title: Molecular characterization of the amplified carboxylesterase gene associated with organophosphorus insecticide resistance in the brown planthopper, Nilaparvata lugens.
abstract: Widespread resistance to organophosphorus insecticides (OPs) in Nilaparvata lugens is associated with elevation of carboxylesterase activity. A cDNA encoding a carboxylesterase, Nl-EST1, has been isolated from an OP-resistant Sri Lankan strain of N. lugens. The full-length cDNA codes for a 547-amino acid protein with high homology to other esterases/lipases. Nl-EST1 has an N-terminal hydrophobic signal peptide sequence of 24 amino acids which suggests that the mature protein is secreted from cells expressing it. The nucleotide sequence of the homologue of Nl-EST1 in an OP-susceptible, low esterase Sri Lankan strain of N. lugens is identical to Nl-EST1. Southern analysis of genomic DNA from the Sri Lankan OP-resistant and susceptible strains suggests that Nl-EST1 is amplified in the resistant strain. Therefore, resistance to OPs in the Sri Lankan strain is through amplification of a gene identical to that found in the susceptible strain.
authors: Cardiff University Centre for Pest Management, Cardiff School of Biosciences, Cardiff University, PO Box 915, Cardiff CF10 3TL, Wales, UK. SmallG@cardiff.ac.uk
authors: G J
authors: GJ
authors: Small
authors: J
authors: J
authors: Hemingway
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases / Q000235:genetics*; D018076:DNA, Complementary; D006430:Hemiptera / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009943:Organophosphorus Compounds; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D007306:Insecticides; D009943:Organophosphorus Compounds; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase