Ömer Özkan

 WHAT IS GENETIC ENGINEERING ?

If we want to make a brief introduction, we take up genes firstly. Genes encode the information necessary for synthesizing the amino-acid sequences in proteins, which in turn play a large role in determining the final phenotype, or physical appearance, of the organism. Genetic engineering (GE) provides some techniques to cut DNA at a number of sites and stick them with any other DNA of another organism. GE often involves the isolation, manipulation and reintroduction of DNA into the cells or model organisms. This transfer is done in two common methods that are biological or electromechanical. By this way, GE passes over the barriers and shuffle the information between completely unrelated species of plants, viruses, animals, humans and bacteria; for example genes from human to sheep, an insect-killing gene from bacteria to soybean. The aim is to discover new characteristics or attributes physically or physiologically, such as introducing a crop resistant to an herbicide or producing a new protein or enzyme.

 Formerly, experiments involved changing DNA by using bacterial vectors. This technology creates inherent uncertainties. When you use this technology, you have no idea where the foreign DNA is going to. Moreover, you also have no idea how it will interact with the genes that code for various proteins. These uncertainties are at

the hearth of the wide range of environmental and health problems. But, latterly, the movement of genes has been far from that technique, which causes some constraints on gene transfer.

At this point, we ask ourselves “What benefit could GE bring to humanbeings?” Some scientist believe that if the genetic information in the chromosomes could be deciphered and the genetic mechanism were examined, we could potentially regulate our health, improve quality of life, and control the biochemical processes in our bodies.This means that we could control our own fate.Besides, we would be able to improve genes of animals and vegetables so they could serve humankind better.At first glance, these ideas which are based upon theory of gene determinism make a sense and seem nice, however, painstacking analysis shows that these ideas based on incorrect theory.

THE HISTORY OF GENETIC ENGINEERING

Prehistoric times to 1900, farmers plant seeds saved from domesticated crops.Some naturalists and farkers commence to recognize “hybrids”, plants produced through natural breeding between related varieties of plants.In 1900s Gregor Mendel took the concept of selective replanting and then selective breeding. He would breed a plant with itself until it showed the desired trait in every new generationof the plant.After he succeeded he would breed two plants with differing characteristics with each other.After all, European plant scientists began using his henetic theory-“classic selection”. 

In 1953 James Watson and Francis Crick publish their discovery of the three- dimensional double helix structure of DNA. Mendel’s early     experiments was the foundation stone of the future genetic engineering. Mendel is the father of genetic engineering.

In 1970s Herbert Boyer and Stanley Cohen used enzymes to cut a bacteria plasmid and add another strand of DNA in the gap. Both bits of DNA were the same type, but this event, offereda window into the intervention of recombinant DNA technology.

In 1990, a young child with a very poor immune system recieved genetic therapy. Some of her leucocytes were genetically manipulated and re-introduced into her bloodstream while she was watching Sesame Street.

Currently, scientists are able to add simple traits to organisms. The power of science is limited to knowledge about genetics, gene locations, and trait interactions, but as knowledge grows, so will scientists’ abilities to manipulate life.^*

HUMAN GENETIC ENGINEERING

 Genetic engineering supplies the ability to add or delete specific genes within a living cell nucleus. Now genetic engineers are starting to modify the genes of human, using three approaches.

1. Cloning          : Cloning uses the DNA of a living individual to create a new one.The most famous example is Dolly, a sheep that was cloned using DNA from a sheep which was cloned using DNA from a sheep that had been dead for six years. A human has not been cloned yet, however a team of researchers announced they are going to try it.
2. Somatic cell panipulation     : Somatic cells are the cells of the body that do not pass DNA on to the next generation. Somatic manipulation seeks to change the genetic make-up of the somatic cells ( organ and tissue cells; lung,brain ). For example, researchers are experimenting with many ways to introduce genes into the blood cells of patients with a blood disorder and into cells of immune system in patients with a rare inherited disorder of the immune system.In stead of approaching the disease with drugs, correct the genetic component of the disease.Diseases like cystic fibrosis, for example, may be treated by inserting a corrective gene into malfunctioning lung cells.Hundreds of trials have been carried out, but in most cases the patients have not been cured.Changes in somatic genes can have an impact solely on a single human, in other words can not be passed on to one’s children.
3. Germline manipulation         : Germ cells ( sperm and eggs ) do pass DNA from one generation to the next. Germline genetic manipulation changes the sex cells (i.e., the sperm and egg, or germ, cells), which pass the parental genes to the next generation.In spite of the fact that germline engineering is sometimes suggested as a way for preventing transmission of genetic diseases, the same outcome can be achieved by preimplanation screening and other means. Designing future generations by means of
   germline manipulation is still in the realm of science fiction, but just barely: some influential scientists are arguing that it should be attempted.Germline engineering is necessary, but to go beyond disease prevention and modify the genetic endowment of children otherwise expected to be healthy.

