Fig. 5.
Increased virulence of ZIKV is associated with a D67N single mutation on E protein. A Progressive changes of mutation frequency of 67 and 68 amino acids in E protein from SW01 (P0) to MA-SW01 (MA-P11) during in vivo passaging. B Survival curve of DP2 C57BL/6 mice infected s.c. with 100 PFU SW01, MA-P5, MA-P8, MA-P10, or PBS (n = 6–10 for each group). C Strategy to construct a single D67N substitution virus (CM1-A) based on pFLZIKV; (D) IFA of ZIKV E protein expression at indicated times (24, 48, 72 h post transfection) in BHK-21 cells transfected with RNA from CAM-WT and CM1-A. E Survival curve of DP2 C57BL/6 mice inoculated s.c. with 100 PFU CM1, CM1A virus, or PBS (n = 8–9 for each group). Survival rate was analyzed by log rank test; P values were indicated by ∗∗∗ (P < 0.001). Data shown are representative of two independent experiments.