Detection of binding sites for biotinylated neoglycoproteins and heparin (endogenous lectins) during cerebellar ontogenesis in the rat: an ultrastructural study.
In a previous paper (Kuchler et al., Eur. J. Cell Biol. 52, 87-97 (1990)), endogenous carbohydrate-binding sites were studied at the optical level during rat cerebellar development on sections of fixed tissue using synthetic tools, biotinylated neoglycoproteins, in conjunction with subsequent avidin-peroxidase staining. It was shown that these tools were capable of revealing carbohydrate-binding sites during development of the rat cerebellum. The staining pattern with the individual probes disclosed variable developmental regulation and consequently suggested that recognition processes during cerebellar development may include several types of carbohydrate determinants. However, studies at the light microscope could not give information on potential membrane-bound localization of carbohydrate-binding sites and therefore discern the possible involvement of these molecules in cell adhesion processes. Furthermore, nuclear staining was suggested at the optical level. In order to elucidate these points, we examined the localization of mannose-, fucose- and heparin-binding sites at the electron microscopic level. Ultrastructural studies demonstrate that these tools are very efficient in detecting intracellular carbohydrate-binding sites, but failed to detect most of them expressed at the cell surface when using immunocytochemical techniques for known receptors, probably because of the interaction of these carbohydrate-binding sites with endogenous membrane-bound ligands. The significance of the nuclear staining and of part of the nucleolus found with fucose-containing neoglycoprotein and of the nuclear staining found with heparin are discussed.
Kuchler
S
S
Laboratoire de Neurobiologie Moléculaire des Interactions Cellulaires CNRS UPR 416, Centre de Neurochimie du CNRS, Strasbourg/France.
Zanetta
J P
JP
Vincendon
G
G
Gabius
H J
HJ
D000818:Animals; D001665:Binding Sites / Q000502:physiology; D001710:Biotin; D002448:Cell Adhesion; D002462:Cell Membrane / Q000378:metabolism; D002466:Cell Nucleolus / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002531:Cerebellum / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D005643:Fucose / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006493:Heparin / Q000378:metabolism*; D007150:Immunohistochemistry; D008358:Mannose / Q000378:metabolism*; D051381:Rats
D006023:Glycoproteins; D005643:Fucose; D001710:Biotin; D006493:Heparin; D008358:Mannose