Dominant negative regulation of the mouse alpha-fetoprotein gene in adult liver. Transcription of the mouse alpha-fetoprotein gene is activated in the developing fetal liver and gut and repressed in both tissues shortly after birth. With germline transformation in mice, a cis-acting element was identified upstream of the transcription initiation site of the alpha-fetoprotein gene that was responsible for repression of the gene in adult liver. This negative element acts as a repressor in a position-dependent manner. 