Seminal fluid molecules (SFMs), which are produced by males and transferred to females during mating, have profound impacts on the feeding, reproduction, and lifespan of female insects, including Aedes aegypti and Ae. albopictus, the main vectors of several viruses that are devastating to human health. Identifying the individual bioactive SFMs and their mode of action in Aedes mosquitoes will provide new pathways and tools for stemming disease spread by this species. We have carefully laid the groundwork for such investigations by identifying seminal fluid proteins in both Ae. aegypti and Ae. albopictus. We are now poised to investigate the functions of individual seminal fluid proteins in regulating female behavior and physiology. One of the proteins we discovered in the seminal fluid is adipokinetic hormone (AKH). Across a range of insects, AKHs? effects include modulating insect response to nutritional stress by inducing release of nutrients from the fat body, mediating oxidative stress, and regulating egg production, feeding, and digestion. AKH?s role in Aedes mosquitoes is unknown and AKH. Given the effects of AKHs in other insects, we hypothesize that seminal fluid-derived AKH is important in regulating the post-mating changes in nutrition-related phenotypes observed in Aedes females. We will test this hypothesis by testing the effect of eliminating seminal fluid AKH on female post-mating responses.
In Aim I, we will compare female blood feeding, blood digestion, egg production, and longevity between females mated to wildtype and AKH-null males.
In Aim 2, we will identify the location of the receptors within females that bind seminal fluid AKH.
In Aim 3, we will determine what genes and molecular pathways are regulated by receipt of seminal fluid AKH. The experiments outlined here will identify behavioral and physiological phenotypes and molecular pathways that are manipulatable through exogenous signaling. Further, they will expand our understanding of the role of adipokinetic hormones. Finally, this proposal will provide outstanding research and training opportunities for many undergraduate students allowing them to learn techniques in studying behavior, physiology, molecular biology, neurobiology, and biochemistry. The PI and the consultants on the project have extensive experience training undergraduates in these techniques.
Each aim i s divided into proposed experiments that are within the scope of a typical individual thesis project at the College of Wooster or could be completed by multiple students working collaboratively on different aspects of the experiment. Such collaborative projects would expose students to a wider range of approaches and methodologies than would be possible if they were working independently. Thus, the funding provided by this grant would greatly strengthen the research experiences and collaborative opportunities for students across the life sciences at The College of Wooster and prepare these students to take integrative multi-disciplinary approaches to problem solving in the careers they pursue after graduation.
This main goal of this proposal is to better understand the overall function of a protein that males transfer to females in their seminal fluid in Aedes aegypti, the mosquito that transmits dengue, Zika, chikungunya, and yellow fever. The particular protein, the adipokinetic hormone, is an important regulator of physiology and behavior in insects but has never before been found in the seminal fluid of any animal. Because seminal fluid proteins are known to affect blood feeding, egg production, and longevity of female Ae. aegypti, we propose to study the impact of seminal fluid derived AKH on these phenotypes to identify potential new targets for mosquito control.
