Genome Editing: What is it? | Teen Ink

Genome Editing: What is it?

November 23, 2023
By pandyar BRONZE, Doylestown, Pennsylvania
pandyar BRONZE, Doylestown, Pennsylvania
1 article 0 photos 0 comments

Genome editing is a procedure where making changes in a DNA sequence occurs. Though this operation has been around since the 1970s, it has just recently started evolving into something more. In past years, gene editing changes were only practiced on embryos or sperm even though it was looked down on. Now, there are many tools that allow for the alteration of DNA sequences. Although the depths of these extraordinary tools are captivating, gene editing is the source of many major conflicts in the scientific and political world. Disputes of this have been around for years but are now making headlines because of the milestones this could cause in the world of science and eventually humanity as well. 

Overview of Techniques

The history of genome editing techniques are minimal but effective. As mentioned previously, CRISPR-Cas9 is the most common technique but this wasn’t discovered until the 2000s. The first ever gene editing technique was conducted in 1983 by researchers at Harvard University where they used a restriction enzyme to cut and modify DNA. Though, in the 1990s, this was polished by ZFNs, zinc finger nucleases, which granted more precision. In the following decade, a new finding was discovered in bacteria. This was the beginning of CRISPR-Cas9, now found to be the most precise genome editing method. These recent advances have proved that the genome editing itinerary has and will continue to develop. From creating new gene therapies, treatments of diseases, to new animal models, the tool is never at rest.  

The Different Methods of Genome Editing

Genome editing has a variety of different methods. The most commonly used method is called the CRISPR-Cas9 system. CRISPR-Cas9, which stands for “clustered regularly interspaced short palindromic repeats”, consists of two parts: an enzyme and an RNA. Scientists use RNA to guide Cas9 to a specific spot on the DNA where editing will be involved. Cas9 then proceeds to unzip the strands of DNA. The RNA then joins a part of the DNA that the Cas9 snips, which is then repaired by a cell. This repair could fix a mistake by adding or removing a gene. This is called a mutation, and can help them analyze genetic diseases. Another method used is the transcription activator-like effector nucleases, also known as TALENs. Here, engineered nucleuses modify genes in many organisms. A nonspecific DNA cleaving nuclease joins a DNA binding domain in order for the TALEN to alter a sequence. These use specific enzymes to cut or bind DNA sequences.  The last, more difficult, tool used to edit genes are ZNFs, zinc finger nucleases. These are engineered proteins that can modify specific DNA sequences. There are many other techniques that are less common such as base editing which can correct genetic code errors as well as create gene knockouts. All these techniques have their advantages and disadvantages but it is undeniable that each and every one has made a major impact in our understanding of genetics and the world of science. 

Advantages and Disadvantages of Each Method

Each of the previous methods come with their own advantages and disadvantages. Although their effect in science is undeniable, there are many downsides to each editing technique, including the ethical concerns. The first system, CRISPR-CAS 9, has an overflow of advantages in the field of research. The trump card for this technique is no doubt the way CRISPR-CAS 9 can cure genetic diseases. Along with that, it is inexpensive, simple, and very useful when researching. The main drawbacks on this are that it is time consuming and can change germlines which is important to pass down along generations. The next technique, TALENs, has the advantage of being precise, flexible, and efficient. These may seem vague reasons but these are compatible with the fact that TALENs can be well suited with a variety of cell types. On the downside, this tool is extremely complex and time consuming. Moreso, the use of TALENs can also effect off target areas and may cause unintended mutations. Just like TALEN, ZNFs are precise and flexible. These traits allow this tool to be an efficient and easy use. Though, some flaws are that it is a complex design and their target range is pretty limited. Overall these tools can improve disease prevention and understanding of genetics. On the other hand, ethical and safety concerns are important to note. Taking all these into note, the tools used in genome editing are an undeniable resource to science but also concern to flag for society as a whole. 

Examples of Successful Genome Editing Projects

Throughout the timeline of genome editing uses, there have been many notable projects. Most, if not all, have been with the use of CRISPR-Cas9. The first ever case of this affecting humans was in 2018 when a Chinese researcher created the first gene-edited children. He implanted these embryos into a woman who gave birth to twins- Lulu and Nana. What’s so special about them is that they were even resistant to HIV. Another case was the first in which CRISPR-Cas9 was used to treat a genetic disorder in the U.S. Victoria Gray, a young woman from Mississippi, was diagnosed with sickle cell disease; it is a very harsh disorder. Using the tool, doctors removed, modified, and inserted cells back into her that could weaken the sickle cells. It was a great milestone for the researchers that believed in this. Overall, these success stories prove that even though gene editing has its consequences, it is a great tool to change people’s lives. 

