a, The C-to-T editing efficiency for the engineered variants at each C of the 21 target sites. n = 21 independent experiments for each group. All values are presented as mean ± s.e.m. The data for BE3 are also used in Fig. 3d. b, SNVs identified in BE3-hA3AY130F and YE1-BE3-FNLS-treated embryos. c, The overlap among SNVs detected from our analysis with predicted off-targets sites by Cas-OFFinder and CRISPOR. d, The distribution of mutation types of DNA off-target SNVs for BE3-hA3AY130F and YE1-BE3-FNLS-treated embryos. e, The distribution of mutation types of RNA off-target SNVs for BE3-hA3AY130F and YE1-BE3-FNLS-treated embryos. f, The expression level of APOBEC1 in BE3 and BE3-FNLS variants. n = 3 biologically independent samples for each group. Box-and-whisker plots: center line indicates median, the bottom and top lines of the box represents the first quartile and third quartile of the values, respectively. The bottom and top of the vertical line represent the minimum and maximum value. g, Editing rate of RNA off-targets for BE3 and BE3-FNLS variants at 36 h post-transfection. n = 3 biological replicates for each group. P value was calculated by two-sided Student’s t-test.