Science Spotlight: CRISPR and Gene Editing

First of all, what the heck is CRISPR? Well, it stands for "clustered regularly interspaced short palindromic repeats" (I know, such a mouthful). This term more broadly refers to a type of technology that allows us to selectively modify the DNA of living organisms - aka gene editing.

But, before we get into gene editing, we got to know the basics of the genes themselves. Genes are tiny, tiny structures that encode for us. It tells our body how to make proteins, synthesize certain molecules, what to create and what not to create. They are basically the instruction manual for our bodies and each person has their own unique instruction manual that determines

More specifically, genes are segments of DNA that code for specific things. For example, a certain gene in your body could encode for a certain protein and how to make it. This DNA is located in each of our cells in the form of chromosomes- tiny threadlike structure that float around inside the nucleus.

What does CRISPR do?

As mentioned before, CRISPR allows scientists to change the genes of a organism, More specifically, it allows scientists to target certain genes in the DNA and modify them by adding, replacing or completely removing them.

How does CRISPR do this? Well technically CRISPR is a type of bacterial defense technology that has been genetically changed to become the gene editing technology that we know as CRISPR.

CRISPR - the bacterial defense- was first discovered in archaea by Francisco Mojica. CRISPR consists of sequences of genetic code (with spacer genes in between) that serve to cleave viral DNA that has infected the host cell. CRISPR does this with the help of an enzyme called Cas 9. They collectively work together due to the actual gene cutting process that we know.

Some of you readers are probably thinking, "There's no way this stuff will be useful." But, as I'll point out in a later section, you couldn't be more wrong. CRISPR has the potential to help create completely new medicines, and specifically alter DNA to gain certain characteristics (GMO's).

How Does CRISPR Work?

CRISPR, as previously mentioned, is a defense system found in bacteria, specifically designed to protect against viruses. Viruses infect bacteria by inserting their own DNA, hijacking the bacteria’s mechanisms to replicate themselves. To defend against this, bacteria use an enzyme called Cas9, along with a sample of the foreign DNA. The Cas9 enzyme is responsible for cutting the viral DNA and identifying sequences of CRISPR DNA. These sequences are called "palindromic" because they are often arranged in reverse order, like a palindrome.

What makes CRISPR different then the rest?

CRISPR, like we mentioned before, is made up of an enzyme called Cas9. This protein makes CRISPR easily usable.

You see, other gene editing techniques were a single protein and to change the target of that protein, one would have to manually change the peptide chains of the protein. On the other hand, to change the target area for CRISPR, you have to only edit a small portion of the RNA sequence. Editing this part is much easier to do then editing a peptide change in a protein.

The first programmable gene editing technique similar to CRISPR was Zinc finger nucleases (ZFN for short). However, the design of this specific protein type led to design restrictions.

How can CRISPR be used?

CRISPR is a marevelous form of technology, no matter how anyone looks at it. But, there are many ways one can use CRISPR:

• Research: CRISPR allows scientists to better understand functionality.

  • This sounds really simple at first, but this is in fact harder to understand than most people think. The reason? Well, its primarily because a lot of times, scientists are unaware of what parts correspond to what functions. For example, maybe a specific adaptation allows animals to walk really fast, but we can't know for sure if that's its only purpose, if it works with other adaptations or if there are any limitations. CRISPR allows scientists to isolate specific genes and identify specific functions for an adaptation or part.

    
    

• Medicine: This is arguably the most obvious type of benefit one can get from CRISPR. There are three main ways CRISPR can we used in the world of medicine:

  • Polygenic diseases- This just refers to genetic disorders that are affect by multiple genes. These types are the most common genetic disease, some notable ones include diabetes, heart disease and many types of cancers.

    
    

• Develop and Test New Therapies: CRISPR is being used to explore potential therapeutic strategies by directly correcting genetic mutations in disease models. For instance, researchers can use CRISPR to edit out harmful mutations in cells derived from patients, allowing them to observe whether the gene correction can reverse disease symptoms or prevent progression. This research is paving the way for potential gene therapies in the future.

  • Functional Genomics: With CRISPR, scientists can carry out genome-wide screens by targeting thousands of genes at once to see how they affect a specific trait or outcome, like drug resistance, cellular growth, or response to stress. This large-scale approach provides insights into gene functions at a scale that wasn’t possible with traditional methods, helping to identify critical genes involved in important biological processes

    
    

• Agriculture: CRISPR is being used to create specific desired traits for a plant or crop.

  • Enhancing Nutritional Value: CRISPR allows scientists to increase the nutritional content of crops by editing genes to enhance vitamins, minerals, and other beneficial compounds. For example, researchers are using CRISPR to increase the vitamin A content in rice, similar to the approach used for “Golden Rice.” This helps combat malnutrition, especially in regions where dietary variety is limited.

  • Improving Crop Yields: CRISPR can be used to boost crop yield by editing genes related to growth rate, photosynthesis efficiency, and nutrient uptake. This is crucial for feeding a growing global population, as it allows farmers to produce more food on the same amount of land. For example, modifying genes in rice and wheat can enhance grain size and density, leading to higher yields.

  • Creating Pest-Resistant Crops: CRISPR enables the development of crops that are naturally resistant to pests by either enhancing plant defense mechanisms or disabling genes that pests rely on for infection. For example, by editing the DNA of cotton plants, scientists can create varieties resistant to bollworms, reducing the need for chemical pesticides and benefiting the environment.

What's Next?

If you think this is the best of gene editing technology, then you're in for a big surprise. While CRISPR is one of the main emerging technologies because of its versatility and usability, it is definitely not the only one out there!

One notable example of this is ‍the NgAgo Protein Gene Editing System. This system allows scientists to cut DNA from a specific site without having to use a RNA strand. This system is early in development and comes from the Argonaute endonuclease family, called Natronobacterium gregoryi Argonaute (NgAgo). This specific protein has been shown to effectively alter DNA in mammalian cells using single-stranded (ss) DNA guides.

Preliminary research on this has also shown that, unlike CRISPR, NgAgo is efficient in editing almost any sequence.

There are even mini Cas 9 enzymes that can be used! These are helpful when the the normal Cas 9 enzyme and RNA strand are too large to work in viruses used for gene therapy. For example, for the bacterium Staphylococcus aureus, scientists developed this mini Cas 9 to effectively alter its genes.

Another variation of the CRISPR Cas - 9 is the ‍‍CRISPR-Cpf1 System. This specific system is easier to use within cells as it only requires on RNA strand. Additionally, this system allows for both deletion and reengineering of DNA at the same location (in other solutions like CRISPR Cas 9, this cannot be done at the same time dur to the target site being deleted).

One last example is the ‍FANA Antisense Oligonucleotide (FANA ASO) technology. The two main benefits for this specific technology compared to CRISPR is that it is even more precise then CRISPR and also provides a reversible method for gene suppression.

But, out of all of these technologies, CRISPR - at least for now - is the most transformative. CRISPR-Cas9 stands out because it’s accessible, versatile, and incredibly precise. It offers researchers a tool that is simpler and more cost-effective compared to earlier gene-editing technologies, making it widely usable across labs with varying resources.

CRISPR’s adaptability is also remarkable—scientists can design guide RNAs to target virtually any gene, across species, in a matter of days. This ease of use accelerates research timelines, allowing labs to generate genetic models or run high-throughput screens much faster than before. As a result, CRISPR has democratized gene editing, enabling innovations in everything from human health and agriculture to microbiology and environmental science.

While newer technologies continue to emerge, CRISPR’s current impact is unparalleled, reshaping how we approach genetic research, disease understanding, and potential treatments.