Figure 2. Syncytial formation and expression of copGFP generated in the cell-cell fusion
assay at different time points after co-cultivation. a) Syncytium was formed after cocultivation
of effector cells and target cells for 24 hours; arrow indicates the fused cell; PC
indicates phase contrast. b) CopGFP expression after co-cultivation of effector cells and
target cells (lower panel) for 1, 2, 3, and 4 days. At day 2 - 4, the amounts of copGFP were
steadily increased in syncytial cells. CopGFP expression was greatest on day 4. Mock (upper
panel) showed background level of copGFP.