Transcription factor which acts as a transcriptional repressor (By similarity). May also function as a transcriptional activator (By similarity). Binds to the palindromic T site 5'-TTCACACCTAGGTGTGAA-3' DNA sequence, or a half-site, which are present in the regulatory region of several genes (By similarity). Binds DNA as a monomer. First detected in the ventral mesodermal cells just above the yolk plug at late gastrula. At the neurula stage, strongly expressed in the cement gland, dorsal root ganglia and otic vesicle region. At the tailbud stage, a strong expression is observed in the dorsal part of the optic cup and trigeminal ganglia, and it is also expressed in the branchial arches, heart anlage, nasal pit, proctodeum and the region around the pronephros. Repression domain 1 (RD1) is involved in transcriptional repression.