Extended Data Fig. 2. Example of enhancer scoring.

Top: calibration images given for one ultraconserved enhancer (hs111) to show different categories of enhancer activity. Randomized embryo images were shown to five reviewers alongside the calibration images displayed at the top. The reviewers scored the strength of enhancer activity independently and blind to the identity of the enhancer allele. Bottom: breakdown of enhancer activity scoring results per embryo for four different alleles tested for the hs111 enhancer: reference allele, allele with 5% of bp mutated #1, allele with 5% of bp mutated #2, and allele with 20% of bp mutated. See Supplementary Information for a similar scoring breakdown of all 23 ultraconserved enhancers selected for mutagenesis.