CRISPR is a dynamic, versatile tool that allows us to target nearly any genomic location and potentially repair broken genes. It can remove, add, or alter specific DNA sequences in the genome of higher organisms. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) are sections of DNA and are sections of genetic code containing short repetitions of base sequences followed by spacer DNA segments. CAS-9 (CRISPR-associated protein 9) is an enzyme. It uses a synthetic guide RNA to introduce a double-strand break at a specific location within a strand of DNA. Bacterial cells use this system to recognize and destroy viral DNA as a form of adaptive immunity.
How does it work?
- CRISPR scans the genome looking for the right location and then uses the Cas9 protein as molecular scissors to snip through the DNA.
- The Cas9 endonuclease uses guide RNAs to direct it to a particular sequence for editing. The RNA’s genetic sequence matches the target sequence of the DNA that needs editing.
- When Cas9 cuts the target sequence, the cell repairs the damage by replacing the original sequence with an altered version.
- Unlike other gene-editing methods, it is cheap, quick, easy, safer and more accurate to use because it relies on RNA–DNA base pairing, rather than the engineering of proteins that bind particular DNA sequences.
Applications
- Researchers use CRISPR-Cas9 to create animal models that mimic human diseases and to understand disease development by mutating or silencing genes.
- Researchers have been able to modify the genomes of specific tissues such as liver and brain tissues using hydrodynamic injection and adeno-associated virus (AAV).
- Researchers can use CRISPR-Cas9 to generate mutants in target genes.
- CRISPR-Cas9 can be used on cells in two main ways: in vivo or ex vivo. In the in vivo method, researchers directly deliver CRISPR-Cas9 to cells within the body using either viral or nonviral techniques. In the ex vivo method, cells are first taken out of the body, treated with CRISPR, and then reintroduced into the body.
- CRISPR was first used for commercial purposes to make bacterial cultures used in cheese and yoghurt production resistant to viral infections.
- CRISPR-Cas9 can also edit single-stranded RNA (ssRNA) sequences.
- These studies are commonly focused on increasing the tolerance of soldiers against biological or chemical warfare. This technology has the potential to influence human performance optimization.
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