Principles of Methods of Genetic Modified Food

There are various techniques used to genetically modify foods. Food may be genetically modified to increase its shelf life, make it resistant to pesticides and insecticides, or improve the crop nutritional yield.Genes use chemical messages that instruct the cell to perform its functions by making proteins or enzymes. By introducing a foreign gene, the altered organism make new proteins or enzymes so that the cell performs new functions. For example, the gene that helps a coldwater fish survive low temperatures can be inserted into a strawberry to make it frost-resistant. The genes can be taken from an animal, plant or micro-organism. If the genes are inserted into another species, the resulting organism is referred to as transgenic.

Bacterial carriers
The natural ability of the bacterium Agrobacterium tumefaciens is the principal technique for genetic modification of plants. This bacterium can infect plants, which makes it a suitable carrier for delivering DNA.

The selected gene is inserted into the bacterium plasmid (a circular piece of DNA) and dropped into a special solution, which is able to make the cells of the bacterium more porous. The solution is then heated, which allows the plasmid to enter the bacterium and express the new genes. Crown gall, a tumor-like growth is resulted when the plant is infected with this bacterium. The ‘recombinant’ (genetically altered bacterium) is allowed to rest and grow. Depending on the plasmid, it may develop extra copies of the new gene. The bacterium is then allowed to infect the target plant so it can deliver the plasmid and the new gene.Inserting additional genes of interest into A. tumefaciens and transfer those genes into plants is commonly used to create transgenic crop plants for agricultural purposes.

Bioloistics
Biolistic method (gene gun), is another widely used process to create transgenic crops. It is a method used for the creation of the two most common transgenic crops –Roundup Ready soybean and Bt-corn. It involves shooting new genes into the potential host. The selected DNA is attached to microscopic particles of gold or the metal tungsten. Like firing a gun, these DNA-laden particles are shot into the target cells using a burst of gas under pressure.

Electroporation
The prepared target cells, together with the selected DNA are immersed in a special solution in electroporation. A short but intense electric shock is then passed through the solution. This results in small tears in the cell walls, which allows the new genetic material access to the nuclei. Aftermath, the cells are placed into another solution and encouraged to repair their breached walls, locking the DNA inside the cell. The selected DNA is incorporated into the host chromosomes to provide the host with a new gene.

Gene silencing
Gene silencing is used to prevent plants like peanuts and wheat from producing the proteins (allergens) that often cause allergies to humans. The gene that is responsible for the undesirable trait is identified. One method to ‘silence’ that particular gene is to attach a second copy of the gene the wrong way round.

Gene splicing
Genetic modification involves genetic engineering, which is also known as gene splicing. It is a technique to splice together DNA fragments from more than one organism. Thus, this prepares a ‘recombinant’ DNA molecule in a test tube, producing a single piece of genetic material containing the original information from multiple fragments which can then be inserted into another organism. This is achieved by cutting up DNA molecules with restriction enzymes and joining these fragments together using DNA ligase. Generally, there are two classifications of genetic modification; modifying of plants and animals.

Viral carriers
Like bacteria and plants, animals can also be genetically modified by viral infection. A virus that will invade the target cells but not cause damage or death is chosen. The selected DNA is thus added to the genetic makeup of the viurs, and then the virus is allowed to infect the target. As the viurs invades the cells and replicates, the selected DNA is added to the target cells.

Lipofection
Lipofection is a method using small bubbles of fat called liposomes as the carriers of selected DNA. The target cells and the liposomes are placed into a special solution. When the liposomes merged with the cell membrane, it allows the DNA to enter the cells for inclusion in the chromosome.

Microinjection
Injection is a method primarily used in animals. The new DNA is injected into the nucleus of a fertilised egg which can then be placed back in the female uterus where the injected cell is allowed to develop normally. Unfortunately, there is a high rate of failure when using this technique as the cells take up and express the desired traits of the introduced DNA infrequently.For microinjection, the selected DNA is injected into a fertilised ovum through a glass capillary tube. The genetically modified egg is then transplanted into the prepared uterus of a receptive female and is allowed to grow to term.

