GENETIC ENGINEERING
Genetic engineering is the alteration of genetic code by artificial means, and is therefore different from traditional selective breeding.
Genetic engineering (GE) is used to take genes and segments of DNA from one species, e.g. fish, and put them into another species, e.g. tomato. To do so, GE provides a set of techniques to cut DNA either randomly or at a number of specific sites. Once isolated one can study the different segments of DNA, multiply them up and splice them (stick them) next to any other DNA of another cell or organism. GE makes it possible to break through the species barrier and to shuffle information between completely unrelated species; for example, to splice the anti-freeze gene from flounder into tomatoes or strawberries, an insect-killing toxin gene from bacteria into maize, cotton or seeds, or genes from humans into pigs.
HOW GENETIC ENGINEERING IS CURRENTLY USED
Here is a brief summary of some of the more important, recent developments in genetic engineering.
) Most of the genetic engineering now being used commercially is in the agricultural sector. Plants are genetically engineered to be resistant to herbicides, to have built in pesticide resistance, and to convert nitrogen directly from the soil. Insects are being genetically engineered to attack crop predators. Research is ongoing in growing agricultural products directly in the laboratory using genetically engineered bacteria. Also envisioned is a major commercial role for genetically engineered plants as chemical factories. For example, organic plastics are already being produced in this manner.
2) Genetically engineered animals are being developed as living factories for the production of pharmaceuticals and as sources of organs for transplantation into humans. (New animals created through the process of cross-species gene transfer are called xenographs. The transplanting of organs across species is called xenotransplantation.) A combination of genetic engineering and cloning is leading to the development of animals for meat with less fat, etc. Fish are being genetically engineered to grow larger and more rapidly.
3) Many pharmaceutical drugs, including insulin, are already genetically engineered in the laboratory. Many enzymes used in the food industry, including rennet used in cheese production, are also available in genetically engineered form and are in widespread use.
4) Medical researchers are genetically engineering disease carrying insects so that their disease potency is destroyed. They are genetically engineering human skin9 and soon hope to do the same with entire organs and other body parts.
5) Genetic screening is already used to screen for some hereditary conditions. Research is ongoing in the use of gene therapy in the attempt to correct some of these conditions. Other research is focusing on techniques to make genetic changes directly in human embryos. Most recently research has also been focused on combining cloning with genetic enginering. In so-called germline ...
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4) Medical researchers are genetically engineering disease carrying insects so that their disease potency is destroyed. They are genetically engineering human skin9 and soon hope to do the same with entire organs and other body parts.
5) Genetic screening is already used to screen for some hereditary conditions. Research is ongoing in the use of gene therapy in the attempt to correct some of these conditions. Other research is focusing on techniques to make genetic changes directly in human embryos. Most recently research has also been focused on combining cloning with genetic enginering. In so-called germline therapy, the genetic changes are passed on from generation to generation and are permanent.
6) In mining, genetically engineered organisms are being developed to extract gold, copper, etc. from the substances in which it is embedded. Other organisms may someday live on the methane gas that is a lethal danger to miners. Still others have been genetically engineered to clean up oil spills, to neutralize dangerous pollutants, and to absorb radioactivity. Genetically engineered bacteria are being developed to transform waste products into ethanol for fuel.
THE PROS AND CONS
Within the field of human embryo research lies a controversial science that could redefine prenatal care: genetic engineering. Genetic engineering not only offers the possibility of eliminating birth defects and genetic illness, but also presents the moral ambiguity of eugenics. The acceptability of genetic engineering, assuming that it will be available in the foreseeable future, must be explored if society is to fully benefit from it.
The most prominent and perhaps the most acceptable reason given for genetic engineering is its potential use in preventative medicine. A few cells from an embryo could be genetically analyzed to detect harmful mutation or predisposition towards disorder, at which point action could be taken either through somatic cell or germ-line gene modification.
Genetic engineering has many medical, agricultural, and personal advantages. For example, animals can be engineered for leaner meat, there can be more ecologically friendly products, productivity of crops can be increased, and bacteria can be engineered to produce drugs needed for livestock. These benefits can be seen in the commercial success, which shows how these products are needed and are used. Other benefits include DNA tests helping newborn screening and used for forensic/identity testing. Cloning can be used to reverse heart attacks.
Some of the benefits just help increase production, while others help ease the treatment of diseases or save lives. Here's a closer look at some of these important pros.
* Producing Human Insulin - help those with diabetes
* Creating New Organs - save lives
* Gene Therapy - fight diseases
* Agricultural Biotechnology - increase productivity, make plants better
A more ambiguous reason for genetic engineering is the elimination of common defects that vary in seriousness, such as sensory impairment. Dozens of chromosomes linked to hearing impairment have been located. Although treatment for such conditions initially looks promising, as the elimination of complete blindness or deafness would alleviate hardships caused by these disabilities, removing serious sensory conditions and actually raising sensory ability to a level above normal are separated by a fine line.
