A Review of the Applications and Mechanisms of CRISPR-Cas9 Systems
Several studies have introduced CRISPR-Cas9 as a prominent genome-editing technology. CRISPR was first established as a bacterial immune system and was later founded as a new genome-editing technology by Jennifer Doudna and colleagues around the turn of the decade. CRISPR is preceded by zinc-finger nucleases (ZFN) and transcription activator-like effector nucleases (TALENs); however, it improves upon these previous genome-editing designs by using RNA as its binding domain and by already containing nucleases—reducing the need to intentionally engineer these domains into the technology. Complementarity between the different RNAs (tracrRNA and crRNA) and protein aspects (Cas systems) of CRISPR act in conjunction to both efficiently assemble and confer its intended purpose. After extensive use in mammalian cell cultures and various model organisms, the CRISPR-Cas system has subsequently been used to mediate several genetic diseases such as sickle cell anemia and some cancers in humans. CRISPR-Cas9’s potential to mediate all other genetic mutations induced by sequence polymorphisms remains promising.