Hepatoblasts are bi-potential cells, which differentiate to hepatocytes or biliary epithelial cells (BECs) at approximately E13. At E9.5, the hepatoblasts delaminate from the epithelium and invade the adjacent septum transversum mesenchyme (STM) to form the liver bud. Liver bud hepatoblasts residing adjacent to the portal veins become BECs that will line the lumen of the intrahepatic bile ducts (IHBD), while the majority of hepatoblasts in the parenchyma differentiate into hepatocytes.
In human liver, the earliest hepatoblasts express CK8, 18, and 19. The derived BECs (cholangiocytes) demonstrate higher CK19 expression, while derived hepatocytes lack CK19 expression. CK8 and 18 expression persists in both cell types.
Similarly, CK19 is absent in hepatoblasts and is only detectable in cholangiocytes in mouse and rat liver.
After E16, the percentage of bipotent cells is dramatically reduced, and most of the cells are unipotent and irreversibly committed to either the hepatocytic or cholangiocytic lineage.
Multiple AncestorsSingle AncestorNo DescendantsDevelops fromPart of Parent