Extensive variation and heteroplasmy in size of mitochondrial DNA among geographic populations of Drosophila melanogaster

Size variation and heteroplasmy in mitochondrial DNA (mtDNA) are relatively common in natural populations of Drosophila melanogaster. Of 92 isofemale lines of flies obtained from various geographic regions throughout the world, 75 lines were homoplasmic and showed a total of 12 different mtDNA size classes. The remaining 17 lines were heteroplasmic, each line carrying two different mtDNAs, and, in all but one case, the mtDNAs in these …