FIG 4.

APOBEC3A restricts MVMi infection in vivo. (A) MVMi genome equivalents were calculated by alkaline gel electrophoresis followed by quantitative Southern blotting. Newborn C57BL/6, BALB/c, and A3KO mice were infected oranasally with 2 × 10⁷ genome equivalents of virus in 5 μl. Mice were sacrificed at 5, 9, or 13 dpi, and DNA was isolated from their spleens and subjected to quantitative PCR (qPCR) to determine relative levels of viral DNA, using the primers 5′-AAGGTACGATGGCGCCTC-3/5′-GTGCTCTTTGGCAGC-3′. MVMi values were normalized to GAPDH, as previously described (45). (B and C) Newborn C57BL/6, BALB/c, A3KO, and A3A mice were infected oranasally with 2 × 10⁷ genome equivalents of virus and sacrificed at 5 dpi. DNA isolated from the spleen (B) and lungs (C) was analyzed by qPCR. Each point represents an individual mouse. ****, P < 0.0001; **, P < 0.0025; ***, P < 0.0035 (by 2-tailed unpaired t test).