About GMOs

What is a GMO?
Some questions and answers on genetic engineering and genetically modified organisms

By Luke Anderson

A GMO (genetically modified organism), also know as a GE (genetically engineered) or transgenic organism, is created by scientists in a laboratory where they insert genes into an organism to create new traits. In the United States, GMOs are not labeled. They are in over 75% of processed supermarket foods in ingredients like soy lecithin, canola, corn syrup, and cotton seed oil.

Haven’t we been breeding new plants and animals for thousands of years? Isn’t that just like genetic engineering?

Genetic engineering is completely different from traditional breeding. In traditional breeding it is possible to mate a pig with another pig to get a new variety, but is not possible to mate a pig with a potato or a mouse. Even when species that may seem to be closely related do succeed in breeding, the offspring are usually infertile—a horse, for example, can mate with a donkey, but the offspring (a mule) is sterile.
With genetic engineering, scientists can breach species barriers set up by nature. For example, they have spliced fish genes into tomatoes.
Other examples of genetic engineering experiments that have already been done include:

  • Spider/Goat – taking a gene from a spider that leads to the production of spider web and putting it into goats so the goats can then be milked for the spider web protein.
  • Fish/Strawberries – taking a gene from an Arctic flounder and putting it into a strawberry to try to make it frost-resistant.
  • Corn/Human – taking a human gene and putting it into corn so that the corn contains human antibodies that attack sperm. The idea is to develop the corn as a plant-gel contraceptive that kills sperm on contact.

Are GMOs grown in Hawaii?

Hawaii has more experimental field trials of genetic engineering than any other state in the nation. Just a few of the many examples of permits granted for field trials include:

  • Corn engineered with human genes (Dow)
  • Sugarcane engineered with human genes (Hawai‘i Agriculture Research Center)
  • Corn engineered with jellyfish genes (Stanford University)
  • Tobacco engineered with lettuce genes (University of Hawai‘i)
  • Rice engineered with human genes (Applied Phytologics)
  • Corn engineered with hepatitis virus genes (Prodigene)1

What is a gene?

Every plant and animal is made of cells, each of which has a center called a nucleus. Inside every nucleus there are strings of DNA, half of which is normally inherited from the mother and half from the father. Short sequences of DNA are called genes. These genes operate in complex networks that are finely regulated to enable the processes of living organisms to happen in the right place and at the right time.

How is genetic engineering done?

Because living organisms have natural barriers to protect themselves against the introduction of DNA from a different species, genetic engineers have to find ways to force the DNA from one organism into another. These methods include:

  • Using viruses or bacteria to “infect” animal or plant cells with the new DNA.
  • Using electric shocks to create holes in the membrane covering sperm, and then forcing the new DNA into the sperm through these holes.
  • Injecting the new DNA into fertilized eggs with a very fine needle.
  • Coating DNA onto tiny metal pellets, and firing it with a special

Is genetic engineering precise?

The technology of genetic engineering is currently very crude. It is not possible to insert a new gene with any accuracy, and the transfer of new genes can disrupt the finely controlled network of DNA in an organism.

Current understanding of the way in which DNA works is extremely limited, and any change to the DNA of an organism at any point can have side effects that are impossible to predict or control. The new gene could, for example, alter chemical reactions within the cell or disturb cell functions. This could lead to instability, the creation of new toxins or allergens, and changes in nutritional value.

For example, when genetically engineered salmon were compared to normal salmon, it was found that the genetic engineering unexpectedly increased the amount of a protein identified as a major food allergen.3 In another case, Australian researchers reported in November 2005 that after 10 years spent developing a genetically engineered pea they had to abandon project after they found out that the altered peas caused lung inflammation and other adverse effects in mice.4 ”The reaction of the mice…might reflect something that would happen to humans,” said deputy chief of CSIRO plant industry T. J. Higgins.5

Why do genetically engineered foods have antibiotic resistant genes in them?

The techniques used to transfer genes have a very low success rate, so the genetic engineers attach “marker genes” that are resistant to antibiotics to help them to find out which cells have taken up the new DNA. These marker genes are resistant to antibiotics that are commonly used in human and veterinary medicine. Some scientists believe that eating GE food containing these marker genes could encourage gut bacteria to develop antibiotic resistance.

“We have such a miserably poor understanding of how an organism develops from its DNA that I would be surprised if we don’t get one rude shock after another.”
— Richard Lewontin, Professor of Genetics at Harvard University2

  1. Statistics on field tests for genetically engineered crops available on the website of “Information Systems for Biotechnology” established as part of the National Biological Impact Assessment Program, a program administered by USDA <www.isb.vt.edu/CFDOCS/fieldtests2.cfm>
  2. Quoted in Michael Pollan, “Playing God in the Garden,” New York Times Magazine, October 25, 1998.
  3. Hill, J.A., A. Kiessling, R.H. Devlin. 2000. Coho salmon (Oncorhynchus kisutch) GE for a growth hormone gene construct exhibit increased rates of muscle hyperplasia and detectable levels of gene expression. Can. J. Fish. Aquat. Sci. 57: 939-50. In “Elements of Precaution: Recommendations for the Regulation of Food Biotechnology in Canada,” The Royal Society of Canada, Ottawa, January 2001, p.182, http://www.rsc.ca/index.php?page_id=119. Lindstrom, C.D., T. van Do, I. Hordvik, C. Endresen, S. Elsayed. 1996. Cloning of two distinct cDNAs encoding parvalbumin, the major allergen of Atlantic salmon salmo salar. Scan. J. Immunol. 44: 335-44.
  4. Vanessa E. Prescott, Peter M. Campbell, Andrew Moore, Joerg Mattes, Marc E. Rothenberg, Paul S. Foster, T. J. V. Higgins, and Simon P. Hogan, “Transgenic Expression of Bean-Amylase Inhibitor in Peas Results in Altered Structure and Immunogenicity,” Agric. Food Chem., 53 (23), 9023 -9030, 2005.
  5. “Australian researchers scrap GM peas after mice fall ill,”AFX News Limited, 17 November 2005