DETECTION OF CYCLODIENE INSECTICIDE RESISTANCE-ASSOCIATED MUTATIONS BY SINGLE-STRANDED CONFORMATIONAL POLYMORPHISM ANALYSIS

Cyclodiene insecticide resistance is associated with replacements of a single amino acid within the putative lining of a delta-aminobutyric acid (GABA)-gated chloride ion channel gene Resistance to dieldrin (Rd l). Only two resistance-associated amino acid replacements have been i dentified; alanine to serine in Drosophila melanogaster, D. simulans, Aedes aegypti, and Tribolium castaneum and alanine to glycine as a sec ond allele in D. simulans. Here we report that single stranded conform ational polymorphism (SSCP) analysis of genomic DNA, amplified by the polymerase chain reaction (PCR) for exon 7 of the Rdl gene, can be use d to genotype strains or individuals of all of these insects. This tec hnique also appears simultaneously to distinguish between D. melanogas ter and D. simulans, sibling species only reliably identifiable by exa mination of male genitalia. The relative advantages of this genotyping technique against other PCR-mediated techniques in monitoring for ins ecticide resistance are discussed.