ABSTRACT
This chapter reviews genetic engineering of mammalian cells using amplification of transfected genes, improved vectors for selection and coamplification of transfected genes, and methods to overcome factors limiting expression of transfected genes. Since the degree of gene amplification, in most cases, is proportional to the level of gene expression, it offers a convenient means to increase expression of any particular gene. Several general features are characteristic of amplification of both endogenous genes and transfected genes in cultured mammalian cells. The encephalomyocarditis series of vectors will be generally useful to rapidly obtain high level amplification and expression of heterologous genes in mammalian cells. It is now known that expression of heterologous secretory proteins from transfected genes introduced into heterologous cells may also be limited as a result of inefficient transport from the ER to Golgi.
