FIG. 4.

Plaque morphology of the wild-type and mutant viruses under solid overlay. BSC-1 cell monolayers were infected with the panel of viruses and then overlaid with a 1:1 mixture of 2× media and 2% LMP agarose. At 24 h, representative plaques were photographed by phase-contrast microscopy (magnification, ×100). Viruses are WR (A), W-B5R⁻ (B), W-B5R_rescue (C), W-B5RΔSCR_1–4 (D), IHD-J (E), I-B5R⁻ (F), I-B5R_rescue (G), and I-B5RΔSCR_1–4 (H). Note the tiny plaques in the B5R deletion viruses (B and F) and the return of large plaques with the rescued virus (C and G) and the viruses lacking the SCR domains (D and H).