Exposure to a sublethal dose of imidacloprid induces cellular and physiological changes in Periplaneta americana: Involvement of α2 nicotinic acetylcholine subunit in imidacloprid sensitivity
Résumé
Neonicotinoids are the most important class of insecticides used as pest management tools during several decades. Exposition of insect to sublethal dose of insecticide induces physiological and cellular changes that could contribute to the adaptation of the insects in order to loss their sensitivity to insecticides. The aim of our study is to demonstrate that a subchronic exposure to a sublethal dose of a neonicotinoid imidacloprid is sufficient to induce molecular changes leading to a loss of imidacloprid sensitivity. We report that in the cockroach, Periplaneta americana, subchronic exposure to a sublethal dose of imidacloprid induced weak changes in detoxification enzyme activity and a significant decrease of the nicotinic acetylcholine α2 mRNA. This molecular effect is correlated to a decrease of imidacloprid sensitivity of cockroaches. Using RNA interference, we shown the key role of nicotinic acetylcholine α2 subunit in imidacloprid sensitivity. Thus, quantitative changes in insecticide targets lead to decreased sensitivity to insecticides. This parameter needs to be considered in order to develop sustainable insect resistance management strategies.