The use of genome editing in treating and preventing human illnesses is of tremendous interest. Several approaches to genome editing are available. A well-known one is called CRISPR-Cas9, which is short for clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9.
A CRISPR-Cas9 system is an exciting option that generates lots of activity in the scientific community. It is faster, less expensive, and more accurate than other gene-editing tools. So how does Cas-9 fit into the CRISPR story?
CRISPR technology was derived from the natural defensive systems of bacteria and archaea, a realm of single-celled microorganisms. To thwart viral assaults, these species employ CRISPR-derived RNA, a molecular relative to DNA, and different proteins. To prevent invasions, organisms cut up virus DNA and store portions of it in their own genome to be utilized as a weapon against the foreign invaders if those viruses attack again. The segment of DNA helps them recognize and dispatch the threat.
To work, this system relies on two key molecules:
- Cas9 – A protein that serves as a pair of molecular scissors that cuts two strands of DNA at a precise point in the genome, allowing to add or delete pieces of DNA.
- Guide RNA (gRNA) – A short pre-designed RNA sequence (approximately 20 nucleotides long) embedded inside a larger RNA scaffold. The scaffold attaches to DNA, and the pre-designed sequence guides Cas9 to the correct region of the genome. This ensures that the Cas9 enzyme cuts at the correct location in the DNA.
Together, they allow scientists to edit genetic code.
Cas9 follows the guide RNA to the proper position in the DNA sequence. When the target DNA is discovered, Cas9 binds to it and cuts it. In addition, it can cut across both strands of DNA, which is a double helix structure, thereby shutting off the targeted gene.
Researchers can trigger gene expression rather than cutting the DNA by using customized forms of Cas9. These tools enable them to investigate the function of the gene.
CRISPR gene editing is significant because it enables scientists to change the genetic code of nearly any creature. It is less complicated, expensive, and more precise than prior gene editing procedures. Furthermore, it offers a variety of real-world uses, such as healing genetic illnesses and developing drought-resistant crops.
CRISPR-Cas9 is a more efficient and adaptable genome editing tool than other available methods. In addition, because the CRISPR-Cas9 system can cut DNA strands, CRISPRs do not need to be linked with separate cleaving enzymes as other tools required.
They can also be easily paired with custom-made “guide” RNA (gRNA) sequences that direct them to their DNA targets. CRISPR-Cas9 may also be used to target many genes at the same time, which distinguishes it from other gene-editing technologies.
CRISPR-Cas9 could address shortages of human organs for transplant procedures and overcome some of the adverse effects of organ transplantation, such as graft-versus-host disease. The method is also being researched to genetically engineer insects to eradicate insect-borne illnesses such as malaria, which is carried by mosquitos, and Lyme disease, which is transmitted by ticks.
Without question, CRISPR-Cas9 is transforming the area of genome engineering.