Biochemistry and cell biology of the interaction of Bacillus thuringiensis CryIC toxin with Spodoptera exigua midgut epithelial cells in vitro

he research documented herein describes the use of Spodoptera exigua midgut epithelial cells (MEC) in studies in vitro designed to clarify the multistep toxicity mechanism of Bacillus thuringiensis CryIC toxin. Spodoptera sp. are world wide lepidopteran pests responsible for extensive economic damage to a variety of agricultural crops.;Initially, a MEC cytotoxicity assay measuring lactate dehydrogenase release was developed to determine the response to CryIC as well as other Bt toxins. These data paralleled the results from larval bioassays thus establishing the validity of the MEC cytotoxicity assay. The MEC contain goblet and columnar cells. The columnar cells are the target cells for the CryIC in vivo. The assay was used to determine the functional significance of various CryIC binding protocols. Under different temperature conditions (0;Identification of CryIC binding proteins on MEC membrane surfaces by...