Electron microscopic studies on the formation of vesicular bodies during cell wall degradation and regeneration in yeast

1977 ◽  
Vol 17 (4) ◽  
pp. 293-297
Author(s):  
V. V. Dmitriev ◽  
A. B. Tsiomenko ◽  
E. N. Ratner ◽  
V. K. Akimenko ◽  
B. A. Fikhte
Keyword(s):  
Cell Wall ◽  
Cell Wall Degradation ◽  
Electron Microscopic ◽  
Microscopic Studies

Electron microscopic studies on the formation of vesicular bodies during cell wall degradation and regeneration in yeast

1977 ◽  
Vol 17 (4) ◽  
pp. 293-297 ◽  
Author(s):  
V. V. Dmitriev ◽  
A. B. Tsiomenko ◽  
E. N. Ratner ◽  
V. K. Akimenko ◽  
B. A. Fikhte
Keyword(s):  
Cell Wall ◽  
Cell Wall Degradation ◽  
Electron Microscopic ◽  
Microscopic Studies

scholarly journals ELECTRON MICROSCOPIC STUDIES ON STREPTOCOCCI

1969 ◽  
Vol 130 (5) ◽  
pp. 1063-1091 ◽  
Author(s):  
John Swanson ◽  
Konrad C. Hsu ◽  
Emil C. Gotschlich
Keyword(s):  
Cell Wall ◽  
Nitrous Acid ◽  
Intact Cell ◽  
M Protein ◽  
Acid Extraction ◽  
Electron Microscopic ◽  
Streptococcal Cell Wall ◽  
Before And After ◽  
Specific Polysaccharide ◽  
Microscopic Studies

The presence of M antigens on group A streptococci is associated with hairlike fimbriae that cover the surface of the streptococcal cell wall and are demonstrable by electron microscopy. These fimbriae also may be associated with R antigen. Like M protein, the surface fimbriae are destroyed by trypsin treatment and reappear when "trypsinized" streptococci are reincubated in fresh, trypsin-free broth. Ferritin-conjugated, type-specific antibodies localize on homologous M+ cells in a pattern suggestive of several M antigenic sites along the length of individual surface fimbria. The M-associated fimbriae remain on the residual cell wall after removal of the bulk of group-specific polysaccharide through nitrous acid extraction. This suggests attachment of the fimbriae to the mucopeptide and minor polysaccharide components remaining in the nitrous acid-extracted wall. The pattern of localization of ferritin-conjugated antibodies on homologous streptococci before and after trypsin exposure and upon reincubation of the trypsinized cells in fresh medium suggests the following hypothesis: M antigen is secreted by the cell, is partially excreted through the otherwise intact cell wall, and is bound by the wall so that M protein occupies a peripheral, exposed position on the surfaces of the streptococcal cell wall.

scholarly journals ELECTRON MICROSCOPIC STUDIES ON STREPTOCOCCI

1973 ◽  
Vol 138 (1) ◽  
pp. 245-258 ◽  
Author(s):  
John Swanson ◽  
Emil C. Gotschlich
Keyword(s):  
Cell Wall ◽  
Horseradish Peroxidase ◽  
Electron Microscopic ◽  
Streptococcal Cell Wall ◽  
Outermost Surface ◽  
Laminar Distribution ◽  
Specific Polysaccharide ◽  
Microscopic Studies ◽  
Group A ◽  
Protein Cell

The location of Group A carbohydrate in the streptococcal cell wall has been studied by several ultrastructural techniques. The findings, based largely on use of ferritin- and horseradish peroxidase-conjugated antibodies, are interpreted as demonstrating a discrete laminar distribution of the group-specific polysaccharide. This carbohydrate layer is located on the outermost surface of the cell wall in organisms lacking protein cell wall antigens.

Intracellular location of enzymes in Rhodopseudomonas spheroides

1968 ◽  
Vol 170 (1020) ◽  
pp. 319-329 ◽  
Keyword(s):  
Cell Wall ◽  
Cytoplasmic Membrane ◽  
Succinic Dehydrogenase ◽  
Particulate Material ◽  
Zinc Protoporphyrin ◽  
Differential Centrifugation ◽  
Electron Microscopic ◽  
Intracellular Location ◽  
Microscopic Studies ◽  
Rhodopseudomonas Spheroides

By differential centrifugation of extracts of pigmented Rhodopseudomonas spheroides a number of constituents, phospholipid and lipid ornithine, and enzymes, zinc protoporphyrin chelatase, succinic dehydrogenase and S-adenosylmethionine-magnesium protoporphyrin methyltransferase, have been found to be associated both with chromatophores and with non-pigmented particulate material. These components are present in both types of material at about the same level. In extracts of non-pigmented organisms the particulate material contains some of the above components, but others are only present in low amounts. The subcellular structures present in the particulate material—ribosomes, cell wall and cytoplasmic membrane—have only been partially separated but, by comparing the distribution of the components listed above with those of known components of ribosomes and cell wall, it is probable that they are associated with cytoplasmic membrane. These studies suggest that the cytoplasmic membrane, apart from lacking the photosynthetic pigments, has a composition similar to that of chromatophores. The data are consistent with the conclusion drawn from electron microscopic studies that chromatophores are derived by invagination of the cytoplasmic membrane.

