Dissecting the gustatory and mechanosensory basis of feeding and egg-laying behaviour in disease-vectoring mosquitoes

Mosquitoes are a critically important threat to public health in Canada and around the globe, transmitting pathogens that cause deadly human disease including malaria, dengue fever, Zika, and West Nile. They transmit these pathogens when they find and bite a human in order to take their blood, using smell to locate a potential victim and their sense of taste and touch to find an optimal place to bite. We believe that it is important to understand the behaviour of these organisms in order to design strategies to improve public health, such as traps and repellents, and that studying sensation in mosquitoes represents a critical opportunity to prevent the spread of disease. In this proposal, we outline a strategy to study taste and touch in mosquitoes taking advantage of the classical laboratory model, the fruit fly, as well as recent technical advances that enable us to directly study the function of genes and neural circuits in the mosquito. Specifically, we aim to identify genes, proteins, and circuits in these animals that are responsible for the taste of salt and the touch of rough texture. Taste and touch show complex interactions as a mosquito navigates its world. For example, salt can be found in human sweat and is an important nutrient on its own, activating many different pathways with dose-dependent positive or negative impacts on feeding behaviour. By contrast, even low levels of salt are a repellent cue for freshwater mosquitoes as they search for places to lay their eggs. In addition to taste, touch guides many different behaviours in mosquitoes, from finding skin and probing for a blood vessel to feed from, to identifying a suitable place to lay eggs. We have previously worked out many of the complexities of taste and touch in the fruit fly, and aim to apply that knowledge to mosquitoes to better understand the similarities and differences between these two organisms. Ultimately, we aim to exploit our findings to prevent mosquitoes from biting humans.