Intestinal Immunolocalization and Insight on the Role of Tachykinin-Related Peptides in the Yellow Fever Mosquito, Aedes aegypti

This study investigates a family of neuropeptides known as tackykinin-related peptides (TKRPs) in the mosquito Ae. aegypti, which is an insect of medical concern owing to its transmission of several arboviruses. As knowledge on TKRPs is limited in this mosquito, this study aimed to create a tk knockout line using CRISPR/Cas9 and characterize the distribution of TKRP immunoreactivity in the midgut over different physiological conditions including starved, sucrose-fed and blood-fed, and across developmental stages. The results demonstrate that TKRP immunoreactivity in the Ae. aegypti midgut is greatest in adult stage mosquitoes. Further, starvation significantly reduced TKRP immunoreactivity in the midgut compared to sugar fed adult mosquitoes, but no change was observed in relation to blood-feeding by females. Overall, this study established the intestinal distribution of TKRPs in Ae. aegypti and identified functional sgRNAs to disrupt the tk gene so that the physiological role of TKRPs can soon be characterized.