scholarly journals THE DEVELOPMENT OF GOLGI COMPLEXES AND THEIR DEPENDENCE UPON THE NUCLEUS IN AMEBAE

1969 ◽  
Vol 43 (2) ◽  
pp. 250-262 ◽  
Author(s):  
Charles J. Flickinger
Keyword(s):  
Endoplasmic Reticulum ◽  
Amoeba Proteus ◽  
Granular Endoplasmic Reticulum ◽  
Dense Material

The production of Golgi complexes was investigated in Amoeba proteus by introducing a nucleus into cells that had been enucleated for 5 days. Golgi complexes were not detected in 5 day enucleates, nor were they observed in amebae fixed 15 min after renucleation. Samples taken at longer intervals after the introduction of a nucleus exhibited an increase in the size and abundance of Golgi complexes. Small curved smooth cisternae, some of which were aligned in parallel to form small Golgi complexes, were observed 30 min after the operation. Aggregations of small Golgi complexes increased in number in amebae fixed 1 to 6 hr after renucleation. Golgi complexes of normal size were present 6 hr after the operation and became more abundant in samples fixed 12 hr, and 1, 2, and 3 days after renucleation. The possible participation of the granular endoplasmic reticulum in the development of Golgi complexes was suggested by two observations. First, the Golgi complexes in renucleates contained a dense material similar to the content of the endoplasmic reticulum in enucleates and early renucleates. Second, examples of continuity between the endoplasmic reticulum and Golgi cisternae were present in renucleates. The possibility that Golgi complexes can be produced in the absence of preexisting Golgi complexes is discussed.

scholarly journals THE EFFECTS OF ENUCLEATION ON THE CYTOPLASMIC MEMBRANES OF AMOEBA PROTEUS

1968 ◽  
Vol 37 (2) ◽  
pp. 300-315 ◽  
Author(s):  
Charles J. Flickinger
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Electron Microscope ◽  
Golgi Apparatus ◽  
Amoeba Proteus ◽  
Granular Endoplasmic Reticulum ◽  
Whole Cells ◽  
Golgi Bodies ◽  
Cytoplasmic Membranes ◽  
In Cells

The dependence of cytoplasmic membranes upon the nucleus was studied by examining enucleated amebae with the electron microscope at intervals up to 1 wk after enucleation. Amebae were cut into two approximately equal parts, and the fine structure of the enucleated portions was compared with that of the nucleated parts and starved whole cells which had been maintained under the same conditions. Golgi bodies were diminished in size 1 day after enucleation and were not detected in cells enucleated for more than 2 days. The endoplasmic reticulum of enucleated cells appeared to increase in amount and underwent changes in its morphology. The sparsely scattered short tubules of granular endoplasmic reticulum present in unmanipulated amebae from stock cultures were replaced in 1–3-day enucleates by long narrow cisternae. In 3–7-day enucleates, similar cisternae of granular endoplasmic reticulum encircled areas of cytoplasm partially or completely. It was estimated that in most cases hundreds of these areas encircled by two rough membranes were formed per enucleated cell. The number of ribosomes studding the surface of the endoplasmic reticulum decreased progressively with time after enucleation. In contrast, the membranes of nucleated parts and starved whole cells did not undergo these changes. The possible identification of membrane-encircled areas as cytolysomes and their mode of formation are considered. Implications of the observations regarding nuclear regulation of the form of the Golgi apparatus and the endoplasmic reticulum are discussed.

scholarly journals THE STRUCTURE OF SOME CYTOPLASMIC COMPONENTS OF PLANT CELLS IN RELATION TO THE BIOCHEMICAL PROPERTIES OF ISOLATED PARTICLES

1957 ◽  
Vol 3 (1) ◽  
pp. 61-70 ◽  
Author(s):  
A. J. Hodge ◽  
E. M. Martin ◽  
R. K. Morton
Keyword(s):  
Endoplasmic Reticulum ◽  
Wheat Root ◽  
Dense Material ◽  
Animal Cells ◽  
Wheat Roots ◽  
Root Cells ◽  
Intact Cells ◽  
Thin Sections ◽  
Isolated Mitochondria ◽  
Silver Beet

