Five families of diverse DNA viruses comprehensively restructure the nucleus
Fig 3
Two types of chromatin reorganization in EBV lytic cells.
The progression of reorganizing chromatin in EBV lytic cells can be described in 2 steps: ROCC type I, characterized by host chromatin condensation without margination; and ROCC type II, defined by both the condensation and margination of cellular chromatin to the periphery of the nucleus. ROCC type I is triggered upon the formation of a viral DNA synthesis complex and its initiation of synthesis. The extensive DNA synthesis that follows gives rise to ROCC type II. The cell line used in this figure is the EBV-positive cell line, iD98/HR1 [23]. Type I reorganization is detected by treating the lytic-induced cells with viral DNA synthesis inhibitors such as GCV or PAA. Close examination of the DAPI channel of cells supporting type II reorganization reveals DAPI signals of lower levels within the “void” of the marginated chromatin. These signals come from the newly synthesized viral genomes. Accordingly, these “void” regions have only background levels of eGFP-H2B signals, indicating the histone-free state of these viral DNA molecules. Scale bar: 10 μm. EBV, Epstein–Barr virus; GCV, ganciclovir; PAA, phosphonoacetic acid; ROCC, reorganization of cellular chromatin.