why might a scientist insert a gene that codes for a human growth hormone into bacteria cell?

One Comment

1. Vicki says:

   September 7, 2010 at 10:27 am

   There are many reasons why scientists might do this, most of them center around the ability of bacteria to produce large numbers of proteins encoded by their genes.

   Perhaps the scientist wants to study a specific human growth hormone, the scientist will need a large supply to work with. Oftentimes extracting hormones from humans is expensive and subject to ethics reviews, so using bacteria is an easy and cheap alternative. Usually, scientists will clone their gene of interest infront of a promoter that can be turned on and regulated by the scientist in some way; this usually takes place on a plasmid. The recombinant plasmid is then transformed into the bacteria where it can be induced to produce huge amounts of the protein (i.e. human growth hormone, if you insert the human growth hormone gene).

   The other idea that comes to mind is that a scientist might want to produce large amounts of the hormone not to study, but to collect and then use in therapeutic medical approaches (i.e. say someone is not producing enough of this hormone, they could be injected with it… but the hormone needs to come from somewhere). This is actually the premise behind insulin injections needed by diabetics. Scientists cloned the human insulin gene into bacteria and had the bacteria produce the insulin!

   Overall, the reason is that bacteria can produce huge amounts of certain proteins fairly easily and without much expense. The reasons why scientists might want these proteins is varied.