Fig. 3

A comparison of viral loads in the brain, peripheral replication kinetics, and blood clearance between the mutants and parental virus. 3-week-old Kunming mice were inoculated by the i.p route with three mutants and WT (\({10}^{6 }\)PFU) respectively and divided into four groups (n = 24). Serum (A), brain (B), liver (C), and spleen (D) were collected at specific time spots, and the gene copies of the samples were analyzed by qRT-PCR. Each sample was a fusion of three mouse tissues. The minimum limit of the test was \({10}^{4.7}\) copies/ml for brain, \({10}^{4}\)copies/ml for serum and \({10}^{5 }\)copies/g for liver and spleen, both represented by dashed lines. (E) The mutants and parental virus (\({10}^{6}\) PFU) by i.v route were inoculated to 6-week-old Kunming mice, and blood was collected at 5, 30, and 60 min and assayed for viral loads by qRT-PCR. Each data represents the mean of three samples. The data are representative of at least three independent experiments, and error bars indicate the SD. Significance was calculated using a one-way ANOVA with multiple comparison tests. * represents a significant difference between WT and mutants (*, P<0.05;**, P<0.01; ***, P<0.001; ****, P<0.0001)