Zebrafish developmental genetics and central nervous system development

The central nervous system (CNS) is the most complex tissue of vertebrates. Recently, the zebrafish has emerged as a powerful genetic system for study ing early development, and large-scale mutagenic screens for embryonic patt erning defects have been accomplished. Mutants isolated in these screens ar e proving helpful in unravelling the molecular hierarchies involved in the development of the CNS. We review here recent studies in zebrafish which sh ed light on the genetic pathways involved in induction and regionalization of the CNS.