The ability tı put genes into living cells was performed in animal related experiments during the late 1970s. Suggestions to begin human gene manipulation followed shortly thereafter, and aroused much discussion.

 Religious, scientific, political and environmental leaders and organizations generally approved of somatic gene therapy, but strongly opposed germline manipulation. In 1983, an allience of 58 religious leaders announced that genetic engineering of the human germline “represents a fundamental threat to the preservation of the human species as we know it, and should be opposed with the same courage and conviction as we now oppose the threat of nuclear extinction.”

In 1990, the National Institutes of Health (NIH) approved somatic gene therapy trials, but said that it would not accept proposals for germline manipulation “at present.” This decision discourged advocates of germline engineering. By the late 1990s, advocates of germline manipulations were ready to begin a combined effort to generate public support.French Anderson, a pioneer of human somatic gene therapy, subjected a proposal to the NIH to begin experiments involving human germline manipulation.He anticipated being ready to human trials as early as 2003.

GENETIC ENGINEERING IN AGRICULTURE

Crops which have been in the first priority of engineering are the major market foods: corn,cotton, canola, soybean, potato, and tomato. The principal field of interest is agronomic traits (how the crops will be cultivated) and how to maximize the market for seeds, herbicides, pesticides, and fungicides. The main genetically engineered characteristics being commercialized are:

         • Herbicide-resistance (plants that can be sprayed with herbicide and not die)

         • Pest-resistance (plants that produce their own pesticide to kill insects)

         • Fungal resistance (plants that kill problem fungi)

         • Virus resistance (plants that are immune to, or kill, problem viruses)

       • Seed sterility

Transgenic vegetables are being developed, but none are commercialized yet. In the meantime, wheat and rice are the subject of concentrated research worldwide, and the race is on to get to the market first with genetically engineered varieties. 

Increasingly too, cash crops or the food of developing countries are targets: plants indigenous to and commercially cultivated in developing countries for industrial country markets are being investigated. Often, the interest is how to modify these crops for their production in the laboratories or fields of industrial countries. For example, vanilla and cocoa bean.

The US is the largest producer, consumer  and exporter of genetically modified foods. People in this country have been disclosed to genetically modified foods since 1996. The first crop to be sanctioned for human consumption was a genetically modified tomato. There are now around 40 different crops that have been allowed into the food chain. These include:

• Chicory Corn (14 varieties), Cotton (5 varieties), Flax Papaya Potato (3 varieties), Soy (3 varieties), Sugarbeet Tomato (5 varieties).

A second-generation of GM food plants is currently under development. Here the goal is to alter the nutritional content of plants. This second-wave is called “functional foods”.The major focuses of this ‘wave’ include: increasing the vitamin and mineral content of foods; modifying the fat, oil and sugar content.

Trees for fruit and forestry are now being GE for:

        · faster growth, providing a nearly endless source for pulp and paper

        · herbicide-, pest-, and insect-resistance; reportedly to increase yield and minimize losses

        · salt tolerance, so that trees can grow on soils that turn salty due to the pressures tree plantations put on water tables

        · altered day length perception, so that trees can grow in a wider range of regions

        · altered fiber content, that will reportedly reduce the amount of chemical treatment needed for paper and pulp production.

        · producing medicines, after insertion of foreign genes

        · environmental clean-up, where the trees are engineered to extract toxins from polluted lands

Use of Vıruses, Bacterıa, and Antıbıotıcs ın Genetıc Engıneerıng

Currently, unprocessed techniques are used to force foreign genes into a life form, each of which  carry their own set of ecological harms. Viruses are used like advance flocks to force the ‘host organism’ to accept the foreign DNA, by breaking into the host’s cells and depositing the foreign DNA there. Bacteria are used to transport the new genetic material into the host organisms. It is feared that the viruses and bacteria used could recombine, to form new and powerful viruses and bacteria, whose effects cannot be predicted, and against which we may have no defense.Antibiotics are used to point whether the “host organism” has accepted the foreign DNA.The use of antibiotics for this purpose is widely criticized because antibiotics are precious defenses for humans and animals against harmful bacteria. There is increasing concern that when humans consume plants with antibiotic resistance genes, the resistance may be passed on to bacteria in the human digestive system, and from there on to other bacteria.

