φ mutant viruses produce less histopathologic injury than wild-type virus.

<p>ND4 Swiss Webster mice were inoculated intracranially with 50 PFU of rsT3D or the indicated φ mutant. (A) Brains from infected mice were resected at 10 d post-inoculation, fixed, and embedded in paraffin. Brain sections were stained with H&E, polyclonal reovirus-specific antiserum, or activated caspase-3-specific antiserum. Consecutive sections from the hippocampal region of representative brains of rsT3D-, K594D-, or I595K-infected mice are shown. Scale bars, 500 µm. (B) Higher magnification images of H&E-stained sections of the dentate gyrus and CA4 region of the hippocampus of mice infected with each virus strain are shown. Scale bars, 100 µm.