(A) Schematic diagram of the Foxl2l protein showing the DNA-binding forkhead homology domain (blue), the location of the nuclear localization signal (NLS), and the viral-2A-egfp insertion site in the foxl2l(uc91) allele. (B) GFP expression in germ cells from a foxl2l(uc91) knock-in allele heterozygote recapitulates endogenous foxl2l expression (compare to Figure 2E and F). (C) Sex ratios of foxl2l(uc91) heterozygotes and homozygotes. (D–F) Representative light micrographs of fish examined in (C) (n = 274, N = 4, *p=1 × 10–7, **p=2 × 10–7). Wild-type adult female zebrafish (D) has characteristic light-yellow pigmentation on ventral belly and a prominent anal papilla (highlighted with red dashed lines) (D’). (E) Wild-type adult male zebrafish (E) has dark yellow pigmentation on ventral belly and lacks an anal papilla (highlighted with red dashed lines) (E’). foxl2l(uc91) homozygous mutant (F) is phenotypically male. IB, stage IB oocyte.