ETHICS

Proponents of genetic argue that the technology is safe, and it is essential to maintain food production that will continue to match population growth and help feed millions in Third World countries more effectively. Others argue that there is more than enough food in the world and that the problem is not production, food distribution, so people should not be forced to eat food that may carry some degree of risk.

Others oppose genetic engineering on the grounds that genetic modifications might have unexpected results, both in the initially modified organisms and their environments. For instance, certain breeds of maize have been developed that are toxic to plant eating insects. It has been said that those strains cross-pollinated with other varieties of wild and domestic maize and passed on these genes with a reputed impact on Maize biodiversity. Subsequent to the publication of these results, several scientists pointed out that the conclusions were based on experiments with design flaws. It is well known that the results from the Polymerase Chain Reaction method of analysing DNA can often be confounded by sample taint and experimental artifacts. Appropriate controls can be included in experiments to eliminate these as a possible explanation of the results. More recent attempts to replicate the original studies have concluded that genetically modified corn is absent from southern Mexico in 2003 and 2004. Also in dispute is the impact on biodiversity of the introgression of transgenes into wild populations. Unless a transgene offers a massive selective advantage in a wild population, a transgene that enters such a population will be maintained at a low gene frequency. In such situations it can be argued that such an introgression actually increases biodiversity rather than lowers it.

Activists opposed to Genetic Engineering assert that there is no way with current recombinant technology to guarantee that Geneticly Modified Organisms will stay under control,  and the use of this technology outside the secure laboratory environments carries unacceptable risks for the future.

Some are anxious about that certain types of genetically modified crops will further reduce the biodiversity in the cropland; for instance, herbicide-tolerant crops will be treated with relevant herbicide to the extent that wild plants (‘weeds’) are not able to survive, and there will be insect-free crops because of plants toxic to insects. Related to this, there could be declines in other wildlife which depend on weed seeds and/or insects for food resources. According to the recent (2003) farm scale studies in the United Kingdom, this is the case with GM sugar beet and GM rapeseed, but not with GM maize (though in the last example, the non-GM comparison maize crop had also been treated with environmentally-damaging pesticides subsequently (2004) withdrawn from use in the EU).

Proponents of current genetic techniques as used on food plants make reference to the benefits which the technology can have in the harsh agricultural conditions of Africa. These people say that with modifications, existing crops could grow stronger under the relatively hostile conditions supplying much needed food to their people. They also make reference to golden rice and golden rice 2, genetically engineered rice varieties (still under development) that contain elevated vitamin A levels. There is hope that this rice may make easier vitamin A deficiency that contributes to the death of millions and permanent blindness of 500,000 annually.

Proponents state that GM crops are not significantly different from those modified by nature or humans in the past, and are as safe or even safer than such methods. Although there is gene transfer  between unicellular eukaryotes and prokaryotes, there have been no known genetic catastrophes as a result of this. They argue that it is politics not economics or science, that causes their work to be closely investigated.

Proponents also remark that species or genera barriers have been crossed in nature in the past. An oft-cited instance is today’s modern red wheat variety, which is the result of two natural crossings made long ago. It is made up of three groups of seven chromosomes. Each of those there groupscame from a different wild wheat grass. First, a cross between two of the grasses took place, creating the durum wheats, which were the commercial grains of the first civilizations up through the Roman Republic. Then a cross happened between that 14-chromosome durum wheat and another wild grass to create what bacame modern red wheat at the time of the Roman Empire.

ECONOMIC AND SOCIAL EFFECTS

Biotechnology companies often asserted that genetically modified seeds are essentially needed to feed the world and reduce poverty in developing countries.In fact this view based  on two assumptions:

• There is a gap between the food production and human population density.According to this result, genetic engineering is the best way to quench hunger and increase production.
• It is important that there is no relationship between the hunger and population density.A country can be hunger even if it is sparsely populated-like Brazil, or densely populated-like Haiti.

