MITOCHONDRIAL TRANSFER-RNA GENES IN A BLACK FLY, SIMULIUM-VITTATUM (DIPTERA, SIMULIIDAE), INDICATE LONG DIVERGENCE FROM MOSQUITO (DIPTERA, CULICIDAE) AND FRUIT-FLY (DIPTERA, DROSOPHILIDAE)

Sequences are given for nine complete genes and one partial mitochondrial tRNA gene of the black fly, Simulium vittatum (Zetterstedt). Sequenced tRNA genes were for alanine, arginine, asparagine, aspartic acid, glutamic acid, glycine, leucine(CUN), lysine, serine(AGN), and valine. Nucleotides were aligned with the same previously sequenced genes in Aedes albopictus Skuse and Drosophila yakuba Burla. A cluster of six tRNA genes, which differ in arrangement in Ae. albopictus and D. yakuba, was amplified by PCR and found to have the same position and orientation in S. vittatum as in D. yakuba. Overall, similarity with either D. yakuba or Ae. albopictus was 86%. Sequences that were common to the three insects suggest that black flies and mosquitoes are as divergent from each other as either is from Drosophila. Sequences for nine species of black flies were obtained for tRNA leucine(CUN) from DNA amplified with another primer set. Little variation occurred within the tRNA gene but, by including the flanking regions to provide 175 base pairs, a phylogeny of the nine species was obtained that was largely consistent with current classification.