Enables RNA polymerase II transcription regulatory region sequence-specific DNA binding activity. Involved in negative regulation of transcription, DNA-templated. Acts upstream of or within several processes, including negative regulation of transcription by RNA polymerase II; post-anal tail morphogenesis; and somitogenesis. Predicted to be active in nucleus. Is expressed in several structures, including central nervous system; retina; small intestine; unsegmented mesenchyme; and urinary system. Human ortholog(s) of this gene implicated in spondylocostal dysostosis. Orthologous to human HES7 (hes family bHLH transcription factor 7). [provided by Alliance of Genome Resources, Apr 2022]