Where does the fear of genetic engineering come from?
Fear comes from ignorance, knowledge enables us to make rational decisions. The word genetics alone triggers fear in many people, as it already has a negative connotation to it through media — genetic contaminations, GMO toxins, genetically modified metabolism, genetically engineered poisons — one reads numerous polarizing headlines about how genetic manipulation affects our food, fueling fear and anxiety. But for us, in science, genetic engineering is a miracle. Without it, humankind would not be where it is today and who knows, maybe it wouldn’t be there at all. People tend to avoid genetically modified foods and prefer products with the label GMO-free — but why? Do you know how genetic modification is created and how this science is used in food production? Let me show you why it is not always as bad as it seems.
Genetic engineering — that has something to do with genes, doesn’t it?
To begin your life’s journey, your mother generously provided you with an X-chromosome. If you are a woman, dear reader, you got another one from your father, if you are a man, you got a Y-chromosome instead (surprise Herny VIII — maybe you should’ve put a little more effort into the heir thing yourself instead of having your women executed). These chromosomes contain your DNA — well tied and crumbled up in the tiniest space.
DNA is the blueprint of our bodies. It determines what cells look like, how many there are and what tasks they perform. This blueprint is exact and can be found in every cell (well, except erythrocytes). You can imagine the DNA as a twisted rope ladder, whose rungs consist of two interlocking pieces (base pairs). These bases are the nucleobases adenine, thymine, cytosine and guanine (A and T, C and G) sticking together tightly. But how does a rope ladder become now a human being?
The DNA can be divided into sections, so-called genes. These begin at a certain base pair and end at another. They are unique and have singular functions, e.g. which eye or hair color you will get. All these bodily functions are usually carried out by proteins — in the form of hormones, enzymes, transporters, receptors, and many more. But how do we get from the gene to the protein? With the help of a biochemical processes called protein biosynthesis.
In short, a ribosome (another helpful protein) comes along and reads the gene, translating it into amino acids and merge them into proteins. You can imagine the gene like a secret code of base pairs only the ribosome can understand. A set of three base pairs is called a sequence and each sequence determines a specific amino acid that will be produced along the way. A bunch of amino acids, in turn, form a protein. An even bigger bunch of proteins, make a human being. If we imagine the rope ladder laid out flat, the human genome has 3,000,000,000 base pairs and is as long as the human being itself (around 180 cm). On it we house about 23,000 different genes! But even though we humans like to think of ourselves as the largest and most magnificent being on planet earth, the genome of the aris japonica, a rare Japanese flower, is about 50-times larger than ours.
So those are genes, but what does that mean for our food?
Genetically modified organisms (GMOs) are organisms (micro-organisms, plants, animals) whose DNA was changed in a way that wouldn’t be possible by nature itself.
Rare animals or previously unexplored plants may have genes with yet unimaginable functions, we can transfer to known organisms, to make use of them. This is one reason why biodiversity is key — life-saving medicines and vaccines have been derived from unexplored organisms. So what would humankind look like if we’d crushed life around us with our huge ecological foot? In truth, up to 80% of all food products have come into contact with genetic engineering on their way to the supermarket. Especially in today’s world, with our fast polished convenience food, you shouldn’t be surprised that not everything can be natural — we owe much of this to science, to food technology.
Nobody wants to advertise with genetic engineering, it’s marketing hell, but I’d like to show you that it’s not entirely evil and shouldn’t be demonized.
Rennet is required for the production of cheese. Rennet consists of enzymes (chymosin and pepsin) that precipitate the protein (casein) present in the milk — the milk loses its stability, flocculates, and separates into liquid whey and cheese curd. Most hard, semi-hard, and also soft cheeses are produced with this technique (sweet milk coagulation).
What some may not know is that this rennet, this enzyme mixture, doesn’t grow on trees, but has to be extracted from the stomachs of calves. Yes, from stomachs, the so-called abomasum of young ruminants. In the animal, this is purely physiological, as the young calves must digest the cow’s/mother’s milk they have taken in. But if we want the same procedure to work for our cheese production, we need to slaughter the calves, take the fresh animal stomachs clean and dry them, put them in saltwater, douse them with whey, incubate at 30 degrees Celsius for one or two days and then pour through a sieve. Yum!
However, nowadays very few cheeses are produced with natural rennet, instead most use rennet substitutes. Therefore microorganisms — usually mold cultures — are used which produce the needed enzymes naturally. This is called microbial rennet exchange material. But as you can imagine not all microorganisms do what we want them to do; it’s necessary to genetically modify them to produce the desired enzymes. This is called GMO rennet. The enzyme content is much higher with this procedure than with microbial rennet and it is cheaper to produce.
So should we rather continue to slaughter young calves to extract enzymes from their stomachs or have small microorganisms produce the same enzyme on a mass scale in the shortest possible time?
Have you ever wondered how they get the lactose out of milk to produce lactose-free products? Lactose is a sugar contained in milk to which many people are sensitive — stomach ache, diarrhea, nausea. Ever since lactose intolerance became widespread and accepted, lactose-free products have sprouted from the ground.
Lactose consists of two molecules (D-galactose and D-glucose) which are broken down and digested by the enzyme lactase. This mechanism is defective in lactose intolerant people, so they have to avoid the intake of lactose in the first place. In lactose-free products, however, the lactose has not been filtered out, as you might think, but instead, an appropriate amount of the enzyme has been added, a pre-digestion takes place in the product itself and consumption is unproblematic. This enzyme is also not growing on trees, but being produced by genetically modified microorganisms.
