Cytoplasmic Microtubules in the Leaf Glands of Phaseolus Vulgaris

1967 ◽  
Vol 2 (4) ◽  
pp. 557-562
Author(s):  
T. P. O'BRIEN
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Phaseolus Vulgaris ◽  
Virus Infection ◽  
Light Microscope ◽  
Cytoplasmic Streaming ◽  
Cortical Microtubules ◽  
Cellular Asymmetry ◽  
Perinuclear Cytoplasm ◽  
Cytoplasmic Microtubules

Preliminary observations on the fine structure of the club-shaped glands on Phaseolus vulgaris leaves are reported. The perinuclear cytoplasm of the apical cells of these glands contains an abundance of microtubules. These occur either as aggregates of 2-8 or more tubules, or they may be organized around a central core of material to form a fibre-like structure. The cells also contain cortical microtubules and are rich in rough endoplasmic reticulum and dictyosomes. The nuclei of these cells also contain a proteinaceous fibre, visible in the light microscope. The possible significance of these structures is discussed in relation to cytoplasmic streaming, maintenance of cellular asymmetry, and reaction to virus infection.

scholarly journals The Fine Structure of the Parathyroid Gland

1958 ◽  
Vol 4 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Jerry Steven Trier
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Connective Tissue ◽  
Light Microscope ◽  
Parenchymal Cell ◽  
Cell Types ◽  
Perivascular Spaces ◽  
Chief Cells ◽  
Golgi Bodies ◽  
Endocrine Tissues

The fine structure of the parathyroid of the macaque is described, and is correlated with classical parathyroid cytology as seen in the light microscope. The two parenchymal cell types, the chief cells and the oxyphil cells, have been recognized in electron micrographs. The chief cells contain within their cytoplasm mitochondria, endoplasmic reticulum, and Golgi bodies similar to those found in other endocrine tissues as well as frequent PAS-positive granules. The juxtanuclear body of the light microscopists is identified with stacks of parallel lamellar elements of the endoplasmic reticulum of the ergastoplasmic or granular type. Oxyphil cells are characterized by juxtanuclear bodies and by numerous mitochondria found throughout their cytoplasm. Puzzling lamellar whorls are described in the cytoplasm of some oxyphil cells. The endothelium of parathyroid capillaries is extremely thin in some areas and contains numerous fenestrations as well as an extensive system of vesicles. The possible significance of these structures is discussed. The connective tissue elements found in the perivascular spaces of macaque parathyroid are described.

scholarly journals THE FINE STRUCTURE OF OSTEOBLASTS IN THE METAPHYSIS OF THE TIBIA OF THE YOUNG RAT

1961 ◽  
Vol 9 (3) ◽  
pp. 583-595 ◽  
Author(s):  
D. A. Cameron
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Light Microscope ◽  
Bone Matrix ◽  
Organic Matrix ◽  
Striking Feature ◽  
Cell Organelles ◽  
Phosphate Ions ◽  
Fine Structures ◽  
Young Rat

The appearance of osteoblasts after fixation with OsO4 is described in this paper. They have the basic structures found in other types of cells. The most striking feature is the array of rough-surfaced membranes of the endoplasmic reticulum; this feature is in keeping with the osteoblast's function of producing collagen as the bone grows. The sacs formed by these membranes probably represent the protein-containing granules described by other workers using the light microscope. They contain fine fibrillary material, and similar fibrils are to be found free in the cytoplasm. These fibrils could be tropocollagen units, although fibrils recognizable as collagen by their structure are found only outside the cell. The arrangement of the cell organelles does not seem to be related to the formation of collagen, but correlation of the fine structures of the cells with the histochemical and cytochemical findings in these cells reported by other workers leaves no doubt that they are directly concerned in the production of the organic matrix. It has not been possible to show that osteoblasts influence the passage of calcium or phosphate ions from the blood to the bone matrix.

