Fig. 3.

Rescue of recombinant ZH virus carrying a deleted IGR. (A) Schematic representation of the deletions in the S segment. NC, noncoding region. (B) Plaques in Vero E6 cells formed by wild-type recombinant ZH₅₄₈ and mutant strains ZH-IGR25 and ZH-IGR20. (C) Viral growth in Vero cells infected by wt and mutant ZH strains at an MOI of 2. (D) Expression of N and NSs mRNAs from the wild-type virus and the recombinant virus carrying the deleted intergenic region. Total RNA from Vero E6 cells uninfected or infected with recombinant viruses ZH-IGR25 to -IGR20 were harvested at 6 h p.i. and used for Northern blotting. The probes detected the N (top) or NSs (bottom) mRNA. (E and F) 3′ RACE analysis of the N (E) and NSs (F) mRNAs from Vero E6 cells infected with RVFV ZH-IGR25 (top) and ZH-IGR20 (bottom). The N and NSs ORFs are indicated by lowercase type, and the intergenic region is represented by uppercase type. The 3′ ends of the RNAs monitored by the beginning of the polyadenylation added in vitro are shown by arrows. The 5′-GCUGC-3′ motif and its complementary sequence are underlined in black and white, respectively.