Cellular localization of the pink bollworm Cry1Ac Bt protein receptor PgCad1 in cultured insect cells

Authors: Melanie Miranda (BS, HTL- ASCP, University of Arizona-Comparative Pathology Core Laboratory, Tucson, AZ)

Transgenic cotton genetically engineered to produce insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are used to manage insect pests, including the pink bollworm (Pectinophora gossypiella), a globally invasive pest of cotton. However, the evolution of resistance to Bt Cry proteins (Cry1Ac and Cry2Ab) by the pink bollworm in parts of Asia has reduced the effectiveness of Bt cotton. Several mutations in the midgut cadherin gene PgCad1 are genetically linked with the resistance of the Cry1Ac Bt toxin, which can result in disrupted cellular trafficking of the cadherin receptor to the surface of the midgut membrane and decrease toxin binding. Here, we established specialized insect histology and immunohistochemistry (IHC) protocols for reliable localization the PgCad1 receptor in cultured Tni insect cell lines. Such protocols may be useful for in situ localization of wild type PgCad1 and mutant variants in midgut cells of the pink bollworm.