A cluster of four transfer RNA genes in mosquito mitochondrial DNA

We have sequenced a 342 base-pair segment of mosquito (Aëdes albopictus) mitochondrial DNA. This segment contains genes corresponding to two of the more unusual of the mosquito mitochondrial tRNAs that we sequenced earlier, tRNAargUCG and tRNAserGCU, as well as genes for tRNAalaUGC and tRNAasnGUU and a portion of a gene that is homologous to mammalian mitochondrial unidentified reading frame 3. There are differences in gene order and directions of transcription between the mosquito mitochondrial sequence on the one hand, and corresponding Drosophila and mammalian mitochondrial sequences on the other, that indicate the occurrence of multiple discrete transpositional events during mitochondrial DNA evolution.