FIG. 3.

Images of nuclear surfaces of mock- and HSV-1-infected Vero cells (A to C) and HeLa cells (D to H) 15 h postinfection obtained by cryo-FESEM after freeze fracturing (A to C) or by FESEM after dry fracturing (D to H) showing remarkable reductions in the number of nuclear pores/μm² and enlargement of the maximal interpore area (asterisks) in HSV-1-infected cells (C and E) compared to mock-infected cells (A and D). Nuclear pores appear on the inner nuclear membrane (i) as round buttons but as a distinct low depression at the outer nuclear membrane (o) in mock-infected cells (A and B). In HSV-1-infected cells, the NPC and/or nuclear material protrudes through normal-sized and enlarged nuclear pores, and a distinctly bordered hole (arrow) was formed as apparent at the outer nuclear surface (C). The overall diameter of the NPC is enlarged and the central pore channel is dilated in dry-fractured HSV-1-infected cells (G and H) compared to NPCs of mock-infected cells (F). Bars, 200 nm.