Genetic Engineering Process Essay Example | Topics and Well Written Essays - 750 words

Genetic Engineering Process - Essay Example An example is cry 1Ab which is a gene that codes certain insecticidal proteins in bacillius thiurengesis, which is a soil bacterium (University of Nebraska 2013). Agorabacterium tumefaciens is another example. 2. Gene insertion An essential component is plasmids, which are minute, self-replicating, circular DNA strands in the bacterial cells. Plasmids are easy to manipulate since they carry few genes and therefore provides routes for new gene introduction to cells (Wolfe 2013). Plasmids are used as the transfer channels. For agorabacterium tumefaciens, which is also a soil bacterium, genes are inserted using recombinant DNA methods. The bacterium possesses a plasmid (Ti). T DNA segment of the bacterium DNA carry genes that lead to tumour formation when it integrates in the maize DNA. However, manipulation of the genes by inserting new ones causes a disruption that makes the maize resistant to frost diseases and herbicides. Restriction endonuclease cleave the Ti plasmid exposing it to introduction of a foreign DNA from another source cleaved by the same enzyme. The genes are connected to the ends of the plasmids; thereafter ligation enzymes seal the ends and reform a structured DNA circle. The manipulated plasmid is then replaced into the bacterium. Antibiotic resistant marker genes must be included in the plasmids; the essence of the marker gene is to provide identification of cells containing the manipulated plasmids. Polymerase chain reaction takes over at this point, where genes are produced en masse. 3. Transformation Introducing plasmids into the organism of interest is through transformation. A few techniques can be employeds for transformation. However, the general concept involves attachment of A. Tumefasciencs to the organism’s cell, in this context the maize maize cell, and transferring a copy of the modified plasmid into the cell. Other methods of transformation other than use of A. Tumefasciens include particle bombardment and protoplast tran sformation. In particle bombardment, tiny tungsten beads with DNA coating of desired traits are shot into small fragments of maize cells that combine and integrate in to the maizes genome. The disadvantage of this method is that it results in unpredictable and unstable gene expression due to multiple copies of the introduced gene. Protoplasm transformation involves enzyme treatment of cell by stripping cell of their cell walls to form protoplast. Osmotic stress is induced to the protoplast in order to take up DNA in the protoplast’s surrounding (GMO education Network n.d). Inducing osmotic stress is by administering electrical shocks to the protoplast or by chemical treatment using polyethylene glycol. The protoplasts are thereafter regenerated into maizes using hormones. The problem with this method is that it is tedious and challenging. However, protoplasm transformation gives accurate and precise outcomes. 4. Selection of modified cells The selection process involves ident ification of cells that have obtained the manipulated plasmids into their genome. In genetic modified food industry, it is advisable to use the marker less insertion system to avoid the risk of marker gene expression in the maize. Typically, marker less transgenic involves screening numerous progeny