Fig 1

(A) To-scale schematic of the two-exon zebrafish nkx3.2 gene locus on chromosome 14. Grey boxes represent the coding sequence, the black box labelled “HD” marks the location of the homeodomain-coding sequence in the second exon, and the white box marks the 1,226bp 3’ UTR, truncated for illustrative purposes. gRNA target site is marked by turquoise background. The sequence of the zoomed in section of exon 1 shows the alignment between the wild-type and mutant (uu2803) alleles. The mutant allele has a 7 base-pair deletion that results in a frameshift and a premature stop codon (highlighted in red) immediately after the deletion site. (B) Wild-type, heterozygous nkx3.2^uu2803/+ and homozygous nkx3.2^{uu2803/uu2803} fish were genotyped by fragment length analysis. The wild-type displayed one peak (297,15), nkx3.2^uu2803/+ fish one wild-type (297,12) and one mutant (290,86) peak and nkx3.2^{uu2803/uu2803} fish one mutant peak (290,53). (C) nkx3.2^{uu2803/uu2803} fish at 90 dpf display a prominent fixed open mouth phenotype compared to wild-type at 90 dpf. Scale bars: 1 cm.