Recombinant dna technology
Recombinant dna technology
Recombinant DNA technology refers to the ability to isolate specific DNA sequences and alter or manipulate them to produce desired effects. More often, recombinant DNA technology is referred to as biotechnology. Recombinant DNA technology is fascinating in that it has developed into a multi-billion dollar industry, and completely revolutionized agriculture and pharmaceutical industries, all within the past 50 years. According to one account, biotechnology was born during a meeting in Hawaii in 1972 between Stanford medical professor Stanley Cohen, and biochemist Herbert Boyer from the University of California (Russo, 2003).
The men were attending a conference on plasmids, and discussed the ability to introduce plasmid DNA into the bacterium E Coli that would allow researchers to actually clone the plasmids in the bacteria. Boyer and Cohen eventually chose different paths, both affected by the growing concerns about the safety of recombinant DNA technology, but this meeting is marked as the beginning of the biotechnology revolution. Cohen stayed in academia and defended recombinant DNA technology in US congressional hearings. During the same time, in 1976 Herbert Boyer partnered with venture capitalist and MIT graduate Robert Swanson to set up and develop the worlds first biotechnology company, Genentech (Russo, 2003).
Since its introduction in the 1970’s the biotechnology industry has exploded, revolutionizing science and agricultural as well as pharmaceutical production. In 2011, Ernst &Young stated in the US alone there were 1,870 public and private biotechnology companies, their revenues worth over 60 billion US dollars (www.ey.com, 2012). To better understand how biotechnology has impacted the world we live in, it is good to have a broad understanding of the underlying principles of recombinant DNA technology. Firstly, two types of DNA are isolated.
The first is bacterial plasmids that will act as the “gene carriers” and the second is DNA from another organism with a gene of interest (Campbell essential biology, 1967). The plasmid is cut in one place, and the DNA is cut in the area of interest for a specific gene. Restriction enzymes cut double-stranded DNA molecules at highly specific locations, called restriction sites, into fragments that can be manipulated (Harrison, Sampson, 1992).
The specificity of the different enzymes depends on the base sequence of the DNA. Some enzymes cut both strands at the same point to produce “blunt ends”, others cut strands at different points producing staggered ends “sticky ends” (Harrison, Sampson, 1992). The DNA fragments are then mixed with the cut plasmids, joining together at their base pairs, or “sticky ends” (G with C and T with A in a sequence). The union is made permanent by a “pasting enzyme” called DNA ligase, thus creating recombinant DNA. (Campbell essential biology, 1967). The bacterium containing the recombinant plasmid is then mass-produced creating clones of the recombinant DNA to be grown in large quantities.
The success of biotechnology companies reflects the high demand and numerous applications of recombinant DNA technology. Animal farming and breeding has been altered, giving animals more meat, as well as giving cows growth hormones to produce more milk (Donnelley & McCarthy, 1994). Biotechnology is responsible for the synthesis of useful proteins to create vaccines and drugs that fight acute or chronic diseases and illnesses. Due to recombinant DNA technology, insulin is readily available to diabetics. Alternatively, genetically modified organisms (GMO’s) have been responsible for advancements in agri-business. In agriculture, biotechnology has allowed for genetically modified crops to produce more yield, and thus more revenue for farmers, by creating pest-resistant, weather- resistant crops (Federici, 2010). Genetically modified food products can be given a longer shelf life through altering the genetics of an organism.
To farmers, and a world with a growing population, genetically modified crops are looking more and more attractive. Weather resistant GMO’s that can grow in otherwise detrimental climates have even been suggested as a solution to world hunger. There is concern about the safety and ethics of genetically modified and engineered organisms. In many European countries, GM foods are clearly labeled, in the US and Canada, there is no mandatory labeling laws for genetically engineered foods or products (Federici, 2010). Scientific data has indicated in some circumstances that animals fed by GM crops have been harmed or died. In some instances animals exposed to GM crops developed abnormally and displayed detrimental reproductive issues (Maghari & Ardekani, 2011). Increasing prevalence of food allergies has also lead to blaming untested genetically modified crops as the source of the allergies (Maghari & Ardekani, 2011). Environmentalists are also enraged at the introduction of genetically modified organisms.
GM seeds, once planted, and harvested, yield seeds of their own and often mix with wild, organic seeds, thus producing offspring that are hybrids of the genetically modified organism. Loss of biodiversity due to the GM resistant strains overtaking natural plant breeds in nature is a serious concern for environmentalists and biologists (Burke, 2012). They claim that the effects of GMO’s have not been researched or experimented long enough to determine if there are any long-term side effects to humans (Maghari & Ardekani, 2011). Although the biological advancements in medicine and science have greatly improved the quality of life of humans, the effects of genetically modified foods and GM animals is concerning.
By providing vaccines otherwise unavailable to humans through biotechnology, many people experience longer then expected life spans. Usefulness of recombinant DNA technology in the worlds healthcare system can not be denied. However, the dependence on GM food in sustaining the world’s population should be examined more in depth. Has enough research been conducted on the effects of GMO’s on humans, animals, biodiversity, and the environment? I would disagree that sufficient data exists to be exploiting the science of biotechnology as vastly as humans have.
Burke, D. C. (2012). There’s a long, long trail a-winding: The complexities of GM foods regulation, a cautionary tale from the UK. GM Crops & Food, 3(1), 30-39. doi:10.4161/gmcr.18041
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Russo, E. (2003). Special Report: The birth of biotechnology. Nature, 421(6921), 456.
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Quaye, W. W., Yawson, R. M., Ayeh, E. S., & Yawson, I. I. (2012). CLIMATE CHANGE AND FOOD SECURITY: THE ROLE OF BIOTECHNOLOGY. African Journal Of Food, Agriculture, Nutrition & Development, 12(5), 6354-6364