title: CYP6B2 Expression in Insecticide-Resistant and -Suspcitible Strains of Helicoverpa armigera.
abstract: A fragment of CYP6B2 gene was obtained from the midgut cDNA library of the fifth instar larvae of the ballworm (Helicoverpa armigera) with RT-PCR. The product of 627 bp was cloned and sequenced. The results of dot blotting analysis of mRNA proved that CYP6B2 is expressed at higher level (mRNA) in an insecticide-resistant strain than in a susceptible strain, showing that the regulation was at transcription level. The mRNA is induced by pyrethroid in susceptible, but not in the insecticide-resistant strains. We guess that mutation in the 5' upstream regulator of the insecticide-resistant strain may lead to the difference in the expression level between resistant and susceptible strains.
authors.affiliation: Shanghai Institute of Entomology, the Chinese Academy of Sciences, Shanghai 200025, China. tangzh@public6.sta.net.cn
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Pei-Jun
authors.initials: PJ
authors.lastname: Zhuang
authors.forename: Zheng-Hua
authors.initials: ZH
authors.lastname: Tang
authors.forename: Hua
authors.initials: H
authors.lastname: Pan
authors.forename: Xiang-Fu
authors.initials: XF
authors.lastname: Wu