The construction and application of a new 17-plex Y-STR system using universal fluorescent PCR

Abstract

Y-chromosomal short tandem repeat (Y-STR) polymorphisms are useful in forensic identification, population genetics and human structures. However, the current Y-STR systems are limited in discriminating distant relatives in a family with a low discrimination power. Increasing the capacity of detecting Y chromosomal polymorphisms will drastically narrow down the matching number of genealogy populations or pedigrees. In this study, we developed a system containing 17 Y-STRs that are complementary to the current commercially available Y-STR kits. This system was constructed by multiplex PCR with expected sizes of 126-400 bp labeled by different fluorescence molecules (DYS715, DYS709, DYS716, DYS713 and DYS607 labeled by FAM; DYS718, DYS723, DYS708 and DYS714 labeled by JOE; DYS712, DYS717, DYS721 and DYS605 labeled by TAMRA; and DYS719, DYS726, DYS598 and DYS722 labeled by ROX). The system was extensively tested for sensitivity, male specificity, species specificity, mixture, population genetics and mutation rates following the Scientific Working Group on DNA Analysis Methods (SWGDAM) guidelines. The genetic data were obtained from eight populations with a total of 1260 individuals. Our results showed that all the 17 Y-STRs are human- and male-specific and include only one copy of the Y-chromosome. The 17 Y-STR system detects 143 alleles and has a high discrimination power (0.996031746). Mutation rates were different among the 17 Y-STRs, ranging from 0.30% to 3.03%. In conclusion, our study provides a robust, sensitive and cost-effective genotyping method for human identification, which will be beneficial for narrowing the search scope when applied to genealogy searching with the Y-STR DNA databank.