Localization of wheat germ agglutinin receptor sites on yeast cells by scanning electron microscopy

The effects of wheat germ agglutinin on Drosophila embryonic cell lines growing on cover-glasses was examined by scanning electron microscopy. At low concentrations of the lectin (5-10 mug/ml), cells spread against the glass surface and fused to form syncytia. At high concentration, damage to the cell surface was evidenced as extensive membrane shrivelling and loss of surface microfilaments. Fusion also occurred under these conditions. There was some indication that the morphology of cells in division remains undisturbed by wheat germ agglutinin. The coalescence of cells and morphologic disotrtion induced by wheat germ agglutinin were not inhibited by N-acetylglucosamine, the hapten inhibitor of the lectin, under the conditions utilized in this study.

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Concanavalin a and wheat germ agglutinin receptors on dictyostelium: Their visualization by scanning electron microscopy with microspheres

The Journal of Cell Biology ◽

10.1083/jcb.71.1.314 ◽

1976 ◽

Vol 71 (1) ◽

pp. 314-322 ◽

Cited By ~ 28

Author(s):

R Molday ◽

R Jaffe ◽

D McMahon

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Cell Surface ◽

Wheat Germ ◽

Cellular Interactions ◽

Con A ◽

Stages Of Development ◽

Lectin Receptors ◽

Plant Lectins ◽

Scanning Electron

The cellular slime mold, Dictyostelium discoideum, is a convenient model for studying cellular interactions during development. Evidence that specific cell surface components are involved in cellular interactions during its development has been obtained by Gerisch and co-workers (1, 2) using immunological techniques. Smart and Hynes (3) have shown that a cell surface protein can be iodinated on cells in aggregation phase, but not in vegetative phase, by the lactoperoxidase procedure. Recently, McMahon et al. (4), and Hoffman and McMahon have demonstrated, by SDS gel electrophoresis, considerable differences in cell surface proteins and glycoproteins of plasma membranes isolated from cells at different stages of development. Plant lectins have also been used to monitor changes in cell surface properties of D. discoideum cells during development. Weeks and co-workers (5, 6) have detected differences in the binding and agglutination of cells by concanavalin A (Con A). Gillette and Filosa (7) have shown that Con A inhibits cell aggregation and prematurely induces cyclic AMP phosphodiesterase. Capping of Con A receptors has also been reported (8). Reitherman et al. (9) have recently reported that agglutination of cells by several plant lectins and the slime mold agglutination, discoidin, changes during development. Such studies indicate that differences in surface properties exist for cells at various stages of development. However, owing to the uncertainties in the factors which contribute to lectin-induced cell agglutination (10), the molecular basis for these observations remain to be determined. In this study, we have used microspheres (11-14) coupled to either Con A or wheat germ agglutinin (WGA) as visual markers to study by scanning electron microscopy the topographical distribution of lectin receptors on D. discoideum cells fixed at different stages of development. We also describe the effect of labeling on the distribution of lectin receptors and on the morphology of the cell surface.

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Methodological basis for an autoradiographic demonstration of insulin receptor sites on the surface of whole cells: a study using light- and scanning electron microscopy

Journal of Microscopy ◽

10.1111/j.1365-2818.1980.tb04090.x ◽

1980 ◽

Vol 119 (2) ◽

pp. 199-211 ◽

Cited By ~ 7

Author(s):

E. Junger ◽

L. Bachmann

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Insulin Receptor ◽

Whole Cells ◽

Methodological Basis ◽

Receptor Sites ◽

Scanning Electron

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Visualization and rapid quantification of autoradiographic labeling in scanning electron microscopy applied to localization of receptor sites on the surface of whole cells

Virchows Archiv B Cell Pathology Including Molecular Pathology ◽

10.1007/bf02899707 ◽

1992 ◽

Vol 62 (1) ◽

pp. 377-383

Author(s):

C. Péchoux ◽

J. Boumendil ◽

D. Dolbeau ◽

C. Souchier ◽

L. Frappait

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Whole Cells ◽

Receptor Sites ◽

Autoradiographic Labeling ◽

Rapid Quantification ◽

Scanning Electron

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Novel Methods to Manipulate Autolysis in Sparkling Wine: Effects on Yeast

Molecules ◽

10.3390/molecules26020387 ◽

2021 ◽

Vol 26 (2) ◽

pp. 387

Author(s):

Gail B. Gnoinski ◽

Simon A. Schmidt ◽

Dugald C. Close ◽

Karsten Goemann ◽

Terry L. Pinfold ◽

...

