samples can be obtained under four mixing ratios(1:1,1:4,1:9,1:19),and the results are clear and reliable.Conclusion In this study,polymorphic Y-SNP loci suitable for paternity identification and individual identification in East China Han population were screened from Y chromosome,and mass spectrometry typing method was established.The micro-sequencing method established by the final selection of 29 loci is applicable to the practice of forensic evidence schools,and can play an important role in the identification of some difficult cases.At the same time,the technology and methods established in this project will help to improve the DNA database and anthropological research in China,and can be applied to many research fields such as population migration and evolution,population history and family changes.