Cytochemistry of acid mucosubstance and acid phosphatase in Cryptococcus neoformans

1974 ◽  
Vol 20 (6) ◽  
pp. 833-838 ◽  
Author(s):  
Thomas A. Mahvi ◽  
Samuel S. Spicer ◽  
Nancy J. Wright
Keyword(s):  
Cell Wall ◽  
Acid Phosphatase ◽  
Cryptococcus Neoformans ◽  
Ultrastructural Level ◽  
Dense Layer ◽  
Strong Activity ◽  
Thin Sections ◽  
Cytoplasmic Bodies ◽  
Cryostat Sections ◽  
Substrate Medium

At the ultrastructural level, dialyzed iron stains only the mucoid capsule in Cryptococcus neoformans, converting it from the most lucent to an extremely dense layer and thus demonstrating its content of acid mucosubstance. After lead staining of thin sections of dialyzed iron treated specimens, the wall exhibits a dense inner and translucent outer layer. The inner layer and mucoid capsule appear thicker in the mother than the daughter cell of budding organisms. C. neoformans cells fixed in suspension and incubated in acid phosphatase substrate medium exhibit at the ultrastructural level activity confined to the mucoid capsule, cell wall, and internal extensions presumed to be plasmalemmasomes. Organisms in small blocks or cryostat sections of pellets fixed in clotted fibrin, when incubated for acid phosphatase, reveal moderate to no reactivity in cell wall and mucoid capsule but strong activity in surrounding fibrin aggregates. In the latter specimens, reaction product indicative of acid phosphatase also is evident in the nuclear envelope, in some of the profiles of presumed granular reticulum, in complex lamellar profiles presumed to be Golgi elements, and in small cytoplasmic bodies and large vacuoles. The morphological specimens disclose counterparts of acid phosphatase reactive structures and show lucent cytoplasm segregated by circular mitochondrial profiles and a difference between the thickness and density of the plasmalemma and other cell membranes.

Fine structure of the macroconidia of Fusarium solani

1975 ◽  
Vol 53 (19) ◽  
pp. 2134-2146 ◽  
Author(s):  
J. P. Tewari ◽  
W. P. Skoropad
Keyword(s):  
Cell Wall ◽  
Fusarium Solani ◽  
Superficial Layer ◽  
Dense Layer ◽  
Inoculum Potential ◽  
Chemical Fixation ◽  
Thin Sections ◽  
Innermost Layer ◽  
Freeze Etching ◽  
Myelin Figures

Ultrastructure of the macroconidia of Fusarium solani as visualized by transmission (ultrathin sectioning and freeze-etching) and scanning electron microscopy is described. The cell wall has four layers. The innermost layer is electron-lucid followed by an electron-dense layer. The next outer layer is spongy in appearance followed by a superficial layer consisting of fine filamentous processes. Freeze-etch replicas of conidia directly removed from the sporodochia and still suspended in the mucilaginous material (in which they are produced) frequently show the conidia connected by the superficial filamentous processes in the cell wall. This agglutination of the conidia is likely to increase the inoculum potential of this pathogen at the sites of infection. Structure of various membrane systems in the cells is described. The endoplasmic reticulum is fairly extensive and fenestrated. Thin sections of routinely fixed conidia show myelin figures. However, such structures were not seen in replicas of conidia that were freeze-etched without use of chemical fixation or cryoprotection.

Ultrastructural localization of carbonic anhydrase in mouse gastric parietal cells

1978 ◽  
Vol 36 (2) ◽  
pp. 532-533
Author(s):  
N. Sugai ◽  
S. Ito
Keyword(s):  
Carbonic Anhydrase ◽  
Picric Acid ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Parietal Cells ◽  
Thin Sections ◽  
Tissue Sections ◽  
Gastric Parietal Cells ◽  
Cryostat Sections ◽  
Precise Distribution

The histochemical localization of carbonic anhydrase in parietal cells has been described by a number of investigators and its presence in these cells at the ultrastructural level has been also reported. However the precise distribution of this enzyme is not clear and there are some questions regarding the validity of the histochemical reaction. In the present study, various modifications of the technique were explored and it was found that tissues fixed in buffered formaldehyde, glutaraldehyde with trinitrocresol or picric acid retained good reaction product localization of this enzyme. Cryostat sections of the fixed tissues were treated with solutions recommended by Hannson. Incubation times that were most favorable 5 to 10 min for light microscopy and 8 to 15 min for electron microscopy. For ultrastructural observations of thin sections, it was found to be important that the reacted tissue sections were post osmicated with 1% osmium tetroxide in 1. 5% potassium ferrocyanide or with aqueous 1% 0s04 for only 3 to 5 min.

