A fairly heated debate with friends the other day spurred me to sit down, put "pen to paper", and seek out answers to the questions that came out of that conversation. We were talking about Genetically Modified Organisms (GMO's) and during the course of the afternoon it became clear to me this issue is quite a "hot topic". Anything related to genes/DNA seems to be "sexy science", or what is making the news recently - cloned sheep, the labeling (or lack thereof) of genetically modified foods, the race to map out the entire human DNA sequence. While everyone was aware of these recent advances, it was apparent the background behind the issues was not clearly understood. Additionally, when trying to track down information that afternoon, it was difficult to find articles written from an unbiased and objective viewpoint.
   For that reason, I decided to do some research of my own and write this article: my goal is to provide you with a brief, impartial overview of genetically modified organisms, discussing how they are created and the reasons individuals may be "for" or "against" their development.

What is a Genetically Modified Organism?
 
   When considering a GMO, several friends thought the genetic modification of organisms had been taking place for thousands of years, in the form of selective breeding. Man has been breeding one animal with another to produce offspring with 'desirable traits' for generations. Typically size, color/markings, and good health were traits selected for. For example, if speed was the desired trait in racehorses, certain stallions with a history of being "fast" (no pun intended) were selected to breed with specific mares. Today, hip dysplasia is a trait prevalent in certain large dog breeds such as the German Shepard and Rottweiller. Owners selectively breed their dogs with one that does not have a history of hip dysplasia in its family lines, in the hope that any offspring will not develop this degenerative condition. Selective breeding does not involve genes from one species being introduced into another. Rather, cows are bred with bulls (or artificially inseminated with semen from a selected bull), stallions are bread with mares and the list goes on, same species to same species.
   It is true that man has genetically modified both crops and animals from their original, "wilder state" through selective breeding for many years. However, for the purpose of this article, a GMO is one containing a transgene: a gene(s) that has been artificially inserted into its genetic structure. For instance, the genetically modified plants grown today may contain a foreign gene from another plant, or even a gene from another species altogether: transgenic canola, engineered to be resistant to a herbicide, contains a gene from a bacterium. This canola plant was "cross bread" so to speak with another species (a bacteria), rather than the traditional selective breeding methods that breed same species to same species.

How is an organism genetically modified?
 
   In the early 1970's, researchers discovered the techniques enabling them to "cut and paste" genetic information from one organism into another. Today, the process of "genetically modifying" an organism is expensive and time consuming. Significant portions of the work are still "trail and error" due to the problems inherent in modifying an organism's DNA - accumulating enough copies of a desired gene, finding a way to introduce a foreign gene into a cell, and preserving the cells ability to reproduce are just a few of the hurdles to overcome.
   There are various techniques used to copy and/or introduce genetic material from one organism into another. Essentially, genes responsible for a selected trait are isolated, modified slightly, copied several times, and inserted into another organism. The following summary (1) is a very brief description of how a genetically modified plant can be created through the use of bacteria:

   1. A large number of enzymes can be used as tools to "cut" genes from plants. Approximately 300 of these        "restriction enzymes" are now available for use in biotechnology. Different enzymes are used to cut and isolate        specific genes.
       Once scientists have "cut" or isolated the genes that control a desired trait in a plant (such as resistance to a        disease), they must replicate enough exact copies of the genes to transform a large number of cells in the target        plants.
       The genes responsible for the desired trait are inserted into a plasmid taken from an E. coli bacterium. Plasmids -        circular pieces of DNA that are found in bacteria - have the ability to reproduce very quickly, and are the basis of        gene cloning.

   2. Once a gene is inserted into a plasmid, the plasmid is put back into the bacterial cell. The altered bacterium is        allowed to replicate, and the desired gene is copied or cloned in every cell.

   3. The 'new genes' are removed from the plasmids and inserted into the target plant cells. The new transgene must        get into the nucleus of a plant cell and be incorporated into one of its chromosomes in order for a plant to be able        to express the new trait.

   4. New plants are grown directly from the modified cells. Every cell in the new plant contains the foreign gene.

   Once the gene has been isolated and cloned, researchers modify it slightly prior to introducing it into the new organism. Promoter and termination sequences (codes which are tacked onto the beginning and end of the gene) are added, allowing the plant to "recognize" this foreign gene and accept it as one of its own genes. A "marker gene" is also added, enabling researchers to identify which cells have incorporated the foreign gene into their chromosomes. The foreign gene may also be modified to express itself in a slightly different way once inside the new plant: a gene may be modified to express itself in an amplified manner. For instance, scientists may "customize" and grow a high oil corn producing 25% oil, compared to the average corn variety that may produce approximately 2%. (2)

What are the benefits associated with GMO's?
 
