Efficient multinucleotide deletions using deaminase-Cas9 fusions in human cells

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• The CRISPR/Cas9 system is a powerful tool for genome editing.
• Conventional CRISPR/Cas9 primarily induces small insertions/deletions (indels).
• Larger, targeted deletions are challenging to achieve with standard CRISPR/Cas9.

Purpose of the Study:

• To develop novel CRISPR/Cas9-based systems for efficient induction of larger deletions.
• To engineer fusion proteins combining Cas9 with deaminases for enhanced deletion efficiency.
• To evaluate the efficacy of these new systems in human cells.

Main Methods:

• Constructed cytidine deaminase-Cas9 (C-DEL) and adenine deaminase-Cas9 (A-DEL) fusion systems.
• Utilized rat APOBEC1 (rA1) and TadA 8e with Cas9, respectively.
• Assessed deletion efficiency and characteristics in human cells.

Main Results:

• Both C-DEL and A-DEL systems demonstrated improved deletion efficiency compared to wild-type Cas9.
• The C-DEL system produced predictable multinucleotide deletions.
• A significant increase in larger deletions at target loci was observed with C-DEL and A-DEL.

Conclusions:

• C-DEL and A-DEL systems offer a practical strategy for generating efficient multinucleotide deletions.
• These novel systems expand the CRISPR/Cas9 toolkit for gene modification applications.
• The developed systems enhance the precision and scope of CRISPR-mediated genome editing.