The Role of Adipokinetic Hormone in Female Aedes aegypti Mosquito Bloodmeal Digestion

Expanding urbanization has extended the reach of Aedes aegypti mosquitoes, enabling bloodfeeding females to transmit pathogens, such as yellow fever, dengue fever, chikungunya, Zika fever, and others, to millions of people each year. Various tools, such as insecticides and release of Wolbachia-infected mosquitoes, among others, have been implemented to decrease the population of mosquitoes; these tools have, however, not been fully effective. In an effort to limit the spread of pathogens, this study focuses on understanding the reproductive biology of the seminal fluid proteins (SFPs) of Aedes aegypti. SFPs, which are received by the female mosquitoes during mating, are known to influence their physiology and behavior. Of all the SFPs, adipokinetic hormone (AKH), which is implicated in the metabolism of energy, stands out the most as it was recently discovered in the seminal fluid of insects. Previous studies show that AKH signaling increases the activity of digestive enzymes and the rate of digestion in flesh flies and firebugs. This study thus served to investigate if AKH plays a role in female Ae. aegypti bloodmeal digestion. The main objective of this project was to investigate if AKH increases the activity of digestion in female mosquitoes. To be able to accomplish this goal, a proper methodology for measuring and analyzing bloodmeal digestion was first investigated. Analysis of the SDS-PAGE of the samples of bloodmeal extracted from the midgut of mosquitoes from various treatment groups at different time points showed that the intensity of the 10kD band at 12 and 20hrs post-feeding was a good indicator of digestion rate. The effects of SFPs on the digestion rate were confirmed. The results from this study show that AKH may not be implicated in bloodmeal digestion. This observation brings us a step closer to understanding the full mechanism and effect of SFPs in mated female Aedes mosquitoes, as they are yet to be fully elucidated