Expression of Vectors for High Level of Expression of Cloned Genes

Expression of Vectors for High Level of Expression of Cloned Genes - In a number of cloning vectors described earlier in this chapter, the main utility has been to clone a gene or a DNA sequence. In other words, they are used for obtaining millions of copies of the cloned DNA segment, for further use in either the genetic engineering experiments or for further basic studies.

With this objective in mind, the cloned genes in these vectors need not express themselves either at the transcription level (production of mRNA) or at the translation level (production of protein).

But, when the cloned gene is used for transformation to generate transgenic plants or animals or for production of microbes to be used in industry, then the cloned gene must be expressed.

Sometimes, a high level of expression of gene is desirable, if the product of cloned gene is to be recovered as a commercial product.

This objective can be achieved through the use of promoters and expression cassettes (an expression cassette is a combination of DNA sequences, which allow faithful expression of the cloned gene).