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Comparison of esterase gene amplification, gene expression and esterase activity in insecticide susceptible and resistant strains of the brown planthopper, Nilaparvata lugens (Stål)
Author(s) -
Vontas J. G.,
Small G. J.,
Hemingway J.
Publication year - 2000
Publication title -
insect molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 93
eISSN - 1365-2583
pISSN - 0962-1075
DOI - 10.1046/j.1365-2583.2000.00228.x
Subject(s) - brown planthopper , biology , esterase , carboxylesterase , gene , delphacidae , microbiology and biotechnology , gene expression , gene duplication , genetics , enzyme , homoptera , biochemistry , pest analysis , botany
Organophosphorus and carbamate insecticide resistance in Nilaparvata lugens is based on amplification of a carboxylesterase gene, Nl‐EST1. An identical gene occurs in susceptible insects. Quantitative real‐time PCR was used to demonstrate that Nl‐EST1 is amplified 3–7‐fold in the genome of resistant compared to susceptible planthoppers. Expression levels were similar to amplification levels, with 1–15‐fold more Nl‐EST1 mRNA in individual insects and 5–11‐fold more Nl‐EST1 mRNA in mass whole body homogenates of resistant females compared to susceptibles. These values corresponded to an 8–10‐fold increase in esterase activity in the head and thorax of individual resistant insects. Although amplification, expression and activity levels of Nl‐EST1 in resistant N. lugens were similar, the correlation between esterase activity and Nl‐EST1 mRNA levels in resistant individuals was not linear.