Fig. 4

Establishment of the sws1/sws2/lws triple mutant (i.e., the RH2 monochromat). a Genomic structure of the SWS2 (blue) and LWS (red) loci. Each locus consists of two paralogous genes (a and b). The arrows and colored boxes indicate the directions of transcription and the translated regions, respectively. The scissors indicate the approximate positions of the target sequences for CRISPR/Cas9 [2, 4, 5]. b Induction of the lws mutations in the sws2 mutant. Top: Production of mosaic mutants (G₀) by microinjection. We obtained four G₀ adults that had the ins/del mutations in the caudal fin. Bottom: Transmission of mutations from the G₀ fish to their offspring (F₁). The asterisk indicates that all four F₁ fish inherited identical mutations; 2- or 1-base deletions in the LWSa and LWSb genes, respectively. c Production of the triple mutant by crossing. The sws2^+1a+14b/lws^−2a−1b double mutant was crossed with the sws1⁻¹⁰ mutant, and their offspring (sws1⁻¹⁰/sws2^+1a+14b/lws^−2a−1b triple heterozygotes) were intercrossed. The genotypes of the mature offspring (F₂) are summarized in the table