title: Glycoconjugates of the avian eye: the development and maturation of the neural retina as visualized by lectin binding.
abstract: The distribution of binding sites for four rhodamine-conjugated lectins has been examined in paraffin-embedded tissue sections of the developing and mature avian neural retina. The method of fixation employed here (95% ethanol:glacial acetic acid) is shown to conserve substantially more in vivo labeled 3H-glycoprotein or 3H-ganglioside than fixation with either 3.7% formaldehyde or 2% glutaraldehyde. Each lectin was shown to be optimally active by direct hemagglutination and inhibitable by the appropriate hapten in the cytochemical assay. Staining with wheat germ agglutinin (leads to N-acetylglucosamine) occurs predominantly to each of the anuclear retinal layers and progressively disappears from each of the nuclear layers. By adulthood, the inner nuclear layer is stained in a gradient which is highest adjacent to the inner nuclear layer while the nuclear layers are virtually unstained. Although similar to wheat germ agglutinin, staining with concanavalin A (leads to mannose) is less intense and persists in the adult nuclear layers. Dolichos biflorus agglutinin (leads to N-acetylgalactosamine) predominantly stains the embryonic ganglion cell layer. With development, this lectin demonstrates profound differences between the major cell types of the inner nuclear layer and the inner (negative) and outer (positive) plexiform layers. Differences between the principal synaptic layers are further accentuated by Ulex europaeus agglutinin I (leads to fucose): Binding sites are virtually absent from the 12th day embryonic retina, but are abundant throughout the retina by the 18th day and persist after hatching. However, in the adult retina staining persists in the outer plexiform layer but is lost from the inner plexiform and nerve fiber layers. In contrast to Dolichos biflorus agglutinin, Ulex europaeus agglutinin I stains the inner nuclear layer uniformly. Temporal differences in the characteristic lectin binding patterns exhibited by each of the major nuclear and anuclear layers of the developing avian neural retina are thus documented.
mesh_terms: D000375:Aging; D000818:Animals; D002642:Chick Embryo; D002645:Chickens; D005732:Gangliosides / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D007700:Kinetics; D009474:Neurons / Q000502:physiology*; D011975:Receptors, Mitogen / Q000378:metabolism*; D012160:Retina / Q000196:embryology / Q000254:growth & development* / Q000276:immunology
chemical_list: D005732:Gangliosides; D006023:Glycoproteins; D011975:Receptors, Mitogen