Fig. 2.

The effect of MCV genes on virus virulence using the intranasal (IN) route of infection. Female BALB/c mice (n=5 per group) were inoculated IN with 5×10³ p.f.u. vΔA49, vΔA49rev, vMC159, or vMC160 or PBS. (a) Clinical signs of illness were monitored daily for 15 days and scored from 0 to 5. Clinical scores were expressed as the mean for each group. One-way analysis of variance (ANOVA) was performed followed by Tukey’s multiple comparison test to determine statistical significance. Asterisks indicate the days on which the clinical signs of illness induced were significantly different between the indicated groups. (*P<0.05, **P<0.01 or ****P<0.0001). (b) The mice were weighed daily, and data were expressed as the percentage of weight change from day 0. To determine statistically significant differences between weight change during virus infection, two-way ANOVA, followed by Tukey’s multiple comparison test, was performed. Asterisks indicate the days on which weight changes induced by vΔA49 were significantly different from those induced by vΔA49rev (*P<0.05).