Enables transcription corepressor activity. Acts upstream of or within cartilage development; inner ear development; and neural crest formation. Located in cytoplasm and nucleus. Is expressed in appendage; ectoderm; genital system; musculoskeletal system; and visual system. Human ortholog(s) of this gene implicated in campomelic dysplasia; lung cancer; and lung carcinoma. Orthologous to human SOX9 (SRY-box transcription factor 9).