FIG. 3.

Immunofluorescent codetection of apoptosis and viral antigens in spinal cords from PV-1-infected TgPVR and nontransgenic Swiss mice. Immunostaining for viral antigen (green) and TUNEL labeling for DNA fragmentation (red) were performed on longitudinal sections through the ventral horn of spinal cords taken from paralyzed mice. (A and B) TgPVR mice 4 days after infection with PV-1 Mahoney; (C) Swiss mouse 2 days after infection with PV-1 Mah-T1022I; (D) TgPVR mouse 3 days after mock infection. Large infected motoneurons exhibiting nuclear condensation (arrow) and apoptotic nuclei from noninfected bystander cells (arrowheads) are indicated. Bars, 20 μm.