The queen bee controls the physiology and behavior of her fellow bees and essentially determines the workings of the entire society of insects. The queen exerts this influence by producing a cocktail of pheromones known as queenmandibular pheromone (QMP), but it has not been clear just how the mixture produces its effects. Beggs et al. noted that one component of QMP, homovanillyl alcohol (4-hydroxy-3-methoxyphenylethanol, or HVA) has a chemical structure similar to that of the neurotransmitter dopamine. The authors therefore tested the effects of the pheromone on dopaminergic function in bees. Exposure of newly emerged adult bees to QMP (a commercially available strip impregnated with nine queen-equivalents of pheromone mixture) for 2 days decreased the amount of mRNA transcript encoding one of the bee’s dopamine receptors. Cultured neurons from the mushroom body normally respond to dopamine with an increase in production of cAMP (adenosine 3′,5′-monophosphate), but neurons taken from flies exposed to QMP also showed a small decrease in production of cAMP. HVA produced responses similar to those evoked by dopamine. Total amounts of dopamine in the brain were reduced in flies exposed to HVA for 2 days. The authors propose that HVA in the QMP mixture may interact directly with dopamine receptors in the bee nervous system, perhaps decreasing the expression of dopamine receptors, thus altering the response of the neurons to endogenous dopamine.
K. T. Beggs, K. A. Glendining, N. M. Marechal, V. Vergoz, I. Nakamura, K. N. Slessor, A. R. Mercer, Queen pheromone modulates brain dopamine function in worker honey bees. Proc. Natl. Acad. Sci. U.S.A. 104, 2460-2464 (2007). [Abstract] [Full Text]