Furthermore, hunger is also connected with globalization.When developing ( 3^rd World Countries) countries accept free trade policies, lowering tariffs and allow goods from industrialized countries to flow in.Haiti ( a very poor country ) experiences this policies.In 1986 Haiti imported approximately 7000 tons of rice, with the majority of rice consumed being grown on the island.After opening its economy to the world, cheaper rice flooded in immediately from US.By 1996 Haiti imported 196,000 of foreign rice at a cost of US $ 100 million a year.As a result, Haitian production became negligible and a dependence on foreign rice appeared.The cost of rice rose and very large number of poor people whimpered of rising grain prices.All in all, hunger increased in Haiti. ( Aristide ²⁰⁰⁰ )

Many opponents of current genetic engineering believe the increasing usage of GM crops majorly has led biotechnology companies to have much more power in agriculture and gain the control of the production chain and farmers as well.So farmers have lost their power and in the future they will dependent on these companies. On the other hand, many proponents of GE claim that high

production and lower pesticide usage has brought higher yields and profitability to the farmers.

It’s important to point out that the data on environmental impingements are much clearer than for human health effects. We know that GM crops can be lethal to beneficial organisms in the environment. We know that other crops and related wild plants can suffer genetic contamination through cross-pollination, that we may have “superbugs” and “superweeds” due to unpredictable patterns of gene escape. We also know that genetically engineered Bt toxin percolates into soil and is stable for eight months or more, where it can have considerable effects on the microbes that prolong soil fertility, etc. The next generation of genetically engineered crops, many of which are designed as small “factories” or “bio-reactors” to produce drugs and industrial chemicals, could have even more significant effects. Biotechnology has been a conveyance for peerless concentration of corporate power over our food and our health.

THE CURRENT STAGE OF GENETIC ENGINEERING

The current stage of GE development can be seen in majorly three fields.

1. The determination of DNA sequence in chromosomes and other genes. U.S govenment supported this field for future natural interest and also private enterprises are extensively involved. Several years ago, there were many reports on developments in this field. The excitement has gradually subsided since scientists have seen the complexity of the problem. This problem is not going to be solved in the near future.
2. Artificial horizontal gene transfer–a synthetic method of gene transfer between different species. Because the structure and function of some small genes are relatively well known, biologists attemp to transfer these genes to other bio-species to ameliorate their functions. Private enterprises have actively been examining this method on animals and vegetables in order to obtain “super products.” Government-supported research institutes principally use horizontal gene transfer to obtain cognition about the genetic mechanism. Because the genetic mechanism is a very complicated system, they can mostly deal blind tests by means of horizontal gene transfer. There are many unknown factors in this field, regardless of whether the method used is direct insertion of genes or simple mixing of genes. The chance of success is very small, and only a few products achieve. The possible side effects of these GE experiments are still unclear. There has not been much successful advance in this field
3. Cloning. “Dolly” is a sheep genetically duplicated using a complete set of chromosomes from an adult sheep. However, scientists have not been able to repeat it. The validity of scientific results is based upon their reproducibility. Since the experiment has not been repeated, many people doubt its validity.Nearly half of the scientific community is not convinced by the result. It would be extremely hard to clone a humankind even in the absence of pressure from social expostulations.

CLOSING

Genetic Engineering ( GE ) is a test tube science and is untimely applied in food production.  In the long term, GE results in the destruction of the human food supply. At present there is no evidence that GE food and GE protein is harmless to human health. The possibility of harm cannot be eliminated. To

develop potentially harmful food when there is an enough supply of natural food is not a judicious thing to do. Biotechnology married to corporations has a tendency to ignore the precautionary principle but it also ignores some basic scientific principles.

            Here is the question that appear on the minds who are anxious about we discussed above: “What can we do?”

Talking about Genetic Engineering is the first step towards protecting ourselves, our families, and our environment from abuses and towards making certain of that the wisdom of our ancestors is brought to bear on something that is sure to impact our future. The next step is both to protect and  to promote biodiversity, particularly within our own territories. We can protect biodiversity by protecting against biopiracy— by preventing appropriation of genetic resources from our territories. We can also protect biodiversity by maintaining the environmental completeness of our ecosystems. To do this, we can work to prevent or clean up pollution, eliminate or reduce pesticide use, prevent or reverse monocropping on a large scale to prevent further loss of traditional medicinal and food plants and animals.

 RESOURCES

• Engineering The Farm  ~ Ethical and Social Aspects of Agricultural Biotechnology
• Edited by: Britt Bailey and Marc Lappé
• Genetic Engineering in Agriculture  ~ Miguel A. Altieri
• http://library.thinkquest.org/
• http://americanradioworks.publicradio.org/
• http://studentweb.tulane.edu
• http://en.wikipedia.org/
• http://online.sfsu.edu
• www.btinternet.com
• www.ipcb.org