Fig. 3

Establishment of her6 mutant lines by genome editing. A. Mutation introduced into the her6 gene by genome editing. Indels were introduced into the bHLH domains by the CRISPR/Cas9 method. The target base sequence (red) and corresponding amino acid sequence are shown above the schematic diagram of the gene product. PAM sequences are underlined. Wild-type and nonsense coding sequences due to frameshifts are shown with gray and white boxes, except for bHLH domains and Orange domains that are shown with blue and orange boxes, respectively. In the mutant line obtained, a frameshift occurred in the N-terminal portion of the bHLH domain due to a 5-bp deletion. B. Morphology of the heads of her6 mutants at 24 hpf. The heads of live embryos obtained by heterozygotic cross (her6+/Δ5) were photographed and then genotyped. Upper row, lateral views with anterior to the left and dorsal to the top. Lower row, dorsal views with anterior to the left. Isthmus regions are shown with arrowheads. Homozygotes alone showed deformed (asymmetric) isthmus (white arrowheads). Numbers of the embryos with the indicated morphology and total scored embryos are shown in the bottom left. Scale bar, 200 μm.