Molecular and General Genetics MGG

, Volume 240, Issue 1, pp 17–22

Knockdown resistance (kdr) to DDT and pyrethroid insecticides maps to a sodium channel gene locus in the housefly (Musca domestica)

  • Martin S. Williamson
  • Ian Denholm
  • Caroline A. Bell
  • Alan L. Devonshire
Original Articles

DOI: 10.1007/BF00276878

Cite this article as:
Williamson, M.S., Denholm, I., Bell, C.A. et al. Molec. Gen. Genet. (1993) 240: 17. doi:10.1007/BF00276878

Abstract

The voltage-sensitive sodium channel is generally regarded as the primary target site of dichlorodiphenyl-trichloro-ethane (DDT) and pyrethroid insecticides, and has been implicated in the widely reported mechanism of nerve insensitivity to these compounds. This phenomenon is expressed as knockdown resistance (kdr) and has been best characterised in the housefly where several putative alleles, including the more potent super-kdr factor, have been identified. We report the isolation of cDNA clones containing part of a housefly sodium channel gene, designated Msc, which show close homology to the para sodium channel of Drosophila (99% amino acid identity within the region of overlap). Using Southern blots of insect DNA, restriction fragment length polymorphisms (RFLPs) at the Msc locus were identified in susceptible, kdr and super-kdr housefly strains. These RFLPs showed tight linkage to resistance in controlled crosses involving these strains, thus providing clear genetic evidence that kdr, and hence pyrethroid mode of action, is closely associated with the voltage-sensitive sodium channel.

Key words

Musca domestica Sodium channel gene Pyrethroids Knockdown resistance (kdr

Copyright information

© Springer-Verlag 1993

Authors and Affiliations

  • Martin S. Williamson
    • 1
  • Ian Denholm
    • 1
  • Caroline A. Bell
    • 1
  • Alan L. Devonshire
    • 1
  1. 1.Institute of Arable Crops ResearchRothamsted Experimental StationHarpendenUK

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