DNA (deoxyribonucleic acid) is a hereditary material that contains the organism’s genetic code (a sequence of codons that code for amino acids), essential for the genotypes and phenotypes of an organism (National Library of Medicine, 2021). The information stored within the genetic code make up the four bases of DNA; adenine, guanine, cytosine and thymine (National Library of Medicine, 2021). Meiosis follows a similar structure to mitosis and is a bodily process that is crucial for reproduction and evolution. In this process, one diploid cell divides, producing two haploid daughter cells, each containing half of the DNA of their parent cell (Wilgar, Facts: In the Cell, 2016).
Furthermore, crossing over, a process that occurs during prophase I of meiosis I, is responsible for expressing genetic diversity. Segments of the genetic code of one cell are exchanged with another, and in combination with independent assortment, results in genetically diverse recombinant cells (National Library of Medicine, 2021). The gametes of the male and female bond to produce a zygote which will rapidly undergo mitosis to grow. Depending on the genetic code of the parents, the alleles of the progeny will either be homozygous dominant or recessive, or heterozygous (Wakim & Grewal, 2021). Mutations to DNA can occur through translation and transcription during interphase of mitosis.
Genome editing, commonly known as genetic engineering, is the manipulation and alteration of an organism’s genome using modern-day advancements. Genetic engineering occurs in a multistage process that follows the bases of cloning, screening and gene transfer (Wilgar, Methods and Technology, 2017).
To begin cloning, a restriction enzyme is inserted into a plasmid to recognises a sequence of DNA that codes for an amino acid. When found, it is cut into two segments. The DNA is left with a single-stranded overhang which won’t combine to form an unbroken molecule without a DNA ligase. The DNA is combined with a plasmid and is introduced with bacteria until the correct sequence is found. The bacteria are then grown in large quantities for transcription and translation to occur (Rana, Sanchez, Yue, & Syed, 2021).
Screening, the second stage, involves testing the bacteria’s DNA for the potential development of disease and missense or nonsense mutations. Screening by hybridization (combining two complementary DNA strands through base pairing) involves using a nucleic acid probe to identify specific sequences, whereas antibody screening uses an antibody against a protein to identify particular sequences that resemble the same gene (Fiechtinger, et al., 2017).
After both processes have occurred, gene transfer takes place. Horizontal gene transfer, a process that bacteria and some eukaryotes undergo, is the non-sexual movement of genetic information between genomes, which occurs in three stages; transformation, transduction and conjugation (University of Leicester, 2006). Transduction, the transfer of DNA from a bacterium to another (using bacteriophages), and conjugation, the transfer of DNA via physical contact, are key processes to replicating and producing bacteria that share the same DNA. (University of Minnesota, 2011).
Recent views of genetic engineering have posed many inquiries regarding the ethics and morals of gene editing. To begin, the creation and introduction of genetic engineering have posed questions surrounding the extent to which it is to be used. However, a prominent moral issue created as a result of genetic engineering is that of a psychological one. According to the US National Library of Medicine, the way someone controls themselves in society is through accepting who they are as a person. If someone is genetically altered, for any reason, they may struggle to accept themselves and thus not take responsibility for their actions (Mameli, 2007). Genetic engineering is used in the departments of health and medicine; however, there is a focus on agriculture.
The treatment and poor living condition of animals have piqued the interest in many communities, questioning the ethics involved. For example, chickens have been genetically engineered to change their genotypes in order to produce greater amounts of meat, for human consumption (Krawczyk, Obrzut, & Calik, 2018). An example of this is the creation of the Ross 308 Broiler chicken, which is a hybrid breed of chicken, modified for larger muscle mass and breast size. As a result of the genetic modification, the Ross 308 Broiler has altered genotypes resulting in a discoloration of the skin, a smaller comb and larger breasts. Larger breasts and more meat is a beneficial modification for humans: however, the genotypes and phenotypes of this chicken will be passed to its offspring, posing a threat to the animal’s future survival (Shukla-Jones, Friedrichs, & Winickoff, 2018). Genetically modified chickens can be sustained for cheaper costs, benefiting society and the economy.
Furthermore, genetic engineering of organisms is highly probable to reduce biodiversity and increased use of insecticides and herbicides. For instance, common soybeans have been modified to have reinforced tolerance to glyphosate herbicide through the expression of a plant enzyme EPSP (enolpyruvylshikimate-3-phosphate) (Phillips, 2008). These environmental factors, along with increased growth and metabolism pose a threat to humans for potential exposure to new foreign allergens. In addition, building tolerance to herbicides could create ecological imbalance, potentially resulting in uncontrolled and rapid growth (Cobb, 2011). Genetic engineering for commercial foods is both a benefit while also an issue. Modern-day foods and livestock are being bred specifically for human consumption, providing us with easy and inexpensive sources of food while potentially jeopardising the survival and longevity of the organism (United States National Research Council, 2004).
As seen from above, extensive research has been conducted to draw upon the conclusion that genetic engineering is today’s dream, not tomorrow’s nightmare. Genetic engineering is a highly versatile and efficient technological advancement that will help innovate the future. Technological advancements have increased the accuracy and efficiency of genetic engineering and are continuing to improve themselves. Overall, the risks of unwanted mutations and problems attached with genetic engineering in an environmental, social, ethical and moral aspect are continuing to be reduced, with the evolving technology unlocking capabilities never once seen before in history. Without genetic engineering, communities and economies would struggle to thrive and evolve.
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