Complete Mitochondrial Genome for Lucilia cuprina dorsalis (Diptera: Calliphoridae) from the Northern Territory, Australia

Abstract

The Australian sheep blowfly, Lucilia cuprina dorsalis, is a major sheep ectoparasite causing subcutaneous myiasis (flystrike), which can lead to reduced livestock productivity and, in severe instances, death of the affected animals. It is also a primary colonizer of carrion, an efficient pollinator, and used in maggot debridement therapy and forensic investigations. In this study, we report the complete mitochondrial (mt) genome of L. c. dorsalis from the Northern Territory (NT), Australia, where sheep are prohibited animals, unlike the rest of Australia. The mt genome is 15,943 bp in length, comprising 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a non-coding control region. The gene order of the current mt genome is consistent with the previously published L. cuprina mt genomes. Nucleotide composition revealed an AT bias, accounting for 77.5% of total mt genome nucleotides. Phylogenetic analyses of 56 species/taxa of dipterans indicated that L. c. dorsalis and L. sericata are the closest among all sibling species of the genus Lucilia, which helps to explain species evolution within the family Luciliinae. This study provides the first complete mt genome sequence for L. c. dorsalis derived from the NT, Australia to facilitate species identification and the examination of the evolutionary history of these blowflies.

Keywords: Australian sheep blowfly; Lucilia cuprina dorsalis; flystrike; mitochondrial genome; phylogenetic analyses.

Figure 1

Circular representation of the mitochondrial (mt) genome of Lucilia cuprina dorsalis collected from the Northern Territory, Australia. Large yellow and red arrows with annotated labels situated in the mt genome map indicate the position of protein-coding genes (PCGs) and ribosomal RNA (rRNA) genes. Blue arrows with annotated labels demarcate the positions of transfer RNA (tRNA) genes. The cox genes refer to the cytochrome c oxidase subunits, nad genes refer to NADH dehydrogenase components, the cob gene refers to the cytochrome b gene, and rrnL and rrnS refer to ribosomal RNA genes, respectively (cf. Table S2).

Figure 2

AT skew and GC skew of protein-coding genes (PCGs) in the mitochondrial genome of Lucilia cuprina dorsalis collected from the Northern Territory, Australia. The x-axis represents the protein-coding genes (PCGs), and the y-axis represents the AT (blue) and GC skew (orange) values associated with these PCGs.

Figure 3

Relative synonymous codon usage (RSCU) in the protein-coding genes (PCGs) in the mitochondrial genome of Lucilia cuprina dorsalis collected from the Northern Territory, Australia. The different colors in the column chart represent the codon families corresponding to the amino acids listed under the columns.

Figure 4

Phylogenetic relationship of Lucilia cuprina dorsalis (Northern Territory, Australia) with 55 members/representatives of the order Diptera. The phylogenetic tree was constructed using the Bayesian inference (BI) and maximum likelihood (ML) methods. The numbers displayed on the branches indicate bootstrap values and posterior probabilities from different analyses in the order: ML/BI. Each member is labeled with the species name, location, and GenBank accession number. Haematobia irritans irritans (Muscidae) was used as the outgroup. Lucilia cuprina dorsalis (Northern Territory, Australia) sequenced in this study is color-coded in red. The family names are labeled as A to E preceding the species names in the following order: A: Muscidae, B: Calliphoridae, C: Oestridae, D: Tachinidae, and E: Sarcophagidae. The tree branches corresponding to the subfamily Luciliinae within the Calliphoridae family are highlighted in blue. The phylogenetic tree presented here is drawn to scale, with a scale bar representing 0.05 estimated substitutions per site.