Zygospores of the Harpellales: an ultrastructural study

1977 ◽  
Vol 55 (24) ◽  
pp. 3099-3110 ◽  
Author(s):  
S. T. Moss ◽  
R. W. Lichtwardt
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Ultrastructural Study ◽  
Storage Materials ◽  
Transmission Electron ◽  
Relationship Of ◽  
The Relationship ◽  
Thickened Wall

Structure of zygospores, their zygosporophores, and conjugants in Harpella melusinae, Trichozygospora chironomidarum, Genistellospora homothallica, and Zygopolaris ephemeridarum is described from light and transmission electron microscope studies. Possession of a thickened wall, presence of storage materials, and formation after hyphal conjugation supports the interpretation of these as zygospores. The relationship of the harpellaceous zygospores to those of other members of the Zygomycotina is discussed.

The flagellar apparatus in zoospores of Phytophthora, Pythium, and Halophytophthora

1992 ◽  
Vol 70 (11) ◽  
pp. 2163-2169 ◽  
Author(s):  
D. J. S. Barr ◽  
N. L. Désaulniers
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Flagellar Apparatus ◽  
Posterior Root ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Cytoplasmic Microtubules ◽  
Relationship Of ◽  
The Relationship

The flagellar apparatuses of 14 species of Phytophthora, 2 of Halophytophthora, and 4 of Pythium are compared in the transmission electron microscope. Except for Phytophthora infestans and Phytophthora mirabilis there were no significant differences in fine structure morphology. There are six flagellar roots: a ribbed triplet consisting of three main microtubules and secondary microtubules; an anterior doublet; a multistranded, band-shaped root of five to nine microtubules; a posterior root of two to four microtubules; and roots consisting of arrays of cytoplasmic microtubules and nuclear-associated microtubules. In P. infestans and P. mirabilis the multistranded root is missing, the posterior root contains five or six microtubules, and the anterior ribbed root contains four main microtubules. The transitional zones in all species are similar. The relationship of the Pythiaceae with other Oomycetes is discussed. Key words: taxonomy, phytogeny, cytology, Oomycetes, Pythiaceae.

Microstructural Evolution and Stress Relaxation in Sputtered Tungsten Films

1993 ◽  
Vol 318 ◽  
Author(s):  
F. M. Ross ◽  
R. R. Kola ◽  
R. Hull ◽  
J. C. Bean
Keyword(s):  
Electron Microscope ◽  
Stress Relaxation ◽  
Microstructural Evolution ◽  
Transmission Electron Microscope ◽  
Specimen Geometry ◽  
Β Phase ◽  
Transmission Electron ◽  
The Relationship

ABSTRACTWe have investigated the relationship between microstructure and stress in very thin sputtered W films. We discuss features of the microstructure, in particular the presence of voids in compressively stressed films, in terms of the evolution of the structure from a metastable β-phase. By developing a novel specimen geometry for the transmission electron microscope (TEM), we present dynamic observations of the β-W→α-W transformation.

Paraliomyces lentiferus: an ultrastructural study of a little-known marine ascomycete

1992 ◽  
Vol 70 (11) ◽  
pp. 2223-2232 ◽  
Author(s):  
S. J. Read ◽  
S.-Y. Hsieh ◽  
E. B. G. Jones ◽  
S. T. Moss ◽  
H. S. Chang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Ultrastructural Study ◽  
Republic Of China ◽  
Mucilaginous Sheath ◽  
Transmission Electron ◽  
Scanning Electron

A collection of Paraliomyces lentiferus from Taiwan, Republic of China, is compared with that of the type description and examined at both scanning and transmission electron microscope levels as part of our review of the taxonomy of the marine Ascomycotina. Particular attention was devoted to the structure of the ascospore appendage. The ascospore wall comprises a mesosporium, an episporium, and a mucilaginous sheath (exosporium?) In addition, there is a single, gelatinous, lateral appendage adjacent to the central septum. The appendage comprises electron-opaque fibrils that in immature ascospores are connected to the ascospore wall via fine electron-opaque strands and larger electron-opaque aggregates of material. The origin of the appendage is discussed. Key words: ascospore, attachment, marine ascomycete, scanning electron microscopy, spore appendage, transmission electron microscopy.

scholarly journals Relationship of leaf ultrastructure of mangrove Kandelia candel (L.) Druce to salt tolerance

