Biosciences Research Seminar - Building an Organ: Cell-Cell Communication and Unconventional Protrusions

The many essential functions of the liver are mediated by its characteristic tissue architecture. Hepatocytes exhibit a distinct apico-basal polarity, aligning with their basal side along blood vessels, while canaliculi form apically and connect hepatocytes to the terminal branches of the biliary network. How liver progenitors self-organize in vivo to establish the functional 3D tissue organization during development is poorly understood. The Ober group employs the transparency of zebrafish embryos and live-imaging to capture the cell behaviours and tissue interactions driving this transition in vivo. 4D-imaging shows that differentiating hepatocytes are surprisingly dynamic and undergo a sequence of distinct cellular events essential for hepatocytes to polarize and subsequently to connect to biliary ducts. Their studies reveal novel modes of cell-cell communication between different hepatic cell types, employing unconventional cell protrusions, are at the center of establishing a functional hepato-biliary ductal network.