The fine structure and development of chlamydospores of Fusarium oxysporum

1972 ◽  
Vol 18 (7) ◽  
pp. 997-1002 ◽  
Author(s):  
I. L. Stevenson ◽  
S. A. W. E. Becker
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cell Surface ◽  
Outer Layer ◽  
Outer Wall ◽  
Wall Layer ◽  
Thin Sections ◽  
Hyphal Wall

Methods have been developed for the rapid, reproducible induction of high-density populations of F. oxysporum chlamydospores. On transferring washed pregerminated conidia to a simple two-salts medium, chlamydospore morphogenesis was evident by 12 h and masses of mature spores could be harvested at the end of 4 days. Electron-microscope studies of thin sections of mature chlamydospores reveal a thick triple-layered cell wall. The cytoplasm contains, in addition to large lipid deposits, a nucleus, mitochondria, and endoplasmic reticulum all typical of fungal cells. Chlamydospores of F. oxysporum exhibit two distinct types of cell surface in thin section. The outer wall layer of two of the isolates studied was smooth-surfaced while the outer layer of the two other isolates was distinctly fibrillose. Some evidence is presented suggesting that the fibrillose material arises through the partial breakdown of the original hyphal wall.

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.

The fine structure of Rhodopseudomonas acidophila

1974 ◽  
Vol 20 (1) ◽  
pp. 13-17 ◽  
Author(s):  
H.-D. Tauschel ◽  
Judith F. M. Hoeniger
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Outer Layer ◽  
Photosynthetic Bacterium ◽  
Thin Sections ◽  
Rhodopseudomonas Acidophila ◽  
Motile Cells ◽  
Similarities And Differences ◽  
Mother Cells

The morphology of the photosynthetic bacterium Rhodopseudomonas acidophila strain P18aF1 1.2 has been investigated with the electron microscope. The cells grow by budding, the sessile buds eventually separating from the mother cells by constriction. In some dividing stages a belt-like structure was observed in the zone of division. Motile cells possess a subpolar tuft of unsheathed flagella. At the site of insertion of the flagella, the cell wall bears 12- to 14-nm wide holes or annuli through which the flagella probably pass. Motile cells readily lose their flagella.The structure of the surface revealed two distinct types: cells with a hexagonally patterned outer layer composed of ring-shaped elements and cells possessing a thick, fibrous capsule. Thin sections showed a well-developed thylakoid system arranged in piles and similar to that of other budding photosynthetic bacteria.The morphology of R. acidophila has been compared with that of R. palustris to show similarities and differences between the two species.

scholarly journals Further Observations on the Fine Structure of Chrysochromulina Ericina Parke & Manton

1961 ◽  
Vol 41 (1) ◽  
pp. 145-155 ◽  
Author(s):  
I. Manton ◽  
G. F. Leedale
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cell Surface ◽  
Light Microscopy ◽  
Flat Plate ◽  
Outer Layer ◽  
Living Cells ◽  
Layered Plates ◽  
Thin Sections ◽  
Micro Anatomy

C. ericina Parke & Manton has been re-investigated to add salient features of micro-anatomy from the electron microscopy of thin sections and also to add photographs of living cells taken with anoptral contrast light microscopy.The most important new observations concern the scales which are shown to be essentially two-layered plates in which the layers in the very large spined scales have become separated except at their edges, with the outer layer greatly hypertrophied to produce a hollow spine with a flared base closed at the bottom by a flat plate. The patterns of external marking on the two layers are very similar in both plate-scales and spines in this species and the orientation of both with respect to the cell surface has been demonstrated by a section of the scales in situ.

scholarly journals THE FINE STRUCTURE OF NEURONS

1955 ◽  
Vol 1 (1) ◽  
pp. 69-88 ◽  
Author(s):  
Sanford L. Palay ◽  
George E. Palade
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cerebellar Cortex ◽  
Dorsal Root Ganglia ◽  
Medulla Oblongata ◽  
Dorsal Root ◽  
Thin Sections ◽  
Lipid Inclusions ◽  
Nissl Substance

