COBALT AS A VITAL STAIN FOR YEAST MITOCHONDRIA IN SQUASH PREPARATIONS

1969 ◽  
Vol 11 (4) ◽  
pp. 987-992 ◽  
Author(s):  
Carl C. Lindegren ◽  
Paraskevi M. Be Miller
Keyword(s):  
Electron Microscopy ◽  
Nutrient Medium ◽  
Yeast Cells ◽  
Yeast Mitochondria ◽  
Inner Membrane ◽  
Vital Stain

Squashes of yeast cells grown in nutrient medium containing cobalt were observed by phase- and electron-microscopy. Co++ is a vital stain that is bound to structures inside the inner membrane of the mitochondria.

scholarly journals BIOGENESIS OF MITOCHONDRIA

1970 ◽  
Vol 46 (1) ◽  
pp. 88-96 ◽  
Author(s):  
K. Watson ◽  
J. M. Haslam ◽  
Anthony W. Linnane
Keyword(s):  
Fatty Acid ◽  
Unsaturated Fatty Acid ◽  
Fatty Acid Content ◽  
Buoyant Density ◽  
Membrane System ◽  
Yeast Cells ◽  
Dense Matrix ◽  
Yeast Mitochondria ◽  
Inner Membrane ◽  
Double Membrane

Morphologically intact structures have been isolated from anaerobically grown yeast cells which have many of the properties of yeast mitochondria. The structures are about 0.5 µ in diameter and contain malate dehydrogenase, succinate dehydrogenase, oligomycin-sensitive ATPase, and DNA of buoyant density 1.683 g/cc, characteristic of yeast mitochondria. The morphology of the structures is critically dependent on their lipid composition. When isolated from cells grown anaerobically in the presence of supplements of unsaturated fatty acid and ergosterol, their unsaturated fatty acid content is similar to that of mitochondria from aerobically grown cells. These lipid-complete structures consist pre-dominantly of double-membrane vesicles enclosing a dense matrix which contains a folded inner membrane system bordering electron-transparent regions which are somewhat different from the cristae of functional mitochondria. In contrast, the structures from cells grown without lipid supplements are much simpler in morphology; they have a dense granular matrix surrounded by a double membrane but have no obvious folded inner membrane system within the matrix. The lipid-depleted structures are very fragile and are only isolated in intact form from protoplasts that have been prefixed with glutaraldehyde

The Intracellular Morphology of Yeast Mitochondria Studied by HVEM

1974 ◽  
Vol 32 ◽  
pp. 64-65
Author(s):  
M. T. Davison ◽  
P. B. Garland
Keyword(s):  
Electron Microscopy ◽  
Batch Culture ◽  
Yeast Cells ◽  
Yeast Mitochondria ◽  
Thin Sections

Ultra-thin sections of suitably grown, fixed and stained yeast cells examined by electron microscopy typically show several mitochondrial profiles per cell section; such observations are usually interpreted as showing several separate mitochondria per cell. Variations in the size and number of mitochondria per cell at different stages of batch culture have been described. The possibility arises that examination of ultra-thin sections failed to distinguish between profiles of individual rounded mitochondria and profiles of much larger cylindrical mitochondria looped across the plane of the section.

Use of electron microscopy to characterize the surfaces of flocculent and nonflocculent yeast cells

1989 ◽  
Vol 35 (12) ◽  
pp. 1081-1086 ◽  
Author(s):  
Byron F. Johnson ◽  
L. C. Sowden ◽  
Teena Walker ◽  
Bong Y. Yoo ◽  
Gode B. Calleja
Keyword(s):  
Electron Microscopy ◽  
Fission Yeast ◽  
Budding Yeast ◽  
The Other ◽  
Yeast Cells ◽  
Scanning Electron Micrographs ◽  
Soft Or ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron

The surfaces of flocculent and nonflocculent yeast cells have been examined by electron microscopy. Nonextractive preparative procedures for scanning electron microscopy allow comparison in which sharp or softened images of surface details (scars, etc.) are the criteria for relative abundance of flocculum material. Asexually flocculent budding-yeast cells cannot be distinguished from nonflocculent budding-yeast cells in scanning electron micrographs because the scar details of both are well resolved, being hard and sharp. On the other hand, flocculent fission-yeast cells are readily distinguished from nonflocculent cells because fission scars are mostly soft or obscured on flocculent cells, but sharp on nonflocculent cells. Sexually and asexually flocculent fission-yeast cells cannot be distinguished from one another as both are heavily clad in "mucilaginous" or "hairy" coverings. Examination of lightly extracted and heavily extracted flocculent fission-yeast cells by transmission electron microscopy provides micrographs consistent with the scanning electron micrographs.Key words: flocculation, budding yeast, fission yeast, scanning, transmission.

