Evolutionary Process Underlying Receptor Gene Expansion and Cellular Divergence of Olfactory Sensory Neurons in Honeybees. [scATAC-Seq]

The olfactory system is intricately intertwined with species adaptation in insects. Genomic studies have unveiled significant duplications and expansions of olfactory receptor genes in social behavior insects. However, the precise mechanisms through which these duplicated genes integrate into olfactory neural circuitries to enhance species-specific adaptative functions remain inadequately understood. Overall design: Honeybee workers were collected from three healthy colonies provided by the Institute of Zoology, Guangdong Academy of Sciences (Guangzhou, Guangdong, China). All colonies were maintained in standard Langstroth hives containing a single hive box with 16,000–20,000 bees and one naturally mated queen. Workers were gathered at there different division of labors (newly emerged worker, nurse and forager), with three biologically replicates per divisor of labors. Newly emerged workers were obtained from capped brood frames when workers emerged from their cells for 1-2 h. To collect age-matched samples of nurse and forager bees, the adult bees that had emerged from their cells were marked on the thorax with paint and returned to the hive. When marked bees were 9 days old, we collected a subset of workers observed performing nursing behaviour (bees with their heads in cells containing larvae). When they were 21 days old, we collected another set of bees observed performing foraging behaviour (returning to the hive carrying pollen loads). For each adult worker, the antennae were separated with surgical scissors and 60 individuals were pooled together.