A nicotinic acetylcholine receptor mutation conferring target-site resistance to imidacloprid inNilaparvata lugens(brown planthopper)

Abstract

Neonicotinoids, such as imidacloprid, are nicotinic acetylcholine receptor (nAChR) agonists with potent insecticidal activity. Since its introduction in the early 1990s, imidacloprid has become one of the most extensively used insecticides for both crop protection and animal health applications. As with other classes of insecticides, resistance to neonicotinoids is a significant threat and has been identified in several pest species, including the brown planthopper, Nilaparvata lugens, a major rice pest in many parts of Asia. In this study,

The invertebrate pharmacology of insecticides acting at nicotinic acetylcholine receptors

“…Heterozygous N. lugens displayed a lower level of resistance, suggesting that the Y151S mutation is required in two separate nAChR genes for high level resistance to occur. 68) Correlating this observation with the findings in N. Lugens that the high and low affinity [ 3 H]-IMI binding sites contain Nlα3 and Nlα1 respectively, this suggests that a mutation in both binding sites is required to achieve high level resistance (it should be noted no investigations were performed on these insects to understand whether any non-target site alterations contributed to resistance. For example, the susceptible and resistant strains were not back-crossed to near isogenicity).…”

“…More recently, the presence of dual affinity binding sites for [ 3 H]-IMI has also been observed in another hemipteran species, Nilaparvarta lugens (brown plant hopper) further solidifying the argument that hemipteran pests have two binding sites. 68,69) Certainly, not all studies on hemipteran pests have identified dual binding sites and this is likely to be down to the difficult nature of the experiments to tease out the very high affinity but low abundance site, as well as differences in interpretation of the data. 67,70) However, a general trend appears to be that when low % Triton X-100 is included in incubations the duality of binding disappears and only a single binding site (low nM K d ) is observed in aphid and fly species.…”

“…[78][79][80] The Y151 amino acid is highly conserved between insects and mammals, so itself is not thought to be directly involved in IMI binding, rather the presence of the serine may induce a conformational change within the binding site rendering it less favourable to interaction. 68,81) The proposed effect of the Y151S on neonicotinoid binding to insect nAChRs has recently been modelled using the crystal structures of Lymnaea stagnalisACh binding protein (Ls-AchBP) in complex with IMI. 56) 2.1.2.…”

A review of experimental techniques used for the heterologous expression of nicotinic acetylcholine receptors

“…In addition, Xenopus oocytes have been used successfully to examine nAChR subunits cloned from several invertebrate species, including the aphid Myzus persicae [89], the brown planthopper Nilaparvata lugens [90], the fruit fly Drosophila melanogaster [69,91], the locust Schistocerca gregaria [92] and the nematode Caenorhabditis elegans [93,94]. Frustratingly, the heterologous expression of invertebrate nAChRs has proved to be extremely difficult [59,95] and, in several instances, this has often been achieved only by co-expression with vertebrate nAChR subunits [65,91,96,97].…”

“…Hybrid nAChRs that contain both insect and vertebrate nAChR subunits have also been used extensively in an attempt to circumvent problems encountered with the inefficient heterologous 12 expression of insect nAChRs [59,95]. This approach has been adopted for studies of nAChRs cloned from insect species, including the aphid Myzus persicae [150,151], the brown planthopper Nilaparvata lugens [90,97], the cat flea Ctenocephalides felis [152] and the fruit fly Drosophila melanogaster [91,96,118,153].…”