BIOLOGY Volume 3 - A Guide to General Biology - 2004

25. APPLIED GENETICS

25.6. Benefits and Risks – Ethical and Social Issues in Genetic Engineering

From the very outset of Introduction/32.html">Genetic Engineering, scientists have been fully aware of Structure/19.html">The Importance of addressing the potential hazards and ethical concerns associated with this new branch of biology. Initially, in 1971, these concerns focused on plans to clone Cancer-causing viral genes in E. coli. There was apprehension that if genetically modified E. coli escaped from the laboratory, the inserted Gene might spread among E. coli populations inhabiting the human gut via plasmid transfer, such as through conjugation (Section 2.3.3). It was also feared that DNA from humans and other mammals, such as mice, might harbor cancer-causing genes (oncogenes) and that these genes could be inadvertently transferred along with adjacent DNA fragments used in genetic engineering. In February 1975, a group of over 100 internationally recognized molecular biologists gathered in California and decided that, until the risks could be accurately assessed, a moratorium should be placed on research involving genetic engineering. This was a remarkable instance of scientific progress being reined in not by a government, but by the scientific community itself. Work on Oncogenic Viruses was suspended. In 1976, special committees were established in the USA and the UK to formulate safety guidelines. Only after appropriate regulations were adopted was research on oncogenic viruses allowed to resume. Yet, to this day, rigorous safety reviews of applied Procedures are still carried out, and debates regarding how strict rules and guidelines should be continue, with the number of advocates for tighter controls growing in both Europe and the USA.

The 1980s witnessed an explosion of interest in genetic engineering. Industrial companies began pouring billions of dollars not into theoretical molecular biology, but into solving applied problems. A new industry was born — biotechnology. This chapter and Chapter 12 examine some of the Applications of biotechnology in agriculture, medicine, industry, and waste management, while the end of this chapter discusses such vital aspects of biotechnology as Gene Therapy and DNA profiling.

Class="center">25.6.1. Human Safety

The first food product containing recombinant DNA approved for sale was the transgenic tomato (Section 25.4.6). Using this example, we will examine the issues concerning the safety of genetically modified foods.

One of the primary safety concerns involves the vectors used to transform plant Cells. These vectors contain Antibiotic Resistance genes, most commonly for kanamycin. These genes end up in The Genome of the transformed plant alongside the desired gene (Fig. 25.1). Transgenic tomatoes contain just such a gene. The concern is that once the tomato is eaten, the kanamycin resistance gene might find its way into the genome of E. coli Bacteria inhabiting the human gut. Because bacteria are eliminated from the body in feces, the gene could spread into the environment and be transferred to other pathogenic bacteria which, upon infecting a person, would prove resistant to Antibiotics. In reality, the tomato gene, along with all the other DNA, will almost certainly be digested in The Stomach; but even if it is not, the probability of the gene passing through a succession of organisms is extremely low. Furthermore, the kanamycin resistance gene is, unfortunately, already widespread in the environment. Nevertheless, researchers continue to search for ways to remove marker genes following transformation.

In 1996, the European Union granted permission to import genetically modified maize from the USA. This maize contains a bacterial gene that enhances its resistance to pests and diseases, as well as a gene for resistance to the antibiotic ampicillin. Environmental activists oppose the introduction of such maize and have threatened protests.

While the public is deeply concerned about The Emergence of genetically engineered foods, the companies that have invested millions of pounds sterling in the research and development of such products are heavily invested in their safety. For instance, PPL, the company that produces the anti-emphysema drug AAT, imports all its experimental sheep from New Zealand to ensure they are free from bovine spongiform encephalopathy (mad cow disease) and related conditions. Transgenic goats used by Genzyme Transgenics to produce Monoclonal Antibodies are fed pesticide- and herbicide-free diets. Furthermore, introducing any animal-derived Proteins or fats into their feed is strictly prohibited to rule out any possibility of disease transmission from other animals to humans. Thus, these products may actually be safer than many traditional foodstuffs.

25.6.2. Environmental Safety

Section 25.4.3 discussed the possibility of creating agricultural crops resistant to plant-pathogenic viruses. Because tobacco mosaic virus (TMV) is used as a vector to transfer the desired genes in this case, There is a possibility that during experiments, plant-pathogenic viral DNA might become packaged within the TMV protein coat. Such a virus could infect all plants susceptible to TMV. To safeguard against such incidents, extensive field trials under natural conditions must be conducted when developing resistant plant varieties.

