Behavioral genetic approaches to visual system development and function in zebrafish.

The zebrafish is a recent vertebrate model system that shows great potential for a genetic analysis of behavior. Early development is extraordinarily rapid, so that larvae already display a range of behaviors 5 days after fertilization. In particular the visual system develops precociously, supporting a number of visually mediated behaviors in the larva. This provides the opportunity to use these visually mediated behaviors to screen chemically mutagenized strains for defects in vision. Larval optokinetic and optomotor responses have already been successfully employed to screen for mutant strains with defects in the visual system. In the adult zebrafish a visually mediated escape response has proved useful for screening for dominant mutations of the visual system. Here, I summarize visually mediated behaviors of both larval and adult zebrafish and their applicability for genetic screens, and present, the approaches and results of visual behavior carried out to date.