Figure 7—figure supplement 1.

(A) RT-PCR for thraa, thrab, and thrb in xanthophores and melanophores sorted by FACS for aox5:palmEGFP and tyrp1b:palm-mCherry, respectively. (B) Sanger sequencing of CRISPR/Cas9-induced mutant allele of thrab revealed a 13 bp deletion. (C) Schematic of Thrab wild-type and mutant proteins illustrating introduction of a novel amino acid followed by a premature stop codon at position 73. DBD, DNA-binding domain; LBD, ligand binding domain. (D) Additional CRISPR/Cas9 mutant alleles for thraa and thrb had phenotypes indistinguishable from wild-type or thrab (Figure 7A). (E) Xanthophore color phenotypes of euthyroid and hypothyroid wild-type fish, and rescue of xanthophore color in hypothyroid fish upon TR mutation (thrab thraa thrb*). (F) HPLC revealed persisting carotenoids in hypothyroid fish mutant for thrab (boxed region), in contrast to the absence of detectable carotenoids in hypothyroid fish that were wild-type for thrab (Figure 6D). (G) Stage of first xanthophore appearance did not differ significantly (p=0.7) between euthyroid fish that were heterozygous or homozygous wild-type for thrab mutation.