title: Morphology, histochemistry and glycosylation of the placenta and associated tissues in the European hedgehog (Erinaceus europaeus).
abstract: There are few descriptions of the placenta and associated tissues of the European hedgehog (Erinaceus europaeus) and here we present findings on a near-term pregnant specimen.
  
  
  
  Tissues were examined grossly and then formalin fixed and wax-embedded for histology and immunocytochemistry (cytokeratin) and resin embedded for lectin histochemistry.
  
  
  
  Each of four well-developed and near term hoglets displayed a discoid, haemochorial placenta with typical labyrinth and spongy zones. In addition there was a paraplacenta incorporating Reichert's membrane and a largely detached yolk sac. The trophoblast of the placenta contained diverse populations of granule which expressed most classes of glycan. Intercellular membranes were also glycosylated and this tended to be heavier in the labyrinth zone. Fetal capillary endothelium had glycosylated apical surfaces expressing sialic acid and various other glycans. Glycogen was present in large cells situated between the spongy zone and the endometrium. Trophoblast cells in the placental disc and under Reichert's membrane, as well as yolk sac endoderm and mesothelium, were cytokeratin positive. Reichert's membrane was heavily glycosylated. Yolk sac inner and outer endoderm expressed similar glycans except for N-acetylgalactosamine residues in endodermal acini.
  
  
  
  New features of near-term hedgehog placenta and associated tissues are presented, including their glycosylation, and novel yolk sac acinar structures are described. The trophoblast of the placental disc showed significant differences from that underlying Reichert's membrane while the glycan composition of the membrane itself showed some similarity to that of rat thereby implying a degree of biochemical conservation of this structure.
authors.affiliation: Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, Oxford Road, Manchester M13 9WL, UK. Electronic address: carolyn.jones@manchester.ac.uk.
authors.forename: Carolyn J P
authors.initials: CJ
authors.lastname: Jones
authors.affiliation: Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark.
authors.forename: A M
authors.initials: AM
authors.lastname: Carter
authors.affiliation: The Paul Mellon Laboratory, "Brunswick", 18 Woodditton Road, Newmarket, Suffolk CB8 9BJ, UK.
authors.forename: W R
authors.initials: WR
authors.lastname: Allen
authors.affiliation: The Paul Mellon Laboratory, "Brunswick", 18 Woodditton Road, Newmarket, Suffolk CB8 9BJ, UK.
authors.forename: Sandra A
authors.initials: SA
authors.lastname: Wilsher
mesh_terms: D000818:Animals; D005260:Female; D006031:Glycosylation; D006364:Hedgehogs; D007633:Keratins / Q000378:metabolism*; D037102:Lectins / Q000378:metabolism*; D010920:Placenta / Q000033:anatomy & histology* / Q000378:metabolism; D011247:Pregnancy; D014327:Trophoblasts / Q000166:cytology* / Q000378:metabolism; D015017:Yolk Sac / Q000033:anatomy & histology* / Q000378:metabolism
chemical_list: D037102:Lectins; D007633:Keratins
keywords: Cytokeratin; Histology; Lectins; Placenta; Reichert's membrane; Yolk sac