CRISPR-Cas9

Posted by Pranav Kakhandiki, Edited by Anika Asthana| Jul 18, 2018, 9:00:00 PM

 

        Gene editing, a field in synthetic biology, is a rapidly emerging subject in today’s world. There are a whole world of possibilities, ranging from creating new organisms, to curing diseases previously thought to be un-curable. CRISPR-Cas9 is a riveting new gene editing technology, standing for Clustered Regularly Interspaced Short Palindromic Repeats. The “palindromic repeats” are small pieces of viruses typically found in bacteria. Cas9 is an enzyme which can cut apart DNA allowing scientists to edit the human genome.

        To truly understand when and why CRISPR can be used, it is important to understand how it works. With so many other gene editing tools, such as ZFNs and TALENs, CRISPR is popular for a reason. Unlike other methods, CRISPR does not need to be paired with separate “cleaving” enzymes. In other words, the Cas9 protein uses small RNAs to cleave DNA, as opposed to using separate enzymes. CRISPR is a “knife” that can cut DNA by matching up a guide RNA to the DNA and then cutting it. After the DNA is cut, the cell loosely “glues” the strands of DNA back together.

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        So how does Cas9 enzyme know which part of the DNA to cut out? The CRISPR-Cas9 complex scans the DNA for Protospacer Adjacent Motifs (PAMs), which are short DNA sequences. CRISPR, then attached to the PAM, unzips the double helix. The Cas9 protein then cuts the DNA in two, successfully eliminating the specific piece of DNA.

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        Now we know how CRISPR cuts out DNA, but what can we do with it? CRISPR can be used to make tiny genomes in the base pairs that make up the genome, which may end up being the difference between life and death. Many major diseases are caused by one just one mutant base pair in the genome, such as sickle cell anemia, cystic fibrosis, and muscular dystrophy. CRISPR can cut out the “bad” DNA, and insert the correct sequence of base pairs. Other uses for CRISPR include mutating animals, potentially making them stronger and faster than biologically standard.  

        So if CRISPR is so great why don’t all doctors use it? CRISPR is fairly accurate, but can sometimes cut out the wrong strand of DNA, creating its own mutation. So as of present day, CRISPR isn’t quite reliable to be tested on humans. Many years into the future, however, technology will not be the factor holding us back from using synthetic biology.

        With so many possibilities and so much new technology, many ethical dilemmas arise. Should people be informed whether they will inherit a disease fifty years later in their life? Can we create new animals to do work for us? Can we give ordinary humans superpowers with one simple operation? Although CRISPR is a new and exciting technology, one must consider the ethics behind such an enormous jump in scientific advancement.

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        Ever since 1979, synthetic biology has been an emerging field in science,  allowing us to sequence entire genomes and change genes. The ethics of this field, however, can be questioned, as it allows us to potentially create new organisms, or change them beyond what is natural. This subject can be viewed both positively and negatively. One one hand, this practice includes removing environmental contaminants, creating safer and cleaner air, diagnosing and monitoring disease in eukarya, creating enzymes for biofuels, and developing new drugs and vaccines.

        However, a multitude of negative effects present themselves. One harmful effect of the use of synthetic biology is the creation of new organisms. New organisms could potentially destroy the ecosystem, killing off native species and ruining the environment. Another is bioterrorism, the intentional release of biological agents such as viruses, bacteria, or toxins using CRISPR to intentionally create harmful viruses would have an adverse impact on our world, as it provides weapons stronger than ever before. Although both of these detrimental uses of CRISPR can negatively affect our world, the questionable ethics of gene editing doesn’t stop there. New technologies are allowing scientists to map the entire genome of a human, letting them predict what diseases one can inherit. Although it sounds phenomenal on the surface, the potential action creates a personal conundrum. The question is: do we want to know if we will inherit a disease later in life? If we know we will inherit a non-curable disease such as Parkinson’s, will knowing this information cause us to live our lives differently? So despite the numerous benefits of CRISPR, the massive negative potential of such a technology forces humans to decide what to do with the power vested in gene editing technology.

        CRISPR is a fascinating technology with incredible potential. Using it, we can achieve feats thought to be impossible, making significant advances in the field of synthetic biology. With so much potential, however, much harmful potential presents itself. We can cure diseases, yet will the same technology, create a disease even worse. We can create a safer environment, but can it destroy in a heartbeat with the creation new organisms. With so much potential in gene editing, one question stands out: What will we do with it?

 

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4 thoughts on “CRISPR-Cas9”

  1. Congratulations young Pranav on penning this thought provoking article highlighting boons and names of gene editing tool CRISPER – Cas9.

    Keep writing on all newer scientific topics in a way it can be consumed by one and all.

    Best wishes,
    Ram

    Liked by 1 person

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