Aug 13, 2021
CRISPR Cas9, the Good and the Bad
Implications of this revolutionary biotechnology
First encountered in 1987, CRISPR, Clustered Regularly Interspaced Short Palindromic Repeats, has become one of the biggest talking points in Science & Medicine. The idea behind CRISPR was developed from the understanding of how bacteria defends itself against bacteriophages. By identifying certain genomic sequences in the phage DNA, bacteria can cut/cleave these sequences, thus degrading the phage DNA defending against the intruder.
The reasoning behind CRISPR is to use the same concept for not only the benefit of humanity but for life. But before we completely legalize this technology and release the hound, there are several questions and implications that must be addressed. Answers to which may just define our future.
How does CRISPR work?
Our DNA is composed of 4 specific building blocks known as nucleotides, each represented by a letter: A, T, C, or G. Specific sequences of these building blocks are known as genes, or protein coding regions, which in code for our traits. The idea behind gene editing is to alter or delete the genomic sequence (sequence of the building blocks) of an organism at specific points in a gene.
In theory, this process is actually relatively simple:
- A guide RNA (designed in the lab) identical to a distinct portion of the gene, is bound to a protein called Cas9.
- When in the organism, the guide directs the protein to the targeted sequence, cutting it at this specific site and “deleting” this part of the DNA.
From here, scientists can monitor the impact of this cut and deduce what role that specific portion of the DNA had on the organisms. However, we can also edit the gene and add in our own DNA sequence.
This is where a key concept comes into play, a template DNA.
3. Unlike in bacteria, a template DNA is also involved. Once the DNA is cut, the template DNA is added, replacing the cut section.
Due to this change in the DNA sequence, new proteins can be expressed that carry out different functions in the organism, which can impact the organism in a variety of ways, both externally and internally.
How can CRISPR be used?
One thing is clear, CRISPR definitely has the potential to revolutionize our lives for the better. As shown before, scientists can use CRISPR to not only study the functions of certain genes but also to directly edit the DNA.
By editing the DNA, scientist can alter traits, capabilities, or behaviors of an organism or species. For example, CRISPR can create crops that yield more produce, change cows so that they don’t release as much gas into the atmosphere, and engineer salmon that can grow faster and live longer.
These possibilities could benefit society, the environment, or even a whole species. While these are all substantial applications, there is one function I haven’t mentioned that stands out among the rest: fighting disease.
Genetic mutations rarely occur, and even when they do, they may not have a large impact. That being said, there are several instances of mutations that can lead to virulent diseases and syndromes. Some examples of these genetic disorders are sickle cell anemia, Turner syndrome, and Klinefelter Syndrome.
If we can use CRISPR to locate & edit the sequences of DNA that are the root cause of each of these disorders, we can eliminate or edit-out these mutations and help cure patients of these genetic disorders. This would equip the medical field with a consistent, effective, and relatively cheap method of treatment.
Potential downfalls of CRISPR
All that I’ve mentioned so far shows just how vital of a role CRISPR can play in the future of medicine and society. However, as I mentioned before, some questions must be addressed before we implement this technology for daily use.
- Is it ethical to simply go in and permanently edit the geneome of other species?
- How do we regulate the usage of CRISPR so that it is not misused?
- Is CRISPR 100% safe?
Let’s say that in the future a gene is found that can make you an exceptional individual athlete (hypothetical). Just like that. With the switch of a few bases, you can become the next LeBron James. You can already imagine the countless number of parents who would line up to have their baby genetically modified to become the next big star. Clearly, this would be a large scale ethical issue at hand.
Another talking point of concern is using CRISPR on other animals, for modifying the traits of other organisms may hurt the environment and have other unwanted side effects on the species itself. The argument can also be made that it is unethical to just go to other animals and alter their DNA as we wish.
On top of all this, there are also worries that CRISPR can actually CAUSE mutations instead of fixing them. For instance, instead of cleaving the DNA at the desired target area, the Cas9 protein can accidentally cut off large portions of your entire genome. Deletion of your DNA strips your cells of the information they need to survive, and as a result, there is massive cell death.
With all these potentials issues, it is key for us to not jump the gun when considering the application of CRISPR in the real world, despite how captivating the initial idea may be.
As George Q. Daley of Harvard medical School said:
One has to raise the bar very high to define what the standards of safety and efficacy are, and what kind of oversight and independent judgment would be required for any approval.
In summation, CRISPR is like humanities secret tool. A tool that, if used with high moral standards and the right regulations, can be forever revolutionary, but if used wrong, can lead to one of our greatest downfalls. The choice is in our hands.
Thank you for your time.
If you enjoyed reading my story and learned a lot, please consider reading some of my other articles.
