Changes in the fine structure of the gut epithelium of Pieris brassicae induced by the delta-endotoxin of Bacillus thuringiensis.

摘要: The morphological changes induced by the delta -endotoxin of Bacillus thuringiensis in the mid-gut epithelium of larvae of Pieris brassicae (L.) are described from observations with the electron microscope. Micrographs taken a few minutes after administration of the toxin showed the onset of a vigorous disruption of the fine structure of the epithelial cells. The subcellular components such as microvilli and mitochondria underwent rapid swelling. The content of the mitochondria seemed to be dissolved during continuous enlargement, finally leaving spherical cavities. The fine and regular endoplasmic reticulum disintegrated by the formation of vacuoles of various sizes in the cytoplasm. The connections between the epithelial cells were loosened by the separation of the cell membranes.