FIG. 3.

RT-PCR amplification of OPN and β-actin mRNA from the RRV-infected intestines of 9-day-old mouse pups. Pups were inoculated by gavage with 50 to 100 μl of RRV (10⁸ focus-forming units/ml), and the entire small intestine was removed at the indicated time points. RNA was extracted, and RT-PCR analysis for OPN and β-actin mRNA was performed. The amount of OPN mRNA increased in response to rotavirus infection between 2 and 16 h p.i., with the maximal response at 4 to 6 h.