Fine structure of conidiogenesis in the holoblastic, sympodial Tritirachium roseum

1973 ◽  
Vol 51 (11) ◽  
pp. 2033-2036 ◽  
Author(s):  
Terrence M. Hammill
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Fine Structure ◽  
Conidiogenous Cell ◽  
Full Size ◽  
Distal Half ◽  
Electron Transmission ◽  
Proximal Half ◽  
Conidiogenous Locus ◽  
Fertile Region

Electron microscopy of conidiogenesis in Tritirachium roseum was done on material fixed in glutaraldehyde followed by OsO4. The walls of conidiogenous cells, though pigmented, lacked well-defined differential electron-transmission layers. Conidial initials developed without the appearance of a rupture in the conidiogenous cell wall, i.e., development was holoblastic. Each successively produced conidiogenous locus developed below and to one side of the previously formed conidium, and the fertile region of the conidiogenous cell elongated in a geniculate pattern. After each conidial initial reached full size, it was delimited by a centripetally developing septum, which increased in thickness, became double, and split during conidial secession. The distal half of a split septum formed the conidial base; the proximal half remained as part of the conidiogenous cell wall. Upon conidial secession, basal frills on conidia, and secession scars on conidiogenous cells were especially conspicuous.

Fine structure of conidiogenesis in the mosquito pathogen Culicinomyces clavosporus (Deuteromycotina)

1983 ◽  
Vol 61 (10) ◽  
pp. 2618-2625 ◽  
Author(s):  
A. O. Inmann III ◽  
C. E. Bland
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Classification Scheme ◽  
Conidiogenous Cell ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Conidiogenous Locus ◽  
Mode Of Development ◽  
Mosquito Pathogen ◽  
Primary Conidium

Conidiogenesis in Culicinomyces clavosporus Couch, Romney, and Rao (Deuteromycotina) is initiated with the growth of conidiogenous cells from vegetative hyphae. Formation of the primary conidium itself begins with a conidial initial which grows through the bilaminar wall at the tip of the conidiogenous cell, wall remnants of the conidiogenous cell often collapsing to form a collarette at the base of conidia. This factor, in addition to the fixed conidiogenous locus, shows that the conidiogenous cell is a phialide. As the conidial initial enlarges, a bilaminar well is synthesized around the cell, and cytoplasmic organelles migrate through the neck of the phialide into the initial. Once the conidium is mature, a septum is formed across the open neck of the phialide and two organelles (dense-core vesicles and autophagosomes), unique to conidia, become evident. The mode of development is enteroblastic–phialidic; Culicinomyces clavosporus is placed therefore in section IVB of the Hughes–Tubaki–Barron classification scheme described by B. Kendrick for the Deuteromycotina.

The fine structure of conidiogenesis in Alysidium resinae (=Torula ramosa)

1977 ◽  
Vol 55 (6) ◽  
pp. 676-684 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Conidiogenous Cell ◽  
Mechanical Rupture

Conidia of Alysidium resinae (Fr.) M. B. Ellis (=Torula ramosa Peck) arise enteroblastically from polyblastic, ampulliform conidiogenous cells after mechanical rupture of the conidiogenous cell wall and are produced in either branched or unbranched acropetalous chains, successively younger conidia being produced enteroblastically from the immediately older conidia. There is no indication that conidial evagination occurs via enzymatically produced channels in the parent wall, protrusion being exclusively mechanical. Attention is drawn to the controversy surrounding the enteroblastic tretic mode of conidiogenesis.

The fine structure of conidial development in the genus Torula. II. T. caligans (Batista and Upadhyay) M. B. Ellis and T. terrestris Misra

1975 ◽  
Vol 21 (12) ◽  
pp. 1921-1929 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Conidiogenous Cell ◽  
The Other ◽  
Conidial Development ◽  
Lowermost Part ◽  
Systematic Relationships ◽  
Lateral Walls ◽  
Scanning Electron

Conidia of Torula caligans (Batista & Upadhyay) M. B. Ellis comb. nov. and T. terrestris Misra were examined by transmission- and scanning-electron microscopy. Torula caligans produced four-celled conidia in which the central cells were distinctly larger than the basal and apical cells. Conidia of T. terrestris were 4- to 7-celled long and ellipsoidal in shape. Conidiogenous cells in both species developed melanin only within the lowermost part of the lateral walls while the other cells of the conidium were uniformly melanized around the circumference of the cell; melanin in these cells being deposited within, at least, half the width of the cell wall. In both species new conidia arose from evagination of the hyaline apex of the conidiogenous cell and are therefore blastoconidia. The systematic relationships between T. caligans and T. terrestris and other species of the genus Torula are discussed.

