Functional characterization of olfactory receptors and molecular species identification of vector mosquitoes.

Mosquitoes are responsible for the transmission of hundreds of etiological agents. Many of these are emerging infectious diseases including, dengue, malaria, yellow fever, and Zika. Not all species of mosquitoes are responsible for vectoring these pathogens however, so accurate identification and surveillance are extremely important and directly impact human health. DNA barcoding allows for a rapid, accurate, and reliable species identification and does not rely on morphological features. Our method utilizes a highly conserved mitochondrial gene cytochrome oxidase 1 (CO1) to determine species identity based on single nucleotide polymorphisms (SNPs). Molecular species identification allows for discrimination between morphologically similar specimens without the need for taxonomical expertise and dramatically decreases hands on time spent identifying individual samples. Timely surveillance of species-specific vector introductions can help mitigate the impact vector disease contributes to public health. Mosquitoes can detect environmental cues by utilizing sensory appendages such as antennae, maxillary palps, and labella. These structures are covered in small hair-like sensilla. Within sensilla reside dendritic extensions of olfactory sensory neurons that are embedded with ligand gated olfactory receptors. Mosquito sensory receptors consist of three main families comprising odorant receptors (Ors), ionotropic receptors (Irs), and gustatory receptors (Grs). Detection of semiochemicals via olfactory receptors modulates behaviors including nectar seeking, host seeking, oviposition site selection, mate selection, and resting place selection, all of which have direct impacts on vector fitness. The discovery of behaviorally relevant odorants and their corresponding receptors has the potential to impact vector surveillance and control by leading to the development of novel deterrents, personal protective compounds, and implementation of push-pull vector management. As the efficacy of current control strategies erodes in the wake of insecticide resistance and behavioral adaptations in mosquito populations, new approaches will become increasingly more important to vector management programs. Deepening our understanding of the chemosensory abilities of vector species may facilitate future improvements in surveillance technologies and may aid in the development of novel methods for disrupting arbovirus transmission.