Fig. 4.

Presence of alternate termination motifs in the S segment. (A) Plaques in Vero E6 cells formed by wild-type recombinant ZH₅₄₈ and the ZH-IGRpenta51-55 and -U:A11 mutants. (B) Viral growth in Vero cells infected by wt and mutant ZH strains at an MOI of 2. (C) N and NSs mRNAs from ZH₅₄₈ and recombinant viruses mutated in the intergenic region analyzed by Northern blotting. Total RNAs from Vero E6 cells uninfected or infected with recombinant viruses were harvested at 6 h p.i. and used for Northern blotting. The probes detected the N (left) or NSs (right) mRNA. (D and E) 3′ RACE analysis of the N (D) and NSs (E) mRNAs from Vero E6 cells infected with RVFV ZH-IGRpenta51-55 (top) and ZH-IGR-U:A11 (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. The mutations are highlighted.