The Tg737 gene encodes a tetratricopeptide repeat containing protein that, when disrupted in TgN737Rpw mutant mice, results in pleiotropic phenotypes that include the proliferation of epithelial cells. In the kidney and liver, this causes a phenotype that resembles autosomal recessive polycystic kidney disease. In the liver, the affected epithelial cells morphologically and immunologically resemble oval cells. Here we describe the isolation, culture, and characterization of epithelial cell lines derived from the livers of wild-type, heterozygous, and homozygous TgN737Rpw mice. Essentially homogeneous celt cultures were established and the expression of liver markers was examined by reverse transcriptase polymerase chain reaction and by immunohistochemistry. All of the celt lines reacted to the A6 antibody that was raised against mouse oval cells and expressed markers seen in oval cells. Cells transplanted into the interscapular fat pads of isogenic mice formed well defined ductular structures. Furthermore, in transfection experiments, we have demonstrated the involvement of Tg737 in cellular proliferation.