Radiation of human mitochondria DNA types analyzed by restriction endonuclease cleavage patterns

Abstract

Human mitochondrial DNA (mtDNA) restriction endonuclease fragment patterns were analyzed using total blood cell DNA isolated from 200 individuals representing five different populations. Thirty-two fragment patterns (morphs) were observed with the enzymes Hpa I, Bam HI, Hae II, Msp I and Ava II yielding thirty-five different combinations of fragment patterns (mt DNA types). The major ethnic groups exhibit quantitative as well as qualitative differences in their mtDNA types, all of which are related to each other by a tree in which the closely related mtDNA types cluster according to geographic origin. Three mtDNA types are postulated to be 'central' to ethnic radiations due to their high frequencies, their appearance in more than one ethnic group, or their presence in other primate species. Genetic distances among populations were computed and employed in construction of an average linkage tree. If one of the three central mtDNA types is the root of the tree, differences in evolutionary rates among the branches become apparent. In particular, the Bushmen appear to have a higher evolutionary rate for mtDNA than the other four populations. Comparisons with nuclear gene frequencies suggest that this higher evolutionary rate may be the product of an elevated mutation rate or fixation of mutations in mtDNA.

Mitochondrial DNA polymorphism in Japanese living in Hokkaido

“…1), five of which (morph 1, 2, 3, 10 and 12) have been reported by Johnson et al (1983) and Horai and Matsunaga (1986). Morph 1 is the most common type in most racial groups, while morph 2 and 3 also have been detected previously in Caucasians, African groups and the Japanese (Johnson et al, 1983;Horai and Matsunaga, 1986). Morph 2 and 3 correspond to morph 3 and 4, re- spectively, reported by Horai and Matsunaga (1986).…”

“…Other morphs, which have been observed only in Caucasians (Brown, 1980;Johnson et al, 1983), were found in neither the Ainu nor the Non-Ainu Japanese.…”

“…BamHI: No variant could be detected with BamHI and all the individuals showed morph 1 reported by Brown (1980) and Johnson et al (1983). Other morphs, which have been observed only in Caucasians (Brown, 1980;Johnson et al, 1983), were found in neither the Ainu nor the Non-Ainu Japanese.…”

“…Morph 2 and 3 correspond to morph 3 and 4, re- spectively, reported by Horai and Matsunaga (1986). Morph 10 has been reported only in Caucasians (Johnson et aL, 1983), whereas morph 12 has been reported only in Japanese by Horai and Matsunaga (1986). One other digestion pattern, which has not been reported previously, is named as morph 14.…”

“…Since the pioneer work by Brown (1980), polymorphism of human mtDNA has attracted a great deal of attention of human population geneticists and anthropologists (Brown, 1980;Denaro et al, 1981;Blanc et al, 1983;Cann and Wilson, 1983;Johnson et al, 1983;Cann et al, 1984;Horai et al, 1984;Wallace et al, 1985;Horai and Matsunaga 1986).…”