In this blog post, we’ll explore how gene editing technology—specifically CRISPR—could impact our future, from treating diseases to solving food shortages.
Everyone has probably had the experience of cutting out a desired shape with scissors while doing origami and gluing it where they want. You may also have had the experience of cutting out parts you didn’t like with scissors and replacing them with something else to increase your satisfaction. What if, instead of paper, you could cut and paste genes that express genetic traits in living organisms? This amazing feat is actually happening right now. Using enzymes in a test tube, scientists can cut out DNA molecules that express desired traits and combine them with self-replicating plasmids to create genes that maximize those benefits. However, since this genetic recombination technology involves intentionally introducing specific genes to modify traits, it can lead to side effects such as the mixing of native DNA with viral DNA, which may result in mutations. To minimize these side effects, a technology has been developed that does not involve introducing specific genes. Instead, it uses “genetic scissors” to cut out undesirable genes already present in the organism, altering the internal genetic makeup to achieve the desired function without introducing external genes. DNA is composed of four nucleotides (A, G, T, C), and since each cell contains billions of nucleotides, it is difficult to decode the entire DNA sequence. However, there is hope that gene scissors can serve as a key to unlocking the secrets of genes by decoding the information contained within DNA. Furthermore, by cutting out genes that make organisms susceptible to pests and diseases during cell culture, it may be possible to create disease-resistant organisms to address food shortages. Gene scissors are also anticipated to offer new treatments for genetic diseases that cannot be cured through medication or surgery. Attempts are being made to edit not only animal and plant genes but also human genes using gene scissors, which has sparked ethical controversy. In particular, editing the genes of germ cells—unlike somatic cells—means that acquired traits are passed on to future generations, raising concerns about the birth of “designer babies.” However, given the numerous benefits that gene scissors can offer, I believe we should not oppose this groundbreaking scientific technology solely on ethical grounds.
Before delving into specific discussions, let’s take a look at CRISPR gene editing. CRISPR, a third-generation gene editing tool, originated from a system in which the body cuts and stores the DNA of invading viruses. When a virus with the same genetic information invades again, the body recognizes the invading DNA based on the stored information and triggers an immune response. CRISPR gene scissors consist of an enzyme protein called “Cas9” and guide RNA; the enzyme protein acts as scissors to cut the gene, while the guide RNA helps locate the target gene. While conventional gene scissors required the creation of a new enzyme protein to act as scissors for each gene to be cut, CRISPR gene scissors have the advantage of being easier to produce and more precise because only the guide RNA needs to be changed. CRISPR gene scissors possess the precision and accuracy to target only specific genes, thereby minimizing the side effects associated with conventional gene scissors and genetic recombination technologies. They can be applied to various fields, including the restoration of extinct animals, the development of new genetically modified plants, and gene therapy. Therefore, CRISPR technology has many advantages and is highly likely to have a positive impact on human life; consequently, ethical controversies should not hinder its development and application.
The greatest strength of CRISPR technology is that it increases the possibility of treating genetic diseases and incurable illnesses that cannot be cured by drug therapy or surgery. Humans have 46 chromosomes, and chromosomes consist of vast amounts of DNA, which in turn is composed of countless nucleotides. There are four types of nucleotides (A, G, T, C), and the sequential combination of these nucleotides carries various genetic information. Since DNA consists of billions of base pairs, decoding all genetic information is extremely difficult and nearly impossible. However, using gene scissors increases the likelihood of unlocking the secrets held by genes. By cutting out a gene whose function we wish to understand, the traits or functions expressed by that gene disappear, allowing us to analyze and decode the gene in question. Therefore, gene scissors are a crucial technology for incurable diseases and genetic disorders that cannot be resolved through drug therapy or surgery. If a disease improves after the gene is cut, this approach could be applied to gene therapy. For example, CRISPR is extremely important for children born with genetic disorders or congenital defects. The rate of children dying from genetic disorders or congenital defects is not insignificant, and while there are few fundamental treatments available, CRISPR allows for the removal of genes that could cause disease in a child before birth, or the preemptive removal of suspected genes to prepare for genetic disorders that may develop later. Therefore, it is possible to manipulate a child’s genes to eliminate diseases and disorders, and to enable the child to pursue their dreams in the future through superior traits. Furthermore, the possibility of treating AIDS, an incurable disease, is increasing through CRISPR. The AIDS virus enters the body by binding to receptors on the cell surface; by using gene scissors to eliminate the gene that produces these receptors, viral penetration can be blocked. Clinical trials are already underway with AIDS patients, and if successful, this will bring a major revolution to the medical field.
Furthermore, in the 1960s, the Panama disease, caused by a fungus, led to the disappearance of existing banana varieties; had gene scissors been available, this extinction could have been prevented. Cloned bananas, which lack genetic diversity, are vulnerable to pests and diseases and have no resistance, leaving them helpless against such threats. However, using gene editing tools, we can cut out genes that make plants vulnerable to pests and diseases or induce internal changes to develop resistant varieties in a short period. Since genes are directly involved in biological processes, being able to decipher even a little more of our genetic code will greatly contribute to improving the health of living organisms. It will also help solve food shortages by making endangered plants more resilient.
Most opponents of CRISPR technology worry that removing or altering genes through genetic manipulation will reduce genetic diversity, leading to a homogenized gene pool and a diminished ability to adapt to rapid environmental changes. However, this argument seems to overlook the individual subjectivity, values, and preferences that each person possesses. Since each person assigns different levels of importance to situations, has different standards for their ideal, and desires different careers for their children, parents will select the genes they prefer when using CRISPR to edit their children’s genes. Furthermore, desired traits vary by generation, and since the genes modified in the current generation are passed down to the next, new genetic modifications will be added in subsequent generations. Consequently, the number of possible genetic designs will be extremely diverse, and genetic diversity will be maintained. Additionally, while individuals may possess standardized genes, these will include enhanced, superior genes, resulting in excellent adaptability to the surrounding environment.
Some worry that CRISPR technology will become a product exclusively for the wealthy due to its exorbitant cost, thereby exacerbating social inequality. However, just as the initial cost of LASIK surgery was very high but has since dropped significantly due to advances in science and technology, CRISPR technology may also be expensive at first but is likely to become more affordable as the technology becomes increasingly commercialized. Therefore, it will not be a technology reserved for the wealthy but one accessible to everyone. Finally, the reason some believe CRISPR technology could be dangerous is that gene-editing technology is still imperfect. Although CRISPR is highly sophisticated and can cut only the targeted genes, exceptional side effects may occur. However, many scientists are currently working to improve CRISPR technology. They are researching methods to cut DNA accurately without errors, and as the technology advances further, CRISPR will become the perfect genetic scissors.
It is true that there are ethical controversies surrounding CRISPR technology. Some people oppose it, arguing that it constitutes excessive interference with life. However, I believe that CRISPR technology will make our lives healthier and more fulfilling. CRISPR will bring new hope to many patients suffering from incurable diseases and, furthermore, help humanity lead long, healthy lives.
