Analysis of HLA-DRB1 polymorphism in the Gidra of Papua New Guinea

The genetic structure of the Gidra-speaking population inhabiting 13 villag es in Papua New Guinea was investigated, based on the analysis of HLA-DRB1 polymorphism. Nei's fixation indices (F-IS, F-IT, and F-ST) showed that the Gidra villages were genetically differentiated. The genetic distances sign ificantly correlated with the geographic distances among the 13 villages. T hus, it is likely that a low intervillage migration rate has been maintaine d since the Gidra community was established. Correspondence analysis reveal ed that the Gidra, who belong to non-Austronesian-speaking groups, are gene tically located at the intermediate point between the Aboriginal Australian groups and the Austronesian-speaking groups. Moreover, the HLA-DRB1*0802 a llele, which has been observed in only two Polynesian groups (Austronesian- speaking groups) of Oceanian populations, was also found in the Gidra, Thes e results suggest that the admixture of Austronesian and indigenous non-Aus tronesian groups beyond the linguistic boundary occurred partly in Papua Ne w Guinea before Austronesian groups spread to the Pacific.