Grant: Discovery Grants Program - Individual

Insects and other terrestrial arthropods are the most abundant group of organisms on our planet thriving in almost every available habitat and using a number of feeding strategies dependent on a diverse range of resources necessary for their survival. Haematophagy (i.e. blood-feeding) has evolved several times among the arthropods with over 14,000 species known to utilize this feeding strategy. Mosquitoes and ticks are two examples of animals utilizing haematophagy and our research primarily focuses on understanding the fundamental biology of these organisms. We explore the physiological roles of signaling molecules derived from the nervous system, with a particular focus on neuropeptides, which are released into circulation as hormones and regulate numerous physiological processes by controlling the activity of visceral organs including the gastrointestinal tract and reproductive organs. Our research aims to discover and characterize neurohormone systems controlling processes related to feeding, digestion, metabolism, excretion, hydromineral balance, reproduction and growth in blood-feeding arthropods including mosquitoes and ticks. An integrative approach is utilized investigating neuroendocrine systems at multiple levels of complexity, which allows the intricate details to be more readily realized and then integrated into the context of the whole organism. We combine a plethora of techniques to localize the receptors of these neurohormones since target organ identification helps to realize the roles of these hormones. Our recent progress has greatly advanced our understanding of the regulation of key physiological processes including desiccation tolerance and gametogenesis. To comprehensively understand these neuroendocrine signaling networks, we use heterologous systems to validate hormone ligand and receptor coupling to deduce intracellular signaling and mechanisms of action. Further, analogs of natural hormones are tested to determine key structural features necessary for ligand-receptor specificity, which helps to identify possible lead compounds useful for improved control strategies that are species-specific and environmentally benign, reducing our reliance on heavily-utilized non-selective insecticides that often do more harm than good. Given many hormones originate in the nervous system, we seek to identify the stimuli (i.e. input) and regulatory networks (i.e. integration) that are involved in the release of these neurohormones (i.e. output). Once particular neuroendocrine systems are elucidated, we examine how target organs interpret the information, which results in a physiological response leading to behavior. Leveraging our advanced knowledge on the biology of these blood-feeding arthropods and exploiting hormone analogs capable of interfering with endogenous neuroendocrine systems, may allow us to revolutionize control strategies in the future to lessen the burden of these medically-important vectors of disease.