And why is it so useful?
Genetic engineering, or genetic modification (GM) , is a faster way to produce new varieties of plant, animal or bacteria than selective breeding. It involves the artificial transfer of selected genes from one living organism to another living organism, which need not be of the same species. Transferring genes in this way can produce genetically modified organisms with different characteristics. In a genetic engineering programme, certain features of a plant or animal will be selected. For example, genes allowing resistance to herbicides, frost damage or disease may be transferred to crop plants.1
How is it done?
1) First, find an organism that naturally contains the desired trait.
2) The DNA is extracted from that organism. This is like taking out the entire cookbook.
3) The one desired gene (recipe) must be located and copied from thousands of genes that were extracted. This is called gene cloning.
4) The gene may be modified slightly to work in a more desirable way once inside the recipient organism.
5) The new gene(s), called a transgene is delivered into cells of the recipient organism. This is called transformation. The most common transformation technique uses a bacteria that naturally genetically engineer plants with its own DNA. The transgene is inserted into the bacteria, which then delivers it into cells of the organism being engineered. Another technique, called the gene gun method, shoots microscopic gold particles coated with copies of the transgene into cells of the recipient organism. With either technique, genetic engineers have no control over where or if the transgene inserts into the genome. As a result, it takes hundreds of attempts to achieve just a few transgenic organisms.
6) Once a transgenic organism has been created, traditional breeding is used to improve the characteristics of the final product. So genetic engineering does not eliminate the need for traditional breeding. It is simply a way to add new traits to the pool.2
Genetic Engineering is reported very badly in the news. But the truth is that it benefits every one of us in one way or another, and only a handful of people realize this. Many drugs that save human lives are produced this way, alongside plants and foods used to feed the growing population of the Earth. Here are some of the products developed through genetic engineering. Take a minute to think about life without them:
Natural insulin can be taken from the pancreas of a pig or cow. It is used to treat diabetes but is limited in supply and doesn’t suit all people. Modern practice is to create insulin synthetically, using genetically modified (GM) bacteria. The gene for insulin secretion is cut from a length of human DNA and inserted into the DNA of a bacterium. The bacterium is then cultivated and soon there are millions of bacteria producing human insulin. It is easier to create high quantities of insulin. It is less likely to cause an adverse reaction. It overcomes ethical concerns from vegetarians and others.3
Scientists have added a gene to wild rice that makes it produce beta carotene. This changes the colour of the wild rice to a golden colour. Beta carotene is needed by humans in order to make Vitamin A. The advantage of golden rice is that it can be used in areas where Vitamin A deficiency is common and so can help prevent blindness3. Millions of people in Africa and other rural regions of the world benefit from this rice every day.
Herbicide resistant crops
Scientists have added genes to crop plants that make them resistant to herbicides. This reduces the quantity of herbicide that needs to be used3. It’s beneficial to the environment, and the people taking care of the crops. It also help increase yield.
Many other drugs, plants and GM animals are produced using the power of genetic engineering. Among them are cows that give human-like milk containing antibodies and other substances to boost the immunity of infants, environmentally friendly pigs, proteins expressed and collected from sheep’s milk. So next time you read an article presenting Genetic Engineering as the worst thing on the planet Earth, think about how it has benefited your life!