Figure 3

Growth curves of GX0101Δ(A+C) and GX0101 in vitro. 100 PFU GX0101 and GX0101Δ(A+C) were inoculated onto six-well plates seeded with 2×10⁶ CEFs and incubated at 37°C, 5% CO₂, respectively. At hours 0, 24, 48, 72, 96, 120 and 144 p.i., the infected cells were trypsinized and serial 10-fold dilutions were added onto six-well plates of CEFs, visible viral plaques were counted on days 5 p.i. by IFA. The means ± SD at each time point were shown, *P < 0.05 compared with those in GX0101 group. It was demonstrated that the mutant virus GX0101Δ(A+C) exhibited a decreased replication ability in CEF compared with GX0101 at hours 72, 96, 120 and 144 p.i. (P < 0.05).