Structure and organization of the mitochondrial genome of the canine heartworm, Dirofilaria immitis

Abstract

This study determined the complete mitochondrial (mt) genome sequence of the canine heartworm, Dirofilaria immitis†, and compared its structure, organization and other characteristics with Onchocerca volvulus and other secernentean nematodes. The D. immitis mt genome is 13814 bp in size and contains 36 of the 37 genes typical of metazoan organisms, and lacks the ATP synthetase subunit 8 gene. All of the genes are transcribed in the same direction. For the entire genome, the nucleotide contents are ∼55% (T), ∼19% (each for A and G) and ∼7% (C), which is very similar to those of the protein-coding genes. In the latter genes, most (∼69%) third codon positions have a T, but rarely (∼1-9%) have a..