The Effect of Diet on Aquaporin Abundance and Localization in the Female and Male Disease Vector Mosquito, Aedes aegypti

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The disease vector mosquito, Aedes aegypti, is found in tropical and sub-tropical regions around the globe and is responsible for the transmission of many deadly diseases such as dengue fever and chikungunya. Adult A. aegypti are sexually dimorphic terrestrial animals since both the males and females feed on nectar for basic nutrients, females mosquitoes require a blood meal from a vertebrate host to produce viable eggs. The blood meal poses an osmoregulatory challenge to the female mosquito because the meal is about 3x its body weight in water, plasma, and proteins. The Malpighian tubules (MTs) are the primary osmoregulatory organ, responsible for producing an ion-rich primary urine through hormone activated ion transport driven by an H+-ATPase. Through diuretic hormone control, the MTs are able to begin secretion of primary urine almost immediately following the onset of blood feeding and this process requires intermembrane transporters called aquaporins (AQPs). The concentration of ions in the lumen of the MTs drives water from the hemolymph into the lumen of the MTs by osmosis to produce primary urine. Osmosis is facilitated by the expression of AQPs in the cells of the MTs. Six AQPs have been identified in A. aegypti, most of which are all selective for water and some solutes. It is hypothesized that a blood meal in female A. aegypti, with knowledge that mRNA levels of AQP1 are increased in the MTs ~3-24hrs post blood meal, will have an effect on the localization and protein abundance of AQPs in the MTs. It was also hypothesized that the starvation of male A. aegypti would have an effect on the localization and abundance of AQPs in the MTs. Thus far, AQP1 & 4 have been localized throughout the body of both the male and female A. aegypti using immunohistochemistry. Immunolocalization of AQPs shows evidence that a blood meal has a significant effect on the localization in the female A. aegypti. It has also been found that, following Western blot analysis, a blood meal may significantly increase the protein abundance AQP1 and 4 in the MTs of the females. It has been shown that in the male A. aegypti, AQP4 abundance is significantly increased in the fat body.