Hepatic parenchyma, biliary ducts and gall bladder forming potency in the hepatic primordium in the quail embryo.

Differentiation potency of the hepatic primordium isolated from 21- to 35-somite stage quail embryos was examined by the transplantation in the coelomic cavity of the chick embryo. The hepatic primordium differentiates into hepatic parenchyma, intra- and extrahepatic bile ducts, and gall bladder. The hepatic parenchyma and two types of biliary ducts can differentiate from any fragment of the hepatic primordium divided at craniocaudal or proximodistal levels, while the gall bladder develops mainly from the proximal area of the primordium. These results indicate that the presumptive areas of hepatic parenchyma and biliary ducts are not arranged in a mosaic way in the young primordium, whereas the presumptive area of the gall bladder is restricted. Isolated hepatic primordial endoderm was found to differentiate to the epithelia of the hepatic parenchyma, bile ducts, and gall bladder under the influence of heterologous mesenchyme.