Frankenfood: the science of genetically engineered crops

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Frankenfood: the science of genetically engineered crops

There is a lot of controversy in the vegan and animal rights community around genetically engineered foods that is often clouded by scaremongering, misconceptions, half-truths, and outdated information. Since I first started blogging about genetic engineering several years ago I have gone back to school to pursue a degree in biotechnology as well as gotten involved in the growing DIYbio* movement that seeks to take biotech beyond the corporate and academic lab and put the tools of modern biology into the hands of citizen scientists and garage biohackers*. In this time I have seen a growing number of people questioning the knee jerk anti-GMO propaganda, but many myths and misconceptions still abound. So I feel it is about time for a re-introduction to the topic.

Genetic engineering, put simply, is the transference of genes between organisms in a controlled manner through a variety of methods under laboratory conditions. When the gene being transferred comes from a distantly related organism, for example transferring a gene from bacteria to a plant, the product is called a transgenic organism. To understand this process and its implications, we must first understand something about genes. Genes are small segments of DNA, consisting of the four chemical bases: adenine, cytosine, guanine, and thymine. Genes ‘code’ for specific proteins that perform a variety of functions and are sorta* like the blueprints for life. The relationship between genes and proteins is explained by long-time vegetarian and Professor of Microbiology and Molecular Genetics, Dr. Emanuel Goldman:

Think of these four individual chemicals in DNA as an alphabet consisting of four letters. Protein is made when these letters are “read” by cellular machinery as a series of “triplets”–that is, different sets of three letters in sequence which designate one or another of 20 amino acids in the intended protein. The arrangement of those four letters in groups of three at a time constitutes the entire dictionary of words of the language; a gene is a collection of those words in sequence, much like this article is a collection of words in sequence. Just as this article can be reprinted in another publication, a sequence of DNA containing a gene from one source can be cut out by molecular “scissors” (which are enzymes) and pasted by molecular “glue” (which are other enzymes) into the DNA of another source. This is what recombinant DNA and genetic engineering accomplishes. When the information of a gene in DNA from an animal is copied and placed in the DNA of bacteria, often those bacteria will be able to produce the animal protein. Similarly, when a foreign gene is inserted into the DNA of a plant, that plant may produce the foreign protein, which is the case in some genetically engineered crops.*

The genetic language of life is common to all living beings: we all share a common ancestor and significant amounts of our genetic code. There are no special categories of “animal genes” and “plant genes”. A gene is a gene is a gene. Furthermore, genes can not suffer; they are not sentient. They are simply bits of DNA. Karl Haro von Mogel gives us further insight using what is likely the most iconic example of transgenic crops:

The fish-tomato example is rather ironic, as this meme began when scientists were experimenting with using the “antifreeze protein” from a species of fish to see if they could keep tomatoes from freezing (They were never commercialized). But as it turns out, a similar antifreeze protein in cod evolved out of noncoding DNA – going from useless sequences (sometimes haphazardly referred to as ‘junk DNA’) into a functional and essential gene. If you put this antifreeze gene in a tomato, is it even a fish gene? Or a junk gene? What if it once was a viral gene that got into fish, and eventually became what it was before a genetic engineer stuck it in a fruit, is it still a viral gene?

It’s an antifreeze gene… that evolved in fish. And you would essentially still be eating a tomato.*

In his book Pandora’s Picnic Basket, Alan McHughen explores this issue even further:

No doubt, some vegetarians will decide that a single pig gene in a soya burger is sufficient to prohibit consumption. Others – perhaps even vegans – will decide, like the rabbi, that the single pig gene lacks the ‘essence’ of the animal and so the burger is therefore suitable for consumption.

