SPONTANEOUS FORMATION OF INTERCELLULAR BILE CANALICULI AND HYBRID BILIARY-PANCREATIC CANALICULI IN COCULTURE OF HEPATOCYTES AND EXOCRINE PANCREAS CELLS FROM CARP

When cultured together in a primary serum-free hormone-free system, he patocytes and exocrine pancreas cells from the carp, Cyprinus carpio, spontaneously establish unique morphological structures that do not oc cur in vivo. These structures include intercellular bile canaliculi be tween neighbouring hepatocytes and hybrid canaliculi between hepatocyt es and pancreas cells. In vivo, carp hepatocytes form only unicellular bile canaliculi; hybrid canaliculi between hepatocytes and exocrine p ancreas cells do not exist at all in nature. This study shows that, in an artificial environment, cells are able spontaneously to establish novel morphological structures that are absent in the animal from whic h the cells have been obtained.