title: Secretory cells in honeybee hypopharyngeal gland: polarized organization and age-dependent dynamics of plasma membrane.
abstract: The honeybee hypopharyngeal gland consists in numerous units, each comprising a secretory cell and a canal cell. The secretory cell discharges its products into a convoluted tubular membrane system, the canaliculus, which is surrounded at regular intervals by rings of actin filaments. Using probes for various membrane components, we analyze the organization of the secretory cells relative to the apicobasal configuration of epithelial cells. The canaliculus was defined by labeling with an antibody against phosphorylated ezrin/radixin/moesin (pERM), a marker protein for the apical membrane domain of epithelial cells. Anti-phosphotyrosine visualizes the canalicular system, possibly by staining the microvillar tips. The open end of the canaliculus leads to a region in which the secretory cell is attached to the canal cell by adherens and septate junctions. The remaining plasma membrane stains for Na,K-ATPase and spectrin and represents the basolateral domain. We also used fluorophore-tagged phalloidin, anti-phosphotyrosine and anti-pERM as probes for the canaliculus in order to describe fine-structural changes in the organization of the canalicular system during the adult life cycle. These probes in conjunction with fluorescence microscopy allow the fast and detailed three-dimensional analysis of the canalicular membrane system and its structural changes in a developmental mode or in response to environmental factors.
authors.affiliation: Institute of Biochemistry and Biology, Department of Animal Physiology, University of Potsdam, Karl-Liebknecht-Strasse 24/25, 14476, Potsdam, Germany.|Department of Neuro- and Sensory Physiology, University of Göttingen Medical Center, 37073, Göttingen, Germany.
authors.forename: Katharina Natalia
authors.initials: KN
authors.lastname: Richter
authors.affiliation: Institute of Biochemistry and Biology, Department of Animal Physiology, University of Potsdam, Karl-Liebknecht-Strasse 24/25, 14476, Potsdam, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Rolke
authors.affiliation: Zoological Institute, University of Cologne, 50674, Cologne, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Blenau
authors.affiliation: Institute of Biochemistry and Biology, Department of Animal Physiology, University of Potsdam, Karl-Liebknecht-Strasse 24/25, 14476, Potsdam, Germany. obaumann@uni-potsdam.de.
authors.forename: Otto
authors.initials: O
authors.lastname: Baumann
mesh_terms: D000199:Actins / Q000378:metabolism; D000375:Aging / Q000502:physiology*; D000818:Animals; D001516:Bees / Q000166:cytology*; D015415:Biomarkers / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D016764:Cell Polarity; D007013:Hypopharynx / Q000166:cytology*; D021621:Imaging, Three-Dimensional; D019476:Insect Proteins / Q000378:metabolism; D021962:Membrane Microdomains / Q000378:metabolism; D008954:Models, Biological
chemical_list: D000199:Actins; D015415:Biomarkers; D019476:Insect Proteins
keywords: Actin cytoskeleton; Cell polarity; Honeybee; Hypopharyngeal gland; Moesin