FIG. 5.

Epon sections of HeLa cells infected with WR (A) or MVA (B) or BHK cells infected with MVA (C) at 8 h postinfection. In all cases cells were infected at an MOI of 10. The region of viral DNA accumulation in the cytoplasm of infected cells is indicated with arrowheads. This region is covered with IVs in HeLa cells infected with WR (A) and BHK cells infected with MVA (C), while no IVs are observed outside this region. Small arrows point to IVs containing a nucleoid. In HeLa cells infected with MVA (B), the region of DNA accumulation (arrowheads) has a few IVs, but more IVs can be found in the rest of the cytoplasm, not localizing to the DNA site. IMVs in panels A and C are indicated with large arrows and do not appear to be present in the DNA region. The latter viral form cannot be detected in HeLa cells infected with MVA (B). N, nucleus. Bars, 1 μm.