Characterization of RYamide neuropeptides and their Receptor in the Disease Vector Mosquito, Aedes aegypti

Insects utilize neuropeptides to fine-tune their physiological systems, including the tissues and organs involved in excretion, respiration, reproduction, and metabolism. The focus of this study is on the recently identified RYamide insect neuropeptides, named for the arginine-tyrosine amidated C-terminus. Here, the molecular basis will be investigated to propose physiological relevance in the disease vector, Aedes aegypti. Utilizing a cell-based functional assay, the endogenous RYamide receptor (RYa-R) was deorphanized and shown to have high specificity to the two mosquito RYamide peptides, with little to no activation by structurally-distinct neuropeptides. RYa-1 immunolocalization was found in the central nervous system, midgut, pyloric valve, ileum, rectal papillae, and surprisingly the seminal vesicles. RYamide and its receptor transcript analysis revealed potential regulatory effects of the digestive, reproductive, and excretory systems, along with a neuromodulatory role within the central nervous system. Further research is needed to confirm the physiological relevance of this novel neuropeptide family.