Genetic engineering refers to the process of changing the characteristics of an organism through direct modifications to its DNA. This process causes the organism to develop features that are useful and desirable to man.
The process of genetic engineering is first initiated by the isolation of the gene to be inserted. The isolated gene is usually obtained from another organism.
Next, the gene sequence is manipulated and tagged with a marker gene. The marker gene used is usually a green fluorescence protein (GFP) that causes the organism to glow under UV light. Alternatively, an antibiotic-resistant gene could be used to provide resistance to the organisms that uptake the gene.
Finally, the gene is spliced with the transmission vector. There are 3 transmission vectors that are widely in use, namely through the viral method, bio-guns, or plasmids.
Viral Method
When using the viral method of gene transmission, the gene is integrated into the virus' genetic information and becomes part of it. The virus is then introduced to the organism which is usually a cell. After being infected by the virus, the genetic information containing the gene sequence is copied to the cell, where it multiplies and infects other cells, thus propagating the necessary genetic information.
Bio-Guns
Bio-guns work by coating gold particles with the genetic material. The gold particles bombard the cells, thus allowing entry to the cells where they can transfer the requisite genetic material to the cells.
Plasmids
The method of using plasmids is a more common transmission vector. The plasmid, a circular ring of DNA, is cut open and the genetic information for transmission is inserted and the plasmid is rejoined again. The cell is induced to take up the plasmid, thus ensuring the absorption of the DNA material.
