Microimaging of Bacillus thuringiensis Toxin-binding proteins in gypsy moth larval gut using confocal fluorescence microscopy

After ingestion by susceptible insect larvae, Bacillus thuringiensis (Bt) insecticidal proteins bind to the brush border membranes of gut epithelial cells and disrupt the integrity of the plasma membrane by forming pores that lead to cell swelling and lysis. The presence or absence of specific Bt toxin-binding molecules on the brush border membrane of gut cells plays a critical role in determining the insecticidal activity of different Bt toxins.