A whole-body transcriptome analysis and expression profiling of odorant binding protein genes in Oedaleus infernalis

To investigate the olfactory mechanisms in Oedaleus infernalis, one of important pests of cereals and pasture in the northern China, the whole-body transcriptome was constructed by RNA-Seq in this study. By de novo assembly, a total of 92,476 unigenes were generated in the adult sample, and 32,693 unigenes (35.35%) were successfully annotated by Blastx. Eighteen putative odorant binding proteins (OBPs) were identified, and phylogenetic analysis indicated the closest genetic relationship of eight OBPs in O. infernalis with those in its sibling species, Oedaleus asaiticus, while five OBPs in O. infernalis with those in Locusta migratoria. qRT-PCR analysis of the expression patterns of all 18 OinfOBPs in different tissues indicated that most OinfOBPs, especially OinfOBP7 and OinfOBP12, had higher expression levels in the antennae meanwhile no or faint expression in other body parts, including heads (without antennae), thoraxes, abdomens, legs, and wings, suggesting that these OBPs may play important roles in olfaction. OinfOBP2 was highly expressed only in male heads. Interestingly, only OinfOBP13 displayed high expressions in nearly all tested tissues. These two OBPs may have different physiological functions in O. infernalis. The remaining OBPs were not or weakly detected in all tested tissues. Our results provide important molecular information for further studies on chemosensory mechanisms in this pest.