Polymorphisms and microvariant sequences in the Japanese population for 25 Y-STR markers and their relationships to...

Y-chromosomal short tandem repeat (Y-STR) markers have been used for forensic purposes such as kinship analysis of male-linage and detection of a male DNA component in a mixture of male and female DNA. Recently, rapidly mutating Y-STR (RM Y-STR) markers were reported that are expected to help distinguish close male relatives. This study provides data of Y-chromosomal haplotypes for 25 Y-STR markers, including six RM Y-STR markers (DYS576, DYS627, DYS518, DYS570, DYS449 and DYF387S1) typed with the Yfiler™ Plus kit in 1299 males of the Japanese population. Discrimination capacity increased from 87.2% for 16 Y-STR markers with the Yfiler™ kit to 99.6% for 25 Y-STR markers with the Yfiler™ Plus kit. We characterized sequences of observed microvariant alleles of eight Y-STR markers and a low-amplified allele of DYS390 by Sanger sequencing. DYF387S1, a multi-locus Y-STR marker that is located at two positions on the human Y-chromosome, was observed in tri-allelic patterns in 51 of 1299 samples (3.9%) and we found an extremely high frequency of the tri-allelic pattern of DYF387S1 in haplogroup C-M131. We also analyzed Y-STR gene diversity in each haplogroup and its relevance to mutation rates.