Figure 3.

a) Schematic of the transgenic fish line fluorescent reporter. The gRNA recognizes the start codon region of EGFP, mutates it upon editing, and thus abolishes expression of the fluorescent protein. b) Representative micrographs of zebrafish at 48 hpf. Non-injected embryos demonstrate strong EGFP expression, while Cas9 RNP-injected embryos show drastically less EGFP expression (scale bars = 300 μm). c) Phenotype frequencies of the injected embryos at 48 hpf are shown. Editing ability is blocked in caged EGFP-4U gRNA until irradiation with 365 nm light at 1 hpf, indicating optical control of gene editing in embryos.