Fig 4.

Viral persistence in mice infected with WT and variant viruses. Brain and spinal cord homogenates were prepared from SJL mice (n = 3) infected with WT and variant TMEV. (A) Viral RNA levels in the brain and spinal cord homogenates from mice infected with viruses for 8 days were compared with the fold VP1 expression using real-time PCR. (B) Infectious titers in the tissue homogenates of mice were assessed by plaque assay on days 8, 21, and 120 (d8, d21, and d120, respectively) postinfection. The values given are the mean numbers from two to three independent experiments (mean ± SD). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ND, not detectable (below the detection level).