R. Shao et al., Numerous gene rearrangements in the mitochondrial genome of the wallaby louse, Heterodoxus macropus (Phthiraptera), MOL BIOL EV, 18(5), 2001, pp. 858-865
The complete arrangement of genes in the mitochondrial (mt) genome is known
for 12 species of insects, and part of the gene arrangement in the mt geno
me is known for over 300 other species of insects. The arrangement of genes
in the mt genome is very conserved in insects studied, since all of the pr
otein-coding and rRNA genes and most of the tRNA genes are arranged in the
same way. We sequenced the entire mt genome of the wallaby louse, Heterodox
us macropus, which is 14,670 bp long and has the 37 genes typical of animal
s and some noncoding regions. The largest noncoding region is 73 bp long (9
3% A+T), and the second largest is 47 bp long (92% AST). Both of these nonc
oding regions seem to be able to form stem-loop structures. The arrangement
of genes in the mt genome of this louse is unlike that of any other animal
studied. All tRNA genes have moved and/or inverted relative to the ancestr
al gene arrangement of insects, which is present in the fruit fly Drosophil
a yakuba. At least nine protein-coding genes (atp6, atp8, cox2, cob, nad1-n
ad3, nad5, and nad6) have moved; moreover, four of these genes (atp6, atp8,
nad1, and nad3) have inverted. The large number of gene rearrangements in
the mt genome of H. macropus is unprecedented for an arthropod.