Impact of natural selection on the polymorphism of HLA-G 3'UTR among five ethnic Chinese populations / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the impact of natural selection and genetic background on the polymorphisms of HLA-G 3-untranslated regions (UTR) among five ethnic Chinese populations.</p><p><b>METHODS</b>PCR and DNA sequencing were used to determine the polymorphisms among 432 individuals from the five ethnic populations. Their genetic background was determined by genotyping of 10 short tandem repeats (STRs).</p><p><b>RESULTS</b>Eight variations were identified among Gelao, Mongolian and Kirgiz populations, while only 7 were found in Shui and Dai people. For all 3 southern populations (Gelao, Shui, and Dai), the observed heterozygosites (Ho) was higher than expected heterozygosities (He). But this was reversed for the 2 northern populations (Mongolian and Kirgiz). The Ho and He of the 10 neutral STRs were in random distribution. Ewens-Watterson testing based on haplotypes of the HLA-G 3'UTR has suggested that a natural selection had occurred in the region where Dai and Shui had inhabited, but not in the northern region where Mongolian and Kirgiz population inhabited. Polygenetic trees based on the HLA and STRs were also different.</p><p><b>CONCLUSION</b>The HLA-G 3'UTR of Dai and Shui people who lived in southern China may have subjected to a selection pressure. Based on current knowledge, this pressure may have been driven by a pathogenic selection.</p>

The polymorphism of HLA-DRB1 and -DQB1 genes in Bai ethnic group in Yunnan province / 中国免疫学杂志

Objective:To investigate polymorphism of human leukocyte antigen (HLA)-DRB1 and -DQB1 genes in Bai ethnic group in Dali,Yunnan province.Methods:Polymerase chain reaction-sequence specific primers (PCR-SSP) were used to determine HLA-DRB1 and -DQB1 alleles in 124 unrelated healthy Bai ethnic individuals living in Eryuan County of the Dali Bai autonomous prefecture,Yunnan province.Results:Among all the 21 DRB1 alleles and 15 DQB1 alleles were identified,the predominant alleles were DRB1*1202(26.61%),DRB1*0901(13.89%) and DRB1*0803(9.92%) on DRB1 locus and DQB1*0301(31.45%),DQB1*0601(10.08%),DQB1*0401(8.06%)and DQB1*0502(8.06%)on DQB1 locus.The most common haplotypes were DRB1*1202-DQB1*0301(20.08%)and DRB1*0803-DQB1*0601(7.19%).Conclusion:The phylogenetic tree constructed according to the HLA-DRB1,-DQB1 allele frequencies of Bais with those of other 10 populations suggests that the Bai ethnic group belongs to the southern group of China,but it keeps genetic distance from others and the HLA genes exhibits a unique profile.This study would provide HLA polymorphism information of Bai for the future investigation on the disease related to the genetic polymorphism.