Fine structure of Arthrobacter crystallopoietes during long-term starvation of rod and spherical stage cells

1973 ◽  
Vol 19 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Charles W. Boylen ◽  
Jack L. Pate
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Fine Structure ◽  
Cell Size ◽  
Morphological Changes ◽  
Thin Sections ◽  
Size And Shape ◽  
Arthrobacter Crystallopoietes ◽  
Total Starvation

Actively growing spherical and rod-shaped cells of Arthrobacter crystallopoietes were subjected to total starvation in buffer for 8 weeks. At intervals, thin sections of cells were prepared and examined by electron microscopy. Starving cells underwent no morphological changes that would account for their unusual survival capabilities. Cell size and shape remained unaltered. There was no thickening of the cell wall and no development of structures similar to those observed in spores or cysts. As the length of starvation increased, the following changes were observed; glycogen deposits disappeared, the number of ribosome particles decreased, the number of vesicular membranes increased within the cell, and the nucleoplasm expanded in volume to fill the emptying cytoplasm.

CYTOLOGY OF PHAGE-INFECTED STREPTOMYCES GRISEUS HYPHAE

1965 ◽  
Vol 11 (1) ◽  
pp. 103-107
Author(s):  
C. M. Gilmour ◽  
E. B. Bradford
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Streptomyces Griseus ◽  
Membrane Disruption ◽  
Hexagonal Shape ◽  
Ultrathin Sections ◽  
Irregular Cell

The fine structure of phage-infected Streptomyces griseus hyphae was examined using ultrathin sections and electron microscopy. The intracellular phage was observed to be uniformly distributed throughout the cytoplasm. The diameter and hexagonal shape of the head compared well with shadowed phage preparations. Alterations in fine structure centered on irregular cell wall disintegration, plasma membrane disruption, and leakage of cytoplasmic components.

scholarly journals THE FINE STRUCTURE AND MODE OF ATTACHMENT OF THE SHEATHED FLAGELLUM OF VIBRIO METCHNIKOVII

1963 ◽  
Vol 18 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Audrey M. Glauert ◽  
D. Kerridge ◽  
R. W. Horne
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Thin Sections ◽  
Basal Disc ◽  
The Core ◽  
Thin Sectioning ◽  
Potassium Phosphotungstate ◽  
Mode Of Attachment

The sheathed flagellum of Vibrio metchnikovii was chosen for a study of the attachment of the flagellum to the bacterial cell. Normal and autolysed organisms and isolated flagella were studied by electron microscopy using the techniques of thin sectioning and negative staining. The sheath of the flagellum has the same layered structure as the cell wall of the bacterium, and in favourable thin sections it appears that the sheath is a continuation of the cell wall. After autolysis the sheath is usually absent and the core of the flagellum has a diameter of 120 A. Electron micrographs of autolysed bacteria negatively stained with potassium phosphotungstate show that the core ends in a basal disc just inside the plasma membrane. The basal disc is about 350 A in diameter and is thus considerably smaller than the "basal granules" described previously by other workers.

Ultrastructure of conidiogenesis in Drechslera sorokiniana

1973 ◽  
Vol 51 (3) ◽  
pp. 629-638 ◽  
Author(s):  
Garry T. Cole
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Outer Wall ◽  
Conidiogenous Cell ◽  
Ultrastructural Examination ◽  
Transmission Electron ◽  
Conidium Formation ◽  
Microscopic Studies ◽  
Relationship Of

An ultrastructural examination of conidiogenesis in Drechslera sorokiniana reveals that conidia develop enteroblastically through channels in the conidiogenous cell wall. These channels probably form by autolysis of the outer wall layers. The data support earlier concepts based on light-microscopic studies of conidium ontogeny in this and other developmentally related species of hyphomycetes. The surface morphology and relationship of wall layers of the conidium and conidiogenous cell at various stages of development are illustrated by scanning and transmission electron microscopy, respectively. This information is summarized in a diagrammatic interpretation of conidiogenesis. Cytodifferentiation during conidium formation and conidiogenous cell proliferation is also examined. A possible association between organelle migration in developing conidiogenous cells and fascicles of microfibrils, proposed in an earlier paper, is discussed. A suggestive explanation is presented for the accumulation of microbodies in conidium initials and apices of proliferating conidiogenous cells. Layers of endoplasmic reticulum which are terminally hypertrophied and juxtaposed to the plasma membrane of developing conidiogenous cells are also noted.

The fine structure of conidial development in the genus Torula. III. T. graminis Desm.

1976 ◽  
Vol 22 (6) ◽  
pp. 858-866 ◽  
Author(s):  
D. H. Ellis ◽  
D. A. Griffiths
Keyword(s):  
Cell Wall ◽  
Fine Structure ◽  
Conidiogenous Cell ◽  
Conidial Development ◽  
Hyaline Zone

Torula graminis produced blastoconidia in acropetalous chains after the evagination of a characteristic conidiogenous cell. Conidia consisted of up to 15 cells and their cell wall was differentiated into an outer melanized zone and an inner hyaline zone. A consistent cytoplasmic feature of conidial cells was the presence of dictyosomal-like membranous stacks often closely associated with the nucleus. Vesicles that developed from the dictyosomal-like cisternae were probably involved in conidial wall synthesis.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

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