title: Distribution of acid phosphatase in chick Hensen's node.
abstract: Acid phosphatase distribution and yolk drop ultrastructure in Hensen's node of chick blastoderm at Hamburger-Hamilton stages 3 and 4 are described. At stage 3 large deposits of the reaction product are localised in type-A yolk drops, where signs of intensive degradation are seen. It seems that during this degradation lipid droplets are being formed in the degrading yolk drops. Partly digested yolk drops with a vesicular appearance are extruded from the cells, especially in deeper layers of the node. The phosphatase reaction product is also distributed into intercellular spaces. At stage 4 the cells of the node are more vacuolated and contain acid phosphatase and electron-dense yolk drops in lesser amounts. The possible physiological role of acid phosphatase in Hensen's node during gastrulation is discussed.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism*; D000818:Animals; D001756:Blastoderm / Q000201:enzymology / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure
chemical_list: D000135:Acid Phosphatase