1. Thin sections of representative neurons from intramural, sympathetic and dorsal root ganglia, medulla oblongata, and cerebellar cortex were studied with the aid of the electron microscope. 2. The Nissl substance of these neurons consists of masses of endoplasmic reticulum showing various degrees of orientation; upon and between the cisternae, tubules, and vesicles of the reticulum lie clusters of punctate granules, 10 to 30 mµ in diameter. 3. A second system of membranes can be distinguished from the endoplasmic reticulum of the Nissl bodies by shallower and more tightly packed cisternae and by absence of granules. Intermediate forms between the two membranous systems have been found. 4. The cytoplasm between Nissl bodies contains numerous mitochondria, rounded lipid inclusions, and fine filaments.

scholarly journals THE CYTOPLASMIC FINE STRUCTURE OF THE DIATOM, NITZSCHIA PALEA

1963 ◽  
Vol 18 (2) ◽  
pp. 429-440 ◽  
Author(s):  
Ryan W. Drum
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Hydrofluoric Acid ◽  
Oil Bodies ◽  
Oil Droplets ◽  
Pennate Diatom ◽  
Thin Sections ◽  
Nitzschia Palea ◽  
Peripheral Cytoplasm

The cytoplasmic fine structure of the motile, pennate diatom, Nitzschia palea was studied in thin sections viewed in the electron microscope. The cells were fixed in OsO4, embedded in methacrylate, and immersed in 10 per cent hydrofluoric acid (HF) for 36 to 40 hours to remove the siliceous cell wall prior to sectioning. The HF treatment did not cause any obvious cytoplasmic damage. The dictyosome complex is perinuclear, and located only in the central cytoplasm. Mitochondria are sparse in the central cytoplasm, but abundant in the peripheral cytoplasm, and fill many of the transvacuolar cytoplasmic strands. Characteristic, amorphous oil bodies fill certain cytoplasmic strands and probably are not leucosin. The pyrenoid appears to be membrane limited, and oil droplets are found adjacent to the pyrenoid. The pyrenoid of another diatom, Cymbella affinis, is also membrane-limited. The membrane limiting the pyrenoid may be a composite of the terminal portions of chloroplast discs, facilitating rapid movement of photosynthate into the pyrenoid matrix, where the characteristic oil droplets may be formed. Carinal fibrils are found singly in each carinal pore, and may be involved in the locomotion of Nitzschia palea.

Cell wall structures of Epicoccum nigrum (Hyphomycetes)

1973 ◽  
Vol 51 (5) ◽  
pp. 1071-1073 ◽  
Author(s):  
J. A. Brushaber ◽  
R. H. Haskins
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Outer Layer ◽  
Secondary Wall ◽  
Outer Wall ◽  
Wall Layer ◽  
Wall Material ◽  
Primary Wall ◽  
Electron Dense Material ◽  
Wall Structures

Two structurally distinct types of secondary wall layers are present in older hyphae in addition to the primary wall. A coarsely fibrous outer wall layer often becomes quite massive and frequently fuses with the outer wall layers of adjacent cells in the formation of hyphal strands. The uneven deposition of this outer layer often produces large verrucosities. The inner secondary wall layer is relatively electron transparent and contains a reticulum of electron-dense lines. The interface of the inner secondary wall with the cytoplasm is often very irregular, and sections of the plasma membrane are frequently overlain by wall material. The outer secondary wall of conidia is composed of an electron-dense material different from that of the outer wall of hyphae. Cells in the multicellular conidia tend to be polyhedral in shape with either very thick primary walls or thin primary walls having a thick inner wall deposit.

AN ELECTRON MICROSCOPE STUDY OF THIN SECTIONS OF HAEMOPHILUS VAGINALIS (GARDNER AND DUKES) AND SOME POSSIBLY RELATED SPECIES

1966 ◽  
Vol 12 (6) ◽  
pp. 1125-1136 ◽  
Author(s):  
Alice Reyn ◽  
A. Birch-Andersen ◽  
S. P. Lapage
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Electron Microscope ◽  
Lactobacillus Acidophilus ◽  
Related Species ◽  
Electron Microscope Study ◽  
Similar Degree ◽  
Gram Positive ◽  
Thin Sections

