CRISPR Cas system is sometimes referred to as "molecular scissors" that can cleave DNA sequences, allowing various forms of genome, and sometimes even epigenome editing. The most popular protein used in this system is Cas9. Sometimes, Cas12a (formerly known as Cpf1) is also used, as it has some distinct features. For example, it can target different sequences to Cas9 and control more genes at the same time.
Our knowledge of CRISPR-Cas systems has evolved dramatically over the years, and given its immense value in research, it will probably continue to do so. Although there are multiple areas where the performance of CRISPR-Cas systems must be improved before the technology can make it to mainstream use for medical purposes, every year brings new advancements that get us closer to this goal. Meanwhile, CRISPR-Cas systems can be used to improve various areas of industry, contributing to the wealth and wellbeing of societies worldwide.
This section provides a summary of the two most popular CRISPR-Cas systems to date- CRISPR-Cas9 and CRISPR-Cas12a, while also giving on overview of the multiple modifications that those systems have undergone since their discovery. It compares the performance of both Cas9 and Cas12a nucleases in prokaryotic and eukaryotic microorganisms, plants, and animals. Furthermore, it introduces several less known alternative CRISPR-Cas systems employing Cas12b and Cas13, and their applications.
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I used the following sources to create this section:
 Aparna Vidyasagar. 2018. What Is CRISPR?. https://www.livescience.com/58790-crispr-explained.html. [Accessed 31 May 2020].
 G. Brett Robb. 2019. Genome Editing with CRISPR‐Cas: An Overview. Current Protocols Vol. 19, Issue 1, https://doi.org/10.1002/cpet.36
 Chylinski, K., Le Rhun, A., & Charpentier, E. (2013). The tracrRNA and Cas9 families of type II CRISPR-Cas immunity systems. RNA biology, 10(5), 726–737. https://doi.org/10.4161/rna.24321
 Shah, S. A., Erdmann, S., Mojica, F. J., & Garrett, R. A. (2013). Protospacer recognition motifs: mixed identities and functional diversity. RNA biology, 10(5), 891–899. https://doi.org/10.4161/rna.23764
 Thomas Swartjes, Raymond H.J. Staals, John van der Oost; Editor's cut: DNA cleavage by CRISPR RNA-guided nucleases Cas9 and Cas12a. Biochem Soc Trans 28 February 2020; 48 (1): 207–219. doi: https://doi.org/10.1042/BST20190563
 Mary Gearing. 2018. CRISPR 101: Cas9 Nickase Design and Homology Directed Repair. https://blog.addgene.org/crispr-101-cas9-nickase-design-and-homology-directed-repair. [Accessed 31 May 2020].
 Brian Wang, Shuqi Yan. 2018. When and how to use nickases for efficient genome editing. https://sg.idtdna.com/pages/education/decoded/article/when-and-how-to-use-nickases-for-efficient-genome-editing. [Accessed 31 May 2020].
 Rees, H. A., & Liu, D. R. (2018). Base editing: precision chemistry on the genome and transcriptome of living cells. Nature reviews. Genetics, 19(12), 770–788. https://doi.org/10.1038/s41576-018-0059-1
 Elie Dolgin. 2017. CRISPR hacks enable pinpoint repairs to genome. https://www.nature.com/news/crispr-hacks-enable-pinpoint-repairs-to-genome-1.22884. [Accessed 31 May 2020].
 Rich Haridy. 2019. CRISPR breakthrough allows scientists to edit multiple genes simultaneously. https://newatlas.com/crispr-cas12a-gene-editing-multiple-eth-zurich/61068/. [Accessed 31 May 2020].
 Ciurkot, K., Vonk, B., Gorochowski, T. E., Roubos, J. A., & Verwaal, R. (2019). CRISPR/Cas12a Multiplex Genome Editing of Saccharomyces cerevisiae and the Creation of Yeast Pixel Art. Journal of visualized experiments : JoVE, (147), 10.3791/59350. https://doi.org/10.3791/59350
 Campa, C.C., Weisbach, N.R., Santinha, A.J. et al. Multiplexed genome engineering by Cas12a and CRISPR arrays encoded on single transcripts. Nat Methods 16, 887–893 (2019). https://doi.org/10.1038/s41592-019-0508-6
 Synthego. 2019. CRISPRa and CRISPRi. https://www.synthego.com/guide/crispr-methods/crispri-crispra. [Accessed 31 May 2020].
 Jennifer Abarca, Zaklina Strezoska, Annaleen Vermeulen. 2018. What is CRISPRa vs CRISPRi?. https://horizondiscovery.com/en/resources/featured-articles/what-is-crispra-vs-crispri. [Accessed 31 May 2020].
 Gebre, Makda & Nomburg, Jason & Gewurz, Benjamin. (2018). CRISPR–Cas9 Genetic Analysis of Virus–Host Interactions. Viruses. 10. 55. 10.3390/v10020055.
 OriGene. 2020. CRISPRa and CRISPRi: Gene Expression Modulation. https://www.origene.com/products/gene-expression/crispr-cas9/crispra-crispri. [Accessed 31 May 2020].
