Abstract: Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) regulates mRNA transcription and translation by binding to the target mRNA coding region, and it plays important roles in the processes of cell polarization, movement, morphogenesis, metabolism, proliferation and differentiation. Due to the lack of available mutant models in mammals, this study used CRISPR/Cas9 technology to construct igf2bp3 gene zebrafish mutants. By microinjecting two gRNA and Cas9 proteins into the single cell stage of zebrafish embryos, PCR and Sanger sequencing confirmed that the igf2bp3 gene knockout strain with a deletion of 1 513 bp was successfully constructed. Fluorescence quantitative PCR results showed that the igf2bp3 gene was expressed in all tissues examined of wild-type adult zebrafish, but the highest expression tissue was ovary, the number of males in homozygous zebrafish and wild-type zebrafish was significantly more than that of females, and the proportion of males and females was close to 0.1, indicating that the igf2bp3 gene might play a role in zebrafish gonad development. The result would lay a foundation for studying the sex-determining genes of zebrafish, and provided new ideas for obtaining fast-growing male fish in the fish farming industry.

Key words: zebrafish; igf2bp3, CRISPR/Cas9, sex determination