Alternative splicing and highly variable cadherin transcripts associated with field-evolved resistance of pink bollworm to bt cotton in India.

Evolution of resistance by insect pests can reduce the benefits of insecticidal proteins from Bacillus thuringiensis (Bt) that are used extensively in sprays and transgenic crops. Despite considerable knowledge of the genes conferring insect resistance to Bt toxins in laboratory-selected strains and in field populations exposed to Bt sprays, understanding of the genetic basis of field-evolved resistance to Bt crops remains limited. In particular, previous work has not identified the genes conferring resistance in any cases where field-evolved resistance has reduced the efficacy of a Bt crop.