More news on from those trying to engineer Cas9 proteins with increased fidelity:
Kleinstiver et al. 2016 High-fidelity CRISPR–Cas9 nucleases with no detectable genome-wide off-target effects. Nature. Published online 06 Jan 2016. http://dx.doi.org/10.1038/nature16526[/URL]
[quote]CRISPR–Cas9 nucleases are widely used for genome editing but can induce unwanted off-target mutations. Existing strategies for reducing genome-wide off-target effects of the widely used [I]Streptococcus pyogenes[/I] Cas9 (SpCas9) are imperfect, possessing only partial or unproven efficacies and other limitations that constrain their use. Here we describe SpCas9-HF1, a high-fidelity variant harbouring alterations designed to reduce non-specific DNA contacts. SpCas9-HF1 retains on-target activities comparable to wild-type SpCas9 with >85% of single-guide RNAs (sgRNAs) tested in human cells. Notably, with sgRNAs targeted to standard non-repetitive sequences, SpCas9-HF1 rendered all or nearly all off-target events undetectable by genome-wide break capture and targeted sequencing methods. Even for atypical, repetitive target sites, the vast majority of off-target mutations induced by wild-type SpCas9 were not detected with SpCas9-HF1. With its exceptional precision, SpCas9-HF1 provides an alternative to wild-type SpCas9 for research and therapeutic applications. More broadly, our results suggest a general strategy for optimizing genome-wide specificities of other CRISPR-RNA-guided nucleases.[/quote]
News articles:
Enzyme tweak boosts precision of CRISPR genome edits [URL]http://www.nature.com/news/enzyme-tweak-boosts-precision-of-[URL='https://www.physicsforums.com/insights/dont-fear-crispr-new-gene-editing-technologies-wont-lead-designer-babies/']crispr[/URL]-genome-edits-1.19114[/URL]
Improved Version Of CRISPR Gene Editing Tool Eliminates Errors [URL]http://www.popsci.com/new-form-[URL='https://www.physicsforums.com/insights/dont-fear-crispr-new-gene-editing-technologies-wont-lead-designer-babies/']crispr[/URL]-is-more-precise[/URL]
The work seems complementary to the work published by the Zhang lab (mentioned in https://www.physicsforums.com/threads/dont-fear-the-https://www.physicsforums.com/insights/dont-fear-crispr-new-gene-editing-technologies-wont-lead-designer-babies/-comments.811056/page-2#post-5305836), so the different modifications can probably be combined to engineer an even more precise enzyme.