(A) DHX29 stably transfected (mDHX29) MEFs were infected with EMCV (multiplicity of infection [MOI] 5) or VSV (MOI 0.5). EMCV and VSV mRNA levels by real-time PCR analysis and virus titers were determined. Virus titers were expressed as plaque-forming units (pfu)/ml. (B) EMCV and VSV mRNA levels and titers were determined in scrambled (Scr) siRNA- and DHX29 siRNA-transfected MEFs 24 h post-infection with EMCV (MOI 5) or VSV (MOI 1). (C) MDA5-knockout (MDA5-/-) and WT MEFs and (D) RIG-I-knockout (RIG-I-/-) and WT MEFS were transfected with DHX29 siRNA or Scr siRNA and then infected with EMCV or VSV at the indicated MOIs. IFN-β production was determined by ELISA. Data from (A-D) are plotted as the mean ± s.d. and are representative of three independent experiments. *P < 0.05, **P <0.01, ***P <0.001 vs. the corresponding control. NS, not significant.