Recently, a reinterpretation of an original Monsanto GMO study was published in the International Journal of Biological Studies which appeared to demonstrate that some aspect of Monsanto’s GMO corn – potentially just additional pesticides – was causing kidney problems in their reexamination of the data. This study was widely proclaimed to be the first published study from by an independent group of Monsanto’s GMO corn (which it was not). None the less, the findings have generated a good bit of conversation on the issue of GMOs and their safety record.
It was way back in the 1970s – almost 40 years earlier – that scientists discovered the machinery and mechanisms that made the direct genetic modification of all kinds of organisms possible. The idea of genetic manipulation is centuries old, as humans have been planting, breeding, and changing creatures for thousands of years. However, the onset of genetic engineering suddenly widened the possibilities far beyond what our ancestors could have imagined – plant genes in animals, animal genes in bacteria!
But what do most people really know about GMOs? Probably not that much. I’m not trying to be insulting – the fact is that both sides of the GMO argument don’t give the back story. They throw out random statistics and statements to try and sway the masses without citing the science. GMOs are synonymous with crops like Bt corn, as if the only creatures ever genetically modified are plants. But, for example, did you know that there are GMOs being sold in pet stores? Do you know how GMOs are made, or what other uses they have?
This subject is complex – so complex I have prepared a three part series that helps explain what is going on underneath the heated debates. This first piece will explain the technology and its widespread use in science. The second installment will then focus on how genetic modification applies to the food supply, and finally, the final post in this trilogy will review the regulatory structure in place to ensure GMO safety. Without further ado, let’s begin exploring what GMOs are, and how they are being used today.
First off: What Are GMOs?
A “genetically modified organism” is any creature whose genetic material has been altered by people using genetic engineering techniques. This usually involves the introduction of a particular gene to a creature which didn’t have it before. Genes are the pieces of DNA that act as blueprints for the thousands of proteins that form the building blocks of life. Proteins provide structure, allow for communication between body parts, and act as enzymes that carry out a cell’s function in the body.
In general, “genetic engineering techniques” refers to recombinant DNA technology. How does it work? Well, recombinant DNA technology uses the cell’s natural process called recombination to introduce new genetic material into a cell.
Normally, when an animal makes its sexual cells, called germ cells (like sperm and eggs), the maternal and paternal DNA in the cell undergo recombination, where bits and pieces from mom’s chromosomes replace ones on dad’s, and vice versa. This genetic shuffling allows the organism to create hundreds of germ cells that are completely, 100% unique. I won’t get into the evolutionary explanation right now for why this is good, but trust me, the more variety in a creature’s offspring, the better, which is why our cells do this.
What GMO scientists do is take advantage of the system already set up in cells to swap around chunks of DNA. There are a number of methods for how to get the DNA in the cell, including hijacking virus machinery, using small, circular bacterial DNA rings called plasmids, creating pores in cell membranes using electric current, or even directly injecting it (there are really, really tiny needles).
In general, scientists expose cells to the desired DNA and whatever vector is being used to get it into the cells, and some cells incorporate the DNA in a useful manner such that the desired protein is produced without altering other functions in the cell. That’s harder to achieve than it sounds. The scientists then use various methods to choose those select cells, and breed them into a population of GMOs.
GMOs as a Process
When making a genetically modified microorganism (GMM), the process is easy – once they’ve got their microbe carrying the desired gene, they’ve got their population. Plants, too, tend to be fairly easy to grow after recombination, though the DNA addition itself can be difficult because their cells have what are called cell walls that make it harder to get DNA into the cell. For animals, the genetic modification is usually done on some kind of stem cell or germ cell, which then has to be implanted into a pregnant mom to be born. The GMO is then bred with other non-GMOs (“wild-type”) to produce offspring that act as carriers, having one copy o fthe desired gene, which are then further interbred to produce a creature with two copies.
The advances in genetic technology over the past few decades have been enormous. What was once a blind process that just hoped to get a gene into a given spot can now be targeted precisely, if we have the genome of the creature mapped. We can create genes that can be turned on at specific times or in specific tissues, that glow to tell us where they are, or even can be removed at will later on.
Make no mistake – there is nothing imprecise about this science. The transfer of genes is highly specific. No matter how long someone works on or eats Bt corn, they will never, ever have the gene incorporate into their tissues – it just doesn’t work that way. These techniques are widely used by all kinds of scientists all over the world, and no one has suddenly “caught” whatever gene(s) they’re working with. While there may be uncertainties about genetic technologies, how to do it in a way that ensures the change only occurs in the desired organism isn’t one of them.
GMOs as a Danger
What is possibly dangerous about this technology is that there isn’t anything keeping these altered, or “transgenetic” organisms from breeding with their non-modified counterparts, thus spreading the transferred gene (transgene) into wild populations. Scientists intentionally breed GMO/non-GMO organisms do this all the time in medical research, for example to create mice with one copy of an altered gene, to determine how being heterozygous (having two different varieties of a gene) affects the organism – but these are unlikely to spread in any way as they are strictly controlled and kept in labs.
When GMO organisms, by default, are grown where they can interact with other organisms (like in the case of crops), there is a chance that these transgenes will be spread from GMO to wild species. What the dangers of this are, exactly, aren’t entirely known, but in general, changing the genetics of wild populations of animals has the potential to have many ecological impacts.
