In situ distribution in different cell types of nuclear glycoconjugates detected by two lectins

Nuclear glycoconjugates were detected in situ by two lectins--Concanavalin A and Wheat germ agglutinin--on tissue sections embedded in the hydrophilic resin glycol methacrylate. These lectins were conjugated with fluorescein isothiocyanate for fluorescence microscopy, and labelled with ferritin for electron microscopy. The ovarian follicle of the lizard Lacerta vivipara was chosen for this study, because it enables four types of nuclei, with different ultrastructures and physiology to be observed on the same section. In this material, all the nucleoli were found to contain a high concentration of receptors for both lectins. The distribution of the receptors located in the chromatin and nucleoli was observed to vary within the same type of nucleus, depending on the lectin used. Some of our results suggest that increased labelling by Wheat germ agglutinin might depend on increased production of ribosomal precursors.