[The polymorphism of four Y-STR loci and its application in forensic medicine].

We have obtained the alleles and haplotype distribution of 100 unrelated males from the Chinese Han and Zhuang populations at the four Y chromosome-specific loci A10, C4, A7.1, A7.2 by fluorescent primers and with 377 DNA sequencer. We observed 7, 6, 6, 6 alleles in loci A10, C4, A7.1, A7.2 respectively, the gene diversity (GD) values are 0.7776/0.629, 0.773/0.732, 0.5978/0.7272, 0.6664/0.6458 (Zhuang/Han). 114 haplotypes were found in 200 males, haplotype diversity (HD) values are 0.9786, 0.9772 (Zhuang/Han). We have confirmed the core repeats and its repeating number of these alleles by sequencing. A tetraplex PCR system consisting of the A10, C4, A7.1 and A7.2 loci was set up and it is of good specificity. We investigated the validation at these four Y-STRs loci in forensic application such as the male specificity, genetic stability and the sensitivity. In conclusion, the four Y-STRs loci are very suitable to forensic medicine analysis and paternity test.