Pesticide Science (1997) 51, 265-270
D. Martinez-Torres, A.L. Devonshire and M.S. Williamson (1997)
Molecular studies of knockdown resistance to pyrethroids: cloning of domain II sodium channel gene sequences from insects
Pesticide Science 51 (3), 265-270
Abstract: Knockdown resistance (kdr) is a target-site resistance mechanism that confers nerve insensitivity to DDT and pyrethroid insecticides. In the housefly, Musca domestica, molecular cloning of the para-type sodium channel gene has revealed two amino acid mutations that are associated with kdr and super-kdr resistance phenotypes. Both mutations are located in the domain II region of the channel; Leu1014 to Phe in the hydrophobic segment IIS6 and Met918 to Thr in the IIS4-IIS5 linker. To investigate whether these mutations also occur in other insects, we have designed degenerate primers based on conserved sequences in the domain II region of the sodium channel and used these to PCR amplify this region from insecticide-susceptible strains of eight diverse insect species representing four different insect Orders: Helicoverpa armigera, Plutella xylostella, Spodoptera littoralis (Lepidoptera), Blattella germanica (Dictyoptera), Tribolium castaneum (Coleoptera), Myzus persicae, Aphis gossypii and Phorodon humuli (Hemiptera). The primers amplified closely related para-type sodium channel sequences from each insect with a minimum of 85% amino acid identity between species. All of the sequences contained 'susceptible' Leu and Met residues at the positions associated with kdr and super-kdr resistance in the housefly. Recent results detailing the presence of a kdr-type Leu to Phe mutation in pyrethroid-resistant strains of two important agricultural pests, P. xylostella and M. persicae, are discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Martin S. Williamson
Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Tribolium castaneum | ||||
| Helicoverpa armigera | ||||
| Aphis gossypii | ||||
| Myzus persicae | ||||
| Plutella xylostella | ||||
| Musca domestica | ||||
| Blattella germanica | ||||
| Spodoptera littoralis | ||||
| Phorodon humuli |
