9个Y-STR基因座荧光复合扩增系统的法医学应用

Forensic Application of 9 Y-STRs Fluorescence-labeled Multiplex Amplification System

目的建立9个Y-STR基因座的复合扩增系统,提高Y-STR的法医学检测效能。方法6-FAM标记DYS434、Y-GATA-A10、DYS438、DYS439,HEX标记DYS531、DYS557、DYS448,TAMRA标记DYS456、DYS444引物,PCR复合扩增,毛细管电泳得到结果,考察扩增系统的个体识别能力、灵敏度、特异性、组织同一性。结果所建立的9个Y-STR复合扩增系统分型清晰,单倍型多样性达0.9968,特异性好,灵敏度高(0.5ngDNA),并且在男女混合斑检验上较常染色体STR分型更有优势。结论9个Y-STR复合扩增系统具有较高的识别能力,对建立Y染色体STR数据库,研究群体遗传学和进行法医学混合斑物证鉴定有重要意义。

Objective In order to increase significantly the discriminatory potential of Y-STR systems available to the forensic community, we have developed a system capable of simultaneously amplifying 9 Y-STR loci by fluorescence-labeled multiplex PCR technique. Methods Primers of STR loci DYS434, GATA-A10, DYS438 and DYS439 were labeled with 6-FAM, primers of STR loci DYS531, DYS557, DYS448 were labeled with HEX, and primers of STR loci DYS456, DYSA.44 were labeled with TAMRA, respectively. PCR products were analyzed using capillary electrophoresis and GeneScan Software on the ABI Prism310 DNA Analyzer. Series experiments were carried out to evaluate the useful value in forensic application such as the sensitivity, male specificity and genotyping DNA different tissues of the same individual. Results 9 Y-STR loci were exactly determined following optimization of the polymerase chain reaction. In a sample of 120 males, a total of 105 different haplotypes was identified, 97 of them being unique. Overall, haplotype diversity was 0.996 8. It was proved that genotyping of these 9 Y-STR loci in some sexual crime should be prior to that of automosomal STR. Conclusion The results suggest that the newly constructed 9-plex will be very powerful for establishing Y-STR database, population genetic studies and mixture stains identification.