Microinjection is common way to create transgenic fish. Mosaic is the first generation but several lines have been produced with the transgene incorporated into the germ line and transgenic fish can then be produced naturally by crossing male and female gametes.

Although many types of transgenic fish exists (e.g. for increased cold tolerance, antibiotic production, ornamental Glofish etc), the main focus had been on so called growth hormone transgenic fish, mainly salmonids, tilapias and carps. These fish have an over-production of growth hormone which results in an increased growth rate of 30-40 times that of wild-types. The final size of some species is increased as well as the growth rate, providing an incentive for commercial breeders to farm such fish. However, for ecological concerns, potential negative effects of transgenic fish in nature largely prevent the commencement of commercial production.

Protoplast transformation
Protoplast transformation is commonly used in plants. The cellulose in the plant cell wall is dissolved away using enzymes leaving a protoplast. DNA can then be inserted to the protoplast which are then cultured on a growth media. This encourages the protoplast to regrow the cell walls and thus eventually grow into a transgenic plant.

The AppliCation of GM FoOd and IngreDienTs

There are around 20 GM foods, additives, flavorings, growth hormone (eg. bovine somatotropin) and enzymes (eg. rennet, used to make cheese) currently approved in Europe. In the US there are more than 40 approved GM foods. Maize, soybean, rape seed oil (canola), tomatoes, chicory, squash and potato are examples of crops that have been modified to make them resistant to insects and viruses to increase tolerant to herbicides. In addition, nutritional enhancement of food crops is currently researching actively, especially with regards to the world's health problems like iron and vitamin A deficiency.

Many foods on supermarket shelves may contain GM ingredients. Modified genes may have been used in an early stage of the food chain, but may or may not be present in the end product. Genetically modified food ingredients, for example, soy flour in bread may have come from GM soybeans. Imported soy (resistant to herbicide) from the United States is one of the main sources of GM ingredients in food products, such as chocolates, potato chips, margarine, mayonnaise and biscuits. Cottonseed oil made from GM cotton (resistant to a pesticide) is also used for frying by the food industry, in mayonnaise and salad dressings. Imported GM corn is mainly used as cattle feed. Imported foods like breakfast cereal, bread, corn chips and gravy mixes, may also contain GM corn as part of the ingredient. Other GM foods available overseas include potatoes, canola oil, sugar-beet, yeast, salmon, bananas, barley, carrots, cauliflower, chicory and coffee.

Types of Genetic Modified Food...

• The Flavr SavrTM Tomato

The first genetically modified crop approved for commercial sale was the Flavr-Savr tomato. The product, developed by a company called Calgene, was approved by the FDA in 1993. It went on sale one year later, but in 1997, due to increasing public concerns and the need for specialized transportation equipment, production ceased. Calgene (which was subsequently bought by Monsanto) wanted to create a tomato with a vine-ripened taste that could withstand the rigors of shipping. What they created was a controversy that is still being debated a decade later.

• Bt (Bacillus thuringiensis) Corn

Bt corn is a hybrid plant bioengineered to produce an insecticide. This induced insecticide provides effective, consistent control of pests such as the European corn borer and offers some protection against the fall armyworm and corn earworm. It does so at a lower cost than insecticides, and with better results. In August of 1995, both the EPA and the USDA approved Bt corn for commercial use as a human food product. The use of Bt corn has increased dramatically, from 1.4% in 1996 to about 30% of total corn acreage (26 million acres) in 1999.

ConTroVerSiaL IsSueS on GM foOD!!!

• Consumer’s right:

Consumer’s right is about disclosing detailed information of the product and allowing consumers to make informed choice. Consumer law is enforced to protect consumer’s rights. Informed choice and the resulting actions from it require access to information and resources. The controversial issue is that not all consumers have access to their rights. This is because consumers do not have the same access to information and resources to make decisions about GM foods due to lack of education or limited access, especially in developing countries. Consumers Association of Singapore is a body to protect the rights of consumers in Singapore.

