Genomic organization of the para-sodium channel α-subunit genes from the pyrethroid-resistant and -susceptible strains of the diamondback moth

We examined the genomic organization of the pora-sodium channel α-subunit gene of the diamondback moth, Plutella xylostella (L.). The nucleotide sequence contained 34 putative exons, which covered almost the entire coding region of the gene producing 1,889 amino acid residues. Deduced amino acid identity to the hscp locus of Heliothis virescens was 84%. Comparison of deduced amino acid sequences of the permethrin-resistant and -susceptible strains showed two substitutions other than kdr and super-kdr-like substitutions. They were Ala to Thr (A1060T) and Pro to Ser (P1836S) at the linker region of the domains II-III and the carboxyl terminus, respectively. Furthermore, we developed PCR amplification protocols for the rapid detection of both substitutions.