Forensic Science Study Of The Three Y-STR Loci

Objective The biomarker's polymorphism in Y-chromosome is lower than those in autosomes. More biomarkers are requested for further genetic analysis. We selected the candidate of Y-STRs loci from GDB Database, and investigated the Y-STRs allelic frequencies and haplotype diversity in Chinese Han population of Shanxi. Their applicability in forensic casework were evaluated.Methods (1) EDTA-treated blood samples were collected from 120 healthy unrelated males in Chinese Han population of Shanxi. The blood of 20 females were collected as negative control. 20 families, different male animals and different tissues (including blood, muscle, et al) of one corpse were analyzed. (2)Genomic DNA was extracted via the method of phenol-chloroform. Primers sequences were synthesize according to GDB, and used to amplify the target DNA. (3)After PCR amplification, analyze the PCR products by non-denaturing polyacrylamide gel electrophoresis (PAGE) followed by silver-staining. (4)Calculate the forensic parameters.Result Six alleles are found in DYS708 locus in 120 Chinese Han population of Shanxi, which are named that DYS708*24,DYS708*25,DYS708*26,DYS708*27,DYS708*28,DYS708*29 .The frequencies of DYS708 are 0.125,0.142,0.267,0.208, 0.150,0.108, respectively. And the Gene Diversity (GD) value is 0.823, both discrimination power (DP) and probability of exclusion (PE) are 0.823 in forensic medicine. No PCR products was observed in 20 female blood, and no mutation was found in 20 father-son pairs. The typing results of different tissues were identical. The locus were specific to the human species. One allele of DYS724 is found in 32 samples,two alleles in 68 samples,three alleles in 20 samples,sequence of DYS724 can not be detected. PCR products of DYS725 have two bands in PAGE,and without genetic polymorphism.Conclusion The DYS708 locus are highly genetic polymorphism and stability. The data obtained can be used in individual identification, paternity test and population genetics investigation for Chinese Han population of Shanxi. DYS724,DYS725 locus are lowly genetic polymorphism, and can not be used as an according in individual identification, paternity test and population genetics investigation. Objective The biomarker's polymorphism in Y-chromosome is lower than those in autosomes. More biomarkers are requested for further genetic analysis. We selected the candidate of Y-STRs loci from GDB Database, and investigated the Y-STRs allelic frequencies and haplotype diversity in Chinese Han population of Shanxi. Their applicability in forensic casework were evaluated.Methods (1) EDTA-treated blood samples were collected from 120 healthy unrelated males in Chinese Han population of Shanxi. The blood of 20 females were collected as negative control. 20 families, different male animals and different tissues (including blood, muscle, et al) of one corpse were analyzed. (2)Genomic DNA was extracted via the method of phenol-chloroform. Primers sequences were synthesize according to GDB, and used to amplify the target DNA. (3)After PCR amplification, analyze the PCR products by non-denaturing polyacrylamide gel electrophoresis (PAGE) followed by silver-staining. (4)Calculate the forensic parameters.Result Four,five,six,six,eight,six,six,five,five,five,four,five,five,four alleles are found in 12 Y-STR loci in Chinese Han population of Shanxi, which are named that DYS650*14,DYS650*15,DYS650*16,DYS650*17;DYS651*7,DYS651*8,DYS651*9,å’ŒDYS651*10,DYS651*11 ; DYS708*24,DYS708*25,DYS708*26,DYS708*27,DYS708*28,DYS708*29;DYS711*60,DYS711*63,DYS711*65,DYS711*68,DYS711*70,DYS711*74;DYS713*36,DYS713*38,DYS713*40,DYS713*42,DYS713*44,DYS713*46;DYS714*10,DYS714*11,DYS714*12,DYS714*13,DYS714*14,DYS714*15;DYS715*12,DYS715*13,DYS715*14,DYS715*15,DYS715*16;DYS716*15,DYS716*16,DYS716*17,DYS716*18,DYS716*19;DYS717*18,DYS717*19,DYS717*20,DYS717*21,DYS717*22;DYS718*14,DYS718*15,DYS718*16,DYS718*17; DYS721*9,DYS721*10,DYS721*11,DYS721*12å’ŒDYS721*13;DYS723*10,DYS723*11,DYS723*11,å’ŒDYS723*13,DYS723*14; DYS726*11,DYS726*12,DYS726*13,DYS726*14; The frequencies of 12 Y-STR loci see table14. The gene diversity values of the Y-STRs loci ranged from 0.730(DYS650) to 0.831 (DYS711). A total of 120 haplotypes were identified in the Y-STR loci, which 120 were unique. The observed haplotype diversity value and discrimination capacity were 0.99. No PCR products was observed in 20 female blood, and no mutation was found in 20 father-son pairs. The typing results of different tissues were identical. The two loci were specific to the human species.Conclusion The Y-STR loci are highly genetic polymorphism and stability. The data obtained can be used in individual identification, paternity test and population genetics investigation for Chinese Han population of Shanxi.