Fig. 4: Identification of compound AZD7648 as a regulator in shifting DSBs repair pattern from NHEJ to MMEJ.

A Workflow of compound screening in embryo gene editing and DNA repair pattern analysis. Zygote, blastocyst, and sequencing icons were created with BioRender (Created in BioRender. Hongyu, C. (2025) https://BioRender.com/qxdvotz), and other elements were designed by the authors. B Heatmap showing NHEJ/MMEJ (N/M) ratios in edited blastocysts treated with various compounds at different sgRNA sites. C Distribution of DNA repair outcomes (WT, NHEJ, MMEJ) under DMSO, Farrerol, or AZD7648 treatment. D Blastocyst development efficiency following compound treatment. E HDR frequencies in individual knock-in embryos at Sod1-A4 and Sod1-G93 loci using different sgRNAs under DMSO or AZD7648 treatment. Each dot represents one embryo; red dashed lines indicate group means. n/N indicates HDR-positive over total injected embryos. Data are from three independent experiments. F Summary of DNA repair pattern distribution (HDR, random indels, WT) for each sgRNA, based on embryos analyzed in (E). G Representative fluorescence images and quantification of mCherry-positive blastocysts following dsDNA-mediated knock-in. White arrows indicate mCherry-positive blastocysts. Scale bars, 100μm. Bar graphs show mean ± SEM (n = 3 experiments, > 20 embryos per group). Statistical significance was determined using two-sided Mann–Whitney U test (E) and unpaired two-sided t-test (G). p-value are indicated in the figure. Source data are provided as a Source Data file.