(A) MEF/wt cells or MEF/PKR0/0 cells were mock-infected or infected with MP-12, rMP12-C13type (C13type), rMP12-NSsR173A (R173A), or rMP12-mPKRN167 (N167), or (C) MRC-5 cells were mock-infected or infected with rMP12-rLuc, MP-12 or rMP12-NSsR173A virus at an moi of 3. Total RNA was harvested at 7 hpi. Northern blotting was performed with the strand-specific RNA probes to detect IFN-β or ISG56 mRNA, or RVFV anti-sense S-segment / N mRNA.