CRISPR-Cas9 is the most accurate and versatile tool that is used to edit genome of an organism. Genome editing tools are genetically engineered nucleases that are used to modify the DNA of an organism by addition, deletion or substitution of targeted genes with the help of nucleases.
CRISPR-Cas9 system is relatively cost-effective and more accurate as compared to other genome editing tools like zinc finger nucleases (ZFN), TALEN and meganucleases. CRISPR has expansive dimensions for application in genetic engineering, pharmaceutical and medical research.
The CRISPR-Cas9 system actively cause a mutation in the genome by inserting the Cas9 enzyme to cleave the DNA at target sequence. A guide RNA called gRNA with approximately 20 base pair sequences complementary to the target DNA sequence, is added to bind the DNA and to guide the Cas9 enzyme to the target sequence of genome.
The gRNA reduces the chances of incising a wrong chunk of DNA and this makes the CRISPR-Cas9 system more precise than other genome editing tools. The cell perceives this as a DNA damage and repair the genome. During the repair, a few base pairs are excised and causes a permanent mutation in the DNA. This property of the system enables the scientists to alter or completely stop the functioning of a specific gene.
CRISPR-Cas9 is a promising technique that can be utilized to treat genetic disorders and conditions such as cancer, cystic fibrosis, hypercholesterolemia and sickle cell anemia. The scientific community proposed the use of the system for germline editing. However, the germline editing is under fire due its controversial nature and passing of changes to the progeny.
While germ-line gene editing is prohibited in several countries including the UK, somatic cell gene editing with CRISPR-Cas9 has been utilized in humans successfully for the treatment of various genetic disorders and critical conditions.
The researcher suggested that the CRISPR system can also be used to alter the transcriptional activity of genes and coordinate the expression of genes for a single function. It can also be utilized to produce transgenic organisms for research, and knockout screening for drug resistance and cancer also be used in therapeutic and pharmaceutical industry. The application of the CRISPR-Cas9 system are vast and ranges from biotechnology to medicine and research.
Keywords: CRISPR-Cas9, genome, genes, DNA