FIG. 3.

Electron micrographs of ultrathin sections of BHK-21 cells electroporated with SFV/Dj-C191 RNA. (A and B) Areas of convoluted ER membranes displaying adhesion via their cytosolic sides (arrows). In panel B, an electron-dense midline similar to those found in intercellular adhesion complexes such as the desmosome can be observed. (C) A typical area of convoluted ER, revealing double-layered membranes and the budding of virus-like particles from these membranes into the ER lumen. (D and E) High-magnification images of some virus-like particles (arrowheads) budding into the ER. In panel D, note the virus-like budding (arrowhead) occurring close to a region in which ER membranes are adhering via their cytosolic sides (arrow). Bars, 100 nm (A, B, D, and E) and 200 nm (C).