Sex-Biased Olfactory Gene Expression In The Antennae Of The Adzuki Bean Beetle, Callosobruchus Chinensis

The adzuki bean beetle, Callosobruchus chinensis (L.) (Coleoptera Bruchidae), is a major pest of economically important leguminous grains. Since chemosensory genes play key roles in insect behaviour, they can potentially be use as new targets for pest control. However, the molecular basis of olfaction is unknown in C. chinensis. In this study, we sequenced the antennal transcriptomes of male and female C. chinensis and estimated of gene expression showed differences in up- and down-regulation of 117 and 98 genes, respectively, between female and male antennae. Among these genes, 1 odorant binding protein (OBP), 1 sensory neuron membrane protein (SNMP) and 1 gustatory receptor (GR) are male antennae-specific expression, whereas 2 OBPs, 23 odorant receptors (ORs) and 14 GRs are female antennae-enriched expression. Quantitative real-time RT-PCR analyses validated strong male antennal-biased expression of seven genes (OBP3, OR1, OR11, OR64, OR89, OR12, and GR5), whereas five genes (OBP4, OR7, OR5, GR15, and SNMP1) were especially expressed to dominantly expressed in female antennae. Sex biases gene expression described here provides important insights in gene functionalization. Meanwhile, our work allows for further functional studies of pheromone and general odorant detection genes, possible meaningful targets for pest management.