Neuroendocrine systems regulating physiological processes in blood-feeding arthropods

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My research program focuses on the biology of blood-feeding arthropods. I examine the mechanisms by which signaling molecules, called neurohormones, are released from the central nervous system and control numerous physiological processes by regulating the activity of tissues in the visceral system including the gastrointestinal tract and reproductive tissues. My research aims to discover and characterize regulatory systems involving hormones and other neurochemicals that control many physiological and behavioral processes related to feeding, digestion, metabolism, excretion, hydromineral balance, reproduction, growth and development in blood-feeding arthropods including ticks (Ixodes scapularis) and mosquitoes (Aedes aegypti). Neuroendocrine systems will be investigated at the molecular, cellular and tissue level in order to determine their importance and contribution to the biology of these organisms. By examining these systems at multiple levels of complexity, the details are more readily realized and we can then integrate this knowledge of individual signalling components to the whole organism. With the identification of tissue targets regulated by hormonal factors, we will use various assessment methods to determine the roles of these neuroendocrine systems in mosquitoes and ticks. For example, targets of primary interest include the tissues of the alimentary canal (i.e. gut), which play roles in digestion and assimilation of ingested materials, elimination of toxins (including pesticides), immune response and are also chiefly involved in the maintenance of salt and water balance. Similarly, other neurochemicals acting as neurohormones regulate processes related to development and reproduction. We undertake a multi-disciplinary approach to characterize these neuroendocrine regulatory systems utilizing techniques that span the realms of physiology, endocrinology and molecular biology to uncover roles and functions. In addition, in order to comprehensively understand these neuroendocrine signaling networks, which include the hormones and their receptor proteins that are expressed in target cells and tissues, we utilize cell-culture based techniques to validate ligand (i.e. the hormone) and receptor (i.e. the cellular target and cellular elicitor) coupling. In this way, we confirm functional interaction, binding specificity and can elucidate intracellular signalling pathways and mechanisms of action. Some of the fundamental questions driving our research on mosquitoes and ticks include: What neurohormones govern ionic and osmotic balance in these blood-feeding human disease vectors? Which hormones control reproductive behavior and related physiological processes? Do similar signalling molecules control common activities in diverse blood-feeding arthropod species? Once the neurochemicals are elucidated, we seek to identify how target cells and tissues interpret the information carried in the form of a chemical message, which ultimately culminates in a physiological response leading to behavior. The information gained from this research can provide fundamental insights for development of lead compounds useful for control or eradication of these disease vectors. More specifically, integrating the knowledge gained on the biology of these blood-feeding arthropods with data obtained from testing of novel compounds capable of interfering with endogenous neuroendocrine signaling networks, may lead to improved vector control strategies in the future. The proposed research will provide fundamental insight into the basic biology of these organisms and further our knowledge on these medically-important species that have adapted to gorging on vertebrate blood and act as chief vectors of various human and animal diseases.