ABSTRACT
The information content of human DNA is accessible to scientists because the simplicity of DNA made gene manipulation possible and facilitated the development of automated gene sequencing technology. The strategy with all of these host systems is the same: the gene of choice is spliced into a DNA molecule carrying the gene regulation sequences from the intended host cell together with a gene that the host cell has to have for growth under certain circumstances. The cDNA is then genetically engineered into a bacterial promoter sequence in a plasmid. The cDNA method was used and the product arrived just as the traditional source of growth hormone came into disrepute. Recombinant DNA technology enabled scientists to clone the viral gene encoding this protein, splice it into the regulatory sequence from a yeast gene and make the viral protein in yeast.
