   Genetically Modified Foods - January 29, 2003 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Genetically modified organisms (GMOs) continue to be a global issue of concern. GMOs are produced when a gene from one organism is introduced into another organism. Many people fear that genetic engineers are creating plant "Frankensteins" that will take over the earth or wipe out a species. Since many gardeners are concerned about GMOs, I though it would be interesting to present some information about GMOs. A gene is a section of DNA that codes for a specific protein. DNA is the genetic material that is passed from generation to generation during the process of reproduction. Genes carry the instructions that allow cells to assemble proteins. Proteins have many possible functions in living cells including enzymes, structural components, energy storage and transfer, motion/motility, immune protection, hormones, and more. Many people have heard that genetic engineers have inserted a fish gene into a strawberry plant. First, it is usually inaccurate to talk about a "fish gene" or a "strawberry gene." Many genes, which are merely blueprints for producing specific proteins, are shared among many organisms. So, while you cannot "breed" a fish with a strawberry, you could theoretically take a gene from a fish, or something else, and introduce it into a strawberry cell, which can subsequently be regenerated into a whole strawberry plant, which will contain an extra gene and an extra protein. By the way, fish genes have not been introduced into strawberries. In traditional breeding, many genes are transferred between related species, without clear control over just which genes are being transferred and which are not. Genetic engineering is far more precise, which is, in fact, one of its greatest benefits. It allows, for example, a single gene from a cold-hardy plant to be introduced into a strawberry to help increase its tolerance to cold weather. Genetic engineering has allowed the gene responsible for making human insulin to be inserted into a certain type of bacteria. That bacteria now makes human insulin, a product that has been used by people with diabetes for years with no adverse effects. This type of "cross-breeding" between humans and bacteria obviously would be impossible without genetic engineering. There is a natural precedent for this type of "cut and paste" operation: The bacterium Agrobacterium tumefaciens performs this type of gene transfer in nature, and is in fact one of the tools molecular breeders use to move genes around. It's true that genetic engineering could be used to produce dangerous products. But the same statement can be made about virtually any technology. Scientists generally agree that products from each type of genetic engineering should be reviewed carefully before they are implemented. Many people have allergies or sensitivities to certain foods, and their reactions to those foods can be severe. Actually, the fact that genetic engineering involves the transfer of a single or only a very few genes makes it even easier to test the allergenicity of the introduced new traits. Each gene encodes a single protein product, which can be readily tested for its allergenic effects. These are tests which should always be taken into consideration before a new GM food is introduced. The FDA is fully aware of the potential problem, so it carefully examines proposals for the transfer of genes coding for any proteins from foods known to contain allergens to other foods. If any such transfers occur in the future, the new product must be labeled to reflect the fact that it is potentially allergenic, unless the manufacturer can demonstrate that the new product will not cause an allergic reaction. Luckily, 90 percent of food allergies occur in response to specific proteins in only eight foods: peanuts, tree nuts, milk, eggs, soybeans, shellfish, fish and wheat. If there is any reason for the FDA to conclude that any product is unsafe, it can be banned. There are other issues of concern related to GMOs. I will try to present them in future columns. The above information was excerpted from an Ohio State University web site. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://ag.arizona.edu/yavapai/anr/hort/byg/. |