Tuesday, 9 August 2011

Genetic Enginering( My Presentation)


Benefits of Genetic Engineering
Genetic engineering facilitates the manipulation and duplication of DNA pieces, for industrial, medical and research purposes. Genetic engineering has produced a revolution in molecular biology. Benefits of Genetic Engineering are experienced in whole array of fields especially in agriculture, in production of valuable proteins and vaccine production.

Benefits of Genetic Engineering in Agriculture
The production of technologies based on genetic engineering is often referred as modern biotechnology. With the improvement of genetic engineering techniques, the time for generating and evaluating new germplasm (a collection of genetic resources for an organism) can be drastically reduced. Genetic engineering may ultimately have their most significant effect on agriculture. Recent advances have raised possibility of development of new plant germplasm through introduction of any gene from any organism into plant.
With respect to agriculture, modern biotechnology has been considered as the second phase of green revolution. Organisms whose genes have been altered by manipulation are called genetically modified organism (GMO). The working of GMO is due to nature of transferred genes, nature of host organism and food web formed. Some useful benefits of genetically modified plants in agricultural biotechnology are:

1.      Improved nutritional quality
2.      Better Nitrogen Fixation
3.      Disease resistant Plant
4.      Enhanced efficiency of minerals used by plants to prevent early exhaustion of fertility of soil.
5.      Reduced post harvest losses

Another genetically modified food is golden rice (Pro Vitamin Pic A enriched). Several other genetically modified foods include, soybeans, corn, cotton, seed oil etc have been formed. But many controversies are associated with genetically modified food including environment and human safety, ethics, food security, poverty reduction etc.

Some success has been achieved in developing varieties resistant to herbicides, viral diseases and insect pest. Genetic engineering promises rapid acceleration of plant breeding efforts for crop improvement.

Benefits of genetic engineering: Production of valuable Proteins
Another benefit of genetic engineering is realized in production of valuable proteins. Recombinant DNA made possible the use of bacteria to produce proteins of medical importance. One such example is that of genetically engineered human insulin which is of great importance and now marketed throughout the world.
Some important genetically engineered proteins include:

Human Insulin

Human insulin or Humulin has great importance. Earlier, patients could not tolerate pig insulin, as it has slightly different amino acid sequence as compared to human. Humulin eventually became cheaper than that extracted from animal pancreas and is now available.

Interferon is an antiviral agent which is secreted by cells which are attacked by virus. Several types of genetically engineered interferon are available in market and gives rise to antitumoral effect (thwarting formation of cancerous tumors).

Growth hormone

In humans, growth hormone helps in treatment of hypopituitary dwarfs. Genetically engineered growth hormones may prove useful in the treatment of bone fractures, skin burns and bleeding ulcers of digestive tract. The human hormone is marketed in United States and bovine hormone is expected to yield bigger cattle and thus more beef. Hence growth hormones are commercially very demanding.

Benefits of genetic engineering: Vaccine production
Vaccines produced by genetic engineering offer an advantage that the microbial strains from which the proteins are extracted do not contain complete viruses. And thus, there are no risks of accidental inoculation with live virus.
Cloning directly into vaccinia virus DNA holds great promise, although vaccines so produced are not yet in the market. Recombinant vaccinia viruses for example, a gene from genital herpes virus within its DNA, can multiply and can subsequently be inoculated into humans. The vaccinia virus produces mild infection, and expresses some of herpes virus protein and produces immunity. Vaccines can be produced using recombinant DNA technology or using cell culture. Vaccines of common use are usually produced by cell cultures or animals. Such vaccines contain weakened or inactivated pathogens. Crop plants can bear cheaper bioreactors to produce antigens to be utilized as Edible vaccines. These edible vaccines are said to be a cheap alternative as compared to recombinant vaccines.
The transgenic plants are treated as edible vaccines and consumption of these transgenic plants viz. transgenic banana and tomato cure diseases like Cholera and Hepatitis-B. Foot and mouth diseases can be cured by feeding them transgenic sugar beet.  In the near future, these vaccines can be used as conventional vaccines.
Humulin was the first therapeutic product to be made commercially by genetically engineered bacterium. Recently a genetically engineered malarial vaccine SPF – 66 has been produced.

Benefits of Genetic Engineering: Production of Disease Resistant Plants
Genetic engineering, promises to have an enormous impact on the improvement of crop species. Genetic transformation can boost plant breeding efforts for developing disease resistant varieties. Now the disease resistant genes can be isolated and transferred to high yielding susceptible plants to produce pathogen free plants. Through gene sequencing, it is possible to locate gene and after identification, gene is isolated and transferred to the host. Several disease resistant somaclones have been identified for resistance to severe potato disease, early blight of potato, caused by Alternaria Solani. Scientists are using Agrobacterium gene transfer system to produce tobacco plants with increased resistance to Tobacco Mosaic Virus (TMV).
Insect resistant plants are also developed, using biotechnological applications. Several biopesticides are developed e.g. Bt cotton, Bt corn, rice, tomato, potato, and soybeans etc.