Even here, though, drawing a line is difficult. Consider what happens if scientists wanted to improve the nutrient balance of legumes. We might use a gene from a Brazil nut, producing a protein rich in cysteine and methionine, amino acids which are deficient in soya bean and other legumes. We have to reject this gene, though, because the resulting protein is allergenic. As an alternative, we find a more suitable, non-allergenic protein from a tomato gene, although this gene provides a protein not quite as rich in the two amino acids. Our soya bean with the modified tomato gene would seem perfect for vegetarian consumption, having better nutritional balance, not being allergenic, and lacking animal genes or products. It would seem acceptable to vegetarians. We later discover the modified tomato protein is identical to a pig protein. Is it still suitable for vegetarian consumers? If not, at what point does it or did it become prohibited?

Lets throw in another question. We just discussed a genetically modified tomato gene. Now assume we find a natural unmodified tomato gene is identical to a pig gene. If ordinary tomatoes (and, in all likelihood, other fruits and vegetables) are suddenly blacklisted because they share a gene with a pig, what do people then eat? If ordinary fruits and vegetables sharing pig genes are not prohibited, there’d be no scientific basis to prohibit GM plants carrying a gene similar or identical to those in pigs.*

Known unknowns

A prevalent argument against genetic engineering is that it’s too risky to alter organisms at the genetic level because we can’t fully predict the consequences. This line of reasoning ignores the concept that genetic engineering only transfers a small, known packet of genes while various “traditional” methods of plant breeding involve transferring or mutating large amounts of genes in an uncontrolled manner. This may be achieved through cross breeding species to create many now-common hybrids. Another method is induced mutation* using radiation or chemical mutagens to alter existing genes rather than transplant known genes (a commonplace example of this process is Mentha piperita – peppermint). Grafting plants can exchange genes in an uncontrolled manner as well*. Gene transfer* also occurs in nature through bacterial*, viral*, or fungal* routes and even between different trees in a process known as inosculation*.

All these methods create potentially greater amounts of unpredictable genetic change than controlled gene transfer in the lab, and despite being more traditional, can actually considered more risky than genetic engineering*. Even traditionally bred crops have the potential to introduce new sources of allergens or undesirable changes, yet crops that are altered in such traditional ways are not subject to the same scrutiny as genetically engineered crops. Genetic engineering, on the other hand, has the potential to create reduced-allergen foods and reduce anti-nutrient content*.

“Why can’t we stick with traditional plant breeding methods? They seem to have worked fine so far.”

We face an inevitable short term growth in population and massive environmental problems related to resource usage. Hybrid crops and synthetic inputs have helped provide the needed increase in food supply since the 1930s, but they’re simply not cutting it anymore. With pressures from disease, pests, and climate change we need every tool at our disposal. Anti-GMO proponents are failing to recognize that humans have been manipulating our food supply for thousands of years – now we’re just doing it smarter. Without human intervention, the barely edible wild ancestors of a large percentage of your local produce market’s stock would be all but unrecognizable to you. Broccoli, brussel sprouts, cabbage, cauliflower, collards and kale are all selectively breed variations of the same wild ancestor.

Other examples include the mighty corn which is actually the descent of the scraggly teosinte*, and just try comparing a wild banana and Cavendish banana*. How many genes had to change to produce such vast differences? We must put genetic engineering in perspective.

  Hybrids (cross between two non-clonal plants) Polyploids (whole genomes duplicated or added) Mutation breeding (Chemical or induced damage to DNA) Crossing Species barriers (interspecific crosses) Transgenics (rDNA method to as a gene-“GMO”) Cisgenics (rDNA method to add a gene)
Examples in common foods Almost everything Strawberries, wheat, bananas, brassicas, others Some bananas, pears, apples, rice, yams, mint, others Pluots, tangelos, some apples, rice, wheat Much corn, canola, soybeans, cotton, papaya coming son
Transfers genes from one species to another Yes, sometimes Yes, often No By definition Yes No
Occurs in nature Yes Yes Yes, transposon movement, mutation from environment Yes, rare, seldom fertile Yes. Agrobacterium, other horiz. transf. N/A
Human intervention Yes, for crop improvement Can be induced chemically to improve crops Yes, to introduce variation for crop improvement Yes, for crop improvement Yes, for precision crop improvement Yes, for precision crop improvement
Number of genes affected 10K to >300K depending on the species 10K to >800K No way to assess 10-300K 1-3 1-3, usually 1
Know what genes moved or affected do No No No No Yes Yes
Know where affected genes are in genome No No No No Yes Yes
Plant patentable Yes Yes Yes Yes Yes Yes
Documented adversity Yes ?? ??? Yes No No
Environmental assessment No No No No Yes Will see
Organic acceptable Yes Yes Yes Yes No No
Time for new variety 5-30 years >5 years >5years 5-30 years <5 years <5 years
Demanding label No No No No Yes Will see

