[Lumen morphogenesis and molecular mechanisms in tubular organs during zebrafish embryonic development]

A network tubular system is an important structure in the body and organ of metazoa. The lumen of tube is fundamental units in the structure, which serve to transport material, divide the organ into different functional compartments and separate the organ from the environment. The defects of lumen formation will lead to abnormalities of the organ morphogenesis and disorder of the function. Zebrafish (Danio rerio)is an important model for development research. Meanwhile easy observation of tubular organ, the relevant mutants, and transgene linages make zebrafish to become an excellent model to study the formation of lumen in the tubular organs, including the blood vessels, neural tube, gut, exocrine pancreas, and pronephric duct, which undergo the typical morphogenesis of lumen that is involved in the organs' development. The process of lumen formation is mainly consisted of induction of extracellular signals, polarization of epithelial cell, directional transportation in the polar cells, the aggregation and transportation of fluid in the lumen, and the reconstruction of cytoskeleton in polar cells and controlled by the precise and complicated molecular networks during embryonic development. This review will summarize our current knowledge on lumen morphogenesis in four kinds of typical tubular organs during zebrafish embryonic development and the related molecular mechanisms as well as to supply helpful reference to the future studies.