scholarly journals A FIBER APPARATUS IN THE NUCLEUS OF THE YEAST CELL

1966 ◽  
Vol 29 (1) ◽  
pp. 129-151 ◽  
Author(s):  
C. F. Robinow ◽  
J. Marak
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Dense Matter ◽  
Short Fiber ◽  
Yeast Cells ◽  
Acid Fuchsin ◽  
Fine Grained ◽  
New Information ◽  
Thin Electron ◽  
Iron Alum

The structure and mode of division of the nucleus of budding yeast cells have been studied by phase-contrast microscopy during life and by ordinary microscopy after Helly fixation. The components of the nucleus were differentially stained by the Feulgen procedure, with Giemsa solution after hydrolysis, and with iron alum haematoxylin. New information was obtained in cells fixed in Helly's by directly staining them with 0.005% acid fuchsin in 1% acetic acid in water. Electron micrographs have been made of sections of cells that were first fixed with 3% glutaraldehyde, then divested of their walls with snail juice, and postfixed with osmium tetroxide. Light and electron microscopy have given concordant information about the organization of the yeast nucleus. A peripheral segment of the nucleus is occupied by relatively dense matter (the "peripheral cluster" of Mundkur) which is Feulgen negative. The greater part of the nucleus is filled with fine-grained Feulgen-positive matter of low density in which chromosomes could not be identified. Chromosomes become visible in this region under the light microscope at meiosis. In the chromatin lies a short fiber with strong affinity for acid fuchsin. The nucleus divides by elongation and constriction, and during this process the fiber becomes long and thin. Electron microscopy has resolved it into a bundle of dark-edged 150 to 180 A filaments which extends between "centriolar plaques" that are attached to the nuclear envelope.

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.

scholarly journals Optimization of Innovative Three-Dimensionally-Structured Hybrid Vesicles to Improve the Cutaneous Delivery of Clotrimazole for the Treatment of Topical Candidiasis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 263 ◽  
Author(s):  
Maria Letizia Manca ◽  
Iris Usach ◽  
José Esteban Peris ◽  
Antonella Ibba ◽  
Germano Orrù ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Yeast Cells ◽  
Unilamellar Vesicles ◽  
Transmission Electron ◽  
Physico Chemical

New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (≤10%), which was replaced with a mixture of glycerol and ethanol (≈90%). A pre-formulation study was carried out to evaluate the effect of both the composition of the hydrating medium and the concentration of the phospholipid on the physico-chemical properties of hybrid vesicles. Four different three-dimensionally-structured hybrid vesicles were selected as ideal systems for the topical application of clotrimazole. An extensive physico-chemical characterization performed using transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), 31P-NMR, and small-angle X-ray scattering (SAXS) displayed the formation of small, multi-, and unilamellar vesicles very close to each other, and was capable of forming a three-dimensional network, which stabilized the dispersion. Additionally, the dilution of the dispersion with water reduced the interactions between vesicles, leading to the formation of single unilamellar vesicles. The evaluation of the in vitro percutaneous delivery of clotrimazole showed an improved drug deposition in the skin strata provided by the three-dimensionally-structured vesicles with respect to the commercial cream (Canesten®) used as a reference. Hybrid vesicles were highly biocompatible and showed a significant antifungal activity in vitro, greater than the commercial cream Canesten®. The antimycotic efficacy of formulations was confirmed by the reduced proliferation of the yeast cells at the site of infection in vivo. In light of these results, clotrimazole-loaded, three-dimensionally-structured hybrid vesicles appear to be one of the most innovative and promising formulations for the treatment of candidiasis infections.

