Figure 8.

Morphological changes associated with BT-R-transfected High-Five cells treated with mosquito and moth toxins. High-Five cells transfected with BT-R₃ cDNA (M5 cells, upper photos) and BT-R₁ cDNA (S5 cells, lower photos) were treated with Cry4Ba and Cry1Ab, respectively. The sequence of cytological changes during the course of toxin-induced cell death was captured by phase contrast microscopy. The long arrow beneath the photographs indicates the stages of cell death: toxin binding, membrane blebbing and cellular swelling. Cytotoxicity is Mg²⁺-dependent and involves exocytosis of the cadherin receptors (BT-R).