Fig. 7.

A model for DNA amplification during the lytic phase. During the latent phase each molecule of EBV is replicated no more than once per cell cycle. The mature viral DNA (both P3HR1 in black and 4012 in red) is associated with chromosomal DNA represented in blue. On entering the lytic phase, each DNA molecule (shown as a replicative intermediate) has seeded a replication compartment (in white) which is devoid of cellular chromatin. During the early lytic phase, 90% of all viral DNAs are used as templates and compartments become juxtaposed but do not intermingle. Late in the lytic phase, the nuclear volume has increased by 50% and the compartments have occupied up to 30% of the nuclear volume. The compartments still have not intermingled, only ∼30% of the viral DNA serving as templates for DNA synthesis. The cellular chromatin is now restricted to the periphery of the nucleus. Late in the lytic phase, the ratio of each viral DNA (P3HR1:4012) remains similar to that in the beginning in the lytic phase, illustrating the coordination of DNA amplification by replication compartments. The amplified DNA is associated with and becomes encapsidated by viral particles late in the lytic phase.