what we study
In-flight mosquito mating (photo credit: Alex Wild)
How do Mosquitoes regulate their INnate behaviors?
WHAT NEUROPEPTIDE PATHWAYS AND CIRCUITS REGULATE THE DRAMATIC SUPPRESSION OF ATTRACTION TO HUMANS AFTER BLOOD-FEEDING?
Many species of mosquitoes, exhibit a pattern of active host-seeking where they search for human hosts to bite and feed on their blood, followed by inhibition after blood-feeding when they almost completely suppress their attraction to host cues.
We are using pharmacological and genetic approaches to understand how mosquitoes regulate their attraction to humans and what anatomical circuits are involved in this dramatic behavioral switch.
WHAT ARE THE NEUROPEPTIDE PATHWAYS THAT CONTROL CIRCADIAN AND SEASONAL BITING RHYTHMS?
Understanding when mosquitoes are actively biting is important for effective vector control. Some species of mosquitoes undergo seasonal changes in reproduction, host-seeking and feeding behavior when they, or their embryos enter a dormancy state called diapause to survive the winter. Neuropeptides, notably Pigment Dispersing Factor (PDF), regulate circadian rhythms in insects and have been implicated in mediating diapause entry in many insects.
We are developing methods to quantify circadian behavior in mosquitoes and genetic techniques to disrupt these pathways and investigate their role in daily and seasonal patterns of host-seeking and reproduction.
WHAT ARE THE SIGNALING MECHANISMS THAT INHIBIT RE-MATING AND PREVENT INTERSPECIES MATING?
Female Ae. aegypti mosquitoes typically mate only once with one male in their lifetime. This single mating event provisions the female with sufficient sperm to fertilize all of the eggs that she will produce for the rest of her life. Successful mating induces lifetime refractoriness to subsequent insemination by other males, thereby enforcing the paternity of the first male. We have implicated HP-I, an Aedes- and male-specific peptide transferred to females, and its receptor in the female, NPYLR1, in rapid enforcement of paternity but the pathways responsible for lifetime changes remain unknown.
We are working to profile the compounds transferred to Ae. aegypti females during satyrization, determine which receptors they activate in the female, and characterize female mating circuitry. These experiments will identify the signals that regulate mating behavior within, and between mosquito species and the cognate receptors in the female that regulate innate mating behavior.