Sugar receptors in the honeybee

• Applicant: Professorin Dr. Ricarda Scheiner-Pietsch
• Subject Area: Cognitive, Systems and Behavioural Neurobiology ; Sensory and Behavioural Biology
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 368605180

The perception and evaluation of sugars plays a central role in the life of a honeybee. Sugars such as sucrose, fructose and glucose are the main food source of honeybees. Forager bees have to evaluate the quality of a nectar source, while nurse bees inside the hive have to account for the honey quality when preparing brood food. On top of this, individual responsiveness to sugar is a pivotal indicator of the physiological state of a honeybee. Experiments of my group and others have shown, for example, that individuals with high sucrose responsiveness perform better in associative learning and memory tests than those with low sucrose responsiveness. Individual differences in sucrose response thresholds even correlate with the intricate social organization in a honeybee colony. In sharp contrast to the wealth of behavioural data on sugar sensing, surprisingly little is known about honeybee sugar receptors and their function in the evaluation of sugar.The goal of this project is to identify the function of all honeybee sugar receptors on different levels of the system. We aim to (1) characterize the three putative honeybee sugar receptors and their splice variants pharmacologically and to identify the signalling cascades involved in sugar perception,(2) understand the role of different taste organs and tissues in the evaluation of a sugar stimulus,(3) relate the behavioural response to different sugars and mRNA expression of selected sugar receptors to division of labour in a honeybee colony.With the comparatively small number of sugar receptors, the honeybee has the potential to become a model for understanding sugar perception in insects and beyond. Because individual differences in sugar perception correlate with multiple behaviours in the honeybee, our analysis of sugar perception on the molecular level will be of paramount importance for understanding the complex relationships between sugar perception, learning and division of labour in a honeybee colony.

• DFG Programme: Research Grants