| 摘要 |
<p>A recombinant DNA composed of (1) bovine papilloma virus, (2) the promoter region of the mouse metallothionein I gene and (3) human growth hormone structural sequences ligated to the metallothionein promoter was constructed. The recombinant was stably maintained as an episome and directed production of human growth hormone when introduced into cultured mammalian cells. Not only was the yield unexpectedly high, purification was vastly simplified because the growth hormone was secreted into the tissue culture medium. The process was suitable for spinner culture. Additionally, recombinant DNA molecules composed of (1) bovine papilloma virus and (2) the whole metallothionein I gene were utilized to render mouse cells resistant to toxic concentrations of cadmium. This combination was utilized as a selective marker to cotransfer other, non-selectable genes (such as human growth hormone) into mammalian cells. </p> |
