Mitochondrial genomics in Calliphoridae (Diptera: Brachycera) and perspectives for dipteran phylogeny

We present the complete mitochondrial DNA (mtDNA) of three Calliphoridae species with medical, sanitary and forensic importance: Chloroprocta idioidea, Calliphora vomitoria and Phormia regina, which had 15004, 16143 and 16635 bp, respectively. Each genome was arranged in the same order described for Pancrustacea, with the exception of P. regina, which presented a duplication involving the tRNA^Ile and tRNA^Gln genes, besides a partial sequence of the tRNA^Met. A similar duplication has been previously described for Chrysomya species (Diptera: Calliphoridae) in the control region of the mtDNA. The average nucleotide composition was heavily biased toward As and Ts (>70%), mainly in third codon positions and non-coding regions (>90%). The phylogenetic reconstructions were conducted for all available dipteran species. The use of single genes (aminoacid or nucleotide sequences) resulted in topologies with low support, whereas the use of amino-acid data sets with concatenated PCGs provided resolution for intraordinal relationships in Diptera. The monophyly of Muscomorpha was not supported, as well as the monophyly of Acalyptratae, which is a major clade of Schizophora. The Calliphoridae was a monophyletic family, but the superfamily Oestroidea was disrupted by the inclusion of Muscoidea species as a sister group of Calliphoridae. Within Calliphoridae, the subfamilies Luciliinae and Calliphorinae were clustered together, related to the Chrysomyinae subfamily. These results may guide future works on parasitism evolution of the myiasis habit within Calliphoridae. In addition, the characterization of complete mitochondrial sequences could provide insights with regard to dipteran relationships and general molecular evolutionary studies on deep-level phylogenies of insects.