title: Complex-type glycoproteins synthesized in the subcommissural organ of mammals. Light- and electron-microscopic investigations by use of lectins.
abstract: The secretory activity in the subcommissural organ (SCO) of the sheep and cow was examined by means of lectin histochemistry and cytochemistry. Among the various lectins tested. Concanavalin A (Con A) revealed glycoproteins rich in mannosyl residues in the rough endoplasmic reticulum of ependymal and hypendymal cells. One of these Con A-positive glycoproteins may represent the precursor of the specific secretory component elaborated in the SCO, giving rise to Reissner's fiber. Lens culinaris agglutinin (LCA) and Phaseolus vulgaris hemagglutinins (E-PHA and L-PHA), known to bind to oligosaccharides, as well as wheat-germ agglutinin (WGA) revealing neuraminic acid, labeled secretory granules located in the apical part of ependymal and hypendymal cells of ruminants, and also Reissner's fiber. Electron-microscopic visualization of WGA-positive material in the Golgi complex shows that complex-type glycoproteins are synthesized in the subcommissural organ of mammals. The electron-dense material is mainly secreted into the ventricular cavity and gives rise to Reissner's fiber. On the basis of lectin affinity for oligosaccharides, a structure of the complex-type oligosaccharide is proposed.
authors.affiliation: Laboratoire de Biologie animale et UA CNRS 677, Université Blaise Pascal, Clermont-Ferrand, France.
authors.forename: A
authors.initials: A
authors.lastname: Meiniel
authors.forename: J L
authors.initials: JL
authors.lastname: Molat
authors.forename: R
authors.initials: R
authors.lastname: Meiniel
mesh_terms: D000818:Animals; D002417:Cattle; D003208:Concanavalin A; D006023:Glycoproteins / Q000378:metabolism* / Q000502:physiology; D006651:Histocytochemistry; D008854:Microscopy, Electron; D009490:Neurosecretory Systems / Q000378:metabolism*; D010835:Phytohemagglutinins; D012756:Sheep; D013351:Subcommissural Organ / Q000196:embryology / Q000378:metabolism* / Q000648:ultrastructure; D014909:Wheat Germ Agglutinins
chemical_list: D006023:Glycoproteins; D010835:Phytohemagglutinins; D014909:Wheat Germ Agglutinins; D003208:Concanavalin A