Abstract: Objective To explore the mutation of Y-STR loci in meiotic allelic transmission in a large pedigree. Methods The oral swabs of 163 male individuals were collected from a Lin pedigree. Twenty-two Y-STR genetic markers were typed with AGCU Y24 fluorescent detection kit （AGCU Y24 system）, which also contained 16 Y-STR markers included in YfilerTM multiple amplification kit （Yfiler system）. The genotyping results of Y-STR loci were compared between each two males in the pedigree. Results There were 20 and 30 kinds of haplotypes obtained with Yfiler and AGCU Y24 systems in 163 male individuals from the Lin pedigree, respectively. The rates referred to haplotype differences （RRHD） of these two typing systems between male pairs were 0.910 5 and 0.922 7, respectively. The average number of marker differences were 6.582 1 and 9.824 8, respectively. The RRHD increased along with the incidents of meiosis. Conclusion Y-STR mutation leads to different Y-STR haplotypes among the male members in a paternal pedigree and the rate of difference increases along with the incidents of meiosis.

Key words: forensic genetics, mutation, genetic markers, Y-STR, pedigree