FIG. 8.

Plaque morphology of gK- and UL20-null viruses carrying syncytial mutations in gB. Plaque phenotypes of gK-null (A, B, C, D, E, and F) and UL20-null (G, H, I, J, K, and L) recombinant viruses containing specific gB mutations on Vero (A, C, E, G, I, and K) and FcgK-1 (B, D, and F), or Fd20-1 (H, J, and L) cells. Confluent cell monolayers were infected with the gK-null viruses containing wild-type gB (A and B), gBsyn3 (C and D), or gBamb1511 (E and F) or UL20-null viruses containing wild-type gB (G and H), gBsyn3 (I and J), or gBamb1511 (K and L) at an MOI of 0.001, and viral plaques were visualized at 48 h postinfection by immunohistochemistry. Insets are shown at 2.4× magnification to facilitate visualization of the nonsyncytial phenotype of the small plaques.