Semester of Graduation

Spring 2020

Degree

Master of Science (MS)

Department

Entomology

Document Type

Thesis

Abstract

The mosquito salivary gland is a critical aspect of mosquito biology because it is integral to the mosquito’s ability to imbibe blood meals and transmit disease-causing pathogens and parasites. This study aimed to characterize the neurochemical regulation of the Aedes aegypti salivary gland and the functional role of inward-rectifying potassium (Kir) conductance in the secretory activity of the salivary gland and feeding biology of Ae. aegypti mosquitoes. Collectively, these data provide insights to the development of novel mode- and mechanism- mosquitocides

In Chapter 2, we demonstrated that Ae. aegypti salivation is stimulated by dopamine and that dopamine increases secretion of amylase, but not apyrase in the saliva. We also showed that pilocarpine stimulates saliva secretion, though it is approximately 30-fold less potent than either dopamine or serotonin, and increases apyrase secretion, but not amylase. In addition, we aimed to determine the spatial expression patterns of the presumptive dopamine receptor through immunohistochemical techniques. Images indicate receptors reactive to the mammalian D1 receptors are expressed at higher density in the distal regions of the medial and lateral lobes of the gland while receptors reactive to mammalian D2 receptors were localized more heavily at the proximal lateral lobes.

In Chapter 3 we aimed to assess the role of Kir channels in the secretory activity of the Ae. aegypti salivary gland, blood feeding ability, and vector competency. Data indicate pinacidil and VU0071063, which are activators of ATP-gated Kir channels, inhibit the secretory activity of the salivary gland by 15- and 13.3-fold respectively. Inclusion of pinacidil and VU0071063 in a blood meal reduces blood-feeding rate to 2.6 ± 1.3% and 8.1 ± 6%, respectively. Importantly, we observed no acquisition of dengue virus or dissemination of a model pathogen by mosquitoes fed pinacidil-treated blood. The data presented in this thesis highlight pharmacological KATP channel activation as a potential novel mechanism to reduce the spread of mosquito-borne pathogens.

Committee Chair

Daniel R. Swale

Available for download on Monday, March 15, 2027

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