The line structure of Haemophilus vaginalis (Gardner and Dukes 1955) was compared with that of four, possibly related species (Butyribacterium rettgeri, Corynebacterium diphtheriae var. mitis, Lactobacillus acidophilus, Haemophilus influenzae) and an unrelated species, Neisseria haemolysans, which had shown a similar degree of Gram-variability as that of H. vaginalis. Although H. vaginalis was first described as a Gram-negative rod, its fine structure, particularly that of cell wall and septa, was more like that of Gram-positive organisms. Also N. haemolysans had a fine structure close to that of Gram-positive organisms, and its typical Gram-positive cell wall varied in. thickness from one cell to another.The study did not solve the problem of the classification of the so-called H. vaginalis, but the appearance of the few strains studied in the electron microscope suggests that it: should be included in Corynebacterium or Butyribacterium rather than in Lactobacillus.

Uredospore development in Puccinia graminis

1969 ◽  
Vol 47 (12) ◽  
pp. 2061-2064 ◽  
Author(s):  
M. A. Ehrlich ◽  
H. G. Ehrlich
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Wall Layer ◽  
Tangential Section ◽  
Puccinia Graminis ◽  
Lipid Bodies ◽  
External Wall ◽  
Additional Information ◽  
Spine Development

The present paper reports a number of electron microscope observations on the protoplasm and walls of developing spores which provide additional information on uredospore wall and spine development and on the fine structure of organelles, particularly of mitochondria and endoplasmic reticulum and of lipid bodies in developing spores. Micrographs of partially extracted uredospore walls and of chromium-shadowed extracted sections demonstrate the architecture of the wall as seen in cross and tangential section. Three distinct wall zones are clearly visible with the external wall layer forming the boundary of the germinal pore.

scholarly journals THE FINE STRUCTURAL ORGANISATION OF ROUS TUMOUR CELLS

1957 ◽  
Vol 3 (6) ◽  
pp. 851-858 ◽  
Author(s):  
M. A. Epstein
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Cell Membrane ◽  
Nuclear Membrane ◽  
Tumour Cells ◽  
Thin Sections ◽  
Outer Nuclear Membrane ◽  
Structural Organisation ◽  
Perinuclear Space

The fibroblast-like tumour cells of Rous sarcomata have been studied in thin sections with the electron microscope. A description is given of the fine structure of the cells which includes some features not hitherto recorded. The tightly packed piles of smooth cisternae usually found only in the centrosome region have been observed, in individual Rous cells, in two separate areas of cytoplasm at opposite poles of the nucleus. Continuity between the perinuclear space and the lumen of rough surfaced cisternae of the endoplasmic reticulum has frequently been found; a similar continuity between the cisternae and the exterior of the cell has also been seen. In some cases, the cell membrane has been shown to have an unbroken connection with the outer nuclear membrane through continuity with the limiting membranes of elements of the endoplasmic reticulum. These findings are discussed.

Fine Structure of Interdental Cells in the Mouse Cochlea

1970 ◽  
Vol 28 ◽  
pp. 140-141
Author(s):  
Roberta M. Bruck
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Young Adult ◽  
Uranyl Acetate ◽  
Ground Substance ◽  
Tectorial Membrane ◽  
Lead Citrate ◽  
Unusual Structure ◽  
Thin Sections ◽  
Collagenous Fibers

An unusual structure in the cochlea is the spiral limbus; this periosteal tissue consists of stellate fibroblasts and collagenous fibers embedded in a translucent ground substance. The collagenous fibers are arranged in vertical columns (the auditory teeth of Haschke). Between the auditory teeth are interdental furrows in which the interdental cells are situated. These epithelial cells supposedly secrete the tectorial membrane.The fine structure of interdental cells in the rat was reported by Iurato (1962). Since the mouse appears to be different, a description of the fine structure of mouse interdental cells' is presented. Young adult C57BL/6J mice were perfused intervascularly with 1% paraformaldehyde/ 1.25% glutaraldehyde in .1M phosphate buffer (pH7.2-7.4). Intact cochlea were decalcified in .1M EDTA by the method of Baird (1967), postosmicated, dehydrated, and embedded in Araldite. Thin sections stained with uranyl acetate and lead citrate were examined in a Phillips EM-200 electron microscope.

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