title: Multidrug resistance protein gene expression in Trichoplusia ni caterpillars.
abstract: Many insect species exhibit pesticide-resistant phenotypes. One of the mechanisms capable of contributing to resistance is the overexpression of multidrug resistance (MDR) transporter proteins. Here we describe the cloning of three genes encoding MDR proteins from Trichoplusia ni: trnMDR1, trnMDR2 and trnMDR3. Real-time quantitative PCR (qPCR) detected trnMDR mRNA in the whole nervous system, midgut and Malpighian tubules of final instar T. ni caterpillars. To test whether these genes are upregulated in response to chemical challenge in this insect, qPCR was used to compare trnMDR mRNA levels in unchallenged insects with those of insects fed the synthetic pyrethroid, deltamethrin. Only limited increases were detected in a single gene, trnMDR2, which is the most weakly expressed of the three MDR genes, suggesting that increased multidrug resistance of this type is not a significant part of the response to deltamethrin exposure.
authors.affiliation: Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, ON, Canada.
authors.forename: Jason
authors.initials: J
authors.lastname: Simmons
authors.forename: Olivia
authors.initials: O
authors.lastname: D'Souza
authors.forename: Mark
authors.initials: M
authors.lastname: Rheault
authors.forename: Cam
authors.initials: C
authors.lastname: Donly
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics* / Q000378:metabolism; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000284:Administration, Oral; D000818:Animals; D018432:Drug Resistance, Multiple / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007306:Insecticides / Q000008:administration & dosage / Q000494:pharmacology; D008317:Malpighian Tubules / Q000502:physiology; D008969:Molecular Sequence Data; D009036:Moths / Q000187:drug effects* / Q000235:genetics*; D009424:Nervous System Physiological Phenomena / Q000235:genetics; D009570:Nitriles / Q000008:administration & dosage / Q000494:pharmacology; D011722:Pyrethrins / Q000008:administration & dosage / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D000097202:ATP-Binding Cassette Sub-Family B Member 4
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D019476:Insect Proteins; D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; D000097202:ATP-Binding Cassette Sub-Family B Member 4; C017180:decamethrin; C095122:multidrug resistance protein 3