Igf2bp1 is required for hepatic outgrowth during early liver development in zebrafish.

IGF2BPs, a subclass of RNA-binding proteins, regulate cellular differentiation, proliferation and migration during multiple organs development, but their functions in liver development still remain unclear. Here, in this study, whole-mount in situ hybridization showed that igf2bp1 was constantly and stably expressed at early stages of embryo development in zebrafish. Both the morpholino-induced knockdown and CRISPR/Cas9-mediated knockout of igf2bp1 led to a reduced-size liver phenotype. Further analysis revealed that igf2bp1 is required for hepatic outgrowth, but not for hepatoblast specification and budding. Deficiency of igf2bp1 resulted in reduced cell proliferation, but had no effect on apoptosis. Therefore, we concluded that igf2bp1 is a critical factor to regulate hepatic outgrowth via cell proliferation during early liver development in zebrafish.