Analysis of antennal transcriptome and odorant binding protein expression profiles of the recently identified parasitoid wasp, Sclerodermus sp.

We constructed an antennal transcriptome of the parasitoid wasp, Sclerodermus sp. (Hymenoptera: Bethylidae). Our analysis of the transcriptome yielded 51,830,552 clean reads. A total of 46,269 unigenes were assembled, among which 29,582 unigenes exhibited significant similarity (E-values≤10(-5)) to sequences in the NCBI nonredundant protein database. Gene ontology (GO) and cluster of orthologous groups (COG) analyses were used for the functional classification of these unigenes. We identified ten odorant binding proteins (OBPs), ten chemosensory proteins (CSPs), eight olfactory receptors (ORs), three ionotropic receptors (IRs), six gustatory receptors (GRs), and two sensory neuron membrane proteins (SNMPs). The expression profiles of the ten OBPs were determined based on a qPCR analysis of RNA extracted from the antennae, legs, and abdomens of wingless and winged female adults and whole larvae and pupae. The highest levels of OBP5, OBP6, OBP7, and OBP9 expression were observed in the antennae of adult females. The highest levels of OBP1, OBP2, and OBP4 expression were observed in the abdomen of winged females. The highest levels of OBP3 and OBP10 expression were observed in larvae and pupae, respectively, whereas OBP8 was expressed at high levels in both larvae and pupae. Our findings establish a foundation for future studies of the molecular mechanisms of chemosensory perception in Sclerodermus sp.