Abstract: To study the polymorphism of mitochondrial DNA(mtDNA) region in Dong、Gelao、Tujia and Yi ethnic population from Guizhou. Method The region sequences in total of 108 samples from four ethnic populations were analyzed by polymerase chain reaction and polyacrylamide gel electrophoresis ( PCRPAGE) and clonal sequencing. Result Only two kinds of polymorphism were found in these populations. One was standard patter, the other was short patter( namely9bp deletion). The average frequency of 9bp deletion in four ethnic populations from Guizhou was 22.2%, and the frequencies of 9bp deletion in Dong、Gelao、Tujia and Yi population were 32.1%、 22.6%、17.2% and 15.0% respectively. Conclusion The frequencies of 9bp deletion are higher in four ethnic populations from Guizhou, which is consistent with their regional distribution, the frequencies of deletion in Tujia and Yi population are similar, this suggests they might originate from a common ancestry.

Key words: Ethnic populations in Guizhou; Mitochondrial DNA; Genetic polymorphism