Research Overview

Research in the Swale Lab focuses on the neurophysiology, molecular physiology, and neurotoxicology of ion channels and ion transporters in insects and arachnids.  Many species of arthropods have significant impacts on human health, animal health, and the economy and therefore, my research program aims to gain fundamental knowledge that we can apply to reduce the burden of arthropod pests and increase the health of beneficial insects through the ultimate development of novel mechanism insecticides, vaccines, or genetic technologies.  Our research, which is of interest to insect and mammalian physiologists, vector biologists, and toxicologists, can be divided into three independent but complementary topics described below:

1. Physiological characterization of potassium ion channels and transporters in the arthropod nervous system

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Immunostaining for Kir channel expression (blue) in the central nervous system of Drosophila melanogaster

This research aims to characterize the fundamental physiology and toxicological potential of under explored ion channels and transporters in the insect nervous system.  We specifically focus on unexplored potassium conductance and transport pathways  in the neuron and glial cells of Drosophila and mosquito nervous systems.  These studies provide fundamental insights into the neural networks used by arthropods to guide insecticide development or provide a holistic understsanding of model organisms for mammalian disease research. These studies employ state-of-the art methods that include patch clamp electrophysiology, extracellular recordings, calcium imaging, genetic manipulations, and immunocytochemistry.

2. Physiological characterization of ion channels for arthropod salivary gland function and feeding

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Isolated tick salivary gland secreting a droplet of saliva

Blood or sap feeding is the root cause for most damage inflicted by arthropods and thus, the development of products aimed at interrupting the feeding process would be a novel and timely invention for controlling arthropods.  The salivary gland of arthropods is essential to successful feeding events whether it be for blood feeding or sap sucking insects.  Despite the significant role the salivary gland plays in feeding and pathogen transmission, there is an underwhelming amount of knowledge pertaining to the neurobiology, membrane physiology, and organization of the feeding systems for the majority of arthropods.  This lack of knowledge limits the ability to develop novel control agents, such as vaccines and synthetic chemistry.  Considering this, my laboratory aims to characterize the physiological role and toxicological potential of ion channels and ion transporters that maintain the cellular milieu of the gland to ultimately enable salivation and feeding.  These studies employ state of the art methods that include calcium imaging, voltage clamp electrophysiology, immunocytochemistry, electron dispersal microscopy, and biological assays.

3. Pollinator Health and Protection

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Schematic overview of the project

Pollinator health is of current interest to the agricultural and scientific community due to the extreme economic benefit these insects provide combined with the unexplained losses that have been observed over the past decade.  The Swale Lab, in collaboration with Dr. Troy Anderson (U. of Nebraska-Lincoln), is integrating a general understanding of bee biology with advanced physiological techniques to understand the interplay  between potassium ion homeostasis, innate antiviral immunity, and overall health of the honey bee, Apis mellifera. These studies integrate a combination of molecular biology, biochemical assays, biological assays, and field studies.

4. Novel strategies for malaria control

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Dr. Swale in front of a semi-field habitat used for studying the horizontal transfer of novel K+ channel insecticides.  Photo taken at ICIPE – Mbita Point, Kenya

The mosquito, Anopheles gambiae, is the vector of the malaria parasite and is considered to be the deadliest animal in the world.  We received funding from the Bill and Melinda Gates Foundation to evaluate cost-effective attract and kill strategies for controlling populations of Anopheles gambiae in Sub-Saharan Africa that will subsequently reduce the morbidity and mortality of malaria.