Acquisition of many diseases requires transmission to humans through the mosquito. One strategy to decrease ill effects of diseases with an obligate mosquito host transfer stage involves an understanding of mosquito sensory biology. However, the visual system of mosquitoes has gone understudied until recent years. The goal of my work was to expand on the existing knowledge in this field. Chapter 2 demonstrates that the major rhodopsin, Aaop1, is expressed in all ommatidial units and in a rhythmic fashion. Furthermore, the management of localization of this protein into and out of rhabdomeric membranes is a light-dependent process that is required for maturation. In Chapter 3 I show that the movement of Aaop1 into the rhabdomeres correlates with an ~1.5 log unit increase in sensitivity to light. This allows for heightened sensitivity during the morning peak activity when the mosquitoes are under low light conditions. During the course of these experiments it became clear that there is an influence of the circadian clock on the visual system in Ae. aegypti. In Chapter 4 I supplement the limited information regarding the circadian clocks effect on gene expression. I describe the generation of a publicly available database of gene expression under both normal light dark and constant dark conditions. This database is now available at http://www3.nd.edu/~bioclock/aedes.html. An in depth analysis of data made available from the Ae. aegypti Circadian Database allowed for two advances in understanding the influence of the circadian clock in mosquitoes. In Chapter 5 I first examine visual system specific genes to reveal a tight regulation of the circadian clock on expression of many genes involved in phototransduction. Secondly, the analysis provided a comparison of Ae. aegypti to other dipterans in which similar studies have been completed. This revealed that the circadian regulation of visual gene expression is conserved between both Ae. aegypti and An. gambiae mosquitoes but not in Drosophila.
|Contributor||Dave Severson, Committee Member|
|Contributor||Giles Duffield, Committee Member|
|Contributor||Joseph OTousa, Committee Chair|
|Contributor||Zain Syed, Committee Member|
|Degree Level||Doctoral Dissertation|
|Degree Discipline||Biological Sciences|
|Departments and Units|