Comparative analysis of Bacillus thuringiensis toxin binding to gypsy moth, browntail moth, and douglas-fir tussock moth midgut tissue sections using fluorescence microscopyThis article is part of a larger document. View the larger document here.
Many strains of Bacillus thuringiensis (Bt) produce insecticidal proteins, also referred to as Cry toxins, in crystal inclusions during sporulation. When ingested by insects, the Cry toxins bind to receptors on the brush border midgut epithelial cells and create pores in the epithelial gut membranes resulting in the death of susceptible insects. Different Bt strains produce a wide variety of Cry toxins. The type of toxins present in the crystals determines the insecticidal potency and specificity of a particular strain.