Project Summary
Mosquitoes utilize highly specialized sensory structures and chemical receptors to detect volatile
odors and to orient toward potential host species. Resources that are generally essential to
mosquito survival and reproduction include blood for egg development, water for egg laying and
immature stages, and nectar for cellular respiration. Currently, a critical gap exists in our
understanding of the molecular receptive basis of behavioral responses to volatile compounds like
carboxylic acids (CAs), which serve as attractants for host seeking females. The act of blood
feeding is a critical link in the transmission of disease-causing pathogens like arboviruses between
humans, and between animals to humans. Therefore, it is imperative that we learn more about
the mechanisms that are fundamental to mosquito chemical sensing, especially in vector species
such as Aedes aegypti and Aedes albopictus. Here we propose to apply a heterologous expression
system to characterize the responses of a prioritized subset of candidate CA chemoreceptors that
are conserved across mosquito taxa. In parallel, we will apply cutting-edge technologies to
generate genetic disruptions of high-priority chemoreceptors, based upon their conservation and
their potential to mediate responses to CAs. We will utilize a uniport olfactometer and dual-choice
assay paradigms to examine the impacts of CAs on adult female behaviors under various
physiological states, comparing wild-type versus gene-disrupted lines. The experiments described
in this proposal will help illuminate the roles that CAs play in the biology of Aedes species. By
extension, the discoveries made are likely to apply to other insect taxa, including those with
medical, veterinary, and agricultural importance. As the efficacy of current control strategies
erodes in the wake of insecticide resistance and behavioral adaptations, deepening our
understanding of the chemosensory abilities of Ae. aegypti and Ae. albopictus may facilitate
future improvements in surveillance technologies and in the development of novel methods for
disrupting arbovirus transmission.