PT - JOURNAL ARTICLE AU - Krishna S. Ghanta AU - Gregoriy A. Dokshin AU - Aamir Mir AU - Pranathi Meda Krishnamurthy AU - Hassan Gneid AU - Alireza Edraki AU - Jonathan K. Watts AU - Erik J. Sontheimer AU - Craig C. Mello TI - 5′ Modifications Improve Potency and Efficacy of DNA Donors for Precision Genome Editing AID - 10.1101/354480 DP - 2018 Jan 01 TA - bioRxiv PG - 354480 4099 - http://biorxiv.org/content/early/2018/06/22/354480.short 4100 - http://biorxiv.org/content/early/2018/06/22/354480.full AB - Nuclease-directed genome editing is a powerful tool for investigating physiology and has great promise as a therapeutic approach that directly addresses the underlying genetic basis of 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 the number of donor molecules available to the HDR machinery, thus limiting HDR efficacy. Here, we explore modifications to both double-stranded and single-stranded repair template DNAs and describe simple 5′ end modifications that consistently and dramatically increase donor potency and HDR efficacy across cell types and species.