Study on the Heredity Stability of a Recombinant Plasmid pET-ChIFN-γ in Escherichia coli

Abstract:

A novel recombinant Escherichia coli BL21(DE3)/pET-ChIFN-γ was successfully constructed for high expression of chicken interferon-γ(ChIFN-γ), and the heredity stability of pET-ChIFN-γ was mainly focused on. It was segregationally unstable of the plasmid under no kanamycin selection pressure, only 69% cells containing plasmid after 100 generations. But it could be controlled by the supplementation of kanamy- cin pressure. The growth characteristics and the morphology of the cultures did not show differences among the generations. The chromatogram of the plasmids between origin strain and 100th generation strain di- gested by restriction enzymes were same, as well as ChIFN-γ expression level, biological activities showed no difference among the generations. It is indicated that recombinant strain CH1 has high heredity stability.

Key words:ChIFN-γ, Heredity stability, Plasmid stability, Generations