OBJECTIVETo understand the genetic polymorphism and population difference of locus DYF155S1 on human Y chromosome.

METHODSUsing minisatellite variant repeat mapping-polymerase chain reaction (MVR-PCR), automated fluorescence detection, DNA sequence analysis, the authors studied the locus DYF155S1 of two chimpanzee and 10 human subjects from each of the following 8 groups: Northern China Hans, Southern China Hans, the Zang (Tibetan) nationality, the Uighur nationality, Japanese, Korean, Black African, White African.

RESULTSIn this study, loci DYF155S1 and DYF155S2 have been detected. There is no difference in all of the samples on the locus DYF155S2; each sample contains one type 4 repeat unit, which is the ancestor gene of locus DYF155S1. On locus DYF155S1, each individual has its specific DNA sequence. The arrangement of the repeat units differs greatly in races: arrangement 3134 in the yellow race, arrangement 134 in the white race, and arrangement null3a1a4a4 in the black race were most common. The average number of the type 4 repeat unit in the white race is much higher than that in the yellow race. The authors also found two new types of repeat unit: type 6 and type 7. Type 6 is the result of the T22A substitution on type 1, which was observed in Japanese (3 samples). Type 7 is resulted from the T22A substitution on type 3, which was observed in the Zang nationality (4 samples), Southern China Hans(1 sample), and Korean (1 sample).

CONCLUSIONLocus DYF155S1 has great genetic polymorphism and obvious population difference. Its significance should receive more attention in forensic science and human genetics research.