Ultrastructural changes in the conidia of Penicillium notatum during germination

1973 ◽  
Vol 19 (7) ◽  
pp. 797-801 ◽  
Author(s):  
J. F. Martin ◽  
F. Uruburu ◽  
J. R. Villanueva
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Ultrastructural Changes ◽  
Dense Layer ◽  
Penicillium Notatum ◽  
Thin Sections ◽  
Resting Spores ◽  
Different Types ◽  
Germ Tubes ◽  
Isolated Cell

To study the changes in the cell wall of Penicillium notatum during germination, thin sections of resting, swollen, and germinating spores, and mycelium were compared with thin sections of the isolated cell walls. In the cell wall of resting spores four distinct layers were found. The outermost layer of the cell wall of resting spores was released during swelling and the two inner layers were extended to form the cell wall of the germ tube. The cell wall of young germ tubes had only two layers but a new electron-dense layer was formed later on the outside. Mycelial cell walls which appeared thinner than those of conidia showed three distinct layers. Large mitochondria that divide during germination were present in both resting and swollen spores. Two different types of vacuoles were found, both of which decreased in size and in number during germination. Endoplasmic reticulum was almost absent in resting spores but increased substantially during swelling.

Histochemical and Ultrastructural Studies of the Digestive Epithelium in a Gastropod Gametolytic Organ

1980 ◽  
Vol 38 ◽  
pp. 568-569
Author(s):  
R. L. Reeder ◽  
S. H. Rogers ◽  
W. A. Shannon
Keyword(s):  
Acid Phosphatase ◽  
Genital Tract ◽  
Reproductive Tract ◽  
Ultrastructural Level ◽  
Conclusive Evidence ◽  
Digestive Organ ◽  
Limited Information ◽  
Ultrastructural Studies ◽  
Morphological Studies

Numerous morphological studies have dealt with the spermatheca of pulmonate gastropods. This globular organ, which is attached to the female portion of the reproductive tract by a long duct in these monoecious animals, has had various functions ascribed to it. Recent histochemical demonstrations of deoxyribonuclease, ribonuclease, protease, and acid phosphatase have provided, however, conclusive evidence that it is a digestive organ for the degradation of superfluous sperm and genital tract secretions. Only limited information concerning the spermatheca is available at the ultrastructural level, a fact providing the stimulus for the present study of this organ in Sonorella santaritana, a desert mountain snail from Arizona.

scholarly journals New methods for confocal imaging of infection threads in crop and model legumes

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Angus E. Rae ◽  
Vivien Rolland ◽  
Rosemary G. White ◽  
Ulrike Mathesius
Keyword(s):  
Cell Wall ◽  
Root Hair ◽  
Periodic Acid ◽  
Confocal Imaging ◽  
Wall Material ◽  
Future Research ◽  
Thin Sections ◽  
New Methods ◽  
Infection Threads ◽  
Imaging Of Infection

Abstract Background The formation of infection threads in the symbiotic infection of rhizobacteria in legumes is a unique, fascinating, and poorly understood process. Infection threads are tubes of cell wall material that transport rhizobacteria from root hair cells to developing nodules in host roots. They form in a type of reverse tip-growth from an inversion of the root hair cell wall, but the mechanism driving this growth is unknown, and the composition of the thread wall remains unclear. High resolution, 3-dimensional imaging of infection threads, and cell wall component specific labelling, would greatly aid in our understanding of the nature and development of these structures. To date, such imaging has not been done, with infection threads typically imaged by GFP-tagged rhizobia within them, or histochemically in thin sections. Results We have developed new methods of imaging infection threads using novel and traditional cell wall fluorescent labels, and laser confocal scanning microscopy. We applied a new Periodic Acid Schiff (PAS) stain using rhodamine-123 to the labelling of whole cleared infected roots of Medicago truncatula; which allowed for imaging of infection threads in greater 3D detail than had previously been achieved. By the combination of the above method and a calcofluor-white counter-stain, we also succeeded in labelling infection threads and plant cell walls separately, and have potentially discovered a way in which the infection thread matrix can be visualized. Conclusions Our methods have made the imaging and study of infection threads more effective and informative, and present exciting new opportunities for future research in the area.

