Transcriptome and differential expression analysis of chemosensory genes in the antennae and heads of Apis cerana cerana drones

The olfactory system plays a critical role in honey bee adaptation to complex and constantly changing environments, as well as in the maintenance of social cohesion. Honey bees have evolved a sophisticated chemical communication system to regulate their intricate social interactions. Despite there is a preliminary understanding of the components, cells, and physiological pathways involved in pheromone response, the molecular mechanisms underlying honey bee drones' mating behavior and pheromone communication remain largely unknown. This study presented the first comprehensive transcriptome analysis of the antennae and heads of Apis cerana cerana drones in response to 9-ODA. Based on gene ontology and KEGG pathway, we found the majority of differentially expressed genes associated with molecular functions and signal transduction. Additionally, we identified 153 genes closely related to olfaction in the transcriptome datasets, including 111 odorant receptors (ORs), 16 odorant-binding proteins (OBPs), nine ionotropic receptors (IRs), 10 gustatory receptors (GRs), five chemosensory proteins (CSPs), and two sensory neuron membrane proteins (SNMPs), and most of them showed relatively high expression levels in the drone antennae. The reliability of these differential genes was validated using RT-qPCR. Our results will contribute to detect the molecular mechanisms of odorant and investigate olfactory functions in the Asian honey bees.