Rapid genome editing by CRISPR-Cas9-POLD3 fusion

Elife. 2021 Dec 13:10:e75415. doi: 10.7554/eLife.75415.


Precision CRISPR gene editing relies on the cellular homology-directed DNA repair (HDR) to introduce custom DNA sequences to target sites. The HDR editing efficiency varies between cell types and genomic sites, and the sources of this variation are incompletely understood. Here, we have studied the effect of 450 DNA repair protein-Cas9 fusions on CRISPR genome editing outcomes. We find the majority of fusions to improve precision genome editing only modestly in a locus- and cell-type specific manner. We identify Cas9-POLD3 fusion that enhances editing by speeding up the initiation of DNA repair. We conclude that while DNA repair protein fusions to Cas9 can improve HDR CRISPR editing, most need to be optimized to the cell type and genomic site, highlighting the diversity of factors contributing to locus-specific genome editing outcomes.

Keywords: CRISPR-Cas9; cell biology; gene editing; molecular biology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CRISPR-Associated Protein 9 / genetics*
  • CRISPR-Associated Protein 9 / metabolism*
  • CRISPR-Cas Systems / genetics*
  • Cells, Cultured / physiology*
  • DNA Polymerase III / genetics*
  • DNA Polymerase III / metabolism*
  • DNA Repair / genetics
  • DNA Repair / physiology
  • Gene Editing / methods*
  • Humans


  • DNA Polymerase III
  • CRISPR-Associated Protein 9

Associated data

  • SRA/SRP050338

Grants and funding

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.