Safety concerns

Another common complaint is that GMOs have not been shown to be a hundred percent biologically safe, but such a complaint stems from a misunderstanding of how science works, a general ignorance of decades of genetic research and the discarding of thousands of studies*. At the time of writing, the scientific consensus on the safety of GMOs is as solid as the scientific consensus regarding the reality of anthropogenic climate change or evolution. As with all science, this could change in the future, just as we might one day find a fossilized rabbit in Precambrian strata and overturn the theory of evolution, but for now the preponderance of the best research points to GMO foods being generally as safe to eat and grow as conventionally bred plants.

An issue that muddles the conversation over genetic engineering is the improper equation of transgenic technology with large corporations like Monsanto. These claims range from reasonable suspicion of corporate misconduct, to grand conspiracies to sicken or control the populace. Invoking Monsanto has become the Godwin’s Law of GMOs, earning its own nickname, argumentum ad monsantium. And while many of the claims are distortions at best, we must also be careful to separate our political ideologies from the issue of whether genetic engineering actually works and is safe. The same goes for patent issues, which is certainly not unique to the field of GMOs. Agricultural scientists Steve Savage notes:

The modern anti-biotechnology narrative would have you believe that certain companies (Monsanto usually being portrayed as the ultimate demon) are using patents in some new paradigm to “control the food supply.” This view ignores the fact that plant variety patents have been a common feature of crop genetics since 1970 and that a great many of those patents are held by universities, by the USDA, and by similar international agencies (Patents for vegetatively propagated plants have been an option since 1930). Actually, the most foundational tools of biotechnology for plant, pharmaceutical or industrial use were patented by scientists at Stanford University. For a time, any group that did genetic engineering needed a license to the Stanford-held, Cohen-Boyer patents that are now considered a “gold standard” for university licensing.

When, in the 1990s, commercial biotechnology entered the agricultural seed market space, the fact that such products were patented was nothing new. For decades, commercial, academic and government researchers have typically patented their inventions. None of this is sinister. If someone develops a crop variety that has real economic value to farmers, it does not matter whether the innovation originated in the public or private sphere, it may well be patented. For any entity to take the following steps to commercialize that trait, the temporary exclusivity afforded by a patent makes it worth their effort and investment to do so.*

There is a good deal of public dialog over patent law already, especially in the medical and computer software fields. Such concerns would mean addressing patent law itself and setting up new incentives for vital research rather than attacking the scientific validity of transgenic technology.

Is genetic engineering the answer the all our problems? No, but it can serve a useful role on a variety of fronts from the production of medicines and vaccines to improved crop varieties and biofortified foods. Overall the current level of fear and sensational rhetoric surrounding the issue is scientifically unjustified, as always we must be skeptical not susceptible.

Jamie Foley was raised in the American South on a steady diet of colloidal silver, cryptozoology, and conspiracy theories. His contrarian curiosity and early passion for science eventually led him to skepticism and rationalism. He now makes his home in Oakland, California as he works on furthering his education and pursuing his interest in biotechnology and genetic engineering. A vegan for a decade, he enjoys exploring the intersections between science, animal rights, and social justice.

Jamie blogs at skepticalvegan.com and tweets as @skepticalvegan.

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