Transcriptional activator. At the 3-somite stage, expressed in the forebrain. At the 12-somite stage, strongly expressed in the forebrain and weakly expressed throughout the central nervous system. At the 25-somite stage, also expressed in the lens. Expressed zygotically. First detected at the tail bud stage and continues to be expressed for at least the first 48 hours of development. The 9aaTAD motif is a transactivation domain present in a large number of yeast and animal transcription factors.