Knockdown of a Nicotinic Acetylcholine Receptor Subunit Gene Bdorß1 Decreases Susceptibility to Oxa-Bridged trans- instead of cis-Nitromethylene Neonicotinoid Insecticides in Bactrocera dorsalis.

ABSTRACT

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that mediate the fast action of acetylcholine in synaptic cholinergic transmissions. Insect nAChRs are the target of several classes of insecticides. Here, the full-length cDNA encoding a nAChR beta1 subunit (Bdorß1) was identified and characterized from a destructive pest, Bactrocera dorsalis. The amino acid sequence of Bdorß1 shows high identities to other insect nAChRs ß1 subunits. Double injection of dsBdorß1 reduced the expression of Bdorß1 and in turn significantly decreased susceptibility to oxa-bridged trans- instead of cis-nitromethylene neonicotinoids. Our results support the involvement of Bdorß1 in the susceptibility of B. dorsalis to oxa-bridged trans- instead of cis-nitromethylene neonicotinoids and imply that these two classes of neonicotinoids might be acting at different nAChR subtypes.