Enables DNA-binding transcription repressor activity, RNA polymerase II-specific and RNA polymerase II transcription regulatory region sequence-specific DNA binding activity. Involved in negative regulation of transcription by RNA polymerase II. Acts upstream of or within cell development; floor plate development; and regulation of neurogenesis. Located in nucleus. Is expressed in several structures, including central nervous system; eye; future midbrain; genitourinary system; and liver. Orthologous to human FERD3L (Fer3 like bHLH transcription factor). [provided by Alliance of Genome Resources, Apr 2022]