Staining yeast cells for electron microscopy by growth in copper-containing nutrient broth

1972 ◽  
Vol 38 (1) ◽  
pp. 17-26 ◽  
Author(s):  
C. C. Lindegren ◽  
Paraskevi M. BeMiller ◽  
Kuo -Chun Liu ◽  
Gertrude Lindegren
Keyword(s):  
Electron Microscopy ◽  
Nutrient Broth ◽  
Yeast Cells

Membrane protein import in yeast mitochondria

2000 ◽  
Vol 28 (4) ◽  
pp. 495-499 ◽  
Author(s):  
K. Tokatlidis ◽  
S. Vial ◽  
P. Luciano ◽  
M. Vergnolle ◽  
S. Clémence
Keyword(s):  
Membrane Protein ◽  
Molecular Mechanism ◽  
Protein Import ◽  
Mitochondrial Matrix ◽  
Yeast Mitochondria ◽  
Inner Membrane ◽  
Protein Insertion ◽  
The Past ◽  
Membrane Protein Insertion ◽  
Membrane Bound

The protein import pathway that targets proteins to the mitochondrial matrix has been extensively characterized in the past 15 years. Variations of this import pathway account for the sorting of proteins to other compartments as well, but the insertion of integral inner membrane proteins lacking a presequence is mediated by distinct translocation machinery. This consists of a complex of Tim9 and Tim10, two homologous, Zn2+-binding proteins that chaperone the passage of the hydrophobic precursor across the aqueous inter-membrane space. The precursor is then targeted to another, inner-membrane-bound, complex of at least five subunits that facilitates insertion. Biochemical and genetic experiments have identified the key components of this process; we are now starting to understand the molecular mechanism. This review highlights recent advances in this new membrane protein insertion pathway.

scholarly journals Targeting and assembly of the oxoglutarate carrier: general principles for biogenesis of carrier proteins of the mitochondrial inner membrane

1998 ◽  
Vol 333 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Annamaria PALMISANO ◽  
Vincenzo ZARA ◽  
Angelika HÖNLINGER ◽  
Angelo VOZZA ◽  
Peter J. T. DEKKER ◽  
...  
Keyword(s):  
High Efficiency ◽  
Dependent Manner ◽  
Yeast Mitochondria ◽  
Inner Membrane ◽  
Mitochondrial Inner Membrane ◽  
Native Electrophoresis ◽  
Surface Receptor ◽  
Inner Membrane Protein ◽  
Oxoglutarate Carrier

We have studied the targeting and assembly of the 2-oxoglutarate carrier (OGC), an integral inner-membrane protein of mitochondria. The precursor of OGC, synthesized without a cleavable presequence, is transported into mitochondria in an ATP- and membrane potential-dependent manner. Import of the mammalian OGC occurs efficiently into both mammalian and yeast mitochondria. Targeting of OGC reveals a clear dependence on the mitochondrial surface receptor Tom70 (the 70 kDa subunit of the translocase of the outer mitochondrial membrane), whereas a cleavable preprotein depends on Tom20 (the 20 kDa subunit), supporting a model of specificity differences of the receptors and the existence of distinct targeting pathways to mitochondria. The assembly of minute amounts of OGC imported in vitro to the dimeric form can be monitored by blue native electrophoresis of digitonin-lysed mitochondria. The assembly of mammalian OGC and fungal ADP/ATP carrier occurs with high efficiency in both mammalian and yeast mitochondria. These findings indicate a dynamic behaviour of the carrier dimers in the mitochondrial inner membrane and suggest a high conservation of the assembly reactions from mammals to fungi.

CHANGES IN THE MITOCHONDRIAL DOUBLE MEMBRANE IN TAPETAL AND SPOROGENIC CELLS IN CYTOPLASMIC MALE STERILE ANTHERS OF PETUNIA

1994 ◽  
Vol 42 (3) ◽  
pp. 173-181
Author(s):  
Dalia Evenor ◽  
Andrey Franck ◽  
Yona Tabib ◽  
Aaron Zelcer ◽  
Shamay Izhar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mitochondrial Membrane ◽  
Early Prophase ◽  
Male Sterile ◽  
Inner Membrane ◽  
Double Membrane ◽  
Cytoplasmic Male Sterile ◽  
Ultrastructural Studies ◽  
Contact Sites ◽  
Close Proximity

Comparative histological and ultrastructural studies were made on the gametogenesis and microsporogenesis in isonuclear fertile and cytoplasmic male sterile petunia lines. Using electron microscopy, changes in the mitochondrial double membrane were observed in the tapetal and sporogenic cells of cytoplasmic male sterile anthers as the first cytological sign of breakdown of the process of microsporogenesis at early prophase I. These changes were manifested by a larger space between the outer and the inner membrane and fewer sites of close proximity (“contact sites”) in the sterile mitochondria, as compared to fertile mitochondria. The mitochondrial membrane of the parietal tissue in the cytoplasmic male sterile anthers was not affected in the same way. Even when total breakdown was already obvious in the tapetal and sporogenic cells, the mitochondria of the parietal layer remained intact.

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