Gene-scissor technology has the potential to revolutionize the food supply of genetically modified foods and the treatment of intractable diseases in the biomedical industry, but there is an ongoing discussion to address safety and ethical issues.
In the modern world, technological developments are happening very quickly. For example, our cell phones were only used for calling and texting just a few decades ago, but with the development of the Internet and communication, we can now perform various functions such as watching videos, searching for data, and using social media. In addition, the development of transportation such as trains, cars, and airplanes, starting with the invention of the steam engine, has made our lives more convenient. I have been thinking about gene recombination technology among these technological developments that have helped us a lot.
Genetic recombination involves the use of genetic scissors. Genetic scissors technology originated from a mechanism originally possessed by amphibians or microorganisms, and in order of development, the first generation of zinc finger nucleases (ZFNs), the second generation of TALENs, and the third generation of CRISPR/Cas9. The technology works by using proteins, which act as scissors, and polynucleotides, which act as tailors, to correct genes by removing or inserting some or all of the sequence for a specific gene, either to make the target gene inactive or to add the desired gene.
Zinc finger nucleases (ZFNs) are the first generation of genetic scissors, consisting of three or four zinc fingers and one nuclease. If restriction enzymes are natural gene scissors, this technology is considered an artificial gene scissor that is a further upgrade of the performance of restriction enzymes. Gene scissors were discovered in the DNA structure of African clawed frogs during research in the mid-1980s, and scientists named them zinc fingers because they contain zinc. Srinivasan Chandrasegaran created the Zincfinger nucleases by stitching together six Zincfingers and combining them with FokI, a restriction enzyme used by bacteria to cut proteins.
The second generation of genetic scissors, TALENs, were derived from the plant pathogen Xanthomonas. The amino acids that make up TALENs are matched to the sequences they cut, so when an amino acid is changed, the sequence it binds is also changed. Since talen recognizes more A bases, it is able to recognize human DNA as well. The third generation of CRISPR genetic scissors was created by combining RNA, which locates the DNA to be edited, with Cas9, which cuts the DNA. The CRISPR/Cas9 technology is derived from a protein that is involved in the immune response of bacteria and has the ability to cut foreign viral genes to protect the bacteria. Another distinguishing feature of CRISPR is the use of ‘Cas9’ instead of ‘FokI’. It works by binding RNA, which acts as a guide, to the DNA sequence it aims to correct, and then Cas9 cuts a specific site in the DNA, and unlike the first and second generations, it does not have a complex protein structure and cuts the DNA deeply.
The difference between first-, second-, and third-generation genetic scissor technologies is that first-generation zinc finger nucleases and second-generation talens do not have the function of gene-cutting enzymes, so it is difficult to fuse gene-cutting enzymes to use these technologies. In contrast, third-generation CRISPR scissor technology has the function of a gene-cutting enzyme itself, eliminating the need for fusion with a separate restriction enzyme. It also differs in terms of selectivity to recognize gene sequences, in that it can utilize complementary sequences of single-stranded RNA (sgRNA) without having to build repeating unit structures of Zinkfinger nucleases or talenes. Because of these differences, CRISPR scissors are now considered a revolutionary technology and are the most commonly used technology for gene editing.
I believe that gene editing using genetic scissors has many advantages, the first of which is the application of genetic scissors technology to the food industry: genetically modified foods (GMO foods). GMO food stands for “genetically modified organism” and refers to agricultural products that have been created using genetic engineering to combine useful genes from one organism with genes from another organism to achieve a specific purpose, such as resisting pests or increasing yields. While there is still an ongoing debate about the use of GMO foods, I am in favor of their development.
The first reason I’m in favor of GMO foods is that the increased diversity of GMO foods will help solve one of humanity’s biggest problems: the food crisis. Currently, the number of hungry people in the world is increasing tremendously, and the number of people on the planet is also growing rapidly. However, it is doubtful that the food production from nature can keep up with the food consumption of the growing population. In particular, Korea is expected to become more dependent on GMO foods in the future. This is because Korea is the second largest importer of grain in the world, and food resources are scarce. According to the Korea Rural Economic Research Institute, the proportion of imported crops is very high, so I think that Korea, which has a low self-sufficiency rate in food, should strive to develop genetically modified foods.
The second reason in favor of GMO foods is that they can benefit human health. Golden rice is an example of a genetically modified food. Golden rice is a rice that has been genetically engineered to biosynthesize beta-carotene, a precursor to vitamin A. Vitamin A deficiency is estimated to kill 670,000 children under the age of five every year. The rice was created to help people suffering from vitamin A deficiency in developing countries.
Opponents of GMO foods question their safety, but while GMO foods have been used for decades for a variety of purposes, including animal feed, there have been no reported cases of people being harmed by the crops they’ve consumed. Rather, there have been cases of people being harmed by eating organic food. In 2011, a case of pathogenic E. coli contamination of organic sprouts in Germany caused 50 deaths and more than 3,000 serious illnesses.
Genetically modified foods take a lot of time and money to develop, and are subject to thorough testing and rigorous vetting. The development and approval process for GMO foods involves first ensuring that the proteins produced by the genes being introduced are structurally similar to toxins, nutritional disruptors, allergens, etc. and that they are not likely to act as toxins or allergens during cooking and processing by breaking down in heat or in artificial gastric and intestinal fluids. The amount of paperwork that must be submitted to get permission to import GMOs is said to be nearly a truckload, and getting permission to grow GMOs in Korea requires a lot of time and money to complete the verification paperwork. Non-edible crops, such as grass, are also subject to a thorough vetting process. Clearly, no other ingredient has been studied and validated as much as GMO crops, and GMOs are subject to a rigorous approval process that must be re-approved every 10 years. Given this thorough process, I don’t think it’s appropriate to discuss the safety or side effects of GMO foods; I think traditional crops that have mutated due to environmental contamination may be more dangerous.
The second advantage of genetic manipulation using genetic scissors is in the biomedical industry. Therapies using gene scissors are playing a big role in developing new gene therapies, such as removing the genes responsible for intractable diseases or correcting damaged genes. Gene editing technology can be utilized to correct or remove specific genes to prevent, treat, and even cure diseases. Recently, researchers have been working on using gene scissors to treat genetic diseases, and it is expected that this technology will enable the treatment of rare genetic disorders. Gene therapy could be more effective and safer than traditional treatments, and it could also be used to study stem cells, which could play an important role in regenerating damaged organs and tissues. As you can see, gene-scissor technology has the potential to revolutionize the biomedical industry.
However, gene scissor technology still faces many challenges. First, some people have raised safety concerns, as gene-scissor technology may not only accurately modify targeted genes, but may also affect non-targeted genes. Second, the ethical issues of gene-scissor technology are also an important debate. For example, if gene scissors are used to modify genes in human embryos, ethical controversies involving human life may arise. To resolve these issues, ethical discussions will need to be conducted in parallel with the development of the technology.
In conclusion, gene-scissor technology has the potential to revolutionize many areas. Genetically modified foods (GMO foods) have the potential to solve food problems and improve human health, and their application in the biomedical industry can greatly help in the treatment of incurable diseases and organ regeneration. However, the development of these technologies requires ongoing discussion and research to address safety concerns and ethical issues. In order for gene scissors technology to bring positive changes to our society, we will need to actively support its development, while carefully addressing the ethical and safety issues that come with it.