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Flow Cytometry ◽

Yeast Cell ◽

Microwave Treatment ◽

Control Flow ◽

Yeast Cells ◽

Sparkling Wine ◽

The Impact ◽

Scanning Electron

Sparkling wine made by the traditional method (Méthode Traditionelle) develops a distinct and desirable flavour and aroma profile attributed to proteolytic processes during prolonged ageing on lees. Microwave, ultrasound and addition of β-glucanase enzymes were applied to accelerate the disruption of Saccharomyces cerevisiae, and added to the tirage solution for secondary fermentation in traditional sparkling winemaking. Scanning electron microscopy and flow cytometry analyses were used to observe and describe yeast whole-cell anatomy, and cell integrity and structure via propidium iodide (PI) permeability after 6-, 12- and 18-months post-tirage. Treatments applied produced features on lees that were distinct from that of the untreated control yeast. Whilst control yeast displayed budding cells (growth features) with smooth, cavitated and flat external cell appearances; microwave treated yeast cells exhibited modifications like ‘doughnut’ shapes immediately after treatment (time 0). Similar ‘doughnut’-shaped and ‘pitted/porous’ cell features were observed on progressively older lees from the control. Flow cytometry was used to discriminate yeast populations; features consistent with cell disruption were observed in the microwave, ultrasound and enzyme treatments, as evidenced by up to 4-fold increase in PI signal in the microwave treatment. Forward and side scatter signals reflected changes in size and structure of yeast cells, in all treatments applied. When flow cytometry was interpreted alongside the scanning electron microscopy images, bimodal populations of yeast cells with low and high PI intensities were revealed and distinctive ‘doughnut’-shaped cell features observed in association with the microwave treatment only at tirage, that were not observed until 12 months wine ageing in older lees from the control. This work offers both a rapid approach to visualise alterations to yeast cell surfaces and a better understanding of the mechanisms of yeast lysis. Microwave, ultrasound or β-glucanase enzymes are tools that could potentially initiate the release of yeast cell compounds into wine. Further investigation into the impact of such treatments on the flavour and aroma profiles of the wines through sensory evaluation is warranted.

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Colloidal gold, a useful marker for transmission and scanning electron microscopy.

Journal of Histochemistry & Cytochemistry ◽

10.1177/25.4.323352 ◽

1977 ◽

Vol 25 (4) ◽

pp. 295-305 ◽

Cited By ~ 441

Author(s):

M Horisberger ◽

J Rosset

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Transmission Electron Microscopy ◽

Yeast Cells ◽

Erythrocyte Membranes ◽

Optimum Conditions ◽

Thin Sections ◽

Good Spatial Resolution ◽

Transmission Electron ◽

Scanning Electron

Electron dense markers of a size suitable for transmission electron microscopy and scanning electron microscopy have been prepared with gold granules labeled with a monolayer of specific macromolecules. The optimum conditions for preparing the markers have been ascertained. The method is simple, rapid and seems to be general since gold granules have been labeled with polysaccharides and proteins. As homogeneous populations of gold granules having different sizes can be prepared, the method is also suitable for double marking experiments. The gold technique is illustrated by the localization of polysaccharides and glycoproteins on yeast cell walls and erythrocyte membranes by transmission electron microscopy and on yeast cells and intact erythrocytes by scanning electron microscopy. Good spatial resolution of the marker was achieved in all cases. The method is also suitable for marking thin sections. Spectrophotometric measurements were used to determine the number of gold granules adsorbed per cell.

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