SEMINAR: Peter Dearden (Univ Otago, NZ)
Wednesday, 20 July, 11:00
Neil Chalmers Theatre, DC2
Director of Genetics Otago & Associate Dean of Research for Health Sciences
University of Otago, New Zealand
Notch signalling has been co-opted by queen honeybees to repress worker reproduction
Eusociality depends on reproductive division of labour. This implies that one individual, the queen in honeybees, can repress reproduction in other females. In honeybees this is achieved through queen bees producing a pheromone, queen mandibular pheromone, which causes worker bees to repress the activity of their ovaries, repressing worker reproduction. Removal of the queen, and thus queen mandibular pheromone, allows the workers to activate their ovaries and begin to lay eggs. We have examined changes in gene expression, using high-throughput sequencing, in worker ovaries as they respond to the absence of queen mandibular pheromone and become activated. Using this dataset we have investigated the mechanisms by which queen mandibular pheromone has its action. While it is not clear how queen mandibular pheromone is detected, or how its activity is transduced, we have identified a cell-signalling pathway that responds to the absence of queen pheromone, and, when blocked, enhances the activation of the ovaries. Comparison of the action of this pathway in the presence or absence of queen pheromone implies that this is the main pathway by which the activity of worker ovaries is constrained in the honeybee, giving us insights into both the mechanism and evolution of reproductive constraint.