Asci of the Pezizales. VII. The apical apparatus of Galiella rufa and Sarcosoma globosum: reevaluation of the suboperculate ascus

1980 ◽  
Vol 58 (11) ◽  
pp. 1235-1243 ◽  
Author(s):  
Don A. Samuelson ◽  
Gerald L. Benny ◽  
James W. Kimbrough
Keyword(s):  
Comparative Analysis ◽  
Outer Layer ◽  
Differential Staining ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Separate Type ◽  
Apparent Change

Light and electron microscopic examinations were made on asci of Galiella rufa and Sarcosoma globosum with emphasis on the development, cytochemistry, and morphology of the apical apparatus. Comparative analysis of the fresh and revived states of the apical apparatus in G. rufa demonstrated no apparent change in wall layering and only minor differences in staining reaction with silver methenamine. Ascal tips of both species were slightly thinner walled than the rest of the ascus and possessed bistratified outer layers. The external stratum of the outer layer was more pronounced and electron dense at the apex in S. globosum. Opercula were distinguished by a cytochemically localized zone of dehiscence in G. rufa and a differential staining of the internal stratum of the outer layer in S. globosum. The ascus tips of G. rufa and S. globosum were most similar to other members of the Sarcosomataceae. The apical apparatuses of the Sarcoscyphaceae differed substantially from those of the Sarcosomataceae and the rest of the Pezizales, constituting a separate type.

Silver Staining of Pancreatic Islets as Revealed by Electron Microscopy

1967 ◽  
Vol 25 ◽  
pp. 44-45
Author(s):  
Kazuaki Misugi ◽  
Nobuko Misugi ◽  
Hiroshi Yamada
Keyword(s):  
Pancreatic Islet ◽  
Silver Staining ◽  
Islet Cells ◽  
Severe Hypoglycemia ◽  
Granular Cell ◽  
Electron Microscopic Level ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Pancreatic Islet Cell ◽  
D Cell

The authors had described the fine structure of a type of pancreatic islet cell, which appeared different from typical alpha and beta cells, and tentatively considered that this third type of granular cell probably represents the D cell (Figure 1).Since silver staining has been widely used to differentiate different types of pancreatic islet cells by light microscopy, an attempt to examine this staining reaction at the electron microscopic level was made.Material and Method: Surgically removed specimens from three infants who suffered from severe hypoglycemia were used. The specimens were fixed and preserved in 20% neutral formalin. Frozen sections, 30 to 40 micron thick, were prepared and they were stained by Bielschowsky's method as modified by Suzuki (2). The stained sections were examined under a microscope and islet tissues were isolated. They were fixed in 1% osmium tetroxide in phosphate buffer for one hour and embedded in Epon 812 following dehydration through a series of alcohols and propylene oxide.

Structure and developmental tendency of the dorsal marginal zone in the early amphibian gastrula

Development ◽  
1971 ◽  
Vol 25 (2) ◽  
pp. 263-276
Author(s):  
Nobushige Ikushima ◽  
Setsuko Maruyama
Keyword(s):  
Outer Layer ◽  
Marginal Zone ◽  
Kinetic Properties ◽  
Electron Microscopic ◽  
Structural Differences ◽  
Peripheral Surface ◽  
Early Gastrula ◽  
A Share

The peripheral surface of a fertilized, uncleaved egg is subdivided through cleavage and is allotted to constituent cells. This is called the primary surface. In an early morula a constituent cell has two kinds of surfaces: the primary surface, and the secondary surface, which does not participate in forming the periphery of the embryo. Electron-microscopic observations showed structural differences between the two surfaces. When the dorsal marginal zone of an early gastrula of Hynobius nebulosus is excised and immersed in Feldman's solution, the piece can easily be separated into two layers: the outer layer, whose constituent cells are given a share of the primary surface, and the inner layer, whose constituent cells are completely covered only by the secondary surface. Both an explanted piece of the outer layer and an intact double-layered piece show three kinds of movement: spreading, convergence followed by stretching, and spherical thickening. The inner layer is kinetically very inert, showing slight spreading and thickening. An explanted piece of the outer layer differentiates into axial mesodermal structures, while the inner layer does not. When a piece of either the inner or the outer layer is implanted in the blastocoel of another gastrula, it induces deuterencephalic and spino-caudal structures and seems to differentiate into axial mesodermal structures. Differences of kinetic properties and differentiation are considered to result from the fact that the outer layer has the primary surface, while the inner layer does not. Functional effects of the primary surface on the movement of tissues and differentiation are discussed.

