Fig. 4. Differentiation of biliary epithelial cells (BEC) in control and Hnf6–/– fetuses. (A-D) CK-positive cells and portal mesenchyme express laminin as detected by immunohistochemistry in control and in Hnf6–/– fetuses at E15.5. In Hnf6–/– fetuses, laminin (arrowheads in D) is found at the basal pole of the BEC surrounding the lumen (asterisks in B,D) of duct-like structures. (A,C) and (B,D) show adjacent sections. (E,F) Double immunofluorescence for CK (green) and for the proliferation marker Ki-67 (red) on liver sections. These were analyzed when the number of CK-positive cells was high enough, i.e. at E14.5 in control fetuses and at E13.5 in Hnf6–/– fetuses. Both in control (E) and in Hnf6–/– (F) livers, the CK-positive cells do not express Ki-67, which is detected in CK-negative cells (arrowheads). dp, ductal plate; m, portal mesenchyme; p, liver parenchyma; pv, portal vein. Scale bars: 50 µm in A,E.
