title: Identification of mutations conferring insecticide-insensitive AChE in the cotton-melon aphid, Aphis gossypii Glover.
abstract: We have identified two mutations in the ace1 gene of Aphis gossypii that are associated with insensitivity of acetylcholinesterase (AChE) to carbamate and organophosphate insecticides. The first of these, S431F (equivalent to F331 in Torpedo californica), is associated with insensitivity to the carbamate insecticide pirimicarb in a range of A. gossypii clones. The S431F mutation is also found in the peach-potato aphid, Myzus persicae (Sulzer), and a rapid RFLP diagnostic allows the identification of individuals of both aphid species with a resistant genotype. This diagnostic further revealed the presence of S431 in several other pirimicarb-susceptible aphid species. The serine at this position in the wild-type enzyme has only been reported for aphids and provides a molecular explanation of why pirimicarb has a specific aphicidal action. A less specific insensitivity to a wide range of carbamates and organophosphates is associated with a second mutation, A302S (A201 in T. californica).
authors.affiliation: Biological Chemistry, Rothamsted Research, Harpenden, Herts, UK.
authors.forename: M C
authors.initials: MC
authors.lastname: Andrews
authors.forename: A
authors.initials: A
authors.lastname: Callaghan
authors.forename: L M
authors.initials: LM
authors.lastname: Field
authors.forename: M S
authors.initials: MS
authors.lastname: Williamson
authors.forename: G D
authors.initials: GD
authors.lastname: Moores
mesh_terms: D000110:Acetylcholinesterase / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001042:Aphids / Q000235:genetics*; D001483:Base Sequence; D002219:Carbamates; D016000:Cluster Analysis; D017931:DNA Primers; D007305:Insecticide Resistance / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D010755:Organophosphates; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D011487:Protein Conformation; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D002219:Carbamates; D017931:DNA Primers; D010755:Organophosphates; D000110:Acetylcholinesterase