Some of these have been identified – for example, the offspring of GM fish and wild-type fish are less viable, so a release of GM fish into streams could doom the local population of a species. But most are amorphous and still untested – like whether having pesticide genes in plants has any lasting effects on the soil they’re grown in or the flora and fauna that surround them.
Sometimes, affecting other animals is actually desired: scientists are working on releasing a kind of modified mosquito which is resistant to the parasite which causes malaria, and are hoping that these resistance genes spread throughout the mosquito population where malaria is most deadly. But in general, the effects that transgenes have on others species that interact or that eat the modified organism are still being evaluated by scientists.
What are GMOs used for?
While people debate about GM corn, the truth is that genetically modified foods are but one of many areas where GMOs are used, and one of the smallest. Most GMOs never go near our tables, and yet they are vital to our every day lives in ways most of us don’t even realize. The big use of GMOs is Scientific Research.
By far the most varied and consistent use of genetic engineering is for biological and medical research. They are not just a neat tool to study biology, they are an essential one. Scientists use genetic engineering to eliminate certain genes altogether within an organism, modify genes by turning them off or on, alter their location, or add copies of specific genes from other organisms. These uses are important tools in all kinds of biological research, including developmental biology, sensory biology, and medical science. The use of GMOs in research cannot be overstated.
Perhaps the field that most uses GMOs, however, is biomedical science. GMOs are central to the study of disease and the development of new vaccines, antibodies, and pharmaceuticals. For example, the life-saving insulin that diabetics must have is produced by a transgenic strain of E. coli, as it has been for over 20 years. The ability to use GMMs like E. coli to produce pharmaceuticals has revolutionized the industry, making some cheaper and safer, not to mention more environmentally friendly. Instead of harvesting large numbers of an animal or plant to extract a medicine, we can engineer a bacteria to make it for us.
More current research is looking into using GMOs to produce vaccines, including one for HIV. Other amazing projects include modifying peanut proteins to protect those with peanut allergies from reacting to them and engineering bacteria to prevent cavities in teeth instead of promoting them.
We’re not just talking about genetically engineered microbes. Transgenic animals are being used much like bacteria to produce pharmaceuticals. While bacteria are great, they are unable to produce certain proteins that require processing by more complicated mammalian systems. While fairly new, research into pharmaceutical production in transgenic animals is already showing promise. In 2009, the US FDA approved ATryn, an anticoagulant, which is produced in the milk of goats.
Transgenic animals are vital to many fields of medical research, not just pharmaceutical production. Most diseases are partly caused by our genetic makeup and over 10,000 diseases are caused by a mutation in a single gene. GMOs allow us to create animal models that can be used to study and understand these diseases, leading to the development of treatments, and every drug that eventually ends up in human clinical trials passes first through these animal models.
Gene knockouts (often in mice) allow researchers to delete specific genes, revealing their hidden functions in the body. Introducing other, novel genes (often from humans) allows scientists to study proteins in a living system without crossing the ethical lines of human research. Much of the research on proteins is done through GM methods, and these studies help us understand how our bodies work at the smallest levels. Studying proteins can lead to understanding diseases and even possible treatments. These methods are so used by biologists that knockout and overexpression models are basically required to get physiological research published in high-impact journals like Science or Cell.
These studies don’t just help understand pathways in cells. Studies into the proteins involved in Anthrax’s pathogenic behavior have not only led to a vaccine but are leading to specific inhibitors that can be taken after exposure to prevent death. Soon enough, the threat of Anthrax as a bioterroist agent will be nullified. Indeed, counter-bioterrorist research relies on GMOs. Transgenic animals are also vital in the emerging research into antibodies, which are quickly rising as a highly safe and effective way to treat a variety of diseases and pathogens. Because antibodies are specific to single compounds, they are an effective and safe way of removing problematic things from our bodies. Until now, antibodies have been hard to use because we naturally produce such small amounts of them. GMOs, however, allow us to produce much larger quantities. Because of GMOs (mostly mice), over 30 fully human antibodies that are produced by other animals have begun clinical trials.
GMOs in Gene Therapy
Perhaps the most up-and-coming role for genetic engineering in biomedical research is its use in gene therapy. Gene therapy uses GM viruses to deliver genes directly into our cells, allowing us to produce products that treat or cure disease. It’s already being used to create diseases caused by lacking genes like severe combined immunodeficiency, but medical scientists predict that gene therapy will explode in the coming century.
Gene therapy may be used to cure a wide range of incurable, genetic diseases, and while it’s hotly debated, it may even be used to cure disease in germ cells and embryos in the future. Because gene therapy affects a person’s genetics directly, it has the potential to revolutionize the way we treat disease, stopping damage at the source instead of trying to patch it up afterward.
I could go on and on about how GMOs have revolutionized biology because the uses of GMOs in research are endless. Catchy phrases like “Just Say No to GMOs” are leading consumers to believe that all GMOs are bad and to support legislation that bans them altogether. Suffice it to say that any complete ban on GMOs would devastate the medical and biological sciences. There are no alternative methods or ways to work around genetic engineering – it is vital to the modern study of biology and disease, period. But what does this all have to do with food? We’ll learn more about that in my next piece about GMOs.