Genetic modification
New medical products are also produced by Describes a cell or organism that has had its genetic code altered by adding a gene from another organism. (GM) - also called Process which involves the artificial transfer of genetic information from one donor cell or organism to another..
This involves modifying the The complete set of DNA found in an organism. of an Living entity, eg animals, plants or microorganisms. by introducing a The basic unit of genetic material inherited from our parents. A gene is a section of DNA which controls part of a cell's chemistry - particularly protein production. from another organism to result in a desired characteristic.
Genetic modification involves these steps:
- selection of the desired characteristic
- the gene responsible for the characteristic is 'cut out' of the The structure made of DNA that codes for all the characteristics of an organism. using A protein which catalyses or speeds up a chemical reaction.
- the gene is transferred and inserted into the Deoxyribonucleic acid. The material inside the nucleus of cells, carrying the genetic information of a living being. of another organism
- growth of the modified organism to produce the new product
Current uses of genetic modification
Type 1 A serious disease in which the body is unable to regulate blood sugar. is a disorder in which the pancreas does not produce enough A hormone that regulates the level of sugar in the blood and can be produced by genetically modified bacteria.. The affected person cannot control their blood A simple sugar used by cells for respiration. levels.
Type 1 diabetes can be controlled by injecting insulin. The extra insulin allows the glucose to be taken up by the liver and other tissues, which results in cells receiving the glucose they need, and blood glucose levels stay normal.
Previously, insulin was extracted from the pancreas of pigs or cattle, but these do not have an identical composition to human insulin. Bacterial cells have been genetically modified - by inserting the human gene for insulin production into their The small circular genetic material present in bacterial cells and used in DNA recombinant technology. so that the Single-celled microorganisms, some of which are pathogenic in humans, animals and plants. Singular is bacterium. produce human insulin.
This diagram shows how the genetic modification of the bacterium works:
Here the human gene for insulin is inserted into a plasmid. This is a small closed circle of DNA present naturally in bacteria. When the bacterium divides, all the bacteria will carry the plasmid, and produce human insulin.
Other examples of genetic modification
Sheep and goats have been genetically modified to produce chemicals in their milk that can be used to treat disease. In one example the milk produced contains a protein needed to treat patients with cystic fibrosis.
Research is also exploring the possibility of providing tissues needed for transplants from animals that have been genetically modified so that the tissues are not rejected by the human immune system.
Potential benefits and risks of genetic modification
There is no doubt that the genetic engineering of bacteria and yeast to produce insulin has revolutionised the treatment of insulin. Because it is 'human' insulin, it does not have the potential side effects of injecting pig or cattle insulin.
But many people do have concerns about inserting human genes into other organisms. The organism involved is Escherichia coli - E. coli for short - whose not genetically modified form is found in huge numbers in the human large intestine.
