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.

A comparison of the effects of several antifungal imidazole derivatives and polyenes on Candida albicans: an ultrastructural study by scanning electron microscopy

1982 ◽  
Vol 28 (10) ◽  
pp. 1119-1126 ◽  
Author(s):  
M. Bastide ◽  
S. Jouvert ◽  
J.-M. Bastide
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Candida Albicans ◽  
Cytoplasmic Membrane ◽  
Electron Microscopic Examination ◽  
Yeast Cells ◽  
Electron Microscopic ◽  
Imidazole Derivatives ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

The early events in the interaction of two polyene (amphotericin B and nystatin) and five imidazole (clotrimazole, ketoconazole, miconazole, isoconazole, and econazole) antimycotics used at fungicidal concentrations with the surface of Candida albicans were studied by scanning electron microscopic examination of treated intact young yeast cells, treated spheroplasts, and spheroplasts liberated from treated young yeast cells. In all cases, treatment lasted 2 h. The polyenes passed through the yeast cell wall and interacted with the cytoplasmic membrane causing the spheroplasts to lose their characteristic spheric form and to liberate their contents. Clotrimazole caused the formation of numerous circular openings in the cytoplasmic membrane, but only when the agent was used to treat spheroplasts directly. Ketoconazole, miconazole, isoconazole, and econazole interacted with the cell wall causing formation of convolutions and wrinkles. The three imidazole derivatives that are structurally closely related, miconazole, isoconazole, and econazole, inhibited the enzyme-catalyzed release of spheroplasts from young yeast cells.

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 Phylogenetic and comparative functional analysis of the cell-separation α-glucanase Agn1p in Schizosaccharomyces

Microbiology ◽  
2014 ◽  
Vol 160 (6) ◽  
pp. 1063-1074 ◽  
Author(s):  
Matthias Sipiczki ◽  
Anita Balazs ◽  
Aniko Monus ◽  
Laszlo Papp ◽  
Anna Horvath ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Mother Cell ◽  
Cell Separation ◽  
Yeast Cells ◽  
Glycoside Hydrolase Family ◽  
Binding Domains ◽  
Yeast Phase ◽  
Mother Cell Wall

The post-cytokinetic separation of cells in cell-walled organisms involves enzymic processes that degrade a specific layer of the division septum and the region of the mother cell wall that edges the septum. In the fission yeast Schizosaccharomyces pombe, the 1,3-α-glucanase Agn1p, originally identified as a mutanase-like glycoside hydrolase family 71 (GH71) enzyme, dissolves the mother cell wall around the septum edge. Our search in the genomes of completely sequenced fungi identified GH71 hydrolases in Basidiomycota, Taphrinomycotina and Pezizomycotina, but not in Saccharomycotina. The most likely Agn1p orthologues in Pezizomycotina species are not mutanases having mutanase-binding domains, but experimentally non-characterized hypothetical proteins that have no carbohydrate-binding domains. The analysis of the GH71 domains corroborated the phylogenetic relationships of the Schizosaccharomyces species determined by previous studies, but suggested a closer relationship to the Basidiomycota proteins than to the Ascomycota proteins. In the Schizosaccharomyces genus, the Agn1p proteins are structurally conserved: their GH71 domains are flanked by N-terminal secretion signals and C-terminal sequences containing the conserved block YNFNAY/HTG. The inactivation of the agn1Sj gene in Schizosaccharomyces japonicus, the only true dimorphic member of the genus, caused a severe cell-separation defect in its yeast phase, but had no effect on the hyphal growth and yeast-to-mycelium transition. It did not affect the mycelium-to-yeast transition either, only delaying the separation of the yeast cells arising from the fragmenting hyphae. The heterologous expression of agn1Sj partially rescued the separation defect of the agn1Δ cells of Schizosaccharomyces pombe. The results presented indicate that the fission yeast Agn1p 1,3-α-glucanases of Schizosaccharomyces japonicus and Schizosaccharomyces pombe share conserved functions in the yeast phase.

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 Iqg1p links spatial and secretion landmarks to polarity and cytokinesis

2002 ◽  
Vol 159 (4) ◽  
pp. 601-611 ◽  
Author(s):  
Mahasin A. Osman ◽  
James B. Konopka ◽  
Richard A. Cerione
Keyword(s):  
Actin Cytoskeleton ◽  
Site Selection ◽  
Protein Trafficking ◽  
Yeast Cells ◽  
Electron Microscopic ◽  
Binding Partner ◽  
Microscopic Studies ◽  
Division Axis ◽  
Bud Site ◽  
Two Hybrid

Cytokinesis requires the polarization of the actin cytoskeleton, the secretion machinery, and the correct positioning of the division axis. Budding yeast cells commit to their cytokinesis plane by choosing a bud site and polarizing their growth. Iqg1p (Cyk1p) was previously implicated in cytokinesis (Epp and Chant, 1997; Lippincott and Li, 1998; Osman and Cerione, 1998), as well as in the establishment of polarity and protein trafficking (Osman and Cerione, 1998). To better understand how Iqg1p influences these processes, we performed a two-hybrid screen and identified the spatial landmark Bud4p as a binding partner. Iqg1p can be coimmunoprecipitated with Bud4p, and Bud4p requires Iqg1p for its proper localization. Iqg1p also appears to specify axial bud-site selection and mediates the proper localization of the septin, Cdc12p, as well as binds and helps localize the secretion landmark, Sec3p. The double mutants iqg1Δsec3Δ and bud4Δsec3Δ display defects in polarity, budding pattern and cytokinesis, and electron microscopic studies reveal that these cells have aberrant septal deposition. Taken together, these findings suggest that Iqg1p recruits landmark proteins to form a targeting patch that coordinates axial budding with cytokinesis.

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.

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.

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