by Shehani Efrem
With the advancement in the field of biotechnology, researchers have overcome many barriers. This has paved the path to new developments in many industries including the food industry. One such result is the introduction of genetically modified (GM) food. What is GM food? Food that is artificially modified by altering the genetic material of the original species by addition (genes from other plants, animals and microorganisms), deletion and substitution of bases. This process is often named as gene technology, recombinant DNA technology or genetic engineering. There are a few steps involved. First the gene or genetic information that gives the desired trait for an organism is identified, followed by copying that genetic information from the organism that has the desired trait. Afterwards, this gene is inserted to the DNA of another organism. This results in producing a brand-new organism and is identified as genetically modified. Some of the current gene editing techniques followed are clustered regularly interspaced short palindromic repeats (CRISPR-Cas9), restriction enzymes, zinc finger nucleases and transcription activator-like effector nucleases. Scientists Boyer and Cohen discovered this technology in 1973 where they inserted DNA from one bacterium to another.
GM food can either be consumed directly or it can be processed into different food ingredients. The key goal of this technology is to develop food with desirable traits. Some of them are, to increase the nutrition value of the food, to increase the yield, to enhance the flavor, to increase the shelf life and supply of food. Moreover, plants that are tolerant to various environmental conditions such as drought and salinity can also be developed.
There is a vast area covered under GM food. One such area is the development of GM crops. Many countries such as Argentina, Brazil, Canada, India, China, Paraguay and South Africa have approved the use of GM crops. However, Sri Lanka has not yet officially approved. For the development of most GM crops such as cereal crops, the desirable gene is introduced into the plant through a species called Agrobacterium. Here, the gene of interest is initially introduced into the bacterium and then the new DNA is transferred to the plant. Some of the other methods used are electroporation (DNA is inserted to the plant cells through minute pores that are created due to electric pulses), biolistic transformation (bombarding the gene of interest with plant cells using DNA-coated beads as carriers), microinjection (directly introducing DNA to the genome), antisense technology (deactivates specific genes). In order to confirm whether the transfer has taken place successfully, a marker gene can be used. The marker gene is attached to the desired DNA before the transfer. Some of the developed GM crops are listed below.
- FLAVR SAVR tomato was developed to increase the shelf life (First commercialized GM crop)
- ‘Golden rice’ was designed to treat Vitamin A deficiency. It has the ability to synthesize beta-carotene which is a precursor of Vitamin A.
- Bacillus thuringiensis (Bt) corn was developed to tolerate herbicides and resist insect pests. Bt corn can be used to feed livestock and to produce various food and drinks.
- GMO papaya also called “Rainbow papaya” was developed to resist ring spot virus and to enhance the productivity.
- GMO apples were developed to resist the browning effect after being cut.
- GMO potatoes were developed to resist diseases and insect pests.
The other vital area is GM animals. Some of the research that has been done to cattle includes, introduction of human genes to increase the antibacterial properties in milk thus reducing the susceptibility to mastitis and editing genes to increase the muscle mass (‘super-muscly’). Pigs have also been genetically modified to increase the muscle mass and to produce omega-3 fatty acids that have the ability to increase health benefits. Chicken eggs contain proteins that can cause allergies. Hence, research has been done by editing genes in chickens to lay non-allergenic/hypoallergenic eggs (without the proteins responsible for allergies).
It is quite important to investigate ethical concerns when studying about GM food. Some of the major concerns are, it can potentially harm the human health and damage the nature; can cause a negative impact for current traditional farming techniques; depth of ‘unnaturalness’ of the technology. It is also important to exactly know whether the genetic change can hinder the normal physiological functions of the targeted animal. According to the World Health Organization (WHO), three main safety issues are considered related to GM food. They are (1)allergenicity, (2)chances of transferring the edited genes in GM food to the human digestive system (probability is low but not zero) and (3)outcrossing. GM food, novel or altered proteins may result in giving allergies when consumed by humans. This is called allergenicity. Outcrossing is the transfer of genes from GM organisms to other species that are not intended to undergo genetic modifications. However, no such complaints have been recorded so far. Many people believe that GM food can alter the DNA when consumed. However, this is not yet verified. Just as consuming a natural fruit does not cause any alterations to our DNA sequence, consuming a GM food would do the same.
There is an increased demand for food with the increasing world population. Many food-based obstacles such as food scarcity can be overcome by using GM food. However, it is yet to be approved and reach the community for consumption in Sri Lanka. According to my point of view, it is important to make the people aware about the benefits of consuming GM food and clear the related myths. On the other hand, government authorities should provide necessary facilities and encourage the research sector to do more findings with regards to GM food.
References
- Bawa, A. and Anilakumar, K., 2012. Genetically modified foods: safety, risks and public concerns—a review. Journal of Food Science and Technology, 50(6), pp.1035-1046.
- Raman, R., 2017. The impact of Genetically Modified (GM) crops in modern agriculture: A review. GM Crops & Food, 8(4), pp.195-208.
- Halford, N. and Shewry, P., 2000. Genetically modified crops: methodology, benefits, regulation and public concerns. British Medical Bulletin, 56(1), pp.62-73.
- Gaj, T., Sirk, S., Shui, S. and Liu, J., 2016. Genome-Editing Technologies: Principles and Applications. Cold Spring Harbor Perspectives in Biology, 8(12), p.a023754.
- Ormandy EH, Dale J, Griffin G., 2011. Genetic engineering of animals: ethical issues, including welfare concerns. Can Vet J, 52(5), pp. 544-50.
- Forabosco, F., Löhmus, M., Rydhmer, L. and Sundström, L., 2013. Genetically modified farm animals and fish in agriculture: A review. Livestock Science, 153(1-3), pp.1-9.
- Photo Credit – Survey suggests public concerns remain over safety of GM foods (newfoodmagazine.com)