Crk adaptor proteins are necessary for the development of the zebrafish retina

Background The development of the central nervous system (CNS) requires critical cell signaling molecules to coordinate cell proliferation and migration in order to structure the adult tissue. Chicken tumor virus #10 Regulator of Kinase (CRK) and CRK‐like (CRKL) are adaptor proteins with pre‐metazoan ancestry and are known to be required for patterning laminated structures downstream of Reelin (RELN), such as the cerebral cortex, cerebellum, and hippocampus. CRK and CRKL also play crucial roles in a variety of other growth factor and extracellular matrix signaling cascades. The neuronal retina is another highly laminated structure within the CNS that is dependent on migration for proper development, but the cell signaling mechanisms behind neuronal positioning in the retina are only partly understood. Results We find that crk and crkl have largely overlapping expression within the developing zebrafish nervous system. We find that their disruption results in smaller eye size and loss of retinal lamination. Conclusions Our data indicate that Crk adaptors are critical for proper development of the zebrafish neural retina in a crk/crkl dose‐dependent manner. Key Findings Crk adaptors are expressed in the developing zebrafish nervous system. Loss of crk and crkl via CRISPR/Cas9 in zebrafish leads to brain edema, heart edema, shorter body axis, and small eye size. crk and crkl mutant zebrafish have retinal lamination defects.