Mitochondrial DNA variation in an Aboriginal Australian population: Evidence for genetic isolation and regional differentiation

The mitochondrial DNA (mt-DNA) variation of in the Walbiri tribe of the Nor thern Territories, Australia, was characterized by high resolution restrict ion fragment length polymorphism (HR-RFLP) analysis and control region sequ encing, Surveying each mt-DNA for RFLPs with 14 different restriction enzym es detected 24 distinct haplotypes, whereas direct sequencing of the contro l region hypervariable segment I (HVS-1) of these mt-DNAs revealed 34 disti nct sequences. Phylogenetic analysis of the RFLP haplotype and HVS-I sequen ce data depicted that the Walbiri have ten distinct haplotype groups (haplo groups), or mt-DNA lineages. The majority of the Walbiri RFLP haplotypes la cked polymorphisms common to Asian Populations, In fact, most of the Walbir i haplogroups were unique to this Population, although a few appeared to be subbranches of larger clusters of mt-DNAs that included other Aboriginal A ustralian and/or Papua New Guinea haplotypes. The similarity of these haplo types suggested that Aboriginal Australian and Papua New Guinea populations may have once shared an ancient ancestral population(s), and then rapidly diverged from each other once geographically separated. Overall. the mt-DNA data corroborate the genetic uniqueness of Aboriginal Australian populatio ns. Human Immunology 62, 954-969 (2001). (C) American Society for Histocomp atibility and Immunogenetics, 2001. Published by Elsevier Science Inc.