FIG. 3.

E4 expression and the onset of genome amplification are not necessarily coincident. (A and B) Tissue sections taken from two different COPV-infected oral lesions. Tissue sections were double stained for the presence of viral genome amplification (DNA) and for E4 expression (E4). Viral DNA was occasionally detected in the absence of E4 (cells indicated by arrows). The nuclei were counterstained using Sytox green (nuclei). (B) E4 expression in cells (indicated by arrowheads) that are not supporting viral genome amplification. A cell (indicated by an arrow) supporting viral genome amplification but lacking E4 is shown in the same field of view. The images were taken using a 40× objective.