FIG 3.

Viral growth kinetics and relative viral RNA quantification in chicken and duck cells. (A and B) CEF and DEF were inoculated with two chicken origin H7N3 HPAI viruses (A/CK/JL/12 and A/CK/PB/16 viruses) at a multiplicity of infection (MOI) of 0.001. The plaque titers from supernatant were determined at 12, 24, 48, and 72 h postinfection on MDCK cells, and each point represents the average of three independent replicates. The asterisk indicates the significance between the two H7N3 HPAI viruses (P < 0.05). (C and D) Total RNA was extracted from CEF and DEF lysates at 12 and 24 h postinfection. vRNA, cRNA, and mRNA were measured by strand-specific RRT-PCR. The fold increase was calculated by comparing the viral RNA detection at 24 hpi to that at 12 hpi for each type of RNA. Each value is the average from three independent experiments. Statistical significance was analyzed by using two-way ANOVA with Bonferroni multiple-comparison test. A P value of <0.05 was considered to be significant.