CRISPR Technology

CRISPR is the abbreviation for clustered regularly interspaced short palindromic repeats. CRISPR itself is a natural sequence of DNA in a prokaryote. CRISPR technology, however, is the process that allows scientists to edit genes. Outside of the lab, CRISPR sequences are naturally being altered in bacteria and archaea (prokaryotes). When a virus attacks a prokaryote, the virus inserts its genetic material into the organism and essentially hijacks the cell, forcing it to make copies of the virus. After recognizing that the virus is an invader, the prokaryote will take a piece of the virus’s genetic information and place it in its own DNA sequence. This lets the cell keep a record of the virus and will help it recognize the pathogen if it ever attacks again. The cell will then copy the virus’ genetic material into RNA (RNA is similar to DNA but only has one strand of bases). This RNA is placed in a specialized enzyme known as Cas9. This enzyme will attach itself to any free-floating genetic material, searching for a match to the virus’ RNA. If the free-floating genetic material matches the RNA, this specialized Cas9 enzyme will cut the foreign genetic material. This prevents the virus from attacking the cell. The CRISPR/ Cas9 system acts like a vaccine, inhibiting a virus from attacking the cell a second time. Scientists such as Jennifer Doudna and Emmanuelle Charpentier wondered if they could use this prehistoric immune system’s technology to edit genes in eukaryotes such as humans or pigs. In a lab, a scientist artificially designs a piece of RNA (known as guide RNA) that corresponds to the gene they want to change and places it inside of a Cas9 enzyme. The Cas9 enzyme then looks for a match to the piece of RNA. When the Cas9 finds the match, the enzyme will cut it, making the gene unusable. The cell then tries to repair the break but this often is not effective and results in the specific gene that was cut being turned off. However, scientists can also add another sequence of DNA to Cas9. The cell then uses this sequence of DNA as an artificial template to rebuild the broken DNA. By cutting the DNA they want to change, scientists can force the gene to repair using DNA they artificially inserted as a manual. CRISPR technology can be used in plants to make them more resistant to the weather and disease. Scientists even want to use this technology to alter the organs in pigs so that they can be transplanted into humans. CRISPR hopefully can be used to eliminate many genetic disorders such as Huntington’s Disease, Tay Sachs, and Cystic Fibrosis. Although CRISPR technology sounds like the perfect solution, debates have arisen about how safe and ethical it is. The well-being of the patient is the main concern and according to Yale Insights, “A series of studies have suggested that CRISPR may cause cells to lose their cancer-fighting ability and that it may do more damage to genes than previously understood” (Licholai, 2019). Also, when using CRISPR technology to change somatic cells, the changes made to the DNA will not be passed down to the organism’s offspring. However, changes made to the gametes of an offspring or to the embryo itself will be inherited by the next generation. This means that any side effects of CRISPR will be present in future generations. Most new technology is expensive and CRISPR technology will be no different. If only wealthy people can afford this treatment, the world will only become more unequal. Not to mention that this technology may have long-term effects that are just not apparent to scientists now. This is why extensive testing is still happening in laboratories around the world. The future for CRISPR technology looks bright but scientists still have a long way to go before CRISPR technology will be ready to use. 

Works Cited 

Ledford, H. (2015). CRISPR, the disruptor. Nature, 522(7544), 20+. https://link.gale.com/apps/doc/A416717887/AONE?u=nysl_oweb&sid=googleScholar&xid=89fc8be1

Licholai, G. (2019, January 16). Is CRISPR Worth the Risk? Yale Insights. https://insights.som.yale.edu/insights/is-crispr-worth-the-risk 

Macura, S. L., PhD. (2016). CRISPR/Cas. In T. Moy & L. Avery (Eds.), The Gale Encyclopedia of Genetic Disorders (4th ed., Vol. 1, pp. 484-486). Gale. https://link.gale.com/apps/doc/CX3630400144/SCIC?u=new30853&sid=bookmark-SCIC&xid=a6a693b7

McGovern Institute. (2014). Genome Editing with CRISPR-Cas9. In YouTube. https://www.youtube.com/watch?v=2pp17E4E-O8

National Human Genome Research Institute. (2017, August 3). ​What are the ethical concerns of genome editing? Genome.gov. https://www.genome.gov/about-genomics/policy-issues/Genome-Editing/ethical-concerns

TED-Ed. (2019). How CRISPR lets you edit DNA - Andrea M. Henle. In YouTube. https://www.youtube.com/watch?v=6tw_JVz_IEc

Vidyasagar, A., & Lanese, N. (2022, February 26). What Is CRISPR? Live Science. https://www.livescience.com/58790-crispr-explained.html

What is CRISPR-Cas9? (2016, December 19). Yourgenome. https://www.yourgenome.org/facts/what-is-crispr-cas9