POSTER NO: 594

Studies of DNA Polymorphism in Tibetan, Dongxiang, Hui and Han Ethnic Groups from the East Edge of Tibetan-Plateau

Xie Xiaodong
Gene Institute of Northwest Ethnic Groups, Lanzhou University, Lanzhou University, Lanzhou 730000, China

The frequency distribution of 2 variable number of tandem repeat (VNTR) loci (D1S80 and apoB) and 9 short tandem repeats (STRs) loci (D16S539, D7S820, D13S317, HUMF13A01, FESFPS, vWA, HUMTH01, TPOX, and CSF1PO) were investigated in Tibetan, Dongxiang, Hui and Han ethnic groups from the east edge of Tibetan-Plateau where many ethnic groups live in a vast area since ancient times ,but few data of population genetics were reported. The technique of amplified fragment length polymorphism (Amp-FLP) was employed for VNTRs locus and the multiplex polymerase chain reaction (PCR), followed by a denaturing polyacrylamide gel electrophoresis (PAGE) and silver staining was used for STRs. The distributions of genotypes in these polymorphisms studied were in agreement with expected values according to Hardy-Weinberg equilibrium. The heterozygosity, the power of discrimination (PD), the paternity exclusion (Pe) and the polymorphism information content (PIC) values were calculated. These statistical scores were found to be highly informative in these populations and proved the loci studied in this paper to be good molecular genetic markers. Based on the allele frequencies of six STR loci, the genetic distances among 21 populations were computed and the phylogenetic tree was constructed. The results showed that these STR loci meet the thesis of neutral mutation-random drift. The phylogenetic relationship revealed by data of D13S317 and HUMTH01 loci agree generally well with the results from anthropological, historical and linguistic studies. They could be used to study population mixture and immigration. Furthermore, the Caucasian associated allele was tested in several of the minorities living in Northwest China. The amounts of Caucasian admixture were estimated beyond 25% only in Hui and Dongxiang. The presence of Caucasian admixture was attributed to the Caucasians living in Central Asia throughout the military activities of Mongolian army during the initial Mongolian Yuan Dynasty. On the basis of these data, the paper discussed the possible origin of Hui and Dongxiang ethnic groups, while the clustering analysis revealed that Tibetan always cluster with the northern Han, Hui, and Dongxiang, suggesting that Tibetan originated from north China.