Genetic Engineering

Genetic engineering, also called genetic modification, is the direct manipulation of an organism's genome using biotechnology. New DNA may be inserted in the host genome by first isolating and copying the genetic material of interest using molecular cloning methods to generate a DNA sequence, or by synthesizing the DNA, and then inserting this construct into the host organism. Genes may be removed, or "knocked out", using a nuclease.

An organism that is generated through genetic engineering is considered to be a genetically modified organism (GMO).Genetic engineering techniques have been applied in numerous fields including research, agriculture, industrial biotechnology, and medicine. Enzymes used in laundry detergent and medicines such as insulin and human growth hormone are now manufactured in GM cells, experimental GM cell lines and GM animals such as mice or zebrafish are being used for research purposes, and genetically modified crops have been commercialized.

Use of Genetic Engineering in the production of Insulin

Genetic engineering processes can make human insulin. Human insulin DNA is placed into the DNA of a second organism. The host organism becomes an insulin-producing factory.

People with diabetes (called diabetics) do not correctly produce or use their insulin protein. The insulin protein helps control how much sugar is in your bloodstream. Millions of diabetics need to take insulin. Insulin from cows and pigs has been used since the early 1900s to treat diabetes. Now human insulin protein can be mass-produced through genetic engineering processes as follows:Isolate Gene

Prepare Target DNA

Insert DNA into Plasmid

Insert Plasmid back into cell

Plasmid multiply

Target Cells Reproduce

Cells Produce Proteins

1. Isolate Gene

The gene for producing HUMAN insulin protein is isolated. The gene is part of the DNA in a human chromosome. The gene can be isolated and then copied so that many insulin genes are available to work with.

2. Prepare Target DNA

In 1973, two scientists named Boyer and Cohen developed a way to take DNA from one organism and put it in the DNA of bacterium. This process is called recombinant DNA technology. First, a circular piece of DNA called a plasmid is removed from a bacterial cell. Special proteins are used to cut the plasmid ring open.

3. Insert DNA into Plasmid

With the plasmid ring open, the gene for insulin is inserted into the plasmid ring and the ring is closed. The human insulin gene is now recombined with the bacterial DNA plasmid.

4. Insert Plasmid back into cell

The bacterial DNA now contains the human insulin gene and is inserted into a bacteria. Scientists use very small needle syringes to move the recombined plasmid through the bacterial cell membrane.

5. Plasmid multiply

Many plasmids with the insulin gene are inserted into many bacterial cells. The cells need nutrients in order to grow, divide, and live. While they live, the bacterial cell processes turn on the gene for human insulin and the insulin is produced in the cell. When the bacterial cells reproduce by dividing, the human insulin gene is also reproduced in the newly created cells.

6. Target Cells Reproduce

Human insulin protein molecules produced by bacteria are gathered and purified. The process of purifying and producing cow and pig insulin has been greatly reduced or eliminated.

7. Cells Produce Proteins

Millions of people with diabetes now take human insulin produced by bacteria or yeast (biosynthetic insulin) that is genetically compatible with their bodies, just like the perfect insulin produced naturally in your body

Advantages and Disadvantages of Genetic Engineering

Advantages1) Disease could be prevented by detecting people/plants/animals that are genetically prone to certain hereditary diseases, and preparing for the inevitable. Also, infectious diseases can be treated by implanting genes that code for antiviral proteins specific to each antigen.

2) Animals and plants can be 'tailor made' to show desirable characteristics. Genes could also be manipulated in trees for example, to absorb more CO2 and reduce the threat of global warming.

3) Genetic Engineering could increase genetic diversity, and produce more variant alleles which could also be crossed over and implanted into other species. It is possible to alter the genetics of wheat plants to grow insulin for example. Disadvantages1)Nature is an extremely complex inter-related chain consisting of many species linked in the food chain. Some scientists believe that introducing genetically modified genes may have an irreversible effect with consequences yet unknown.

2) Genetic engineering borderlines on many moral issues, particularly involving religion, which questions whether man has the right to manipulate the laws and course of nature.