Molecular cloning and functional characterization of two duplicated two-cysteine containing type I interferon genes in rock bream Oplegnathus fasciatus

► Two duplicated type I interferon genes have been identified in rock bream. ► They belong to subgroup-d of two cysteine containing IFNs and are orthologous to zebrafish IFNφ4. ► The expression of two IFNs showed significant induction upon challenge with different immune stimuli in blood and head kidney. ► The rbIFN1 produced in E. coli showed bioactivity of inducing Mx gene expression. ► Two IFNs are involved in in rock bream host response to both viral and bacterial pathogens.