Comparison of syncytial cell sizes. (A) Sf21 cells were infected with indicated recombinant baculoviruses and cell fusions were induced as described above. Syncytial cell formation was examined under a fluorescence microscope with a green filter. The bar represents 50 μm. (B) Statistical summary of syncytial cell sizes induced by various recombinant baculoviruses as indicated. The vertical axis represents the sizes of fused cells and the horizontal axis indicates the various E1 constructs expressed by baculoviruses. The average size of syncytial cells induced by the indicated recombinant virus is indicated by a dash. The cell sizes of a single nucleus or multiple nuclei are indicated.