Abstract: The genetic polymorphisms of micro satellite loci, DXYS156Y on the Y chromosome and DXYS156X on the X chromosome were studied by using PCR method follow ed by PAGE, in 520 males of 10 populations ( 2 Han subpopulations and 8 ethnic minorities) in China. The result shows that the ten alleles with different length fragments were found in Chinese populations surveyed. Among them, five are alleles 130bp, 135bp, 140bp, 145bp, 150bp on the X chromosome, and the others are alleles 160bp, 165bp, 170bp, 175bp, 180bp on the Y chromosome. The locus DXYS156Y has a high polymorphic information content, and the allele 165bp with the frequency range from 0. 23— 0. 77 is predominant in Chinese populations, followed by alleles 160bp, 170bp, and 175bp with the frequency range from 0. 02— 0. 36, 0. 01— 0. 50 and 0. 03— 0. 31, respectively, while the allele 180bp takes the last place with the frequency range from 0. 02— 0. 05. The DXYS156X has a low information content, and the allele 140bp, with the frequency range from 0. 86— 0. 98, is the most common type, while the other alleles have a quite low frequencies. The allele frequency of DXYS156Y in Chinese populations and that of DXYS156X in human populations have not been reported so far.

Key words: Chinese, Microsa tellite DNA, DXYS156, Genetic polymorphism