2012 ◽  
Vol 51 (No. 10) ◽  
pp. 476-480 ◽  
Author(s):  
D. L Qiu ◽  
P. Lin ◽  
J. W Su
Keyword(s):  
Electron Microscope ◽  
Salt Tolerance ◽  
Transmission Electron Microscope ◽  
Kandelia Candel ◽  
Leaf Ultrastructure ◽  
Treatment Control ◽  
Environment Change ◽  
Membrane Breakdown ◽  
Transmission Electron ◽  
Relationship Of

The leaf ultrastructure of mangrove Kandelia candel (L.) Druce planted in pots under different salinity conditions was compared under a transmission electron microscope (TEM). The results showed that the plasmalemma in plants grown in salinity conditions of 0&permil; treatment (control) and 25&permil; treatment was tightly combined, while in plants with salinity of 50&permil; treatment, the plasmalemma crimpled remarkably and plasmolysis occurred. The nucleus and its two-layer membranes were obvious in control plants. In the case of 25&permil; treatment, the membrane breakdown was observed, nucleoplasm dispersed in cytoplasm, and the electron density of cells was lower than that in control plants. In plants treated with 50&permil; salinity the nucleus collapsed and no structure of the nucleus could be observed. As far as chloroplasts in control plants were concerned, they were oblong with a typical arrangement of grana and stroma thylakoids and one or two grains of starch. However, the chloroplasts in plants treated with 25&permil; salinity were swelling and usually contained more grains of starch and few plastoglobuli. Most chloroplasts had a reduced number of grana, particularly of thylakoids in grana as compared with control plants. The chloroplasts of plants treated with <br />50&permil; salinity had a considerably reduced system of grana and stroma thylakoids, and sometimes they were even defor-<br />med morphologically. They were mixed-up and contained more grains of starch and plastoglobuli. The indistinct structure of mitochondrial cristae was observed only in plants treated with 50&permil; salinity. These showed that mitochondria are cell organs less sensitive to hypersaline conditions than chloroplasts and nucleus, and it was deduced that respiration was more conservative to an environment change than photosynthesis.

A Reproducible Selective Stain for Cardiac Sarcoplasmic Reticulum

1974 ◽  
Vol 32 ◽  
pp. 214-215
Author(s):  
R. A. Waugh ◽  
J. R. Sommer
Keyword(s):  
Complex System ◽  
Electron Microscope ◽  
Sarcoplasmic Reticulum ◽  
Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Transmission Electron

Cardiac sarcoplasmic reticulum (SR) is a complex system of intracellular tubules that, due to their small size and juxtaposition to such electron-dense structures as mitochondria and myofibrils, are often inconspicuous in conventionally prepared electron microscopic material. This study reports a method with which the SR is selectively “stained” which facilitates visualizationwith the transmission electron microscope.

Surface Structure of the Spores of Glugea Weissenbergi

1969 ◽  
Vol 27 ◽  
pp. 238-239
Author(s):  
Sanford H. Vernick ◽  
Anastasios Tousimis ◽  
Victor Sprague
Keyword(s):  
Electron Microscope ◽  
Surface Structure ◽  
Transmission Electron Microscope ◽  
Mature Spore ◽  
Spore Surface ◽  
Sectioned Material ◽  
Transmission Electron ◽  
Surface Detail

Recent electron microscope studies have greatly expanded our knowledge of the structure of the Microsporida, particularly of the developing and mature spore. Since these studies involved mainly sectioned material, they have revealed much internal detail of the spores but relatively little surface detail. This report concerns observations on the spore surface by means of the transmission electron microscope.

A New High Resolution Transmission Electron Microscope with Second-Zone Objective Lens

1969 ◽  
Vol 27 ◽  
pp. 176-177 ◽  
Author(s):  
H. Tochigi ◽  
H. Uchida ◽  
S. Shirai ◽  
K. Akashi ◽  
D. J. Evins ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Transmission Electron Microscope ◽  
Objective Lens ◽  
High Excitation ◽  
Transmission Electron ◽  
New Instrument

A New High Excitation Objective Lens (Second-Zone Objective Lens) was discussed at Twenty-Sixth Annual EMSA Meeting. A new commercially available Transmission Electron Microscope incorporating this new lens has been completed.Major advantages of the new instrument allow an extremely small beam to be produced on the specimen plane which minimizes specimen beam damages, reduces contamination and drift.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

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