DNA-based detection of Bt resistance alleles in pink bollworm

Shai Morin, Scottie Henderson, Jeffrey A. Fabrick, Yves Carrière, Timothy J. Dennehy, Judith K. Brown, Bruce E. Tabashnik

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


Evolution of resistance by pests is the main threat to long-term insect control by transgenic crops that produce Bacillus thuringiensis (Bt) toxins. We previously identified three mutant alleles (r1, r2, r3) of a cadherin gene in pink bollworm (Pectinophora gossypiella) linked with recessive resistance to Bt toxin Cry1Ac and survival on transgenic Bt cotton. Here we describe a polymerase chain reaction (PCR)-based method that detects the mutation in genomic DNA of each of the three resistant alleles. Using primers that distinguish between resistant and susceptible (s) alleles, this method enables identification of 10 genotypes (r1r1, r1r2, r1r3, r2r2, r2r3, r3r3, r1s, r2s, r3s, and ss) at the cadherin locus. For each of the three resistant alleles, the method detected the resistance allele in a single heterozygote (r1s, r2s, or r3s) pooled with DNA from the equivalent of 19 susceptible (ss) individuals. The results suggest that the DNA-based detection method described here could greatly increase the efficiency of monitoring for resistance to Cry1Ac compared to bioassays that detect rare individuals with homozygous resistance.

Original languageEnglish (US)
Pages (from-to)1225-1233
Number of pages9
JournalInsect Biochemistry and Molecular Biology
Issue number11
StatePublished - Nov 2004


  • Bacillus thuringiensis
  • Bt cotton
  • Cadherin
  • Molecular monitoring
  • Pectinophora gossypiella
  • Resistance detection

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Insect Science


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