Fine structure of basidiospores of the cedar-apple rust fungus Gymnosporangium juniperi-virginianae

1977 ◽  
Vol 55 (9) ◽  
pp. 1057-1063 ◽  
Author(s):  
Charles W. Mims
Keyword(s):  
Fine Structure ◽  
Thin Layer ◽  
Lipid Droplets ◽  
Germ Tube ◽  
Rust Fungus ◽  
Spore Wall ◽  
Lipid Bodies ◽  
Pore Region ◽  
Hilar Region ◽  
Endoplasmic Reticula

Each basidiospore of Gymnosporangium juniperi-virginianae contains many ribosomes as well as lipid droplets, mitochondria, small vesicles, endoplasmic reticula, and structures thought to be microbodies. Mature spores are either uninucleate or binucleate although larger, tetranucleate spores were occasionally observed. The spore wall appears as a thin layer except around the hilar region where two layers are evident. Germination is almost always lateral although no germ pore region was noted in the wall. Vacuolation takes place during germination and lipid bodies disappear. The wall of the germ tube arising from the spore is continuous with that of the spore. A large number of vesicles is present in the germ tube. Basidiospores may also germinate by repetition.

Ultrastructure of teliospore germination and basidiospore formation in the rust fungus Gymnosporangium clavipes

1981 ◽  
Vol 59 (6) ◽  
pp. 1041-1049 ◽  
Author(s):  
Charles W. Mims
Keyword(s):  
Lipid Droplets ◽  
Germ Tube ◽  
Rust Fungus ◽  
Spore Wall ◽  
Pore Region ◽  
Synaptonemal Complexes ◽  
Germ Pore ◽  
Teliospore Germination ◽  
Cytoplasmic Vesicles ◽  
Prophase Nucleus

A mature teliospore of Gymnosporangium clavipes is two celled with a long pedicel. The spore wall appears multilayered and a germ pore region is present in the wall at each end of the teliospore. The cytoplasm of the spore is dense and packed with lipid droplets. A single, dense, prophase nucleus is present in each cell. Synaptonemal complexes were observed in younger spores but not in mature, germinable spores. The cytoplasm of a germinating spore appears less dense than that of a nongerminating spore. During germination a germ tube emerges from the germ pore region of each cell. Cytoplasmic vesicles are numerous in the tip of the rapidly elongating promycelium. The nucleus enters the promycelium and divides meiotically. Centripetally developing septa divide the promycelium into four uninucleate cells each of which gives rise to a sterigma at the tip of which a basidiospore initial develops. Cytoplasmic vesicles are prominent in the tip of the developing sterigma and in the basidiospore initial. Once the nucleus has entered the basidiospore initial it divides mitotically. During this time time a septum develops within the sterigma and the spore is delimited from the sterigma by the formation of a second septum at the base of the spore.

Fine structure of teliospores of the cedar-apple rust Gymnosporangium juniperi-virginianae

1975 ◽  
Vol 53 (6) ◽  
pp. 544-552 ◽  
Author(s):  
Charles W. Mims ◽  
Frank Seabury ◽  
E. L. Thurston
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Basal Cell ◽  
Spore Wall ◽  
Cellular Structures ◽  
Lipid Bodies ◽  
Germ Pore ◽  
Transmission Electron ◽  
Single Nucleus

Teliospores of the cedar-apple rust Gymnosporangium juniperi-virginianae were examined using transmission electron microscopy. Each ellipsoid spore is divided into two cells by a transverse septum. A second septum separates the basal cell of the teliospore from a long, hyaline, cylindrical pedicel. The fine structure of these septa is considered. The cytoplasm of the teliospore is very dense and contains a complement of cellular structures including ribosomes, vacuoles, mitochondria, and a large number of structures thought to be lipid bodies. Each cell of the teliospore contains a single nucleus, in which the chromatin is often considerably condensed. Two germ pore regions are present in each cell. The spore wall is thinnest in these regions and is different in structure than elsewhere around the spore.