Heterochromatin, the synaptonemal complex and crossing over

1984 ◽  
Vol 71 (1) ◽  
pp. 159-176 ◽  
Author(s):  
S.M. Stack
Keyword(s):  
Electron Microscopy ◽  
Lycopersicon Esculentum ◽  
Synaptonemal Complex ◽  
Electron Microscopic Examination ◽  
Differential Staining ◽  
Crossing Over ◽  
Mitotic Metaphase ◽  
Plantago Ovata ◽  
Electron Microscopic ◽  
Metaphase Chromosomes

A combined light- and electron-microscopic examination of chromosomes from two angiospermous plants, Plantago ovata and Lycopersicon esculentum, and a mammal, Mus musculus, was performed. From this investigation three observations have been made that may be relevant to the observed lack of crossing over in heterochromatin. (1) Differential staining indicates that heterochromatin represents a smaller fraction of the length of pachytene chromosomes than it represents in the length of mitotic metaphase chromosomes. Since the synaptonemal complex (SC) runs throughout the length of these pachytene chromosomes, it is under-represented in heterochromatin. Considering the evidence for a rough correlation between the length of SC and the amount of crossing over, this could result in less crossing over in heterochromatin than expected on the basis of its length in mitotic metaphase chromosomes. (2) Electron microscopy indicates that, unlike the SC in euchromatin, the SC in heterochromatin is densely ensheathed in highly compact chromatin. If crossing over occurs in the SC or even in the surrounding chromatin, the compaction of the chromatin may prevent the penetration of enzymes needed in recombination. (3) Finally, a difference in the structure of SCs in euchromatin versus heterochromatin was observed that could be associated with the lack of crossing over in heterochromatin.

Light and scanning electron microscopic observations of calcium oxalate crystals produced during growth of Sclerotium rolfsii in culture and in infected tissue

1984 ◽  
Vol 62 (10) ◽  
pp. 2028-2032 ◽  
Author(s):  
Z. K. Punja ◽  
S. F. Jenkins
Keyword(s):  
Oxalic Acid ◽  
Calcium Oxalate ◽  
Sclerotium Rolfsii ◽  
Crystal Formation ◽  
Positive Staining ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Characteristic Energy ◽  
Electron Microscopes ◽  
Scanning Electron

Crystals produced during growth of Sclerotium rolfsii on cellophane overlaying water agar were identified as calcium oxalate based on their solubility characteristics in certain acids, positive staining reaction with silver nitrate – dithiooxamide, and characteristic energy-dispersive X-ray emission spectrum. Addition of calcium salts to water agar enhanced crystal formation. Similar crystals of calcium oxalate were observed with the light and scanning electron microscopes in sugar beet and carrot leaf tissues infected by Sclerotium rolfsii. They frequently formed along the infecting hyphae or were associated with hyphal aggregates and were observed in abundance within the tissue. Addition of oxalic acid solutions to leaf discs resulted in necrosis of the tissue, and crystals similar in all respects to those produced in infected tissues were formed. These observations indicate that the oxalic acid produced by Sclerotium rolfsii in culture or in diseased tissue may sequester available calcium to form calcium oxalate, and provide evidence for the role of oxalic acid in pathogenesis.

scholarly journals Electron Microscopic Comparative Analysis of Smear Layer Removal by Ethylenediaminetetraacetic Acid and Chitosan Using Ultrasonic Activation: An In Vitro Study

