CRISPR guide RNAs with guardrails, bacterial sensors for pathogen detection and more

Kyushu University and Nagoya University researchers reported in Nature Biomedical Engineering a “safeguard gRNA” strategy to improve the on-target specificity of gene editing by adding cytosine stretches to the 5′-end of conventional guide RNAs, which limit the formation of Cas9-gRNA complexes in a length-dependent manner.

The team used its allele-specific indel monitor system (AIMS), which enables rapid, real-time quantification of allele-editing patterns without sequencing analysis, to monitor the effects of cytosine stretches on unwanted insertions and deletions, and establish optimal cytosine-extended constructs for a range of applications, including bi-allelic editing, mono-allelic editing and correction of disease-associated mutations via homology-directed repair (HDR)...