scholarly journals THE FINE STRUCTURE OF ASTROCYTES IN THE CEREBRAL CORTEX AND THEIR RESPONSE TO FOCAL INJURY PRODUCED BY HEAVY IONIZING PARTICLES

1965 ◽  
Vol 25 (2) ◽  
pp. 141-157 ◽  
Author(s):  
David S. Maxwell ◽  
Lawrence Kruger
Keyword(s):  
Cerebral Cortex ◽  
Fine Structure ◽  
Electron Microscope ◽  
Reactive Astrocytes ◽  
Lipid Bodies ◽  
Particle Irradiation ◽  
Fibrous Astrocytes ◽  
Primitive Forms ◽  
Focal Injury ◽  
Glycogen Particles

Normal and reactive astrocytes in the cerebral cortex of the rat have been studied with the electron microscope following focal alpha particle irradiation. The presence of glycogen and approximately 60-A fibrils identify astrocyte cytoplasm in formalin-perfused tissue. The glycogen particles facilitate the identification of small processes and subpial and perivascular end-feet. Both protoplasmic and fibrous astrocytes contain cytoplasmic fibrils and should be distinguished on the basis of the configuration of their processes and their distribution. Acutely reactive astrocytes are characterized by a marked increase in the number of glycogen granules and mitochondria from the first day after irradiation. These cells later hypertrophy and accumulate lipid bodies and increased numbers of cytoplasmic fibrils. The glial "scar" consists of a greatly expanded volume of astrocyte cytoplasm filled with fibrils and displays no signs of astrocyte death, reversion to primitive forms, or extensive multiplication.

scholarly journals Growth and Differentiation of the Golgi Apparatus in the Red Alga, Callithamnion Roseum

1974 ◽  
Vol 14 (3) ◽  
pp. 633-655
Author(s):  
EVA KONRAD HAWKINS
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Red Algae ◽  
Developmental Stages ◽  
Spore Wall ◽  
Red Alga ◽  
Wall Formation ◽  
Golgi Vesicles

The fine structure of the Golgi apparatus during development of tetrasporangia of Calli-thamnion roseum is described. Dictyosomes and associated vesicles of 4 developmental stages of sporangia are examined. The wall of sporangia exhibits a heretofore unseen cuticle in red algae. Development of the spore wall and a new plasma membrane around spores occurs through fusion of adjacent Golgi vesicles along the periphery of cells. Observations are discussed in relation to wall formation and expansion of tetrads and in comparison with other work on growth and differentiation of the Golgi apparatus.

The fine structure and selected histochemistry of ungerminated basidiospores of Agrocybe acericola

1996 ◽  
Vol 74 (5) ◽  
pp. 780-787 ◽  
Author(s):  
Donald G. Ruch ◽  
Kiki Nurtjahja
Keyword(s):  
Fine Structure ◽  
Acid Phosphatase ◽  
Glyoxylate Cycle ◽  
Outer Wall ◽  
Spore Wall ◽  
Malate Synthase ◽  
Marker Enzyme ◽  
Wall Ultrastructure ◽  
Membrane Bound ◽  
The Glyoxylate Cycle

The basidiospore wall of Agrocybe acericola is composed of two distinct layers that are continuous around the spores. At the germ pore, the outer wall is very thin and the inner wall becomes thicker. The plasma membrane is appressed to the inner wall and lacks distinct invaginations. The protoplasm is densely packed with ribosomes. Spores contain very little lipid distributed at each end. Mitochondria are well defined and distributed throughout the cytoplasm. Spores are binucleate, with the two nuclei lying on a line nearly perpendicular to the long axis of the cell. Various sizes of single membrane-bound vacuoles are widely distributed in the cytoplasm. These vacuoles were shown to contain acid phosphatase, indicating lysosomal activity. Microbody-like organelles are observed, which are probably glyoxysomes, since assays of malate synthase, a marker enzyme of the glyoxylate cycle, are positive. Keywords: Agrocybe, spore wall ultrastructure, basidiospore ultrastructure, glyoxylate cycle, malate synthase, acid phosphatase.