Both North America and Europe have developed regulations governing the release of genetically modified organisms (GMOs) into the environment. Each EU member state has its own regulatory bodies, and all uses of GMOs are publicly debated. For example, widespread controversy surrounded the application of genetically engineered "ice-minus" bacteria. The wild-type bacterium inhabits many agricultural plants and makes them sensitive to frost because the protein it secretes promotes ice crystal formation on the plants. Genetic engineering was used to produce so-called "ice-minus" bacteria, from which the gene encoding this protein had been deleted. The goal was to spray a suspension of these bacteria onto plants, such as strawberries, to make them more frost-resistant. Heated debates ensued regarding the environmental risks of releasing GMOs, yet authorization for The Use of these modified bacteria was ultimately granted. Following this case, regulations were made clearer and less restrictive.

The first permit for the widespread use of a GMO in the UK was issued by the Department of the Environment in 1994. The Organism, produced by the Belgian company Plant Genetic Systems (PGS), was a new variety of oilseed rape carrying a gene for resistance to the herbicide Basta (Section 25.4.4). By that time, over 60 small-scale field trials of this transgenic plant had been conducted in the UK and more than 1,000 in North America. According to the developing company, the environmental risk posed by this rape is minimal. The problem, however, is that outside the field where it is cultivated, transgenic rape can turn into a troublesome weed that cannot be eradicated using the herbicide Basta. Additionally, it can cross-pollinate with related plants, such as wild mustard, thereby transferring herbicide resistance to wild plant populations.

Another concern is that the creation of herbicide-resistant crops could, in the opinion of some scientists, lead to the need to use increasing quantities of herbicides, particularly Basta, although the companies involved argue the opposite — that herbicide use will actually decrease because they will be more effective.

In a similar fashion, Transgenic Plants might potentially pass on resistance to diseases, drought, and other environmental stressors to weeds; the resulting "superweeds" could rapidly colonize agricultural land. A serious environmental threat could also be posed by genetically engineered fish, such as the giant salmon mentioned in Section 25.5.3. Although they are kept in enclosed enclosures, it is known that predatory birds hunting for fry can occasionally drop them into the open sea. The consequences of this and whether it might disrupt the balance in wild salmon populations remain unknown. Despite these concerns, industrial production of GMOs is expanding in many countries. So far, no noticeable adverse environmental impacts have been documented.

25.6.3. Animals and Ethics

People often assume that, by virtue of their intellect, they have the right to redesign other organisms for their own benefit. In recent years, however, this anthropocentric viewpoint has been increasingly re-examined. While a major driving force behind the creation of modified animals is commercial profit, it remains unknown whether the biological "design" of these animals is equipped to cope with the additional stress caused by heightened milk, meat, egg, and other product yields. It is also unclear what consequences might arise from integrating human genes into the genomes of laboratory animals — a technique widely used today to study the MOLECULAR MECHANISMS OF numerous diseases. Despite all these concerns, The production of genetically modified animals for agriculture, pharmacology, and medicine is a reality of modern life, and Transgenic Animals are undoubtedly among the best-cared-for in the world.

25.6.4. Patenting

In 1992, an American biotechnology company attempted to patent new varieties of cotton and soybeans they had developed through genetic engineering. Under this scheme, farmers would have been required to pay royalties to the patent holder every year for using these crops. Although patenting was permitted, these patents were challenged by the international community. In 1991, the U.S. National Institutes of Health attempted to patent The Human Genome, but after numerous protests from various countries, the application was withdrawn. Nevertheless, following nucleotide sequencing, the human gene responsible for breast cancer (BRCA1) was patented in the USA, and attempts are underway to patent a second such gene (BRCA2).

Some European companies are attempting to strip farmers of their rights to the offspring of transgenic animals. The European Parliament and national governments must carefully balance the interests of farmers, producers, and consumers.

25.6.5. Insurance

In 1997, a committee on the ethical implications of genetic manipulation was convened in the UK. On the agenda was the question of insurance companies: should such companies base their business practices on the results of genetic tests? Should they deny coverage or raise premiums for individuals who have a high probability of dying from a specific disease, such as Lung Cancer or Heart disease? Insurance companies argue that they ought to have access to the results of any genetic tests undergone by a person applying for life insurance.

25.6.6. Cloning

The cloning of Dolly the sheep in 1997 was an inevitable consequence of advances made in genetics and biotechnology (Section 21.1.4). It has now become possible to create numerous identical copies of animals possessing desirable traits. One of the ethical dilemmas is that this technique could potentially be applied to humans, although such work is currently prohibited.