Binding properties of Bacillus thuringiensis Cry1C delta-endotoxin to the midgut epithelial membranes of Culex pipiens.

The Cry1C delta-endotoxin from Bacillus thuringiensis is toxic to both lepidopteran and dipteran insect larvae. To analyze the dipteran-specific insecticidal mechanisms, we investigated the properties of Cry1C binding to the epithelial cell membrane of the larval midgut from the mosquito Culex pipiens in comparison with dipteran-specific Cry4A. Immunohistochemical staining of the larval midgut sections from Culex pipiens showed that Cry1C and Cry4A bound to the microvilli of the epithelial cells.