Eugenics (The improvement of humanity by altering its genetic composition by encouraging breeding of those presumed to have desirable genes) is rightly seen as a major risk to developing genetic engineering technology. Eighteen percent of people interviewed in the United Kingdom said that if they could choose, they would make their child less likely to exhibit aggressive or alcoholic behaviour. Technically, if the gene for this behaviour were isolated, it most likely could be altered, but it should be understood that a genetic predisposition towards certain behaviour neither guarantees that the behaviour will manifest nor does it guarantee that the behaviour will not be apparent even if the genetic predisposition is not present. Thus, not only is genetically engineering behaviour morally and ethically questionable, it is highly unfeasible. Also, whether genetic engineering is undertaken for good or bad, the quality of the outcome must be considered. In the recent experiments in cloning Dolly (a cloned Lamb), many of the mistrials were largely oversized, causing undue pain to both the lamb and the mother. And finally, thought must be given to the psychological trauma that may result from any genetic choice made; family members of victims of Huntington's disease sometimes display signs of guilt that they have escaped a positive diagnosis while their loved one must suffer, much like the survivor of a major natural disaster feeling guilty that they lived while many others did not.
THE HUMAN GENOME PROJECT
Completed in 2003, the Human Genome Project (HGP) was a 13-year project coordinated by the U.S. Department of Energy and the National Institutes of Health. During the early years of the HGP, the Wellcome Trust (U.K.) became a major partner; additional contributions came from Japan, France, Germany, China, and others.
Project goals were to
* identify all the approximately 20,000-25,000 genes in human DNA,
* determine the sequences of the 3 billion chemical base pairs that make up human DNA,
* store this information in databases,
* improve tools for data analysis,
* transfer related technologies to the private sector, and
* address the ethical, legal, and social issues (ELSI) that may arise from the project.
To help achieve these goals, researchers also studied the genetic makeup of several nonhuman organisms. These include the common human gut bacterium Escherichia coli, the fruit fly, and the laboratory mouse.
A unique aspect of the U.S. Human Genome Project is that it was the first large scientific undertaking to address potential ELSI implications arising from project data.
Another important feature of the project was the federal government's long-standing dedication to the transfer of technology to the private sector. By licensing technologies to private companies and awarding grants for innovative research, the project catalyzed the multibillion-dollar U.S. biotechnology industry and fostered the development of new medical applications.
Molecular Medicine
* Improved diagnosis of disease
* Earlier detection of genetic predispositions to disease
* Rational drug design
* Gene therapy and control systems for drugs
* custom drugs
Technology and resources promoted by the Human Genome Project are starting to have profound impacts on biomedical research and promise to revolutionize the wider spectrum of biological research and clinical medicine. Increasingly detailed genome maps have aided researchers seeking genes associated with dozens of genetic conditions, including myotonic dystrophy, fragile X syndrome, neurofibromatosis types 1 and 2, inherited colon cancer, Alzheimer's disease, and familial breast cancer.
A new era of molecular medicine characterized less by treating symptoms and more by looking to the most fundamental causes of disease. Rapid and more specific diagnostic tests will make possible earlier treatment of countless maladies. Medical researchers also will be able to devise novel therapeutic regimens based on new classes of drugs, immunotherapy techniques, avoidance of environmental conditions that may trigger disease, and possible augmentation or even replacement of defective genes through gene therapy.
Genetic Engineering is a test tube science and is prematurely applied in food production. A gene studied in a test tube can only tell what this gene does and how it behaves in that particular test tube. It cannot tell us what its role and behaviour are in the organism it came from or what it might do if we place it into a completely different species. Genes for the colour red placed into petunia flowers not only changed the colour of the petals but also decreased fertility and altered the growth of
the roots and leaves. Salmon genetically engineered with a growth hormone gene not only grew too big too fast but also turned green. These are unpredictable side effects, scientifically termed pleiotropic effects.
We also know very little about what a gene (or for that matter any of its DNA sequence) might trigger or interrupt depending on where it got inserted into the new host (plant or animal). These are open questions around positional effects. How do we know that a genetically engineered food plant will not produce new toxins and allergenic substances or increase the level of dormant toxins and allergens? How about the nutritional value? And what are the effects on the environment and on wild life? All these questions are important questions yet they remain unanswered. Until we have an answer to all of these, genetic engineering should be kept to the test tubes. Biotechnology married to corporations tends to ignore the precautionary principle but it also ignores some basic scientific principles.
Tirath Singh Bancil