• Product labeling:

It is not mandatory in some countries such as United States and Singapore. Singapore follows closely with the regulations set by CODEX for labeling of GM food. FSANZ requires labelling of GM food where that food contains novel DNA (the transferred gene or genes) or protein (the product of the novel DNA). If the food is indistinguishable from the conventional alternative (e.g., if it is a refined oil that has no novel DNA or protein, but was produced from GM plants) then labelling is not required. This is one area of concern for some people who would like to avoid all GM products due to philosophical or ethical objections to the process.

• Religious and Ethnical Concerns:

GMOs are seen as “unnatural” food since GMOs are produced by the transfer of genes from different species. The term “Frankenfood” is also being used to refer to GM foods due to the fact that it is made by tampering with nature by mixing genes among species which is an act of violation of nature of lives.

There are also objections to consuming animal genes in plants and vice versa. Genes can be transferred from any organisms to another. For example vegetarians are concerned about consuming vegetables that contain animal genes which will then violate their religious beliefs. However, technologists point out that although there may be an ethical dilemma, the chemical structure of DNA is the same in all living organisms. It is only the sequence of the nucleotides within the DNA which determines the genetic makeup of the organism.

• Environmental Concerns:

Farming of GM foods might result unintended transfer of transgenes through cross-pollination where, the conventional crops could no longer be sold as 'non-GM'. However, bioengineers argue that cross-pollination poses negligible risk as pollen must travel over "moats" constructed between GM crops and other species.

GM food such as those that are pest resistant might result in unintentional poisoning of “non-target” species of insects. For example, Bacillus thuringiensis (Bt) crops would be just as poisonous to ecologically beneficial insects that feed on the Bt corn or cotton plant. Other potential effect is that those animals that feed on those insects might be affected as their food’s population decreases, resulting in loss of fauna biodiversity. Another possible effect of the GM technology will be on the diversity of the world's food crops. If only a few GM varieties of the major food crops are grown, the risk that a disease could wipe out a large proportion of food production is much greater.

• Food Safety:

As non-GMO foods contain allergens, pesticides residues or microbiological contaminants, thus transfer of genes to produce GM foods might also contain allergens from the plant where the gene is extracted. Antibiotic resistance is a concern as there’s a possibility of transfer of GM DNA from the plant to gut microflora of humans and animals. Such genes have the potential to adversely affect the therapeutic efficacy of orally administered antibiotics.

Genetic modification of plants may result in alteration in nutritional composition or level of anti-nutrients which in turn may affect the nutritional status of the consumer or population groups. For instance, GM rice (accumulation of xanthophylls, increase in prolamines) may result in nutritional imbalances in the consumer. Various toxicants are known to be inherently present in different plants. Genetic engineering has the potential to alter such constituents or produce newer toxicants; toxicity potential.

BeneFits of GM FoOd!!

1. Genetically engineered food is cost effective. Because it is designed to resist pests and grow under non-optimal conditions, it can also help people in areas where regular crops would not grow. Large savings in production may lead to financial gain and help fight poverty.

2. Genetically engineered food can be naturally pest-resistant and thus reduce the need for additional chemicals, pesticides, and other dangerous additives, which might harm human’s health.

3. Genetically engineered food may help reduce world hunger. As new species are altered to grow faster or more effectively, they can be used to feed poor nations or chosen for countries where crops may not normally grow because of less desirable environmental conditions.

4. GM foods can help against certain diseases or provide specific nutrients, such as the “golden rice” which is able to provide vitamin A due to the gene implanted from daffodil. “Golden rice” also contains a gene that will increase the uptake of iron from the soil by the rice plant and another that will increase the rate of absorption of that iron into the human body. This can help to reduce the nutritional deficiency of vitamin A and Iron around the world especially the developing countries whereby they do not have access to nutritious foods and since rice is a staple in those areas.

