CRISPR Gene Editing

Is it possible to create a human being immune to all types of diseases or cure conditions that were once incurable? Well, now it is! CRISPR, a new form of gene-editing technology, allows scientists to 'delete' and 'paste' genes into DNA more quickly and accurately. Sounds fascinating, but there are both benefits and ethical concerns to using this technique.  

Now, some history of CRISPR. CRISPR-Cas systems are adaptive immune response systems that defend prokaryotes against bacteriophages. They shield prokaryotes from viral infections by clipping the nucleic acids of invading viruses. Yoshizumi Ishino, a Japanese scientist, discovered CRISPRs in E. coli in 1987. While studying a gene for alkaline phosphatase conversion, he unintentionally cloned an odd set of repetitive sequences interspersed with spacer sequences. But due to the lack of knowledge of CRISPR and data, it remained a mystery. Then in 1993, researcher J.D. van Embden discovered that different strains of Mycobacterium tuberculosis had different spacer sequences between the repetitive DNA. He used a method known as spoligotyping to classify M. tuberculosis strains based on their spacer sequences. Subsequently, his research team identified other sequences in several other bacterial genomes and referred to them as CRISPRs. Scientists were fascinated by this mechanism and wanted to manipulate it. 

In 2012, George Church, Jennifer Doudna, Emmanuelle Charpentier, and Feng Zhang hijacked CRISPR-Cas9 for genome editing. First, they found out that by designing guide RNA to target a specific region in the genome, they were able to ‘cut’ and ‘paste’ different sections of the DNA. Then, further research led them to realize that CRISPR-Cas9 can silence or activate genes and delete or add new genes. This groundbreaking research has led scientists to believe that curing genetic disorders such as sickle-cell anemia and cystic fibrosis is possible. Clinical trials are already happening!

Despite these advancements, there are major ethical concerns with editing an organism’s genomes, whether human beings, other species, or the environment. For example, a recent incident occurred in 2019, in which scientist He Jiankuim stunned the world when he announced he had facilitated the development of HIV-resistant genetically modified infants. Later that year, he was found guilty of conducting “illegal medical practices” and sentenced to 3 years in prison. The court had found out that Jiankuim and his team forged ethical evaluation papers and misinformed doctors by implanting gene-edited embryos into two women without their knowledge. Although Jiankuim was complicated from an ethical standpoint, some people supported his work because the babies developed immunity to HIV. Are you in favor of or opposed to Jiankuim's work? 

Although this is a problematic incident, the use of CRISPR technology has led to great advancements. Jennifer Doudna, one of the founders of the technique, has always wanted to cure sickle-cell anemia, which has affected millions of people worldwide. Doudna and her team repaired the single mutation that makes red blood cells sickle-shaped. After six long years, the researchers used CRISPR-Cas9 to replace the faulty beta-globin gene with a restored variant to create healthy, adult red blood cells. On March 30, 2021, the FDA approved the treatment. Although there is still much to be done before the treatment is made available to the public, according to Jennifer Doudna, “the launch of this trial is an essential first step on that path.”  

CRISPR can be used for different things besides curing diseases. Scientists are using it to develop more sustainable techniques for creating fuel and chemicals, and enhancing agricultural crops to better feed the world's rising population. For example, Eck, a Cornell University professor, and her colleague Zachary Lippman utilize CRISPR to make the groundcherry more appealing to farmers. They targeted a gene in the fruit that makes it more compact as it grows and causes the fruit to be 25 percent bigger. Recent advancements in CRISPR suggest that this technology might help us by providing an answer to the energy crisis. The use of CRISPR has allowed phototropic algae to produce twice as much biodiesel. Instead of using fossil fuel resources, bioenergy can help reduce pollution and possibly end the energy crisis.