(A and B) Actin architecture of NIA3 wild-type-strain (wt)-, NIA3 US3 null strain-, or NIA3 US3 rescue strain-infected SK-6, ST, and RK13 cells at 8 h p.i. (A) and 12 h p.i. (B). At the indicated time points p.i., SK-6, ST, and RK13 cells were paraformaldehyde fixed, permeabilized, and stained with FITC-conjugated polyclonal PRV-specific antibodies and phalloidin-Texas Red to visualize PRV antigens and actin filaments, respectively. Bar, 10 μm. (C) One-step growth curves for NIA3 wild-type (solid line), NIA3 US3 null (dashed line), and NIA3 US3 rescue (dot-dash line) viruses in SK-6, ST, and RK13 cells.