Figure 8.

A schematic diagram illustrating giant cell cycling in CTP-DB and -BL cultures. Microscopic images of distinct cellular morphologies of the giant cell cycle; magnification ×200, scale bar 50 μm (initiation, self-renewal, and termination phases), and ×100, scale bar 100 μm (stability phase). Initiation, self-renewal, termination, and stability represent the four different stages of the giant cell cycle. Post-HCMV infection and via endoreplication, the 2 N PECs go into the initiation phase. Subsequently, polyploid cells (>4 N) and tetraploid cells (4 N) are produced in the self-renewal/dedifferentiation phase. During the termination/differentiation stage, the intermediate cells (2–4 N) will be generated from multinucleated or mononucleated giant cells through budding. Intermediate PECs enter the stability stage and are afterward replaced by diploid small PECs (2 N).