Complementation assays with UL12. UL12 was transfected into induced 293/ΔBGLF5 cells. Genome DNA equivalents (A) and green Raji titers (B) were assessed and compared to those obtained with noncomplemented 293/ΔBGLF5 cells, BGLF5-complemented 293/ΔBGLF5 cells, and induced 293/EBV-wt cells (i.e., the same data as presented in Fig. 2). (C) The same experiments were conducted with 293 cells as target cells. (D) Two electron micrographs of induced 293/ΔBGLF5 cells complemented with UL12. Note the irregular nuclear envelope and the presence of C-type nucleocapsids and of extracellular mature virions (arrows). INM, inner nuclear membrane; ONM, outer nuclear membrane; nuc, nucleus; cyt, cytoplasm; HC, heterochromatin; B and C, B- and C-type capsids. Bar, 0.2 μm.