More 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
• Bioprocessing for forestry products
• Better natural waste management
• More efficient processing

Society

• Increased food security for growing populations

GeneTic MoDificaTion ProCeSs

Genetic modification process, which is part of Food Biotechnology, also known as Genetic engineering, Recombinant DNA technology, and Gene splicing. It can be defined as organisms in which the genetic material (DNA) has been altered in a way that does not occur naturally. The resulting organism is then said to be "genetically modified," "genetically engineered," or "transgenic". This application of biological techniques to food crops, animals and microorganisms involves the isolation, manipulation and reintroduction of DNA into cells or model organisms.

Genetic Modified Organisms are organisms that have genetic material modified outside the organism’s natural reproductive process and is able to multiply itself or to transmit genetic material. The purpose of genetic modification is to introduce new characteristics or attributes physiologically, making a crop resistant to herbicide, introducing a novel trait or improving the present traits, or producing a new protein or enzyme.

GeneticModification/Engineering:
1) DNA Extraction.
This is the first step in genetic modification process. It involves extracting DNA from a desired orgamism.

2) Gene Cloning
During DNA extraction, the entire DNA from the organism is extracted. Gene cloning is used to separate the single gene of interest from the rest of the genes extracted and make copies of it.

3) Gene Design
Once a gene has been cloned, the gene is designed to work inside a different organism. This is done in a test tube by cutting the gene apart with enzymes and replacing gene regions that have been separated.

4) Transformation/ Gene Insertion
Since plants have millions of cells, it would be impossible to insert a copy of the modified gene into every cell. Thus, tissue culture is used to propagate abundance of plant cells called callus, which the new modified gene will be added.

The new gene is inserted into some of the cells using various techniques such as the gene gun, agrobacterium, microfibers, and electroporation. The main objective is to transport the new gene(s) and deliver them into the nucleus of a cell without damaging or killing it. Transformed plant cells are then regenerated into transgenic plants. The transgenic plants are grown to maturity in greenhouses and the seed they produce, which has inherited the modified gene, is collected. The transgenic seeds will then hand over to a plant breeder who is responsible for the final step.

5) Backcross Breeding
In backcross breeding, transgenic plants are crossed with selected breeding lines using traditional plant breeding methods to combine the desired traits of selected parents and the modified gene into a single line. The offspring are repeatedly crossed back to the selected line to obtain a high yielding transgenic line. As a result, the plant will obtain a yield potential close to current hybrids that expresses the trait encoded by the new modified gene.

WhAt is GM FooD??

What is GM food?
GM food is produced from plants or animals which have had their genes changed in the laboratory by scientists.

The principles for the production GM foods :
1. Pest resistance
Crop losses from insect pests can be staggering resulting in devastating financial loss for farmers and starvation in developing countries. Many people want farmers to use fewer chemical. Thus GM Technology is aimed at achieving fewer pesticides used, energy savings, & increased yields.

2. Herbicide Tolerance
GM crops are more resistant to herbicide.

3. Disease Resistance
There are many viruses, fungi and bacteria that cause plant diseases. GM crops and plants that are genetically-engineered tend to be more resistance to these diseases.

4. Cold Tolerance
Unexpected frost can destroy sensitive seedlings. Thus antifreeze gene in crops can prevent that and survive through unfavourable condition.

5. Drought Tolerance
Creating plants that can withstand long periods of drought will help people to grow crops in formerly in hospitable places.

6. Salinity Tolerance
About one- third of the world’s irrigated land is unsuitable for growing crops because of contamination with high levels of salt. Most trees and crop plants are highly sensitive to salty conditions. Creating plants that can withstand long period of high salt content in soil and groundwater will help people to grow crops in formerly in hospitable places.

7. Nutrition
Malnutrition is common in third world countries where impoverished peoples rely on a single crop such as rice for the main staple of their diet. If rice could be genetically engineered to contain additional vitamins and minerals, nutrient deficiencies could be alleviated.