Females of the Southern House mosquito, Culex quinquefasciatus, rely on environmental cues, also known as oviposition attractants (OAs), to locate suitable sites for laying eggs. Their antennae are endowed with hair-like structures called sensilla. We have already identified three types of sensilla on the antennae of the Southern House mosquito that detect OAs. This research is aimed at testing the hypothesis that both odorant-binding proteins (OBPs) and odorant receptors (ORs), which are harbored in these sensilla, are essential for reception of OAs. Affinity of OBPs mined from the Culex genome towards a small set of known OAs will be measured. Function of OBPs with high affinity for OAs will be further evaluated by RNAi and electrophysiology to unambiguously identify those involved in OA reception. Candidate ORs identified from the genome will be expressed in the Xenopus oocyte system and tested against a panel of odorants, which include known OAs. A comparison of their response profiles with the profiles obtained from the mosquito antennae in our preliminary studies will allow identification of receptors and their localization in the OA-detecting sensilla. The olfactory proteins involved in OA reception will be used to screen a library of natural products to prospect for a second generation of OAs. Compounds already identified in preliminary studies and those derived from the above-mentioned molecular approaches will be tested by indoor behavioral studies and ultimately in the field. That way we plan to develop better OAs for monitoring and surveillance as well as to pave the way for novel environmentally friendly strategies for controlling Culex mosquito populations.
Mosquitoes in the genus Culex are vectors of pathogens causing human diseases throughout the world, including filariasis, various types of encephalitis, and in the United States they spread West Nile Virus while feeding on birds and humans. Vector surveillance and monitoring of Culex populations are reliant on chemical cues to attract gravid females searching for oviposition sites, but current trapping technologies need improvements, particularly the development of better oviposition attractants (OAs). This research is aimed at advancing our knowledge of mosquito olfaction as well as to develop a second generation of OAs, which may be used for trapping, surveillance and possibly green chemistry for controlling mosquito populations.
|Pelletier, Julien; Xu, Pingxi; Yoon, Kyong S et al. (2015) Odorant receptor-based discovery of natural repellents of human lice. Insect Biochem Mol Biol 66:103-9|
|Yin, Jiao; Choo, Young-Moo; Duan, Hongxia et al. (2015) Selectivity of odorant-binding proteins from the southern house mosquito tested against physiologically relevant ligands. Front Physiol 6:56|
|Xu, Pingxi; Choo, Young-Moo; De La Rosa, Alyssa et al. (2014) Mosquito odorant receptor for DEET and methyl jasmonate. Proc Natl Acad Sci U S A 111:16592-7|
|Leal, Walter S (2014) The enigmatic reception of DEET - the gold standard of insect repellents. Curr Opin Insect Sci 6:93-98|
|Ueira-Vieira, Carlos; Kimbrell, Deborah A; de Carvalho, Washington J et al. (2014) Facile functional analysis of insect odorant receptors expressed in the fruit fly: validation with receptors from taxonomically distant and closely related species. Cell Mol Life Sci 71:4675-80|
|Xu, Pingxi; Choo, Young-Moo; Pelletier, Julien et al. (2013) Silent, generic and plant kairomone sensitive odorant receptors from the Southern house mosquito. J Insect Physiol 59:961-6|
|Leal, Walter S (2013) Odorant reception in insects: roles of receptors, binding proteins, and degrading enzymes. Annu Rev Entomol 58:373-91|
|di Luccio, Eric; Ishida, Yuko; Leal, Walter S et al. (2013) Crystallographic observation of pH-induced conformational changes in the Amyelois transitella pheromone-binding protein AtraPBP1. PLoS One 8:e53840|
|Leal, Walter S; Choo, Young-Moo; Xu, Pingxi et al. (2013) Differential expression of olfactory genes in the southern house mosquito and insights into unique odorant receptor gene isoforms. Proc Natl Acad Sci U S A 110:18704-9|
|Xu, Pingxi; Leal, Walter S (2013) Probing insect odorant receptors with their cognate ligands: insights into structural features. Biochem Biophys Res Commun 435:477-82|
Showing the most recent 10 out of 13 publications