Orthogonal Cas9-Cas9 chimeras provide a versatile platform for genome editing

Area of Science:

• Molecular Biology
• Gene Editing Technologies

Background:

• Developing precise and versatile genome editing tools is essential for advancing therapeutic applications.
• Current tools face limitations in targeting range and specificity.

Purpose of the Study:

• To establish RNA-programmable Cas9-Cas9 chimeras as advanced genome engineering systems.
• To evaluate the targeting repertoire, specificity, and efficiency of these novel chimeras.

Main Methods:

• Construction and testing of single- and dual-nuclease Cas9-Cas9 chimera formats.
• Assessment of genome editing activity and specificity at target sites.
• Analysis of deletion product precision at a therapeutically relevant BCL11A enhancer locus.

Main Results:

• Cas9-Cas9 chimeras demonstrated an expanded targeting range and high editing specificity.
• Dual-nuclease chimeras exhibited enhanced target site activity compared to monomeric Cas9.
• Precise deletions between target sites were generated, with up to 97% accuracy at the BCL11A enhancer.

Conclusions:

• Cas9-Cas9 chimeras represent a significant advancement in genome engineering toolsets.
• Their ability to produce precise deletions makes them highly valuable for therapeutic genome editing.
• These systems offer a promising platform for applications requiring defined sequence outcomes.