2019 ◽  
Vol 4 (1) ◽  
pp. 37-41
Author(s):  
Arthanarieswaran A Sivakumar ◽  
Anjaneya S Prasad ◽  
Saravanapriyan Soundappan ◽  
Chakravarthy S Vineetha ◽  
Ravi Vaiyapuri ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Ethylenediaminetetraacetic Acid ◽  
In Vitro Study ◽  
Smear Layer ◽  
Vitro Study ◽  
Electron Microscopic ◽  
Ultrasonic Activation ◽  
Layer Removal

An Electron Microscope Study of the Outer Layers of Barley Leaves Infected with Rhynchosporium secalis

1974 ◽  
Vol 1 (2) ◽  
pp. 313 ◽  
Author(s):  
CC Ryan ◽  
CJ Grivell
Keyword(s):  
Cell Wall ◽  
Outer Layer ◽  
Electron Microscope Study ◽  
Electron Microscopic Examination ◽  
Ruthenium Red ◽  
Electron Microscopic ◽  
Before And After ◽  
Barley Leaves ◽  
Epidermal Cell Wall ◽  
Wall Following

An electron microscopic examination was made of barley leaves before and after infection by R. secalis. Ruthenium red was used as an electron-opaque stain for pectic material. In uninfected leaves the adaxial surface consisted of wax, cuticle, pectic and inner and outer layer of the epidermal cell wall. Following penetration, infecting hyphae grew between the pectic layer and outer layer of the epidermal wall. The pectic and cuticular layers remained largely intact in leaf lesions until conidia were produced, whereas the cell wall was degraded and replaced by hyphae.

Electron Microscopic Studies of Base Sequence in DNA

1974 ◽  
Vol 32 ◽  
pp. 300-301
Author(s):  
Michael Beer
Keyword(s):  
Base Sequence ◽  
Staining Reaction ◽  
Extended Form ◽  
Electron Microscopic ◽  
Microscopic Studies

I shall review the work on the electron microscopic determination of base sequence in DNA restricting myself to the approach in which one kind of base is selectively marked. The requirements for success are 1. Appropriate staining reaction: stain must be detectable yet sufficiently compact to allow resolution of adjaconts. Reactions must be sufficiently selective and sufficiently gentle to preserve the.polynucleotide chain. 2. Deposition of polynucleotide chains in untangled and sufficiently extended form. 3. Means for accurately enumerating unmarked bases between the marked ones.

scholarly journals LOCALIZATION OF CARBONIC ANHYDRASE ACTIVITY IN TURTLE AND TOAD URINARY BLADDER MUCOSA

1972 ◽  
Vol 20 (9) ◽  
pp. 696-702 ◽  
Author(s):  
SEYMOUR ROSEN
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Activity ◽  
Cobalt Sulfide ◽  
Toad Urinary Bladder ◽  
Staining Reaction ◽  
Luminal Surface ◽  
Electron Microscopic ◽  
Turtle Bladder ◽  
Mucosal Cells ◽  
Sulfide Compound

Carbonic anhydrase activity was demonstrated in a distinct population of mucosal cells of whole stretched bladder of turtle and toad. The apical portions of the cells containing the enzyme were discretely stained as noncontiguous polygonal forms and allowed an estimation of the luminal surface representation of this epithelium. The slight luminal surface (0.8% or less) occupied by cells with carbonic anhydrase activity in the toad bladder contrasted with a greater representation in turtle bladder (6.4-12.2%) and correlated with the relative capacity of these tissues to acidify. After completion of the enzyme staining reaction the tissues of the turtle bladder were directly processed for electron microscopic observations without osmium tetroxide postfixation. The deposition of the electron-opaque cobalt sulfide compound was selective and was found only in cells with luminal representation and small apical granules, the recently described "third cell type"; cobalt sulfide was mainly present in the cytoplasm, an observation consonant with the known localization of carbonic anhydrase primarily in supernatant fractions.

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