Interferon And Interferon Regulatory Factors 1/7 In Grass Carp

IFN plays a crucian role in innate immune system in all the vertebrates.Although several evidence show that there are similar IFN system between fish and mammali-an,the detailed pathway of signalling transduction and molecular mechan ism is still not elucidated clearly.To futher understand the molecular mechanism of IFN system in fish,we cloned the genome of CiIFN and CiIF1/7(Interferon regulatory factor 1/7),and carry out the multiple sequence alignment and phylogene tic analysis.The analysis of tissue expression suggest that both CiIFN and CiIRF7 can be induced by Poly(I:C). we express and purify the DBD domains, nDBD domains and the full ORFs of CiIRF7 in prokaryotic cell,respectively,and also clone 8 different segme nts of CiIFN promoter region.The EMSA(electrophoretic mobility shift assay) show that the DBD domain of CiIRF7 can specially bind to the CiIFN promoter,indicate-that it may be the potent regulator of CiIFN transcription.Then we identified two IFN-inducibe gene in fish:CiIFI58 and CiGigl, which can be strongly induced by I-FN.The analysis of tissue expression showed that both genes had constitutive expression in most of the tissue examin-ed,and upregulated by Poly(I:C).To further study the in vivo inducton activity of CIRF 1/3/7 to CiIFN,we constructed the recombinant vector(pcDNA3.1-CiIRF1/3/7) for eukaryotic expression,and the recombinant lucife rase report system(pGL-3-basic/CiIFNP1-8).