The Phenomenon that is Genetic Transformation
November 17, 2011
Genetic transformation is when the genetic makeup of an organism is altered by it receiving external genetic material (Barnhart and Hopper, 2011). Bacterial transformation was first seen during an experiment by Fredric Griffith in 1928. In the experiment there were two strains of bacteria, a virulent strain, and non-virulent strain. Virulent simply means disease causing, and therefore non-virulent means harmless. He killed the virulent strain with heat and then mixed it with the non-virulent strain, to his astonishment the virulent properties were exhibited (Barnhart and Hopper, 2011). To explain, the virulent bacteria was killed by the heat, but its DNA was not destroyed so the non-virulent strain of bacteria picked up the DNA from the environment. This is genetic transformation.
In our experiment, we transformed E. coli cells. We used E. coli cells for a few reasons, it's single celled so we simply have to insert genes into a single cell for it to exhibit the trait, it reproduces quickly so we see results fast, there is a commonly used non-virulent strain, and it is cheap to grow and does not require a lot of resources. A plasmid is what we are going to use to give the E. coli cells their extra genetic material. Plasmids are separate pieces of DNA that are not part of the circle of DNA that holds most of the genes in a genome (Brooker et al., 2011). The plasmid, pGLO, is what we put inside the E. coli, it contains three genes: bla, araC, and GFP. The gene bla stands for β- lactamase, which breaks down ampicillin, an antibiotic that kills E. coli (Barnhart and Hopper, 2011). The gene araC and the gene GFP work together. The araC gene when turned on, also turns on the GFP gene, it is called a promoter gene. The GFP gene is a gene taken from a luminescent jellyfish, when turned on it glows in the presence of UV light. So for the GFP gene to be turned on...
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