Forensic Genetics Of Sex Marker Polymorphism Genetic Markers

During the last20years, the forensic DNA database was growing up rocketly. The genetic markers of identification technology are difficult to meet the actual needs in the massive database, so it is imperative to select new genetic markers to increase the foren-sic discrimination. As the human sexual chromosomes have curious genetic role in pop-ulation genetics, Polymorphic genetic marker system on the human sexual chromosomes has the particularly important usefulness in crime casework, paternity testing in disputed cases and in mass disaster investigations. Based on this, Other Y-STR loci are being screened and evaluated aiming to improve and supply the forensic technology.Fifteen STR genetic markers(DXS10011, DXS101, DXS165B12, DXS6795, DXS6800, DXS6801, DXS6803, DXS7132, DXS7133, DXS7423, DXS7424, DXS8377, DXS8378, DXS9898and HPRTB), located on X chromosome were selected. The pri-mers for multiplex PCR were designed by Primer Premier5.0software and labeled by four fluorescences (FAM, VIC, NED and TET). The developed multiplex PCR system was used for investigating the polymorphisms of the X-STR markers in Han, Tibetan, Uighur Zhuang and Dong populations. The thirteen STR genetic markers (DYF393S1, DYF404S1, DYS444,DYS460, DYS481,DYS510,DYS513,DYS518, DYS534, DYS543, DYS570,DYS576and DYS627), located on Y chromosome were selected. The primers for multiplex PCR were designed by Primer Premier5.0software and labeled by four fluorescences (FAM, VIC, NED and TET). The developed multiplex PCR system was used for investigating the polymorphisms and mutation rate of the Y-STR markers in Han population, the application of Y-STR haplotype resolution for the individuals who have the same surname.Results:the15X-STR loci were detected high polymorphism and observed perfect forensic parameters, mainly showed as the list below;(1) Genetic marker of DXS10101with highest Discrimination Power from0.928to0.953in males and from0.9575to0.9908in females, respectively;(2) Cumulative Probability of Exclusion (CPE) of15X-STR markers in trios range from0.99999990to0.999999994;(3) Cumulative Proba-bility of Exclusion(CPE) of15X-STR markers in duos range from0.99996to0.999998,(4)1046haplotypes of15X-STR makers were found, and no haplotype were shared among the10populations with1048male individuals, only one haplotype is twice in Tibetan population and Shandong Han population respectively;(5) the haplotype diver-sity of the15X-STR loci range from0.999942to1among the10populations.In Chinese Han population, the average genediversity of the13Y-STR was0.8684.269differen haplotypes were observed from270Han Chinese, the haplotype diversity was0.999364. For the investigation of the individuals have the same surname, among65individuals of CAO,35different haplotypes of13Y-STR were detected and the haplo-type resolution was0.5385(35:65). The haplotype resolution can reach up to0.6462(42:65) by integrating with the17Y-STR from Y-filer. Among40individuals of LAN, She enthic population from Fujian province, The haplotype resolution of13Y-STR can reach up to0.450(18:40). The haplotype resolution can reach up to0.750(30:40) by in-tegrating with the17Y-STR from Y-filer and distinguish different She males on the lev-el families within three genetions.Conclusion, The genetic markers selected by our study, located on the human sexual chromosomes have high polymorphism and highly valuable in forensic genetics and can provide considerable genetic information for forensic cases.