Electron microscopic characterization of cell wall degradation of the 400,000-year-old wooden Sch�ningen spears

2005 ◽  
Vol 63 (2) ◽  
pp. 118-122 ◽  
Author(s):  
U. Schmitt ◽  
A. P. Singh ◽  
H. Thieme ◽  
P. Friedrich ◽  
P. Hoffmann
Keyword(s):  
Cell Wall ◽  
Cell Wall Degradation ◽  
Electron Microscopic

The fine structure of some strains of Humicola Traaen

1974 ◽  
Vol 20 (2) ◽  
pp. 237-239 ◽  
Author(s):  
M. de Bertoldi ◽  
F. Mariotti ◽  
C. Filippi
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Cell Surface ◽  
Outer Wall ◽  
Wall Layer ◽  
The Other ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Different Types ◽  
Microscopic Studies

The fine structure of three unclassified strains of Humicola and of H. grisea has been investigated. The hyphae of all the strains show septa with Woronin bodies of the ascomycetous type. The cytoplasm contains many nuclei per cell, mitochondria, ribosomes, and endoplasmic vesicles, all typical of fungal cells. Electron-microscopic studies of thin sections of mature aleuriospores reveal a thick multilayered cell wall and an accumulation, inside the spore, of β-hydroxybutyrate granules. Aleuriospores exhibit different types of cell surface; the outer wall layer of two strains is smooth, while the outer layer of the other strains is rough because of the presence of melanizing bodies on the cell wall matrix. The fine structure of phialospores and microconidia is also described. Differences in the fine structure among the strains studied are reported.

A Study of the Structure of the Cell Wall of Spirillum Serpens Using Frozen, Hydrated Specimens

1976 ◽  
Vol 34 ◽  
pp. 136-137
Author(s):  
Kenneth A. Taylor ◽  
David A. Grano ◽  
Wah Chiu
Keyword(s):  
Cell Wall ◽  
Negative Bacterium ◽  
Electron Microscopic ◽  
Identical Particles ◽  
Gram Negative ◽  
Microscopic Studies ◽  
Hexagonal Arrangement

Based on chemical and electron microscopic studies (Buckmire and Murray, 1970), the cell wall of Spirillum serpens VHA, a Gram-negative bacterium, is composed of several components including protein, lipopolysaccharide, and peptidoglycan. By a gentle heating of the bacteria at 60°C, the outermost components of the cell wall are separated from the rest of the cell, and can be purified by simple procedures. In the negatively stained preparations, it has been shown by Buckmire and Murray that these components appear in both lamellar and tubular forms made up of identical particles in a closely packed hexagonal arrangement. These particles are approximately 90 Å in diameter, with a center-to-center spacing of approximately 150 Å, and are connected by Y-shaped links.

THE INTEGRITY OF THE CELL WALL DURING BUD FORMATION IN YEASTS

1965 ◽  
Vol 11 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Dan O. McClary ◽  
Wilbert D. Bowers Jr.
Keyword(s):  
Cell Wall ◽  
Mother Cell ◽  
Budding Yeast ◽  
Dark Field ◽  
Yeast Cells ◽  
Constant Thickness ◽  
Full Thickness ◽  
Electron Microscopic ◽  
Bud Formation ◽  
Microscopic Studies

Dark-field and electron microscopic studies of budding yeast cells have shown an extension of a wall of full thickness, rather than a break in the wall, when the bud emerges. The bud appears as a minute bulge and grows steadily, not explosively, during which time both it and the mother cell are enclosed within a single wall. The wall maintains essentially a constant thickness throughout the growth of the bud, and at maturity both the wall and the cytoplasm of the two cells are separated by a cleavage wall which is laid down between them.

Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

1978 ◽  
Vol 36 (2) ◽  
pp. 46-47
Author(s):  
Jan Zarzycki ◽  
Joseph Szroeder
Keyword(s):  
Mammary Gland ◽  
Protein Denaturation ◽  
Chemical Constituents ◽  
Freeze Substitution ◽  
Electron Microscopic Examination ◽  
Mouse Mammary Gland ◽  
Electron Microscopic ◽  
Preparation Methods ◽  
Microscopic Studies ◽  
Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

1967 ◽  
Vol 25 ◽  
pp. 74-75
Author(s):  
L. V. Leak
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Green Algae ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Electron Microscopic ◽  
Photosynthetic Membranes ◽  
Blue Green Algae ◽  
Cell Biol ◽  
Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

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