title: Down-regulation of honey bee IRS gene biases behavior toward food rich in protein.
abstract: Food choice and eating behavior affect health and longevity. Large-scale research efforts aim to understand the molecular and social/behavioral mechanisms of energy homeostasis, body weight, and food intake. Honey bees (Apis mellifera) could provide a model for these studies since individuals vary in food-related behavior and social factors can be controlled. Here, we examine a potential role of peripheral insulin receptor substrate (IRS) expression in honey bee foraging behavior. IRS is central to cellular nutrient sensing through transduction of insulin/insulin-like signals (IIS). By reducing peripheral IRS gene expression and IRS protein amount with the use of RNA interference (RNAi), we demonstrate that IRS influences foraging choice in two standard strains selected for different food-hoarding behavior. Compared with controls, IRS knockdowns bias their foraging effort toward protein (pollen) rather than toward carbohydrate (nectar) sources. Through control experiments, we establish that IRS does not influence the bees' sucrose sensory response, a modality that is generally associated with food-related behavior and specifically correlated with the foraging preference of honey bees. These results reveal a new affector pathway of honey bee social foraging, and suggest that IRS expressed in peripheral tissue can modulate an insect's foraging choice between protein and carbohydrate sources.
authors.affiliation: School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Navdeep S
authors.initials: NS
authors.lastname: Mutti
authors.forename: Kate E
authors.initials: KE
authors.lastname: Ihle
authors.forename: Adam
authors.initials: A
authors.lastname: Siegel
authors.forename: Adam G
authors.initials: AG
authors.lastname: Dolezal
authors.forename: Osman
authors.initials: O
authors.lastname: Kaftanoglu
authors.forename: Gro V
authors.initials: GV
authors.lastname: Amdam
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics*; D001522:Behavior, Animal; D019422:Dietary Sucrose / Q000378:metabolism; D015536:Down-Regulation; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D055504:Insulin Receptor Substrate Proteins / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D034622:RNA Interference
chemical_list: D019422:Dietary Sucrose; D019476:Insect Proteins; D055504:Insulin Receptor Substrate Proteins