Rearrangements and low diversity in mitogenomes of the Wolbachia-infected endoparasitoid Dipterophagus daci (Strepsiptera) when compared to its tephritid fruit fly hosts

Insect mitogenome organisation is highly conserved, yet, some insects, in particular with parasitic life cycles, have rearranged mitogenomes. Furthermore, intraspecific mitochondrial diversity can be reduced due to the presence of maternally inherited bacterial endosymbionts like Wolbachia which affect host reproduction and fitness. We have sequenced mitogenomes of the Wolbachia-infected strepsipteran endoparasitoid Dipterophagus daci (Halictophagidae) and four of its 22 known tephritid host species using total genomic extracts of parasitised flies. This first-sequenced halictophagid mitogenome revealed extensive rearrangements relative to the four fly mitogenomes which exhibited the ancestral insect mitogenome pattern. Compared to the only four other strepsipteran mitogenomes, the D. daci mitogenome had additional transpositions of one rRNA and two tRNA genes, and a single nucleotide frameshift deletion in nad5 requiring -1 translational frameshifting, or resulting in a large truncation. Dipterophagus daci displays an almost completely endoparasitic life cycle when compared to more basal Strepsiptera with free-living adults. Our results support the hypothesis that the transition to extreme endoparasitism evolved together with increased levels of mitogenome changes. Furthermore, intraspecific mitogenome diversity was substantially smaller in D. daci than the parasitised flies suggesting that Wolbachia had reduced mitogenome diversity because of a role in the endoparasitoids fitness.