Figure 3

Effect of insulin 2 (C96Y)-EGFP expression on ER morphology. Clone #4S2 cells untreated (A, B) or treated with 2 μg/ml doxycycline for 3 days (C, D) or 6 days (E, F) were washed in PBS and fixed. The cells were processed for transmission electron microscopy as described in the methods. ER structures in uninduced cells (A, B, arrows), and distended ER structures in mutant insulin expressing cells following doxycyline-induction (D-F, arrows) are indicated. The presence of apoptotic cells was evident in doxycyline-induced cells (C, arrowheads).