May function as a switch in neuronal development (By similarity). Acts as a negative regulator of transcription. Plays a role in dorsoventral patterning of the embryo. Expressed in all cells until gastrulation, becoming restricted to the developing central nervous system later, where expression is in the forebrain, midbrain and hindbrain but maximally at the midbrain-hindbrain boundary. Expressed both maternally and zygotically. Expressed in oocytes and throughout embryogenesis, whereas expression in adults is undetectable. Ventralized embryos.