Fig. 1.

Cytopathic effects and viral antigen expression in alveolar type I cells infected with RCoV-P or SDAV. Live cells were photographed at 10× magnification 24 h after inoculation with RCoV-P, SDAV, mock inoculation, or exposure to UV-inactivated RCoV-P or SDAV. Arrowheads point to cytopathic effects in the virus-inoculated cells. To visualize viral antigen, cells were fixed 24 h after inoculation with virus and immunolabeled for viral nucleocapsid antigen using a FITC-conjugated secondary antibody. Nuclei were stained with DAPI. Representative fields from 6 experiments are shown.