Identification and functional characterization of AcerOBP15 from Apis cerana cerana (Hymenoptera: Apidae)

Coordination in honeybees is heavily dependent on their chemoreception system, in which odorant-binding proteins are very important. A previous study based on the antennal transcriptome of Apis cerana cerana revealed that OBP15 was significantly up-regulated at 25-day-old. To further unravel and clarify its functional role, we first cloned and characterized AcerOBP15 from the antennae of worker bees. Sequence and phylogenetic analysis showed that AcerOBP15 belongs to the Minus-C OBPs family. AcerOBP15 was primarily expressed in forager antennae and legs. A fluorescent binding assay showed that AcerOBP15 had strong binding affinity to most floral volatiles, a restricted number of bee pheromone components and non-volatile compounds, among which the highest is myrcene. Based on RNAi and EAG assays, AcerOBP15 may be required for myrcene recognition. Taken together, we suggest that AcerOBP15 plays a dual role in olfactory and gustatory reception when foraging. Our study lays a theoretical foundation for further studies regarding the mechanism of chemoreception in A. cerana cerana.