Prefertilization ovule development in Capsella: the dyad, tetrad, developing megaspore, and two-nucleate gametophyte

1986 ◽  
Vol 64 (4) ◽  
pp. 875-884 ◽  
Author(s):  
Patricia Schulz ◽  
William A. Jensen
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Acid Phosphatase ◽  
De Novo ◽  
Periodic Acid ◽  
Aniline Blue ◽  
Ovule Development ◽  
Periodic Acid Schiff ◽  
Fluorescent Material ◽  
Autophagic Vacuoles

Ovules of Capsella bursa-pastoris at the dyad and tetrad stages of meiosis and at the megaspore and two-nucleate stages of the gametophyte were studied with the electron microscope. The cells of the dyad and tetrad are separated by aniline blue fluorescent cross walls and receive all types of organelles and autophagic vacuoles that were present in the meiocyte. Autophagic vacuoles enclose ribosomes and organelles and show reaction product for acid phosphatase. Autophagic vacuoles and some plastids are absorbed into the enlarging vacuoles of the growing megaspore. Other plastids appear to survive meiosis and there is no evidence for their de novo origin. Some mitochondria appear to degenerate in the enlarging megaspore but others look healthy and there is no evidence for the de novo origin of mitochondria. The nucleolus of the developing megaspore becomes very large and the cytoplasm is extremely dense with ribosomes. The cell wall is thickened by an electron-translucent, periodic acid – Schiff negative, aniline blue fluorescent material and contains plasmodesmata that link the megaspore with the nucellus. The plasmalemma of the growing megaspore produces microvilluslike extensions into this wall that disappear with the formation of the two-nucleate gametophyte. Plasmodesmata disappear from the cell wall at the four-nucleate stage.

scholarly journals FINE STRUCTURE OF THE GRAM-NEGATIVE BACTERIUM ACETOBACTER SUBOXYDANS

1964 ◽  
Vol 20 (2) ◽  
pp. 217-233 ◽  
Author(s):  
G. W. Claus ◽  
L. E. Roth
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Walls ◽  
Negative Staining ◽  
Homogeneous Layer ◽  
Physical Treatment ◽  
Thin Sections ◽  
Gram Negative ◽  
Acetobacter Suboxydans ◽  
Negative Cell

The morphological features of the cell wall, plasma membrane, protoplasmic constituents, and flagella of Acetobacter suboxydans (ATCC 621) were studied by thin sectioning and negative staining. Thin sections of the cell wall demonstrate an outer membrane and an inner, more homogeneous layer. These observations are consistent with those of isolated, gram-negative cell-wall ghosts and the chemical analyses of gram-negative cell walls. Certain functional attributes of the cell-wall inner layer and the structural comparisons of gram-negative and gram-positive cell walls are considered. The plasma membrane is similar in appearance to the membrane of the cell wall and is occasionally found to be folded into the cytoplasm. Certain features of the protoplasm are described and discussed, including the diffuse states of the chromatinic material that appear to be correlated with the length of the cell and a polar differentiation in the area of expected flagellar attachment. Although the flagella appear hollow in thin sections, negative staining of isolated flagella does not substantiate this finding. Severe physical treatment occasionally produces a localized penetration into the central region of the flagellum, the diameter of which is much smaller then that expected from sections. A possible explanation of this apparent discrepancy is discussed.

The Ultrastructure and Ontogeny of Pollen in Helleborus Foetidus L

1968 ◽  
Vol 3 (2) ◽  
pp. 161-174
Author(s):  
P. ECHLIN ◽  
H. GODWIN
Keyword(s):  
Cell Wall ◽  
Tapetal Cell ◽  
Pollen Grains ◽  
Ultrastructural Level ◽  
Low Molecular Weight ◽  
Cell Organelles ◽  
Helleborus Foetidus ◽  
Ubisch Bodies ◽  
Ubisch Body ◽  
Development Proceeds

The ontogeny of the tapetum and Ubisch bodies in Helleborus foetidus L. has been examined at the ultrastructural level, and their development has been closely linked with that of the sporogenous cell and pollen grains. During development the tapetum passes through successive phases of synthesis, maturity and senescence, ending in complete dissolution. During the anabolic phase of growth, precursors of the Ubisch bodies are formed as spheroidal vesicles of medium electron density within the tapetal cytoplasm; they are associated with a zone of radiating ribosomes, which, as development proceeds, can clearly be seen to be situated on strands of endoplasmic reticulum. The callose special wall round the microspores and the tapetal cell wall now disintegrate and the pro-Ubisch bodies are extruded through the cell membrance of the tapetal cells, where they remain on the surface of the anther cavity and soon become irregularly coated with sporopollenin. Deposition of sporopollenin continues on the Ubisch bodies at the same time as upon the exines of the developing pollen grains. In both cases, the later stages of sporopollenin deposition are associated with electron-transparent layers of unit-membrane dimensions appearing in section as white lines of uniform thickness. Continuing deposition of sporopollenin leads to the formation of compound or aggregate Ubisch bodies. It is conjectured that the sporopollenin is synthesized from the compounds of low molecular weight released into the anther loculus by the breakdown of the callose special wall and the tapetal cell wall. The final stages of tapetal autolysis involve the disappearance of all the cell organelles. An attempt is made to relate the findings to those described in other recent studies on Ubisch body formation and to combine them in a common ontogenetic pattern.

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