Modification of Crops to Enhance Nutritional Value

Genome editing is useful for a lot of things. Manipulating genes in agriculture is one of many important applications. Researchers can use tools to better crops’ nutritional value by modifying fields. One way they can do this is by removing harmful traits in certain plants. It can also speed up the process of crop growth as well as editing it to adapt to environmental factors such as weather and diseases. In the end, genome editing in agriculture has various benefits for the health of the crops. 

Creation of New Animal Models for Research

Another useful application is for the field of animal research. Using genome editing would allow the creation of new animal models to help us understand more about human diseases. Scientists can create mutations in animal genes that can then be inflicted on humans by using CRISPR-Cas9. Overall, using genome editing on animal models is greatly beneficial for not only animal but human diseases as well. 

Possibility of Unintended Consequences

While genome editing can create many beneficial possibilities for the future of society, there are also risks that should be considered. Some of these risks include unintentionally creating disruptive species, accidentally causing mutations that create diseases, and also designer babies, a controversial term for genetic enhancement. With creating disruptive species, entire ecosystems could be destroyed, ruining crops. As for mutations, it is very possible for CRISPR-Cas9 and other genome editing tools to fumble up and mutate off target. It is important to understand the issues that  genome editing brings to the table.

Creation of "Designer Babies"

As mentioned earlier, “designer babies” are a very controversial topic. It essentially means using genome editing to pick and choose specific traits that you would like in your offspring like physical or mental characteristics. This is considered unethical for many reasons such as the possibility of developing a society that offers a hold over certain traits. Something else to take into consideration is who would be manipulating genes; this opportunity would only be available to those who can afford it. These sole reasons allow the argument of morals to be brought over. It’s obvious how important genome editing is to the field of science but for the sake of society, it’s necessary to be cautious. 

Implications for Society as a Whole

Genome editing is a tool that can affect society as a whole in ways such as the health of humans, the agriculture of the environment, and benefitting the field of science. Though, it is important to be cautious of the downsides like the diversity of a community, the demographics this would be available to, and the ability to pick and choose certain traits over others. It brings into question if the advancement of this tool would create a society in which specific characteristics are favored more than the minority group of features. Therefore, it is necessary to use genome editing in an ethical and resourceful way that benefits everyone. 

Summary of Key Findings

All in all it is beyond doubt that genome editing brings a grand amount of understanding to the field of science and research. It has come so far from the 1980s and the techniques and tools used are constantly being improved for the better.  It is important to understand the significance of gene editing and its role in refining society. Some of these roles consist of treating genetic diseases, creating animal models to learn more about disorders, and developing new and far advanced technologies. Genome editing wouldn't be possible without the array of tools by its side. CRISPR-Cas9, the most common, is extremely convenient and resourceful to use. TALENs and ZNFs are techniques that are not only precise and very flexible but are unfortunately also complex. These tools allow genome editing to better people’s lives by milestones. From researching diseases to treating them and even modifying crops, it is unbelievable how far this mechanism has come. 

Future Directions for Genome Editing Research 

          All things said, the future for genome editing looks bright. It’s a great source for research and benefitting people’s lives. Its advances will be able to treat many genetic and non-genetic diseases. Furthermore, it will modify crops that can adapt and develop traits that could resist many harmful factors such as pests and pollutants. It is clear how far genetic engineering has come and it will be unbelievable how far researchers will advance. 

Final Thoughts 

           Overall, the tide of importance that genome editing brings in is undeniable. It is a great resource for modern science and research. It has allowed so many possibilities for society as a whole. By benefiting us with the ability to treat genetic diseases, genome editing has been a promising mechanism. 


The author's comments:

I’m a junior in high school and I hope to pursue a career in microbiology. After watching a documentary about genome editing, I was inspired to research it more. After months of frequent searching and googling, I finally had the idea to write about it and the paper eventually transformed into a research-esque piece. It is in the middle of a scientific paper and an article that an average reader can understand.

Bibliography

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Anzalone, A. V., Koblan, L. W., & Liu, D. R. (2020, June 22). Genome editing
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Niglia, S. (n.d.). Gene Editing Pros and Cons – 8 Advantages and
     Disadvantages. ExploreBioTech. Retrieved November 6, 2023, from

     explorebiotech.com/gene-editing-pros-and-cons/

 


Daley, J. (2021, October 26). Four Success Stories in Gene Therapy. Nature.
     nature.com/articles/d41586-021-0


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