CRISPR/Cas9-induced nos2b mutant zebrafish display behavioral abnormalities.

The immunomodulatory function of nitric oxide synthase (NOS2) has been extensively studied. However, some behavioral abnormalities caused by its mutations have been found in a few rodent studies, of which the molecular mechanism remains elusive. In this research, we generated nos2b gene knockout zebrafish (nos2b ) using CRISPR/Cas9 approach and investigated their behavioral and molecular changes by doing a series of behavioral detections, morphological measurements, and molecular analyses. We found that, compared with nos2b zebrafish, nos2b zebrafish exhibited enhanced motor activity; additionally, nos2b zebrafish were characterized by smaller brain size, abnormal structure of optic tectum, reduced mRNA level of presynaptic synaptophysin and postsynaptic homer1, and altered response to sodium nitroprusside/methylphenidate hydrochloride treatment. These findings will likely contribute to future studies of behavioral regulation.