



The most commonly used gene editing tools are the class 2 CRISPR systems including Cas12 and Cas9. However, we know there are off-target effects associated with these.





Therefore, we must optimise current Cas proteins or explore alternatives such as Cas3 which belongs to the class 1 CRISPR system.





Researchers at UCSF have shown the viability of Cas3 as a genome-editing tool in a study found on bioRxiv .





The researchers found CRISPR-Cas3 system was able to create 'large deletions ranging from 7 - 424 kb' in Pseudomonas aeruginosa with high speed and efficiency. Whereas, Cas9 caused point mutations and smaller deletions. The CRISPR-Cas3 system was also able to create large deletions in Escherichia coli and Pseudomonas syringae, showing that the Cas3 system's ability to cause large deletions is portable.





'CRISPR-Cas3 could facilitate rapid strain manipulation for synthetic biological and metabolic engineering purposes, genome minimization, and the analysis of large regions of unknown function.'





CRISPR-Cas3 seems as though it is a very useful gene editing tool that can be used to remove large amounts of the genome. This could be helpful for many reasons as quoted above.









Reference:

https://www.biorxiv.org/content/10.1101/860999v1.abstract