A preliminary study of the fine structure of the oökinete, oöcyst, and sporozoite formation of Leucocytozoon simondi Mathis and Leger

1968 ◽  
Vol 46 (3) ◽  
pp. 303-307 ◽  
Author(s):  
Sherwin S. Desser ◽  
K. A. Wright
Keyword(s):  
Energy Source ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Epithelial Cells ◽  
Cell Membrane ◽  
Light Microscope ◽  
Dense Material ◽  
Blue Staining ◽  
Preliminary Study

The major features of the cytology of oökinetes, oöcysts, and sporozoites of Leucocytozoon simondi Mathis and Leger as seen in KMnO4-fîxed midguts of Simulium rugglesi and examined in the electron microscope, are related to their appearance in Giemsa-stained light microscope preparations. Thus, blue-staining regions of oökinete and oöcyst and the posterior, darkly stained region of sporozoites correspond to regions of endoplasmic reticulum; light "vacuole-like" regions correspond to accumulations of dense material which were not membrane enclosed; and minute red-stained spots at the anterior tip of sporozoites correspond to paired organelles. The dense material of oökinetes which, in oöcysts, is segregated into developing sporozoites may function as an energy source for sporozoites. The structure and development of these stages is similar to that of Plasmodium spp. The oöcyst of L. simondi develops extracellularly, enclosed by the basal lamina of the midgut with most of its surface surrounded by the basal cell membrane of midgut epithelial cells. This location of the oöcyst may be important in determining the subsequent pattern of development of this species.

scholarly journals THE FINE STRUCTURE OF ACANTHAMOEBA CASTELLANII

1968 ◽  
Vol 39 (1) ◽  
pp. 95-111 ◽  
Author(s):  
Blair Bowers ◽  
Edward D. Korn
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Cell Surface ◽  
Golgi Complex ◽  
Acanthamoeba Castellanii ◽  
Dry Weight ◽  
Dense Material ◽  
Fibrillar Material ◽  
Cytoplasmic Microtubules ◽  
Filamentous Material

The fine structure of the trophozoite of Acanthamoeba castellanii (Neff strain) has been studied. Locomotor pseudopods, spikelike "acanthopodia," and microprojections from the cell surface are all formed by hyaline cytoplasm, which excludes formed elements of the cell and contains a fine fibrillar material. Golgi complex, smooth and rough forms of endoplasmic reticulum, digestive vacuoles, mitochondria, and the water-expulsion vesicle (contractile vacuole) are described. A canicular system opening into the water-expulsion vesicle contains tubules about 600 A in diameter that are lined with a filamentous material. The tubules are continuous with unlined vesicles or ampullae of larger diameter. Centrioles were not observed, but cytoplasmic microtubules radiate from a dense material similar to centriolar satellites and are frequently centered in the Golgi complex. Cytoplasmic reserve materials include both lipid and glycogen, each of which amounts to about 10% of the dry weight.

Zoospore ultrastructure of Zygorhizidium affluens and Z. planktonicum, two chytrids parasitizing the diatom Asterionella formosa

1988 ◽  
Vol 66 (6) ◽  
pp. 1054-1067 ◽  
Author(s):  
Gordon W. Beakes ◽  
Hilda M. Canter ◽  
George H. M. Jaworski
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Water Potential ◽  
Cell Nucleus ◽  
Core Region ◽  
Planktonic Diatom ◽  
Internal Water ◽  
Asterionella Formosa ◽  
Cytoplasmic Microtubules ◽  
Single Mitochondrion

The fine structure of zoospores of two Zygorhizidium species pathogenic on the freshwater planktonic diatom Asterionella formosa Hassall, are described. Zygorhizidium affluens Canter and Z. planktonicum Canter have monocentric operculate sporangia and zoospores which have single lipid globules to which the cell nucleus and single mitochondrion are closely adpressed. Several features place Z. affluens in the Chytridiales sensu Barr. These include having its kinetosome and nonfunctional centrioles not closely associated with the nucleus and having a ribosome-rich core region delimited by endoplasmic reticulum. However, there are no cytoplasmic microtubules or membranous rumposome complex in this species. In contrast, zoospores of Z. planktonicum have dispersed or loosely aggregated ribosomes and a rumposome complex. The zoospores of this species appear to belong to the same morphological subtype as the pathogenic genus Synchytrium, which has also been placed in the Chytridiales. Zygorhizidium planktonicum zoospores possess a number of vesicle types apparently unique to this species and have a nonfunctional centriole which is constructed of a ring of singlet microtubules and is often completely disassociated from the kinetosome. Both species contain "peripheral vesicle" systems which are probably involved in regulating internal water potential. From this study it seems unlikely that the two species are closely related, although they have been placed in the same genus.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

scholarly journals Microtubule–microtubule sliding by kinesin-1 is essential for normal cytoplasmic streaming in Drosophila oocytes

