title: Linkage of genes for sodium channel and cytochrome P450 (CYP6B10) in Heliothis virescens.
abstract: Genetic linkage of hscp (heliothis sodium channel protein) and CYP6B10 was discovered in Heliothis virescens. The hscp gene encodes the sodium channel target of pyrethroid insecticides and cytochrome P450 genes encode important enzymes involved in detoxication of various pesticides. Previously, two mechanisms, nerve insensitivity due to sodium channel and synergism by propynyl aryl ethers, were observed in pyrethroid-resistant H virescens and were not separated by repeated back-crossing. We hypothesized genetic linkage of target site insensitivity and monooxygenase-mediated detoxication. Single nucleotide polymorphisms were discovered in IIS6 of hscp; Hpy of hscp and CYP6B10. Segregation of these and other markers was tested in backcrosses. We observed cosegregation of hscp to CYP6B10, but both genes assorted independently of y, ye and sex. Genes y and ye assorted independently of each other. This was the first observation of linkage between genes controlling detoxication and sodium ion channel insensitivity in a species known to express high levels of pyrethroid resistance. Linkage was not likely because this species has 31 chromosomes; therefore, we will investigate the possibility of a resistance cassette. We expect similar linkage in other noctuid pests.
authors.affiliation: Department of Environmental Toxicology, Clemson University, Clemson, SC 29634, USA.
authors.forename: Sujin
authors.initials: S
authors.lastname: Park
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Brown
mesh_terms: D000818:Animals; D003433:Crosses, Genetic; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D005838:Genotype; D019476:Insect Proteins / Q000235:genetics*; D007305:Insecticide Resistance / Q000235:genetics; D007306:Insecticides / Q000494:pharmacology; D008297:Male; D009036:Moths / Q000235:genetics*; D010641:Phenotype; D011722:Pyrethrins / Q000494:pharmacology; D015222:Sodium Channels / Q000235:genetics*
chemical_list: D019476:Insect Proteins; D007306:Insecticides; D011722:Pyrethrins; D015222:Sodium Channels; C108458:cytochrome P-450 CYP9A1; C017160:cypermethrin; D003577:Cytochrome P-450 Enzyme System