Genetic Diversity in the HLA classⅠA Gene of the Nine Taiwan Aboriginal Tribes and Han Chinese as Revealed by High Resolution Sequence-Based HLA Typing: Implication for the Origins and Dispersal of the Taiwan Aborigines

• Main Authors: Lai Shin-Mei, 賴欣梅
• Other Authors: Chen Yao-fong
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/03107674799582879989

碩士 === 慈濟大學 === 人類遺傳學研究所 === 90 === The polygenic HLA (human leukocyte antigen) gene complex is the most polymorphic cluster of functional genes known. The high polymorphism of HLA genes makes these functional genes ideal genetic markers for studying inter-relationships among various human populations. Combined the results of HLA polymorphism with evidences from socio-cultural, archaeological and linguistic studies, we may understand better the origin and dispersal of human populations. In this study we have used sequence-based typing (SBT) to analyze the degree of polymorphism of classΙ HLA-A gene in the nine Taiwan aboriginal tribes (Amis, Atayal, Bunun, Paiwan, Puyuma, Rukai, Saisiat, Tsou, and Yami) and Taiwan Han Chinese. The allele frequencies of each population are estimated by a maximum-likelihood method and used to calculate genetic distances between pairwise populations according to Nei’s formula. Phylogenetic tree is then constructed from these genetic distances. The results show limited genetic diversity of Taiwan aborigines, especially the Yami tribe. The distributions of allele frequencies of Taiwan aborigines versus Han Chinese are different. All the Taiwan aboriginal tribes have a high percentage of A*2402 allele ranging from 30% in Saisiat to 88% in Paiwan and Taiwan Han Chinese has 21%. We found a new HLA-A allele A*2420 in Atayal and Saisiat, and the allele frequencies are 15% and 13%, respectively. Analysis of allele frequencies and genetic distances of HLA-A gene reveals that Amis and Yami are different from other Taiwan aboriginal tribes. From the phylogenetic tree, nine Taiwan aboriginal tribes are divided into three clusters：the first one includes Paiwan, Bunun, Tsou and Rukai; the second one is Yami; and the third one includes the other four tribes. The third cluster can be further divided into three groups: the first one is Amis; the second includes Atayal and Saisiat; and the third includes Puyuma. In the future, when there are more genetic data from the Philippine and Southeast Asia populations, we may understand much more about the origin and dispersal of Taiwan aborigines in particular, and the Austronesians in general.