title: A single amino acid change in the para sodium channel protein is associated with knockdown-resistance (kdr) to pyrethroid insecticides in German cockroach.
abstract: Previous genetic and pharmacological studies suggest that knockdown-resistance (kdr) to pyrethroid insecticides likely results from a mutation(s) in the para sodium channel gene. In this study, para sodium channel genes from an insecticide-susceptible German cockroach strain, CSMA, and a kdr-type German cockroach strain, Ectiban-R, were cloned and sequenced. Comparison of the nucleotide sequences of paraCSMA and paraEctiban-R revealed two nucleotide differences at nt 1491 and nt 2979, respectively. Only the difference at nt 2979 (G in paraCSMA and C in paraEctiban-R) resulted in an amino acid change (Leu993 in CSMA and Phe993 in Ectiban-R). Leu993/Phe993 is located in the highly conserved membrane-spanning segment 6 of domain II (IIS6). Furthermore, reverse transcription-polymerase chain reaction (RT-PCR) sequence analysis using another two insecticide-susceptible and one kdr German cockroach strain, revealed that C2979 was specifically associated with kdr resistant strains, whereas only G2979 was present in all susceptible strains. These results suggest that a single amino acid change from Leu993 to Phe993 is responsible for the kdr-type resistance in German cockroach.
authors.affiliation: Department of Entomology, Michigan State University, East Lansing 48824, USA.
authors.forename: K
authors.initials: K
authors.lastname: Dong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003058:Cockroaches / Q000235:genetics; D018076:DNA, Complementary; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007305:Insecticide Resistance; D007930:Leucine; D008969:Molecular Sequence Data; D010649:Phenylalanine; D011722:Pyrethrins; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000235:genetics* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D019476:Insect Proteins; D011722:Pyrethrins; D015222:Sodium Channels; D010649:Phenylalanine; D007930:Leucine