AMINO-ACID CHANGE ASSOCIATED WITH THE MAJOR POLYMORPHIC HINC-II SITE OF ORIENTAL AND CAUCASIAN MITOCHONDRIAL DNAS

Abstract

The mitochondrial DNA (mtDNA) from 116 Oriental and Caucasian blood samples were analyzed for their Hinc II restriction endonuclease cleavage patterns using Southern analysis and 32P human mtDNA probes. Seven distinct patterns were found, all of which could be interrelated by single nucleotide changes. The predominant pattern (mtHinc II-2) was found in 97% of the Caucasians and 73% of the Orientals. This mtDNA morph had one more Hinc II site than did the 2nd most common morph (mtHinc II-1), which was found only in 20% of the Orientals. Three additional patterns were in a single Oriental sample, a 4th in a single Caucasian sample, and a 5th in one member of each population. The polymorphic site that differentiated mtHinc II-1 and mtHinc II-2 was cloned and sequenced. A single nucleotide change was found that created an Hinc II site and changed the amino acid sequence of the URF5 gene. Comparison of these sequences with those of other primates [15] revealed that the Asian mtHinc II-1 and mtHinc II-4 mtDNA were identical in this region with those of chimpanzees and orangutans. The Asian mtHinc II-1 mtDNA may be ancestral to other human mtDNA.