The ion channel seizure regulates Adipokinetic hormone cell excitability. Rebecca J. Perry, Jason T. Braco, Erik C. Johnson. Department of Biology, Wake Forest University, Winston-Salem, NC.

   The mechanisms of how organisms maintain metabolic homeostasis in light of dynamic nutrient availability is not completely understood. In Drosophila, the adipokinetic hormone (AKH) is a principal hormone that functions in this process. AKH signaling regulates energy levels, through the direct mobilization of trehalose during low hemolymph sugar. Adipokinetic hormone is required for starvation-induced hyperactivity, an adaptive behavior that assists in foraging. In order to better understand AKH signaling, we are conducting a genome-wide RNAi based screen targeting different ion channels that regulate AKH cell physiology. We evaluated the consequences of RNAi expression in AKH cells on AKH related phenotypes, specifically lifespan and locomotion during starvation. From this initial behavioral screen, we identified the channel encoding the seizure potassium channel as a candidate AKH regulatory element. Expression of the seizure RNAi in AKH cells leads to lengthened lifespan during starvation. Additionally, there were observable changes in starvation-induced hyperactivity. We confirmed seizure expression in AKH neuroendocrine cells through analysis of the transcriptome on this cells type with RNAseq. We will also report preliminary experiments on AKH cell activation in a seizure mutant background and report other findings from the genome-wide RNAi screen and expression data.