Fig. 1

Zebrafish gdf5 knockout generated with CRISPR/Cas9. (A) To-scale schematic of the two-exon gdf5 gene locus on chromosome 6, with the 4267 bp intron truncated. White boxes represent the 5′ and 3′ UTRs, the dark grey box represents the sequence coding for the 22 aa signal peptide, the light grey boxes represent the sequences coding for the rest of the prodomain (334 aa), and the black box represents the sequence coding for the 118 aa mature domain. “CS” indicates the position of the 5 aa cleavage site. The sequence of the zoomed in section of exon 2 shows the alignment between the wild-type and mutant (uu3703) alleles. The mutant allele has a 5-base deletion that results in a frameshift and a premature stop codon highlighted in red. (B) Wild-type, heterozygous gdf5^+/uu3703, and homozygous gdf5^{uu3703/uu3703} fish were identified by fragment length analysis. The wild-type displayed one peak (246.18), gdf5^+/uu3703 displayed one wild-type peak (246.08) and one mutant peak (241.18), and gdf5^{uu3703/uu3703} displayed one mutant peak (241.35). (C) At 60 dpf there is no outward phenotypic difference between gdf5^{uu3703/uu3703} and wild-type (caudal fins were clipped for genotyping). Scale bars: 5 mm