Figure 6.

Cellular morphology, ultrastructural, and respiratory changes induced on activation of DNNRF-1 in MycER^TM cells. (A) Phase microscopy and COX histochemistry of cells from control, Myc-ER^TM, and a DNNRF-1-ER^TM/Myc-ER^TM clone 48 h after addition of 4-OHT in 0.5% serum. Cells had been serum starved for 48 h prior to 4-OHT addition. (B) Electron micrographs of Myc-ER^TM and DNNRF-1-ER^TM/MycER-ER^TM cells 48 h after 4-OHT addition. The arrows point to mitochondria; asterisks highlight the dilated ER. High-power magnification of mitochondria in Myc-ER^TM cells and DNNRF1-ER^TM/Myc-ER^TM cells illustrates the distinct morphologies of these mitochondria in 0.5% serum. Note that the Myc-ER^TM mitochondria have been magnified 2.5× to allow comparison with the mitochondria in the DNNRF1-ER^TM/Myc-ER^TM cell line. Bars: upper panels, 2 μm; lower panels, 200 nm.