   Genetic engineering is a very powerful technology allowing scientists to introduce genes into an organism: in essence, any organism could be engineered to produce a trait not seen before. This "ability" is thought to have many benefits for society. Research into genetically modifying organisms may lead to our ability to "reverse" various hereditary diseases. Genetically modified crops are thought to produce higher yields per acre than their traditional counterparts, resulting in a more efficient use of farmland. The following are examples of the many benefits observed (or expected) from the development and use of GMOs:

• The first genetically engineered product - human insulin produced by a bacterium - was approved for human use in 1982. Human DNA carrying the information for making insulin was inserted into E. coli bacteria, enabling the bacteria to produced insulin. (3) This bacterial GMO provided a reliable source for human insulin, as up until this point insulin for use by diabetics was harvested from beef or pork pancreas. The insulin from these animal sources differed slightly from human insulin, causing some immune reactions and drug resistance. It is thought the "GMO insulin" now in use is basically "equivalent" to human insulin, and perhaps less likely to cause an immune reaction.
• Gene therapy is another instance where the "genetic modification of an organism" has the potential to be of great benefit to society. Gene therapy aims to correct a hereditary disease in an individual through the insertion of a functioning gene into the DNA of their cells (in essence replacing a non-functioning gene with one that functions properly) (3). Though this line of research is in its beginning stages, gene therapy has been suggested as a possible treatment for Cystic Fibrosis, Huntington's disease, Emphysema, Hemophilia, and Adenine Deaminase Deficiency (ADA). (4)
• Genetically engineered plants resistant to insects, viruses, and fungi have been developed. Research is moving toward shifting the physiology of a plant during its life cycle - for example, directing a plant to put less energy into leaves and more into its seeds and fruit, or promoting more aggressive root development to produce a "heartier" plant. Scientists are also exploring the possibility of engineering crops for industrial and transportation uses, such as alternate sources of fuel, oil, and "bioplastics". (2) Additionally, plants could be modified to produce specific compounds such as vaccines, nutritional supplements (i.e. increased vitamin A content etc.) and other pharmaceutical compounds. (5)

What are the problems associated with GMO's?
 
   As discussed earlier, genetic engineering is a very "new" and powerful science. The advances in biotechnology allow us to make changes to the basic building blocks of an organism, changes that would likely not occur naturally in nature. There is concern that science is "playing God" without knowing enough about the effects the changes can have on our bodies, health, and environment. The following are several examples of the many concerns expressed (or expected) from the development and use of GMO's:

• Foremost in many minds is the concern for human health, related to the "allergenicity" or the possible introduction of an allergen into a product (i.e. peanut genes into an apple). For example, genes "cut" from a peanut and "pasted" into an apple could possibly transfer the factors causing the allergy into the apple.
• The labeling of GMO's is a difficult issue to resolve for several reasons: should GMO labeling be on a voluntary basis or made mandatory by government legislation? What information should be included on the label - how the organism was made and/or where the foreign genes came from? Companies are unsure how labeling will affect the marketing of their product, especially in foreign countries where labeling standards may be different. Additionally, it will be difficult and costly to "segregate" the GM crops from the non-GM ones at the grain elevators and transportation ports. (6)
• The possibilities and consequences of 'foreign gene flow' are not understood at this time. A number of questions have been raised concerning "gene jumping" - the ability of the foreign gene to move into other weeds, plants, animals etc. There is, for example, research indicating that foreign genes have the ability to move from GM crops into non-GM plants such as weeds: weeds with resistance to one or more herbicides have been documented in several countries. (7)
• Due to the possibility of an inherent bias in the test or experimental results published by companies involved in biotechnology research, an independent testing and monitoring body should be established. "Follow up" on the test results, reports of gene jumping, etc. is necessary to determine the full extent of these activities. This leads to the question of who would fund such an organization - the public requesting the organization be formed or the industry creating the GMO's?
• There are many questions concerning the effects of GMO's which have yet to be answered: do environmental changes cause a GMO to, for example, produce a normally inactive toxin? What are the long-term effects on the environment? Wildlife? Many individuals feel that the impact GMO's may have on the environment is not well understood, and that much more testing should be required before GMO's move outside laboratory and into "the real world"

Where do you go from here?
 
   The genetic modification of organisms is very "new" science, and research is only beginning to understand the mechanisms and functions of genes and DNA. It seems that for every report stating GMO's are safe to human and environmental health, there is another saying the opposite. In this article I briefly discussed some of the benefits and problems associated with GMO's, with my intent being to provide you with an initial understanding of this issue.
   I strongly encourage you to do some "research" of your own to become more familiar with this topic, as the issues presented in this article are a very small portion of the information available. A variety of credible sources of information on genetics, gene modification techniques, and genetically modified organisms are available: local libraries, introductory biology textbooks, research journals, and even newsmagazines are good resources to consider. As you are reading this article off an Internet website, the following sites contain very informative articles and information regarding GMO's, and are good places to start looking for information:

   1. http://www.agwest.sk.ca - Ag-West Biotech Inc. is an organization funded by Saskatchewan's Department of         Agriculture and Food. This site contains a wide variety of articles and educational information regarding cloning,         Biotech Q & A's, and an animated demo concerning how transgenic plants are developed.
   2. http://online.sfsu.edu/~rone/Welcome.htm - a website by a philosophy professor at San Francisco State         University. The site contains information related to an Environmental Ethics course at the university. Scroll down         and click on "Environmental Ethics" or "Genetic Engineering and its Dangers" to access several papers and         opinion essays.
   3. http://scope.educ.washington.edu/gmfood - this site is published by the University of Washington, University of         California (Berkley) and the American Association for the Advancement of Science. SCOPE is set up to be a         "forum for the investigation and discussion" of GM foods. The site provides information on topics such as gene         transfer and resistance, suggestions for further reading, and a "library" of all the information the society has         collected concerning GM foods.