 Yao, R., Liu, D., Jia, X., Zheng, Y., Liu, W., & Xiao, Y. (2018). CRISPR-Cas9/Cas12a biotechnology and application in bacteria. Synthetic and systems biotechnology, 3(3), 135–149. https://doi.org/10.1016/j.synbio.2018.09.004
 X. Zhang, J. Wang, Q. Cheng, X. Zheng, G. Zhao, J. Wang, (2017) Multiplex gene regulation by CRISPR-ddCpf1, Cell Discovery 3, 17018; doi:10.1038/celldisc.2017.18
 Wang M, Mao Y, Lu Y, Wang Z, Tao X, Zhu JK. Multiplex gene editing in rice with simplified CRISPR-Cpf1 and CRISPR-Cas9 systems. J Integr Plant Biol. 2018;60(8):626‐631. doi:10.1111/jipb.12667
 Zetsche B, Gootenberg JS, Abudayyeh OO, et al. Cpf1 is a single RNA-guided endonuclease of a class 2 CRISPR-Cas system. Cell. 2015;163(3):759‐771. doi:10.1016/j.cell.2015.09.038
 Cell. 2020. CRISPR Systems: What’s the Difference?. https://www.cell.com/pb-assets/products/research-arc/infographics/CrisprVizInfo_vol1a.pdf. [Accessed 31 May 2020].
 Strohkendl I, Saifuddin FA, Rybarski JR, Finkelstein IJ, Russell R. Kinetic Basis for DNA Target Specificity of CRISPR-Cas12a. Mol Cell. 2018;71(5):816‐824.e3. doi:10.1016/j.molcel.2018.06.043
 Alok, A., Sandhya, D., Jogam, P., Rodrigues, V., Bhati, K. K., Sharma, H., & Kumar, J. (2020). The Rise of the CRISPR/Cpf1 System for Efficient Genome Editing in Plants. Frontiers in plant science, 11, 264. https://doi.org/10.3389/fpls.2020.00264
 Adiego-Pérez, B., Randazzo, P., Daran, J. M., Verwaal, R., Roubos, J. A., Daran-Lapujade, P., & van der Oost, J. (2019). Multiplex genome editing of microorganisms using CRISPR-Cas. FEMS microbiology letters, 366(8), fnz086. https://doi.org/10.1093/femsle/fnz086
 Banakar, R., Schubert, M., Collingwood, M., Vakulskas, C., Eggenberger, A. L., & Wang, K. (2020). Comparison of CRISPR-Cas9/Cas12a Ribonucleoprotein Complexes for Genome Editing Efficiency in the Rice Phytoene Desaturase (OsPDS) Gene. Rice (New York, N.Y.), 13(1), 4. https://doi.org/10.1186/s12284-019-0365-z
 Breinig M, Schweitzer AY, Herianto AM, et al. Multiplexed orthogonal genome editing and transcriptional activation by Cas12a. Nat Methods. 2019;16(1):51‐54. doi:10.1038/s41592-018-0262-1
 Fillip Port, Maja Starostecka, Michael Boutros Multiplexed conditional genome editing with Cas12a in Drosophila (2020) https://doi.org/10.1101/2020.02.26.966333
 B. Paul, G. Montoya CRISPR-Cas12a: Functional overview and applications (2020) Biomedical Journal Vol.43, Issue 1, pages 8-17 https://doi.org/10.1016/j.bj.2019.10.005
 Chen, P., Zhou, J., Wan, Y. et al. A Cas12a ortholog with stringent PAM recognition followed by low off-target editing rates for genome editing. Genome Biol 21, 78 (2020). https://doi.org/10.1186/s13059-020-01989-2
 Ming, M., Ren, Q., Pan, C. et al. CRISPR–Cas12b enables efficient plant genome engineering. Nat. Plants 6, 202–208 (2020). https://doi.org/10.1038/s41477-020-0614-6
 Strecker, J., Jones, S., Koopal, B. et al. Engineering of CRISPR-Cas12b for human genome editing. Nat Commun 10, 212 (2019). https://doi.org/10.1038/s41467-018-08224-4
 UniProt. 2019. CRISPR-associated endonuclease Cas12b. https://www.uniprot.org/uniprot/T0D7A2. [Accessed 23 July 2020].
 Broad Institute of MIT and Harvard. 2019. Scientists engineer new CRISPR platform for DNA targeting. https://www.broadinstitute.org/news/scientists-engineer-new-crispr-platform-dna-targeting. [Accessed 23 July 2020].
 Yan, F., Wang, W. & Zhang, J. CRISPR-Cas12 and Cas13: the lesser known siblings of CRISPR-Cas9. Cell Biol Toxicol 35, 489–492 (2019). https://doi.org/10.1007/s10565-019-09489-1
 Teng, F., Guo, L., Cui, T. et al. CDetection: CRISPR-Cas12b-based DNA detection with sub-attomolar sensitivity and single-base specificity. Genome Biol 20, 132 (2019). https://doi.org/10.1186/s13059-019-1742-z
 Wang, D., Tai, P.W.L. & Gao, G. Adeno-associated virus vector as a platform for gene therapy delivery. Nat Rev Drug Discov 18, 358–378 (2019). https://doi.org/10.1038/s41573-019-0012-9
 Joel McDade. 2017. CRISPR 101: Targeting RNA with Cas13a (C2c2). https://blog.addgene.org/crispr-101-targeting-rna-with-cas13a-c2c2. [Accessed 23 July 2020].
 Omar Abudayyeh and Jonathan Gootenberg. 2020. Tips and Tricks for Cas13. https://zlab.bio/cas13. [Accessed 23 July 2020].
 Genetic Engineering & Biotechnology News. 2019. CRISPR-Cas13 Developed as Combination Antiviral and Diagnostic System. https://www.genengnews.com/news/crispr-cas13-developed-as-combination-antiviral-and-diagnostic-system/. [Accessed 23 July 2020].