Ultrastructure of freeze-substituted appressoria produced by aeciospore germlings of the rust fungus Arthuriomyces peckianus

1991 ◽  
Vol 69 (8) ◽  
pp. 1655-1665 ◽  
Author(s):  
E. C. Swann ◽  
C. W. Mims
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Key Words ◽  
Direct Contact ◽  
Germ Tube ◽  
Rust Fungus ◽  
Mitotic Division ◽  
Extracellular Material ◽  
Dialysis Membrane ◽  
Fungus Infection

Aeciospores of Arthuriomyces peckianus germinated readily on moist strips of dialysis membrane and developing appressoria were observed within 3 to 6 h after spores were deposited on membranes. A single germ tube typically emerged from each binucleate spore and grew until its tip contacted the dialysis membrane. The germ tube tip was then transformed into a swollen appressorium that adhered tightly to the membrane, apparently as a result of an extracellular material that surrounded the appressorium base. Virtually all the spore cytoplasm and both nuclei moved into the germ tube and developing appressorium. Following a synchronous mitotic division of the two nuclei, a septum formed to delimit the now tetranucleate appressorium from the germ tube. As the appressorium matured, an apparently wall-less region developed in the central portion of the appressorium appressed against the dialysis membrane. In this region the fungus plasma membrane appeared to make direct contact with the underlying dialysis membrane. A funnel-like or cone-like structure referred to as the appressorial cone then developed in the wall-less region. The appressorial cone extended up into the cytoplasm of the appressorium and was lined by the fungal plasma membrane. Numerous branched elaborations of the plasma membrane were associated with the inner portion of the cone. Key words: rust fungus, infection structures, electron microscopy.

Ultrastructural Studies on the Effects of Korean Panax Ginseng on the Theca Interna of Rat Ovary

1979 ◽  
Vol 07 (04) ◽  
pp. 333-344 ◽  
Author(s):  
Moo Rim Byung
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Panax Ginseng ◽  
Lipid Droplets ◽  
Ultrastructural Studies ◽  
Dense Bodies ◽  
Rat Ovary ◽  
Theca Interna ◽  
Morphologic Changes

An investigation was conducted to delineate the fine structure of steroid-producing ovarian theca interna cells following administration of Korean Panax ginseng to rats for 60 days. The cytoplasmic changes were observed in the ginseng-treated theca interna cells, increased number, size and density of the mitochondria, and increased size of the smooth surfaced endoplasmic reticulum, the rough surfaced endoplasmic reticulum and the Golgi apparatus. The nucleus and nucleolus were slightly enlarged and increased numbers of dense bodies were seen whereas lipid droplets were decreased in number. The changes may result from hyperfunction of the steroid-producing cells. Morphologic changes seen may represent stimulating effects on the steroid-producing cells of the theca interna in ginseng-treated animals.

CHANGES IN CELL FINE STRUCTURE OF LIMA BEAN AXES DURING EARLY GERMINATION

1966 ◽  
Vol 44 (3) ◽  
pp. 331-340 ◽  
Author(s):  
Shimon Klein ◽  
Yehuda Ben-Shaul
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Cell Walls ◽  
Lipid Droplets ◽  
Lima Bean ◽  
Amorphous Substance ◽  
Golgi Bodies ◽  
Early Germination ◽  
Almost All ◽  
Vacuolar Content

Changes in cell fine structure were studied in axes of green lima bean seeds soaked in water for 1–48 hours. At the beginning of the imbibition period the cortical and pith cells and to a smaller degree the cells of the future conductive tissues contain several vacuoles filled with an amorphous substance. Almost all of the cells contain lipid droplets arranged exclusively along cell walls. The endoplasmic reticulum appears in the form of long tubules, predominantly occupying the peripheral parts of the cell, surrounding the nucleus. A large concentration of ribosomes, mostly unattached, can be found in the cytoplasm. Similar particles make up the bulk of the nucleolus, but could not be found in plastids, which frequently contained starch, but were devoid of internal membranes. Only very few Golgi bodies occur. No changes in fine structure seem to occur during the first 4 hours of imbibition, but after 24 hours the lipid droplets and the vacuolar content have disappeared, the endoplasmic reticulum is more evenly distributed throughout the cells, and a large number of Golgi bodies can be seen.

