CRISPR: Genome-Editing and Beyond

The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system has been seized upon with a fervor enjoyed previously by small interfering RNA (siRNA) and short hairpin RNA (shRNA) technologies and has enormouspotential for high-throughput functional genomics studies. Editing via (CRISPR)-CRISPRassociated (Cas) constitutes a next-generation method for programmable and high throughput functional genomics. CRISPR-Cas systems are readily reprogrammed to induce sequence-specific DNA breaks at target loci, resulting in fixed mutations via host-dependent DNA repair mechanisms. Bacteria and archaea acquire resistance to invading viruses and plasmidsby integrating short fragments offoreign nucleic acids at one end of the CRISPR locus. CRISPR loci are transcribedand the long primary CRISPR transcript is processed into a library of small RNAs that guide the immune system to invading nucleic acids, whichare subsequently degraded by dedicated nucleases.