Biology Department Special Seminar | Ke Dong, Michigan State University | Pyrethrum and pyrethroid insecticides target voltage-gated sodium channels and olfactory receptors

Pyrethrum is a botanical insecticide extracted from dried flowers of Chrysanthemum cinerariaefolium. Pyrethroids are synthetic derivatives of pyrethrins and used in pest control worldwide due to their high insecticidal activity and low mammalian toxicity. Both pyrethrins and pyrethroids exert their toxic effects by targeting voltage-gated sodium channels. Besides insecticidal activity, pyrethrum and volatile pyrethroids also possess strong insect repellent activity and are common ingredients of mosquito coils and other mosquito-repellent devices. Despite global use as insect repellents, the mechanism underlying pyrethrum/pyrethroid repellency remains enigmatic. In the first part of my seminar, I will overview our work to understand the molecular interactions between voltage-gated sodium channels and pyrethroids. In the second part of my talk, I will highlight our recent efforts to elucidate the molecular basis of pyrethrum/pyrethroid repellency. Our work suggests an involvement of both sodium channels and olfactory receptors in pyrethrum/pyrethroid repellency.