CRISPR stands for clustered regularly interspaced short palindromic repeats, which are segments of DNA of a particular structure found widely in bacteria and archaea (prokaryotes). CRISPR-Cas9 is a method of genome editing that exploits a natural DNA-snipping enzyme in bacteria, called Cas9 (CRISPR-associated protein 9) to target and edit particular genes.
In nature, the CRISPR-Cas9 system is part of the prokaryotic immune system which can snip out DNA acquired from foreign sources such as phages (bacterial viruses). The same molecular technique is now being used to enable genetic material to be cut from and pasted into the genomes of other organisms, including humans. It might offer a tool for curing genetically based diseases.
When the bacteria detect the presence of the viral DNA, it produces two types of short RNAs:
- Cas9 nuclease that can cut DNA
- Guide RNA (gRNA) that recognizes the sequence to be edited
This enzyme can be used to cut any DNA sequence at a specific location by changing the guide RNA to match the target. Scientists can replace a mutant gene with a healthy gene (carrying the desired sequence) using this technique. It can be performed in in vitro cultures and it can target more than one gene.
Some applications include:
- Research
- Drug development
- Agriculture
- Human Diseases