So must all lactose intolerant people live without dairy products forever or should they enjoy it by using genetically produced enzymes?
Have you ever asked yourself how deep-frozen bread rolls still rise so nicely, have such a pleasant crust and color, and are ready to eat in no time at all? What the baker usually performs early in the morning in his bakery, are tasks that have to be carried out now by enzymes (amylases and xylanases). As in the examples above those enzymes are produced by GMOs. So there is no baking roll without genetic engineering!
So do we renounce our convenience in favor of genetic engineering?
How do you get a bacterium to produce a certain enzyme?
In short, you locate your gene of interest in a cell, cut it out, insert it into the bacteria and the bacteria produces the protein withing its normal metabolism.
In the majority of cases, E. coli is used, since it is the most thoroughly investigated bacterium and it works rapidly. In bacteria, the DNA is freely available in small ring-shaped plasmids (not in the chromosome as in our case), which they can also exchange with each other. This form of free DNA can easily be modified and transferred. Therefore bacteria are ideal to use for genetic modification.
Isolation and recombination
First of all, we need to isolate donor and recipient DNA from the respective cell or bacterium. The donor DNA may be isolated from animal tissue or a plant, and contains the gene of interest. To find the gene on the DNA, there are specific restriction enzymes (you can simply buy them online) that find the exact base pair location and excise the gene. At the same time, a target plasmid is isolated from the bacterium and cut with the same restriction enzyme. Donor and target are thus opened and the gene is exposed. By subsequent recombination, the gene is inserted into the plasmid and “glued” with ligases (other enzymes). The gene of interest is now inserted into a plasmid and can now be transferred into the bacterium for the protein synthesis.
Transformation and selection
The recombined plasmid contains the gene of interest and must now be transferred into the bacterium, for which there are different processes (depending on the bacterium). This is called transformation. Since the incorporation of the plasmid into the bacterium works by chance (and unfortunately not always), we need to find out which bacterium contains the recombined plasmid and which doesn’t. This can be done with the help of fluorescent dyes that can be linked to the desired gene. With that technique, it’s possible to visualize whether the incorporation has worked or not — under a microscope. The successfully modified bacteria can then be selected and multiplied to start enzyme production on a large scale!
Is genetic engineering good or bad?
As early as 10,000 years ago, the first farmers made use of genetic modification — even if they didn’t know they did. In the beginning, maize still had very small cobs (2.5 cm), but by carefully selecting the most productive plants and crossing them (which is called cultivation), over thousands of years humans created a maize cob about 50 times the volume of its ancestor. Corn is thus one of the oldest cultivated plants in the world.
Darwin already showed that with evolution it is possible to change the genome and adapt it to certain conditions — but this process takes ages! One possibility to accelerate these natural changes and to steer them into desired courses is genetic engineering. The aim of crossing plants is to generate plants that are as resistant and high-yielding as possible, prevent famines, and guarantee food supply for the growing world population. We’re now producing enough food for 8 billion people (the problems of malnutrition and undernourishment are unfortunately not eradicated thereby). Increasing the yield has not remained the only goal, resistance to pests, drought, wind, and weather, as well as increasing the nutritional value are now also of interest.
Genetic engineering must be used in an appropriate manner and for the right purposes. I’d like to show you two examples of genetic engineering and afterwards you decide if this technology is good or bad.
Genetic engineering to maximize profits without regard for the environment
Monsanto. A giant agricultural corporation with a worldwide monopoly on genetically modified seeds. The company has a strict licensing policy, which means that every farmer who grows Monsanto seeds must acquire an annual license to use them, in addition to the seeds, and cannot reapply part of the yield next year. Still, the farmers are forced to use the seeds to compete with other farmers, simply to keep their business. If they quit, they’re doomed. This licensing policy is solely to maximize profits for Monsanto and undermines each and every farmer. Furthermore, the danger of having all the seeds of the world in the hands of one single megacorporation is unimaginable.
Traditional agriculture, an ecologically and economically sound agriculture, becomes completely impossible. Furthermore, the priority use of genetically modified maize and genetically modified soya promotes monocultures, which has proven to have serious consequences for soil and water quality, and climate in general. Furthermore, genetically modified maize and soya are primarily used for low-cost animal feed production to produce cheap meat, which is fatal for the animals (not their natural food), for humans (meat of inferior quality) and for the planet (greenhouse gas emissions).
Genetic engineering could prevent irreversible blindness in children
Large parts of the world’s population suffer from vitamin A deficiency, which affects children in particular. Vitamin A is essential for the development and maintenance of a healthy eye function. To combat this, a type of rice has been developed that has an increased vitamin A content — with the help of genetic engineering methods. Due to its high beta-carotene content, rice appears particularly colorful, almost golden — the golden rice.
This rice variety was developed as early as 1992 and could have prevented the irreversible blindness of children for 20 years now, if it had been approved. However, profit-oriented food lobbies decided against it, as it should have been distributed to poorer sections of the population without licensing restrictions and conditions.
Fast, uncomplicated use in the production of enzymes for food technology, improved plant varieties for increased yields and pest resistance to guarantee food for the growing world population, and the prevention or treatment of diseases — there is much to be said for genetic engineering. However, there are still consequences for humans that are difficult to assess, since it is a relatively new technology and long-term studies are needed.
However, a healthy dose of rationality should be applied (as with everything else) and one should not react blindly to scare news from the media. Genetic engineering is not evil per se. It has done invaluable work for mankind and we would not be where we are now without it. Who knows, maybe an epidemic would have already killed us, because yes, even the development of a vaccine for diseases like Corona is based on genetic engineering.