Fig 1. Loss of igf2bp3 results in skewed male:female sex ratios.

A. Generation of the igf2bp3 mutant allele by Cas9. Schematic showing the igf2bp3 locus on chromosome 19. Exon 1 of igf2bp3 was targeted by CRISPR-Cas9, resulting in a 7 bp deletion and frameshift. B. Schematic of the igf2bp3^la659Tg with a 6 kb Tg(nLacZ-GTvirus) retroviral insertion in intron 1. C. The igf2bp3^Δ7 mutant is predicted to be protein null. The igf2bp3^Δ7 mutation generates a premature stop codon at residue 46 whereas the igf2bp3^la659Tg results in a predicted truncated protein of 65 amino acids. D. Loss of igf2bp3 results in skewed sex ratios. Adult zygotic igf2bp3^Δ7 and MZigf2bp3^la659Tg mutant fish show a significant male bias compared to wild type, heterozygous igf2bp3^Δ7 as well as igf2bp3^la659Tg, and Zigf2bp3^la659Tg fish. Asterisks indicate level of significance (p *<0.05, **<0.01, ***<0.001). E. The igf2bp3^Δ7 mutation results in reduced igf2bp3 levels. qRT-PCRs at the 1-cell and 4-cell stages show significantly reduced igf2bp3 transcript levels in igf2bp3^Δ7 mutant embryos (p<0.001).