How can Genetically Modified Organisms have a beneficial effect in our lives?
The idea of genetic modification is nothing new. People have been altering the genetic make-up of plants and animals for hundreds of years, using traditional breeding techniques. By artificial selection, humans have intervened in animal or plant reproduction to ensure that certain desirable traits are represented in successive generations. Artificial selection for specific traits has resulted in a variety of different organisms, ranging from sweet corn to hairless cats. But the practice of artificial selection limits us to naturally occurring variants. Nevertheless, in recent decades, the field of genetic engineering has specialized to such a level that we can now have perfect control over the genetic adaptations we introduce into an organism (Phillips; 2008). As BBC doctor Dr Colin Thomas explains, "The difference in genetic modification today is that we now have the technology to introduce a specific set of genes into an organism without relying on a structured breeding program to get the result" (Thomas).
Using recombinant DNA techniques, we are able to mobilize new genes from one species into an utterly separate species, even with a different genome. Through genetic engineering we have been able to optimize agricultural performance and facilitate the production of valuable pharmaceutical substances. However, the release of transgenic plants has stirred up many heated debates surrounding the environmental and human health risks that could result from the use of genetically modified organisms (GMOs) as a whole. On the other end of the spectrum, scientists have been pushing barriers through the use of plant and animal cells in order to improve human health by pharmaceutical means; ultimately leading to the production of modified human cells.
Genetic modification (GM) is the technology of altering genetic material of an organism by the direct addition or removal of DNA. Understanding how DNA operates at a molecular level, and in particular how its chemical sub-units can link, split and re-unit (known as recombinant DNA technology), enables scientists to chop and splice DNA and to manipulate individual genes. Any organism that has been manipulated in this way is known as a genetically modified organism (Phillips; 2008).
Genetic modification of plants can be done in two ways. One of them uses a natural soil bacterium called Agrobacteria tumefaciens. If left to their own devices, naturally these bacteria damage plants. When they enter the plant's cells, the bacteria fix into place some of their own genes into the plant's genome. Unfortunately, this causes the plant to code for the production of detrimental tumors (Samples; 2003).
Advantageously, according to Ian Sample's article in The Guardian, "geneticists can extract these tumor-causing genes from the bacteria, rendering the bacteria harmless, and replace them with genes for useful traits, such as pest resistance or herbicide tolerance" (Samples; 2003). Therefore when plants encounter the GM bacteria, they wedge the valuable gene to the plant. The other technique is using a gene gun. Ian Sample explains how it is used, "This fires tiny gold particles coated with genes that produce useful traits, directly into a plant's cells" (Samples; 2003).
GM enables scientists to research the effects of changes in genetic structures in a controlled environment. GM plants, fish and mammals have all been created to understand gene function. GM animals (especially mice) have been developed as models for humans in medical research (Schadt et al; 2002). Without the ability to genetically modify different organisms, it would be difficult to understand the mass of different DNA sequences (including human genes) and their functions. Once the functions of different genes and combinations are identified, the relationships between genetics and agricultural or health problems can start to be explored. For example, the modification of genetics can help understand the cause and susceptibility to disease in plants and animals, or the productive yield of an agricultural crop (Philips; 2008).
In contrast to this, there are concerns on the effects of genetic modification. These range from the effects on biodiversity as a result of releasing GMOs into the environment. There are also concerns surrounding human health effects of GMOs and ethical issues raised by the kinds of changes scientists could make, particularly in respect to humans and higher mammals.
The human health effects of GMOs have been a hot debate topic for many years. In 1999, the leading medical journal, The Lancet, published the details of the experiments conducted by scientists at the Scottish Crop Research Institute and Nutrition Research Group in Dundee, UK. The experiment was carried out to investigate the possible effects of feeding GM potatoes to lab rats. Its purpose was to terminate controversial claims that GM crops were harmful to humans. Although the research was looked upon with a vast amount of conflict and was said to be deeply flawed, it showed shocking and important conclusions that helped to aid scientists since; but has by no means ended the debate around whether or not genetic modification of crops harmed humans.
The research carried out by Dr. Pusztai and Dr. Ewan observed the effects of feeding rats on genetically modified potatoes that produce lectin, a protein originally found in the snowdrops flower (BBC News; 1999). According to BBC News, "Lectin increases potato plants' resistance to attacks by insects and worms" (BBC News; 1999). However, the two doctors reported that lectin binds strongly to human cells that aid immunity. In their Lancet Research Letter, BBC News has reported that they noted results of cell damage in the rat's stomachs, and in parts of their intestines. BBC News further adds, "Other rats were fed potatoes simply spiked with the lectin and because these animals did not suffer the same ill effects, they concluded that the GM device used to carry the new gene into the potatoes might have been the source of the problem" (BBC News; 1999).
In many instances, GM seeds have caused damage on indigenous landscapes, animals and people that have come into contact with it (Melnick; 2008). In 2005, the agricultural company Monsanto's 'Biotechnology Cotton' was banned in India, because it destroyed livestock. Melnick reports in her article Fear of Famine Drives EU Support of Genetically Modified Crops "The cotton had been injected with material from bacillus thuringiensis, a bacteria that kills bollworms, which is a cotton parasite" (Melnick; 2008).
