Characterization of complete mitochondrial genome of three Horse flies of the genus Tabanus (Diptera: Tabanidae): comparative analysis

Mol Biol Rep. 2023 Dec;50(12):9897-9908. doi: 10.1007/s11033-023-08837-z. Epub 2023 Oct 21.

Abstract

Background: Tabanidae (Horse-Flies or Deer-Flies) are one of the most economically important as well as medically significant haematophagous insect family within the order Diptera. Members of this group are also responsible for the mortality of substantial number of live-stock every year. Due to their pathogen transmission potential and vector competencies makes them an important insect group to study. Till now, mitochondrial genome of 18 species of tabanids were available.

Methods and results: The complete mitogenome of three species T. diversifrons (15,809 bp), T. rubidus (15,878 bp) and T. tenens (15,872 bp) were generated by Next generation sequencing method. They consist 37 genes, with a positive AT skew and a negative GC skew. The gene order of these three species is similar to the typical gene arrangement of infra-order Tabanomorpha. Most of the tRNAs showed typical clover-leaf secondary structure except trnS1, which lacks the DHU arm. The sliding window analysis showed that the nad4L is the most conserved while atp8, and nad6 are the most variable genes. Moreover, the ratios of non-synonymous to synonymous substitution rates indicated that all PCGs under the purifying selection. Phylogeny revealed Chrysops and Haematopota are monophyletic while species of Hybomitra are nested within the polyphyletic clade of Tabanus. T. diversifrons exhibits sister relationship with Atylotus miser. Two morphologically divergent species T. rubidus and T. tenens are found to be genetically similar and indistinguishable by mitochondrial genome.

Conclusions: The hypervariable genes like atp8 and nad6 can be used as molecular markers for the identification of recently diverged lineages of family Tabanidae. Further, to address uncertainties arising from the two morphological divergent species, it is imperative to obtain data from nuclear gene markers.

Keywords: Mitogenomes; Phylogenetic; Tabanidae; Vector.

MeSH terms

  • Animals
  • Deer* / genetics
  • Diptera* / genetics
  • Genome, Mitochondrial* / genetics
  • Phylogeny
  • RNA, Transfer / genetics

Substances

  • RNA, Transfer