Supplementary Figure 1: One-step generation of mouse models carrying point mutations via direct injection of BE3 into zygotes.

a, The target sequence in Tyr exon 1. The target sequence is underlined. The PAM sequence and the intended base mutation are shown in blue and red, respectively. b, A mutant mouse (Tyr-7, 2-weeks old, right) produced by intracytoplasmic injection of BE3 mRNA and Tyr sgRNA. c, Genotyping analysis of the mutant mouse in (b) showing a base mutation in Tyr, leading to the replacement of Arginine by a termination codon. d, Progeny with the mutant parents carrying TYR^{R223stop/R223stop}. All 24 pups exhibit an albino phenotype. e, The target sequence in Dnd1 exon 2. The target sequence is underlined. The PAM sequence and the expected base mutation are shown in blue and red, respectively. f, The representative images of WT and mutant (Dnd1-15) gonads carrying an Oct4-EGFP transgene (E12.5). Left, bright-field image of the gonads. Right, the same gonads under fluorescent illumination. Two independent mutants were analyzed. Scale bar, 200 μm. g, Genotyping analysis of the mutant gonad in (f) showing a base mutation in Dnd1, leading to the replacement of Glutamine by a termination codon. h, Summary of base editing efficiency in embryos or mice generated through direct injection of BE3 mRNA and Tyr sgRNA or Dnd1 sgRNA into zygotes. i, An adult mouse (9-weeks old) carrying a point mutation in Dnd1 and its testis. Scale bar, 1.0 mm. j, Histological analysis of the Dnd1 mutant testis shown in i. No germ cells in seminiferous tubules. Scale bar, 100 μm. k, Histological analysis of the ovary from one adult Dnd1 mutant mouse, indicating no germ cells. Scale bar, 100 μm. Two independent mutants were analyzed for each group in i-k.