FIG. 7.

Effects of gC-containing supernatants on growth of v20 or 20ΔgC. CEC were infected with 100 PFU of v20 or v20ΔgC. At 24 h p.i., medium was removed and viruses were grown for another 48 h with supernatants collected from cells infected with parental v20 (SN v20) or the gC-negative mutant v20ΔgC (SN v20ΔgC). Plaques were detected by IIF with the MDV-specific antiserum. Plaques were photographed with a fluorescence microscope (Zeiss Axiovert 25) and a digital camera (Zeiss Axiocam), and plaque areas were determined with the ImageJ software. Means and standard deviations (error bars) of 100 plaques in each combination of virus and supernatant are given.