Analysis of chemosensory gene families in the beetle Monochamus alternatus and its parasitoid Dastarcus helophoroides

We assembled antennal transcriptomes of pest Monochamus alternatus and its parasitoid Dastarcus helophoroides to identify the members of the major chemosensory multi-gene families. Gene ontology (GO) annotation indicated that the relative abundance of transcripts associated with specific GO terms was highly similar in the two species. In chemosensory gene families, we identified 52 transcripts encoding putative odorant-binding proteins (OBPs), 19 chemosensory proteins (CSPs), 10 olfactory receptors (ORs), 8 ionotropic receptors (IRs), 2 gustatory receptors (GRs), and 5 sensory neuron membrane proteins (SNMPs) in these two transcriptomes. Predicted protein sequences were compared with Dendroctonus ponderosae, Tribolium castaneum and Drosophila melanogaster. The results of phylogenetic trees showed that some clusters included only OBPs or CSPs from D. helophoroides, some clusters included only OBPs or CSPs from M. alternatus, while some clusters included OBPs or CSPs from both M. alternatus and D. helophoroides. The identification of the chemosensory genes and the phylogenetic relationship of these genes between two species might provide new ideas for controlling M. alternatus and improving current strategies for biological control.