Neurophysiological mechanisms underlying sex- and maturation-related variation in pheromone responses in honey bees (Apis mellifera)

• Published in: Journal of Comparative Physiology 2015-07, Vol.201 (7), p.731-739
• Main Authors: Villar, Gabriel, Baker, Thomas C, Patch, Harland M, Grozinger, Christina M
• Format: Article
• Language: English
• Subjects: Aging - physiology; Analysis of Variance; Animal Physiology; Animals; Apis mellifera; Arthropod Antennae - metabolism; Bees - growth & development; Bees - physiology; Behavior, Animal - physiology; Biomedical and Life Sciences; central nervous system; electrophysiology; Fatty Acids, Monounsaturated; Female; females; Gene Expression; honey bees; Insect Proteins - metabolism; Life Sciences; Male; males; Motor Activity; Neurosciences; nurses; olfactory receptors; Original Paper; peripheral nervous system; Peripheral Nervous System - growth & development; Peripheral Nervous System - physiology; Pheromones; Psychophysics; Sex Characteristics; sex pheromones; sexual maturity; Social Behavior; social structure; Zoology
• ISSN: 0340-7594; 1432-1351
• DOI: 10.1007/s00359-015-1006-7

In the honey bee (Apis mellifera), social organization is primarily mediated by pheromones. Queen-produced 9-oxo-2-decenoic acid (9-ODA) functions as both a social and sex pheromone, eliciting attraction in both female workers and male drones, but also affecting other critical aspects of worker physiology and behavior. These effects are also maturation related, as younger workers and sexually mature drones are most receptive to 9-ODA. While changes in the peripheral nervous system drive sex-related differences in sensitivity to 9-ODA, the mechanisms driving maturation-related shifts in receptivity to 9-ODA remain unknown. Here, we investigate the hypothesis that changes at the peripheral nervous system may be mediating plastic responses to 9-ODA by characterizing expression levels of AmOR11 (the olfactory receptor tuned to 9-ODA) and electrophysiological responses to 9-ODA. We find that receptor expression correlates significantly with behavioral receptivity to 9-ODA, with nurses and sexually mature drones exhibiting higher levels of expression than foragers and immature drones, respectively. Electrophysiological responses to 9-ODA were not found to correlate with behavioral receptivity or receptor expression, however. Thus, while receptor expression at the periphery exhibits a level of plasticity that correlates with behavior, the mechanisms driving maturation-dependent responsiveness to 9-ODA appear to function primarily in the central nervous system.