First coined by Jack Williamson in his1941 science fiction novel Dragon’s Island the term genetic engineering admittedly harbors an eerie connotation. In recent years, the term GMO has gained both positive and negative publicity from several different industries. Understanding the principles behind this technique along with its potential risks and benefits can help to make informed decisions about the ethical and political considerations linked to genetic engineering.
By definition, genetic engineering is the process of transferring specific desirable genes from the genome of one organism into another. Genetic engineering equips the host organism with a new trait or function. The strategy improves the quality of products in many fields, including agriculture, industrial biotech, medicine and research.
The process of genetic engineering is relatively straightforward. First, researchers isolate a gene of interest within an organism. The gene typically codes for a beneficial attribute or function, such as pesticide resistance. Biological molecules known as restriction enzymes splice the gene out of the host cell genome. The gene sequence is amplified using polymerase chain reaction. Once there is enough DNA to work with, the new gene is inserted into the target organism. This process is called transgenesis. The new gene, now called the transgene, permeates the cell’s nucleus and incorporates into the host genome.
There are several different ways to perform transgenesis. A common technique uses an instrument called a gene gun. The gun blasts tiny DNA-covered gold particles into the cell. The gold then dissolves leaving the DNA to be taken up within the nucleus. A more effective method enlists the use of the plasmid of an agrobacterium. In nature, the bacterium possesses the ability to transfer its own DNA into plant cells. By harnessing the natural abilities of agrobacterium and modifying its plasmid to include the transgene of interest, researchers use this as a ready-made gene delivery system. After the successful transfer of a gene into an organism, the organism produces offspring with other members of the species until the transgene is present in a large population.
A genetically modified organism, or GMO, is an organism whose genome has been artificially altered using genetic engineering. Farmers have been genetically modifying organisms for thousands of years by practicing artificial selection and crossbreeding crops with advantageous attributes. However, the GMO label on produce now refers to the direct manipulation of an organism’s genome using lab-based biotechnology.
The first lab-based genetically modified organism was created in 1973, when researchers Herbert Boyer and Stanley Cohen developed anti-biotic resistant E. coli bacteria. Herbert Boyer went on to found the genetic engineering company Genentech, which later discovered and patented a way to produce the human hormone insulin using bacteria. In 1982, the FDA approved the hormone for human use.
Genetic modification for use in agriculture was not far behind. In 1986 field trials of herbicide resistant tobacco plants were tested in the US and France. The first commercialized transgenic plant was introduced to the market in 1994 when the Californian biotech company Calgene released the Flavr Savr tomato, which was engineered for a longer shelf life. However, the costs of creating the tomato outweighed the profit, and Calgene eventually stopped producing the Favr Savr. In the same year the European Union approved commercial use of herbicide resistant tobacco. A year later the EPA and the FDA approved the Bt potato, making it the first pesticide-producing crop in the US.
Many current uses of GMOs exist in several different industries. In agriculture, large staple crops such as corn, soybeans, and wheat are often genetically modified to be herbicide resistant. In the US, an estimated 88% of these crops are GM. Genetic modifications in farm animals allow them to produce more milk, eggs, and muscle. GMOs are utilized within the health sector, as well. In addition to hormone-producing bacteria, genetically modified organisms provide many pharmaceutical agents for vaccines and other drugs. In environmental science, GMO bacteria are used to digest pollutants in the soil.
With the introduction of genetically modified organisms came a slew of new environmental policies. Currently, in order to be used a GMO must gain the approval of at least one government agency, including the FDA or EPA. However, due to the lack of long-term environmental studies there is very little evidence about the safety and widespread effects of GMOs in nature, and therefore it is difficult to make judgments on the appropriate usage of GMOs. Consequentially, there is much controversy surrounding these topics.
A commonly discussed issue is the unmonitored spreading of modified genes. Many crops use wind dispersal as a mechanism for spreading seeds, and thus can spread their genetic information across great distances. In 2001, genetically engineered DNA was found in a native Mexican corn crop, actualizing concerns of “genetic pollution”. Genetic pollution would decrease biodiversity in crops, potentially making them more susceptible to a mass wipeout from disease. In response to this concern, the 2003 Cartagena Protocol on Biosafety was written and signed by 166 countries. The protocol ensures that detailed information about the transportation of all GMOs is collected and controlled in an effort to protect biodiversity.
Another concern is GMO competition within the environment. A genetically modified species typical gains a new function that increases its rate of survival. The new trait may give it a competitive advantage over another neighboring species, allowing it to take over its space and resources. This could have detrimental effects on population balance, and could cause unforeseen problems for the entire ecosystem.
In addition to the environmental concerns, GMOs present a plethora of legal and ethical questions. For example, many debate whether it is ethical to file intellectual property on the genetic sequence of an organism. Biotech companies argue that IP-based revenue is used to promote further research, while others worry that ownership of a particular sequence prevents widespread research and hinders scientific discovery. Recently, the U.S. Supreme Court ruled that patents can’t be filed on naturally occurring human gene sequences. However, the specificity of the ruling left room for loopholes, and does not apply to all GMO products. It is likely that legal debates surrounding genetic data are far from over.
Despite the many controversies surrounding GMO products, the technique provides potential on several different research horizons. With world population increasing at an exponential rate, problems involving global health and hunger must unavoidably be addressed, and genetic engineering may prove as a useful tool in unforeseen areas. Before completely dismissing or condoning a scientific technique, it is important to weigh the benefits and consequences on both a short and long term scale. More studies are needed to evaluate the safety of genetic engineering and to realize its full potential for scientific discovery.
- Published in Genetic Technologies