Profiling early growth response (Egr-1) gene expression in the honeybee brain during foraging

Immediate early genes (IEGs) are the first expressed genes in the brain upon induction by any stimulus. IEGs unique properties of immediate expression provide us ample opportunities to investigate the regulatory genes propelled by behavioral changes. Different types of IEGs have been found to be activated by different behavioral characteristics. Foraging of honeybees is one of the most well characterized behaviors among social insects. However, only a little knowledge has been accumulated about the molecular mechanisms that regulates the foraging behavior, due to availability of few studies. Finding which IEGs are involved in monitoring or inducing a behavior is likely the first promising adventure to open the lid for uncovering the underlying complex regulatory biology.  Egr-1 is one of most widely studied IEGs that was found to have been induced by different behaviors including learning and memory. Like the most IEGs, Egr-1 expression is also transient, indicating activation of its downstream genes’ role in monitoring the behavior. Honeybee foraging is a complex behavior in which learning and memory of food location is a primary goal of foraging. In our recent studies, involvement of Egr-1 in honeybee foraging and associative learning had been demonstrated. In this study we aim to examine the expression dynamics of Egr-1 during consecutive trips of foraging. It may be noted that, during foraging, a forager bee repeatedly flies back and forth multiple times from the hive to the feeder, communicate each other and motivate other foragers in the hive and accomplished the food collection. Examining at which flight trip, Egr-1 reaches highest expression level, then drops, could help in finding the downstream regulatory pathway genes that monitors the complex foraging behavior.