Sequence, secondary structure, and phylogenetic analyses of the ribosomal internal transcribed spacer 2 (ITS2) in the Orthopodomyia signifera group (Diptera: Culicidae)

Mosquitoes of the Orthopodomyia Signifera group are little known and of uncertain epidemiological importance. The group consists of five species (i.e., Or. signifera, Or. alba, Or. kummi, Or. waverleyi, and Or. pulcripalpis) based on the current morphological taxonomy. Internal transcribed spacer 2 (ITS2) sequences of the rDNA were obtained. The Orthopodomyia ITS2 ranged in size from 288 to 346 base pairs (mean=312) and are slightly AT enriched (45% GC on average). Putative secondary structures reveal a three-domain model that also feature homologies specific to mosquitoes (e.g., a conserved motif on the 3' aspect of the third helix: GARTACATCC). Phylogenetic analyses of the ITS2 data and molecular evidence of hybridization between Or. signifera and Or. kummi are presented. To our knowledge, this study represents the first molecular-based phylogenetic analysis of the Orthopodomyia.