MITOCHONDRIAL-DNA VARIATION IN NATURAL-POPULATIONS OF DROSOPHILA-IMMIGRANS

The mitochondrial DNA restriction patterns of seven natural population s of Drosophila immigrans from North Vietnam, Taiwan, and Japan were a nalyzed. Using twelve restriction endonucleases we recognized a total of 18 mtDNA haplotypes. The mean number of nucleotide substitutions be tween mtDNA haplotypes (pi(ij)) was estimated to be from 0.002 to 0.01 6. The amount of mtDNA divergence within a population (pi) was estimat ed to be from 0.0014 to 0.0077, while the net nucleotide differentiati on among populations (d) ranged from -0.0004 to 0.0045. The estimated G(st) value from mtDNA haplotype frequencies of each population was 0. 205, indicating relatively uniform genetic constitution throughout the investigated D. immigrans populations. However, nucleotide diversity of the seven populations showed that the Taiwan and the southern Japan populations formed one cluster; the Sapporo population is slightly di stanced from this cluster. The latitudinal systematic mtDNA differenti ation among populations is discussed.