Population genetic study of 34 X-Chromosome markers in 5 main ethnic groups of China.

Suhua Zhang,Yuzhen Gao,Lagabaiyila Zha,Li Li,Jifeng Cai,Kuan Sun,Zheng Wang,Qi Zhao,Chaoneng Ji,Yingnan Bian,Chengtao Li

doi:10.1038/srep17711

Abstract

As a multi-ethnic country, China has some indigenous population groups which vary in culture and social customs, perhaps as a result of geographic isolation and different traditions. However, upon close interactions and intermarriage, admixture of different gene pools among these ethnic groups may occur. In order to gain more insight on the genetic background of X-Chromosome from these ethnic groups, a set of X-markers (18 X-STRs and 16 X-Indels) was genotyped in 5 main ethnic groups of China (HAN, HUI, Uygur, Mongolian, Tibetan). Twenty-three private alleles were detected in HAN, Uygur, Tibetan and Mongolian. Significant differences (p < 0.0001) were all observed for the 3 parameters of heterozygosity (Ho, He and UHe) among the 5 ethnic groups. Highest values of Nei genetic distance were always observed at HUI-Uygur pairwise when analyzed with X-STRs or X-Indels separately and combined. Phylogenetic tree and PCA analyses revealed a clear pattern of population differentiation of HUI and Uygur. However, the HAN, Tibetan and Mongolian ethnic groups were closely clustered. Eighteen X-Indels exhibited in general congruent phylogenetic signal and similar cluster among the 5 ethnic groups compared with 16 X-STRs. Aforementioned results proved the genetic polymorphism and potential of the 34 X-markers in the 5 ethnic groups.

Highlights

Identification of the genetic information of populations is an important task for which different types of genetic markers can be used, including autosomal[1,2], mtDNA2,3, Y-Chromosome[2,3,4] and X-Chromosome[5,6,7]
34 X-Chromosomal markers (16 X-STRs and 18 X-Indels) of 500 samples from 5 main ethnic groups of China were genotyped for 100 individuals in each ethnic group (50 females and 50 males)
16 X-STRs and 18 X-Indels were detected with same PCR components and PCR conditions in 5 main ethnic groups of China

Summary

Introduction

Identification of the genetic information of populations is an important task for which different types of genetic markers can be used, including autosomal[1,2], mtDNA2,3, Y-Chromosome[2,3,4] and X-Chromosome[5,6,7]. Growing number of scientists is becoming interested in X-Chromosome research, using X markers (X-STRs, X-SNPs and more recently X-Indels) for studying the genetic structure of human populations, ancestry proportions in admixed populations as well as for forensic investigations[5,6,7,8,9]. A set of 34 X- chromosomal markers (16 X-STRs and 18 X-Indels) was evaluated in the 5 main ethnic groups of China. The aim was to obtain detailed genetic information of the 34 X-Chromosome markers and to improve the current knowledge on the genetic background of the 5 ethnic groups of China

Methods

Results

Conclusion