scholarly journals Fusion Body Formation, Germ Tube Anastomosis, and Nuclear Migration During the Germination of Urediniospores of the Wheat Leaf Rust Fungus, Puccinia triticina

2009 ◽  
Vol 99 (12) ◽  
pp. 1355-1364 ◽  
Author(s):  
Xiben Wang ◽  
Brent McCallum
Keyword(s):  
Leaf Rust ◽  
Germ Tube ◽  
Rust Fungus ◽  
Puccinia Triticina ◽  
Rust Fungi ◽  
Wheat Leaf Rust ◽  
Virulence Phenotype ◽  
Close Proximity ◽  
Wheat Leaf ◽  
Germ Tubes

Vegetative or parasexual recombination is thought to be a key mechanism for the genetic diversity of cereal rust fungi. The process of germ tube fusion leading to hyphal anastomosis and nuclear recombination was analyzed in wheat leaf rust fungus, Puccinia triticina. Germ tube anastomosis was observed in 27 P. triticina isolates, each representing a different virulence phenotype. Germ tube fusion bodies (GFBs), which appeared as viscid globules formed at tips of germ tubes, were essential for germ tube anastomosis. The formation of GFBs was affected by the urediniospore density and the length of illumination during germination. GFBs were formed at the highest frequency when urediniospores were spread to a concentration of 1 × 106 urediniospores/ml and incubated in dark for 12 to 24 h during germination. GFB attached to either the side of another germ tube (“tip to side”) or to another GFB formed at the tip of a second germ tube (“tip to tip”). In “tip to side” anastomosis, two nuclei in the germ tube bearing the GFB migrated into the second germ tube through the GFB which resulted in four nuclei within this germ tube. In “tip to tip” anastomosis, nuclei in both germ tubes migrated into the fused GFB and all four nuclei came into close proximity. Urediniospores of isolates MBDS-3-115 and TBBJ-5-11 were stained with DAPI (4′,6′diamine-2-phenylindole) and Nuclear Yellow (Hoechst S769121), respectively, and then mixed and germinated on water agar. Some fused GFBs contained nuclei stained with DAPI and nuclei stained with Nuclear Yellow in close proximity, demonstrating the fusion between genetically different P. triticina isolates. In some fused GFBs, “bridge-like” structures connecting different nuclei were observed.

Fine structure of sporangiole development in Choanephora cucurbitarum (Mucorales)

1982 ◽  
Vol 60 (11) ◽  
pp. 2313-2324 ◽  
Author(s):  
Michael T. Higham ◽  
Kathleen M. Cole
Keyword(s):  
Electron Microscopy ◽  
Germ Tube ◽  
Tube Wall ◽  
Outer Wall ◽  
Spore Wall ◽  
Wall Layer ◽  
Choanephora Cucurbitarum ◽  
Dark Staining ◽  
Granular Vesicles ◽  
Scanning Electron

Spore development was studied in Choanephora cucurbitarum by using transmission and scanning electron microscopy. Sporangioles are produced by expansion of the ampulla wall. A two-layered spore wall is then constructed within the spine-covered sporangiole wall. The outer spore wall layer is longitudinally grooved and is devoid of spines or appendages. The inner wall layer is thinner and electron transparent. During wall production, dark-staining granular vesicles were observed in the spore cytoplasm. Their contents stained similarly to the material of the outer wall layer. Mature spores possessed a third, innermost wall layer. This was identified as a new wall layer, which was continuous with the germ-tube wall of germinated spores. Released spores were observed to be contained within the sporangiole during dispersal and germination.

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