Bt signifies Bacillus thuringiences. This bacterium contains insect toxin gene. Bt toxin gene is cloned from the bacteria and expressed in plant to provide resistance from insects, without requirement of insecticides. These modified disease resistant plants are called transgenic plants.

Top of Form

1.Plastic Plants

So that we would not have to be dependent on petroleum-based plastics, some scientists have genetically engineered plants that produce plastic within their stem structures. They claim that it biodegrades in about six months. If the genes escape into the wild, through cross-pollination with wild relatives or by other means, then we face the prospect of natural areas littered with the plastic spines of decayed leaves. However aesthetically repugnant that may seem, the plastic also poses a real danger. It has the potential for disrupting entire food-chains. It can be eaten by invertebrates, which are in turn eaten, and so forth. If primary foods are inedible or poisonous, then whole food-chains can die off.

2.Assessing the Price

For all the advantages claimed for genetic engineering, in the overwhelming number of cases the price seems too high to pay. In order to ensure megaprofits for multinational corporations well into the next century, we will have to mortgage the biosphere, seriously compromise life on the planet, and even risk losing what it means to be a human being. Genetic engineering poses serious risks to human health and to the environment. It raises serious ethical questions about the right of human beings to alter life on the planet for the benefit and curiosity of a few. 

3.Human Genes

As more and more human genes are being inserted into non-human organisms to create new forms of life that are genetically partly human, new ethical questions arise. What percent of human genes does an organism have to contain before it is considered human? For instance, how many human genes would a green pepper have to contain before you would have qualms about eating it? This is not merely a hypothetical query. The Chinese are now putting human genes into tomatoes and peppers to make them grow faster. You can now be a vegetarian and a cannibal at the same time! For meat-eaters, the same question could be posed about eating pork with human genes. What about the mice that have been genetically engineered to produce human sperm? How would you feel if your father was a genetically engineered move
4.Imprecise Technology
A genetic engineer moves genes from one organism to another. A gene can be cut precisely from the DNA of an organism, but the insertion into the DNA of the target organism is basically random. As a consequence, there is a risk that it may disrupt the functioning of other genes essential to the life of that organism.

5.Side Effects
Genetic engineering is like performing heart surgery with a shovel. Scientists do not yet understand living systems completely enough to perform DNA surgery without creating mutations which could be harmful to the environment and our health. They are experimenting with very delicate, yet powerful forces of nature, without full knowledge of the repercussions

6.Widespread Crop Failure
.Genetic engineers intend to profit by patenting genetically engineered seeds. This means that, when a farmer plants genetically engineered seeds, all the seeds have identical genetic structure. As a result, if a fungus, a virus, or a pest develops which can attack this particular crop, there could be widespread crop failur

7.Threatens Our Entire Food Supply
Insects, birds, and wind can carry genetically altered seeds into neighboring fields and beyond. Pollen from transgenic plants can cross-pollinate with genetically natural crops and wild relatives. All crops, organic and non-organic, are vulnerable to contamination from cross-pollinatation

Health Hazards
1.No Long-Term Safety Testing—Genetic engineering uses material from organisms that have never been part of the human food supply to change the fundamental nature of the food we eat. Without long-term testing no one knows if these foods are safe. 
2.Toxins—Genetic engineering can cause unexpected mutations in an organism, which can create new and higher levels of toxins in foods. (Inose 1995, Mayeno 1994) 
3.Allergic Reactions—Genetic engineering can also produce unforeseen and unknown allergens in foods. (Nordlee 1996) 
4.Decreased Nutritional Value—Transgenic foods may mislead consumers with counterfeit freshness. A luscious-looking, bright red genetically engineered tomato could be several weeks old and of little nutritional worth. 
5Antibiotic Resistant Bacteria—Genetic engineers use antibiotic-resistance genes to mark genetically engineered cells. This means that genetically engineered crops contain genes which confer resistance to antibiotics. These genes may be picked up by bacteria which may infect us. (New Scientist 1999) 
6.Problems Cannot Be Traced—Without labels, our public health agencies are powerless to trace problems of any kind back to their source. The potential for tragedy is staggering. 
7.Side Effects can Kill—37 people died, 1500 were partially paralyzed, and 5000 more were temporarily disabled by a syndrome that was finally linked to tryptophan made by genetically-engineered bacteria. (Mayeno 1994)
Environmental Hazards
  1. Increased use of Herbicides—Scientists estimate that plants genetically engineered to be herbicide-resistant will greatly increase the amount of herbicide use. (Benbrook 1999) Farmers, knowing that their crops can tolerate the herbicides, will use them more liberally. 
  2. More Pesticides—GE crops often manufacture their own pesticides and may be classified as pesticides by the EPA. This strategy will put more pesticides into our food and fields than ever before. 
  3. Ecology may be damaged—The influence of a genetically engineered organism on the food chain may damage the local ecology. The new organism may compete successfully with wild relatives, causing unforeseen changes in the environment. (Metz 1997) 
  4. Gene Pollution Cannot Be Cleaned Up
Once genetically engineered organisms, bacteria and viruses are released into the environment it is impossible to contain or recall them. Unlike chemical or nuclear contamination, negative effects are irreversible.

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