2016 ◽  
Vol 113 (34) ◽  
pp. E4995-E5004 ◽  
Author(s):  
Wen Lu ◽  
Michael Winding ◽  
Margot Lakonishok ◽  
Jill Wildonger ◽  
Vladimir I. Gelfand
Keyword(s):  
Cytoplasmic Streaming ◽  
Cell Types ◽  
Nurse Cells ◽  
Wild Type ◽  
Actin Cortex ◽  
Microtubule Motor ◽  
Multiple Cell ◽  
Cytoplasmic Microtubules ◽  
Two Populations

Cytoplasmic streaming in Drosophila oocytes is a microtubule-based bulk cytoplasmic movement. Streaming efficiently circulates and localizes mRNAs and proteins deposited by the nurse cells across the oocyte. This movement is driven by kinesin-1, a major microtubule motor. Recently, we have shown that kinesin-1 heavy chain (KHC) can transport one microtubule on another microtubule, thus driving microtubule–microtubule sliding in multiple cell types. To study the role of microtubule sliding in oocyte cytoplasmic streaming, we used a Khc mutant that is deficient in microtubule sliding but able to transport a majority of cargoes. We demonstrated that streaming is reduced by genomic replacement of wild-type Khc with this sliding-deficient mutant. Streaming can be fully rescued by wild-type KHC and partially rescued by a chimeric motor that cannot move organelles but is active in microtubule sliding. Consistent with these data, we identified two populations of microtubules in fast-streaming oocytes: a network of stable microtubules anchored to the actin cortex and free cytoplasmic microtubules that moved in the ooplasm. We further demonstrated that the reduced streaming in sliding-deficient oocytes resulted in posterior determination defects. Together, we propose that kinesin-1 slides free cytoplasmic microtubules against cortically immobilized microtubules, generating forces that contribute to cytoplasmic streaming and are essential for the refinement of posterior determinants.

scholarly journals Hepatitis C virus infection induces endoplasmic reticulum stress and apoptosis in human fetal liver stem cells

2019 ◽  
Vol 248 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Xuan Guo ◽  
Wei‐Li Liu ◽  
Dong Yang ◽  
Zhi‐Qiang Shen ◽  
Zhi‐Gang Qiu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endoplasmic Reticulum ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Infection ◽  
Endoplasmic Reticulum Stress ◽  
Fetal Liver ◽  
Hepatitis C Virus Infection ◽  
Human Fetal Liver ◽  
Liver Stem Cells

Fine structure of the haplosporidan Kernstab, a persistent, intranuclear mitotic apparatus

1975 ◽  
Vol 18 (2) ◽  
pp. 327-346
Author(s):  
F.O. Perkins
Keyword(s):  
Fine Structure ◽  
Nuclear Envelope ◽  
Light Microscope ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Interphase Nuclei ◽  
Mitotic Apparatus ◽  
Pole Body

The fine structure of the haplosporidan mitotic apparatus is described from observations of plasmodial nuclei of Minchinia nelsoni, M. costalis, Minchinia sp., and Urosporidium crescens. The apparatus, which is the Kernstab of light-microscope studies, consists of a bundle of microtubules terminating in a spindle pole body (SPB) at each end of the bundle. A few microtubules extend from SPB to SPB, but most either extend from an SPB and terminate in the nucleoplasm or lie in the nucleoplasm, free of either SPB. The bundle lengthens during mitosis, increasing the SPB-to-SPB distance by a factor of 2 to 3 as compared to interphase nuclei. SPBs are not in contact with the nuclear envelope, being found always in the nucleoplasm which is delimited by the nuclear envelope throughout mitosis. The mitotic apparatus is persistent through interphase, at least in a form which is not significantly different from that found in mitotic nuclei.

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