Cloning,phylogenetic evolution and expression of rabbit IFN-γ gene

Chinese white rabbit IFN-γ gene was amplified by RT-PCR method from the PBMCr stimulated by ConA.Then the PCR product was purified and ligatured with pMD18-T vector.The positive recombinant was used for sequencing.The complete length of white rabbit IFN-γ gene was 501 bp,which encoded 167 amino acids.The front 20 amino acids consist of signal peptide.Compared with the IFN-γ genes of other species,there were some differences in the nucleotide sequence and deduced amino acid sequence.There were 3 N-glycosylation sites and 3 Cys in the deduced amino acid sequence.The host E.coli strain BL21(DE3) transformed with recombinant pETIFN-γ can express a recombinant protein with molecular weight of 22.6 kDa under the induction of IPTG,which amounted to 19.2 % in the total protein of the induced bacteria by the assaying of gel scanning.