Identification and Preliminary Characterization of Odorant-Binding Proteins in Neoceratitis asiatica (Diptera: Tephritidae)1

Abstract

The fruit fly Neoceratitis asiatica (Becker) (Diptera: Tephritidae) is a monophagous pest that damages only wolfberry, Lycium barbarum L. The odorant-binding proteins (OBPs) of insects are part of the initial steps of the olfactory signal transduction cascade involved in solubilizing and transporting chemical signals to the olfactory receptors. We studied the OBP genes of N. asiatica by using data from RNA-seq cDNA libraries of adult flies. Seventeen putative OBP sequences in N. asiatica were identified, corresponding to 13 OBPs of Drosophila melanogaster (Megen) (Diptera: Drosophilidae). Thirteen of the N. asiatica genes belong to the classic subfamily, four are in the minus-C subfamily, and none were members of the plus-C and dimer subfamilies. A phylogenetic tree was constructed to elucidate the evolutionary relationship between N. asiatica and other related species. This investigation of OBP evolution in monophagous, oligophagous, and polyphagous fruit flies revealed that the OBPs in N. asiatica are more oligo and conserved. These findings lay a foundation for uncovering the relationships between monophagous insects and their OBPs.