HLA CLASS-II ALLELES IN AINU LIVING IN HIDAKA DISTRICT, HOKKAIDO, NORTHERN JAPAN

The Ainu people are considered to be the descendants of preagricultura l native populations of northern Japan, while the majority of the popu lation of contemporary Japan (Wajin) is descended mainly from postneol ithic migrants. Polymorphisms of the HLA-DRB1, DRB3, and DQB1 alleles were investigated in DNA samples of 50 Ainu living in Hidaka district, Hokkaido. Unique features of the Ainu in this study were high inciden ces of DRB11401, DRB1*1406, and a newly described allele, DRB1*1106 ( 20%, 17%, and 5%, respectively). On the other hand, several common all eles in Wajin (DRB11502, 1302, 0803, and 1501) were found at relative ly low frequencies (1-2%) in Ainu. Previously DRB11406 was described as a characteristic allele of some Native American or northeast Asian ethnic groups, and DRB11106 had been found in only two Singapore Chin ese and one Korean. Principal component analysis of various population s based on HLA class II allele frequencies places the Ainu population midway between other east Asian populations, including Wajin, and Nati ve Americans. These observations may support the hypothesis that the A inu people are the descendants of some Upper Paleolithic populations o f northeast Asia from which Native Americans are also descended. (C) 1 996 Wiley-Liss, Inc.