Process for creating an insect-resistant plantSince the 1990s, scientists have been able to change the genetic makeup of plants and animals that are used for human consumption. These products are called genetically modified foods (GMFs), or genetically modified organisms (GMOs). GMFs are produced to enhance or improve the organism's natural traits. In order to produce GMFs, scientists combine genes from different organisms. For instance, researchers have added genes to plants, such as corn, to make them more nutritious or insect resistant. This is done through a process called recombinant DNA technology.
In addition to crops, animals have also been genetically engineered. Researchers can genetically alter animals, including chickens and cows, to increase their productivity of meat, eggs, and milk. Not all genetically modified plants are grown as food crops. Plants, including trees, have been genetically modified to help reduce the amount of heavy metal pollution in contaminated soil, lessening an environmental concern.
There are four main ways to create genetically modified foods (GMFs).
Biolistics: Biolistics has been used to genetically alter plants. It involves directly inserting new genes into the plant. Microscopic pieces of gold or titanium are coated with the new gene and loaded into a cartridge (sometimes called a "gene gun"). The microscopic particles are fired through the plant cells, leaving behind the new DNA. The DNA then combines with the plant chromosomes.
Injection: Injections are mainly used in animals. New DNA is injected through a very thin needle into the nucleus of a single cell, usually a fertilized egg that is later inserted into a female uterus. This procedure, however, is often unsuccessful because in some cases, the cells do not express the desired traits of the new DNA.
Protoplast transformation: Protoplast transformation is often used to create genetically modified plants. Enzymes are first used to dissolve the cell wall of the plant. This leaves behind a protoplast. Then DNA is added and the cell is grown in a special environment to help the protoplast re-grow cells walls. This new plant is now genetically altered.
Vectors: Vectors have been used to create genetically altered plants and animals. Scientists change the genetic makeup of a virus or bacterium so it carries new DNA instead of viral or bacterial DNA. In other words, the disease-causing genes are removed, and new genes are inserted. The vector is then inserted into the organism's cells or tissue.
Technologies for genetically modifying foods offer dramatic promise for meeting some of the 21st century's greatest challenges. But like all new technologies, they also pose some risks, both known and unknown. Controversies surrounding GM foods and crops commonly focus on human and environmental safety, labeling and consumer choice, intellectual property rights, ethics, food security, poverty reduction, and environmental conservation.
GM products: Benefits and controversies Benefits
Crops
* Enhanced taste and quality
* Reduced maturation time
* Increased nutrients, yields, and stress tolerance
* Improved resistance to disease, pests, and herbicides
* New products and growing techniques
Animals
* Increased resistance, productivity, hardiness, and feed efficiency
* Better yields of meat, eggs, and milk
* Improved animal health and diagnostic methods
Environment
* "Friendly" bioherbicides and bioinsecticides
* Conservation of soil, water, and energy
* Bio-processing for forestry products
* Better natural waste management
* More efficient processing
Controversies
Safety
* Potential human health impacts, including allergens, transfer of antibiotic resistance markers, unknown effects.
* Potential environmental impacts, including: unintended transfer of transgenes through cross-pollination, unknown effects on other organisms (e.g., soil microbes), and loss of flora and fauna biodiversity.
Access and intellectual property
* Domination of world food production by a few companies
* Increasing dependence on industrialised nations by developing countries
* Biopiracy, or foreign exploitation of natural resources
Ethics
* Violation of natural organisms' intrinsic values
* Tampering with nature by mixing genes among species
* Objections to consuming animal genes in plants and vice versa
* Stress for animal
Labeling
* Not mandatory in some countries (e.g., United States)
* Mixing GM crops with non-GM products confounds labeling attempts.
Society
* New advances may be skewed to interests of rich countries.
Although researchers believe that GMFs most likely do not have any negative effects on human health, long-term studies are needed to evaluate the safety of GMFs for human consumption. Preliminary evidence suggests that GMFs may trigger allergic reactions. Researchers speculate that introducing a gene into a plant may create a new allergen, which may cause allergic reactions in sensitive people. To date, all GM foods available in the market have been proved as fit for human consumption.
The environmental problem of GM crops is, it can potentially permeate other non-modified crops that are growing nearby. The movement of genes from GM plants into conventional crops or related species in the wild (referred to as "outcrossing"), may have an indirect effect on food safety and food security. This risk is true, as was shown when traces of a maize type which was only approved for feed use appeared in maize products for human consumption in the United States. Several countries have adopted strategies to reduce mixing, including a clear separation of the fields within which GM crops and conventional crops are grown.
Finally the labels must be designed to clearly convey accurate information about the product in simple language that everyone can understand. In January 2000, an international trade agreement for labeling GM foods was established. More than 130 countries, including the United States, which is the world's largest producer of GMFs, signed the agreement. The policy states that exporters must label all GMFs so that importing countries can decide whether or not they want to purchase the products.
The writer is an agriculturalist and environmentalist
Email: asayedmas@yahoo.com
