Colony-Level Immunity Benefits and Behavioral Mechanisms of Resin Collection by Honey Bees

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

Abstract PI Spivak Proposal # IOS-0717530 Colony-level immunity Benefits and Behavioral Mechanisms of Resin Collection by Honey Bees This proposal aims to determine if resins, complex plant secretions with diverse antimicrobial properties, provide a colony-level immune defense against pathogens in honey bee colonies. Bees harvest resin (or propolis) for use as caulk within the nest cavity. To test the hypothesis that plant resins play an integral role in honey bee immunity, product levels of seven immune-related genes and the presence of key pathogens will be compared in honey bees collected from resin-rich and resin-poor colonies. It is expected that the immune system in bees from resin-rich colonies will be relatively down-regulated, as indicated by lower immune-related gene transcript levels and lower microbe levels, suggesting that the presence of resin and lack of microbes causes the bees to invest less in the production of immune proteins that are energetically costly. Colonies also will be tested to determine if they collect more resin in response to pathogen challenge, which would indicate that the bees are self-medicating. Additionally, the stimuli that initiate and regulate resin collection at the individual and colony levels will be ascertained by observing the frequency of recruitment signals (bee dances and trembling) by individual resin foragers from high- and low-resin collecting colonies. This research will exploit the recently sequenced honey bee genome, which has provided new gene candidates for immunity and techniques for assessing the activity levels of gene products. Harvesting resin, which ultimately benefits the collective immune system of social individuals, is a fascinating example of environmental effects on innate immunity. An applied goal is to promote the natural defenses of honey bees, the world's most important pollinators of native and agro-ecosystems, and the economic health of the beekeeping industry. The experiments will actively engage graduate and undergraduate students in research that spans disciplines from beekeeping to molecular genetics.