5'-Modifications improve potency and efficacy of DNA donors for precision genome editing

Elife. 2021 Oct 19:10:e72216. doi: 10.7554/eLife.72216.


Nuclease-directed genome editing is a powerful tool for investigating physiology and has great promise as a therapeutic approach to correct mutations that cause disease. In its most precise form, genome editing can use cellular homology-directed repair (HDR) pathways to insert information from an exogenously supplied DNA-repair template (donor) directly into a targeted genomic location. Unfortunately, particularly for long insertions, toxicity and delivery considerations associated with repair template DNA can limit HDR efficacy. Here, we explore chemical modifications to both double-stranded and single-stranded DNA-repair templates. We describe 5'-terminal modifications, including in its simplest form the incorporation of triethylene glycol (TEG) moieties, that consistently increase the frequency of precision editing in the germlines of three animal models (Caenorhabditis elegans, zebrafish, mice) and in cultured human cells.

Keywords: C. elegans; CRISPR; HDR; biochemistry; chemical biology; chemical modifications; genetics; genome editing; genomics; human; modified donors; mouse; zebrafish.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics*
  • DNA / genetics*
  • DNA Repair*
  • DNA, Single-Stranded / genetics*
  • Gene Editing / methods*
  • HEK293 Cells
  • Humans
  • K562 Cells
  • Mice / genetics*
  • Zebrafish / genetics*


  • DNA, Single-Stranded
  • DNA

Associated data

  • Dryad/10.5061/dryad.f7m0cfxwr