Knockdown of a Nicotinic Acetylcholine Receptor Subunit Gene Bdorβ1 Decreases Susceptibility to Oxa-Bridged trans- instead of cis- Nitromethylene Neonicotinoid Insecticides in Bactrocera dorsalis

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 (Bdor beta 1) was identified and characterized from a destructive pest, Bactrocera dorsalis. The amino acid sequence of Bdor beta 1 shows high identities to other insect nAChRs beta 1 subunits. Double injection of dsBdor beta 1 reduced the expression of Bdor beta 1 and in turn significantly decreased susceptibility to oxa-bridged trans-instead of cis-nitromethylene neonicotinoids. Our results support the involvement of Bdor beta 1 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.

Automated summary

Nicotinic acetylcholine receptors (nAChRs) play a crucial role in mediating the fast action of acetylcholine in synaptic transmissions. In this study, a gene encoding nAChR beta1 subunit was identified and characterized in a destructive pest, Bactrocera dorsalis. The results suggest that this subunit is involved in the susceptibility of B. dorsalis to a specific class of neonicotinoid insecticides.