Transcriptional repressor that is an essential upstream regulator of neural crest determination and mesoderm induction. Functions by recruiting the transcriptional corepressor tle4. Also acts in a negative auto-regulator loop by inhibiting the transcription of its own gene. Interacts with tle4. Initially located within the dorsal blastopore lip (Spemann organizer) at the mid-gastrula stage. As expression fades in the neuroectoderm, expression begins in the head mesoderm in two regions at the lateral borders of the presumptive neural plate. These regions correspond to neural crest cells originating from the mesencephalon (anterior) and the rhombencephalon (posterior; rhombomeres 2, 4 and 6). Subsequently expressed within trunk premigratory neural crest cells. Expression disappears when neural crest cells begin to differentiate and migrate, except for those which populate the hyoid arch. Expressed both maternally and zygotically. Maternal expression decreases until the late blastula/early gastrula stage when zygotic expression begins. Expressed at an almost constant level through the subsequent developmental stages. By dorsal wnt signaling. Inhibited by bmp signaling. The C-terminus is required for transcriptional repression and mesoderm induction.