Transcriptional repressor (By similarity). Controls the convergence and extension movements of medial neural plate precursors during gastrulation. Expression is initiated at the late blastula stage in the presumptive dorsal marginal zone, prior to blastopore lip formation. At the onset of gastrulation, expressed in the superficial layer of cells in the dorsal blastopore lip (Spemann organizer). In the open neural plate, expressed dynamically in a row of cells along the dorsal midline that are destined to become the floor plate of the neural tube. Only weakly expressed in the posterior region of the newly forming notochord. After neural tube closure, expression is detected only in the tailtip and a small area located at the midbrain/hindbrain boundary. Expressed both maternally and zygotically. Maternal expression levels are low and become further reduced after fertilization. Zygotic expression begins at the mid-blastula transition and peaks during the gastrula/neurula stages before declining again by stage 34. By FGF-signaling. Inhibited by bmp-signaling.