To mitigate these fears, GM technology has helped the pharmaceutical industry and thus the treatment of various human diseases. In many ways, structurally, chemically, and in the nature of reproduction or synthesis, plant DNA and animal DNA are very similar, if not identical. The recent discoveries of DNA sequences of the human genome as well as genomes of some plant and bacteria species shows extensive conservation of a number of processes operating in the cells of all organisms. This discovery has opened a new avenue to utilize plant research in the battle against human diseases. For example, when genes from plants or animals are placed inside of bacteria, they will often follow those instructions and produce a protein foreign to them.
In 1978 using this technique, the company Genentech utilized a strain of the bacteria E. Coli to mass-produce the human protein insulin for the treatment of diabetes (BBC h2g2; 2003). In 1986, the hormone that promotes growth in humans was the first protein pharmaceutically produced in plants (Barta et al; 1986), and in 1989, the first antibody was made to aid people with immune deficiency (Hiatt et al; 1986). Phillips states in her journal Genetically Modified Organisms (GMOs): Transgenic Crops and Recombinant DNA Technology, "both cases used tobacco, which has since dominated the industry as the most intensively studied and utilized plant species for the expression of foreign genes" (Phillips; 2008). The use of animals in the study of GM technology has also been a tremendous help for medical research. Phillip adds, "Transgenic animals are routinely bred to carry human genes or mutations of specific genes, thus allowing the study of the genetic determinants of various diseases" (Phillips; 2008).
Due to the breakthroughs in GMOs, scientists have been able to draw on this research to help them better understand human genetics and ultimately develop genetically modified human cells. There are many examples of how genetically modifying human cells have helped to cure diseases.
Human genetic engineering is the manipulation of a human's genetic material to alter the proteins it codes for and thus produces. This is performed on the unborn individual's particular genes. It can be altered in the egg or sperm cells before they fuse, or in a very early-formed embryo, in order to control what traits it will possess when born. Human genetic engineering research has been performed on animals such as mice, as testing on humans is considered unethical. Human Inheritable Genetic Modification or IGM as it is more commonly known first became apparent in 2000. Many hopeful parents with genetic diseases would benefit greatly from IGM technology, as it would prevent genetic diseases such as Huntingdon's Disease and Schizophrenia being inherited by their children (Bio-Medicine; 2003-2009). IGM could therefore also be used to enhance normal human characteristics that are inherited, such as height, intelligence, eye or hair colour (Bio-Medicine; 2003-2009). Such techniques provoked significant debates about the ethics of using such techniques to engineer what some call "designer babies" (Frankel and Chapman; 2001).
At present, there is a technique being used that involves genetic modification of human cells in treating mitochondrial genetic diseases. Mitochondria are the site of respiration in human cells, which contain genetic material called mitochondrial DNA (mtDNA) and it's inherited matrilineally. Scientists have proposed techniques such as ooplasmic transfer (OT) and nuclear transfer (NT) to avoid the inheritance of mtDNA mutations (Bredenoord et al; 2008). This involves taking some of the contents of a donor cell and injecting it into the egg cell of a woman with infertility problems (Whitehouse; 2001). OT is the transfer of normal mitochondria to a carrier's egg cell that contains mutant DNA (Bredenoord). In the case of NT, a donated egg has the nuclear DNA removed, and replaced with nuclear DNA from the woman who has mtDNA mutation. So it ends up with normal mtDNA from the donor, and the main genetic material (nuclear DNA) from the mother who has abnormal mtDNA. Thus there are three genetic parents: the mother, the female mitochondria donor, and the father. Researchers have reported in the journal Human Reproduction, "this is the first case of human germ line genetic modification resulting in normal healthy children" (Whitehouse; 2001). But there are still important morals we need to consider, as Bredenoord et al suggest: "(the) implications of having 'three genetic parents', the ethics of egg donation, and the health and safety risks for children conceived as a result of one of these techniques" (Bredenoord et al; 2008).
Another case of how research into the GM of human cells is leading to breakthroughs involves making changes to human white blood cells, so that they kill cancerous B cells, and ultimately cure patients with highly lethal B cell cancers, such as acute lymphoblastic leukemia (CancerWeb; 2002). Research showed that modifying the immune system's T cells could be effective in fighting malignancies associated with B cells. The process involves taking the patients own T cells, manipulating them by inserting a gene that enables them to produce a receptor to recognize B cell cancers, and then returning them to the patient where they should be able to attack and kill the tumor cells. Advantageously, the technique uses the patient's own T cells, so there is little risk of compatibility issues or rejection (Battacharya; 2003). Results published in 2007 showed positive results. Researchers were able to eradicate cancer in 44% of mice bearing human acute lymphoblastic leukemia tumors. Genetically modifying the patients T cells has been a lot more successful compared with previous techniques such as human stem cell transplant (Ottmann et al; 2007).
Research into genetically modified organisms has significantly aided advances in human genetics and has resulted in the introduction of genetically modified human cells, which has subsequently led to cure and treat many diseases. Without GMO research we may have never known the depths we could go into human genetics. However, GM of any cell is by no means a closed subject. There are still important questions that scientists are unable to answer. Is the idea of changing the underlying biology of embryos ethical? Tom Shakespeare, in his article Brave New World II, significantly says, "No one yet knows whether genetically modified human beings might face problems as they begin to age, when they themselves come to reproduce" (Shakespeare; 2000). Furthermore, the world population is increasing at an unstoppable rate, inevitably putting pressure on resources; so we need to find a solution. According to BBC Dr. Colin Thomas, "Genetically modified crops may be the only real way of efficient mass production without pesticides" (Thomas). Finally, the nature of science encourages us to take steps and achieve new discoveries, so that we can improve our lives for the better.