1. Electron micrographs of thin sections of material fixed with buffered osmium tetroxide have been used for comparison of the fine structure of isolated cytoplasmic particles from silver beet petioles and roots of germinating wheat with that of the cytoplasm of the intact cells. 2. Mitochondria of wheat roots have an external double membrane and poorly oriented internal double membranes. As compared with the structures seen in situ, the isolated mitochondria showed evidence of some disorganisation of the fine internal structure, probably due to osmotic effects. The possible influence of such changes on the enzymic properties of the isolated mitochondria is discussed. 3. The isolated plant microsomes are mainly spherical vesicular structures consisting of (a) an outer membrane enclosing (b) either an homogeneous slightly dense material (wheat root microsomes) or some granular dense material (silver beet microsomes) and (c) small dense particles, mostly associated with the vesicle membranes. 4. The cytoplasm of the wheat root cells does not contain any structures similar to the isolated microsomes but has a very dense reticular network, consisting of membranes with associated small dense particles, here called the endoplasmic reticulum. The observations indicate that the isolated microsomes arise mainly by rupture and transformation of the membranes of this structure. The effects of such extensive changes in the lipoprotein membranes on the enzymic activities of the endoplasmic reticulum, as studied in isolated microsomes, is discussed. 5. Meristematic wheat root cells contain structures which consist of smooth membranes with associated vacuoles and are similar to the Golgi zones of animal cells. The membranes of these zones probably contribute to the microsomal fraction under the conditions of preparation used for the enzymic and chemical studies previously reported.

Origine et formation de différents types de vacuoles induites par la multiplication d'Alphavirus Sindbis dans divers systemes cellulaires

1979 ◽  
Vol 25 (12) ◽  
pp. 1452-1459 ◽  
Author(s):  
Yves Lombard ◽  
Philippe Poindron ◽  
Aimé Porte
Keyword(s):  
Endoplasmic Reticulum ◽  
Glial Cells ◽  
Chicken Embryo ◽  
Cytoplasmic Membrane ◽  
Dense Material ◽  
Newborn Mice ◽  
Electron Dense Material ◽  
Double Membrane ◽  
Single Membrane ◽  
Chicken Embryo Fibroblasts

Spherule-containing vacuoles and nucleocapsid-bearing vacuoles (cytopathic vacuoles types 1 and 2 respectively of Grimley et al. 1968) induced by Alphavirus Sindbis were studied in brains from newborn mice, chicken embryo fibroblasts, and two lines of tumoral glial cells from muridae. Endoplasmic reticulum (ER) elements and finely granular electron-dense material also seen in contact with nucleocapsids seemed to be involved in the formation of the classical single-membrane spherule-containing vacuoles. A second type of spherule-containing vacuoles were characterized by their double membrane and an amorphous electron-dense content and were probably derived from mitochondria. Nucleocapsid-bearing vacuoles were formed from modified ER elements and seemed to be linked to excessive synthesis of viral material. Such ER alterations were not observed in RG6 cells. In these cells, there were only spherule-containing vacuoles, while nucleocapsids were seen associated with the cytoplasmic membrane only.

scholarly journals SUBSURFACE CISTERNS AND THEIR RELATIONSHIP TO THE NEURONAL PLASMA MEMBRANE

1962 ◽  
Vol 13 (3) ◽  
pp. 405-421 ◽  
Author(s):  
Jack Rosenbluth
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Nerve Cell ◽  
Plasma Membranes ◽  
Granular Endoplasmic Reticulum ◽  
Supporting Cells ◽  
Golgi Membranes ◽  
Subsurface Cisterns ◽  
Central Nervous Systems ◽  
Neuronal Plasma Membrane

Subsurface cisterns (SSC's) are large, flattened, membrane-limited vesicles which are very closely apposed to the inner aspect of the plasma membranes of nerve cell bodies and the proximal parts of their processes. They occur in a variety of vertebrate and invertebrate neurons of both the peripheral and central nervous systems, but not in the surrounding supporting cells. SSC's are sheet-like in configuration, having a luminal depth which may be less than 100 A and a breadth which may be as much as several microns. They are separated from the plasmalemma by a light zone of ∼50 to 80 A which sometimes contains a faint intermediate line. Flattened, agranular cisterns resembling SSC's, but structurally distinct from both typical granular endoplasmic reticulum (ER) and from Golgi membranes, also occur deep in the cytoplasm of neurons. It is suggested that membranes which are closely apposed may interact, resulting in alterations in their respective properties. The patches of neuronal plasmalemma associated with subsurface cisterns may, therefore, have special properties because of this association, resulting in a non-uniform neuronal surface. The possible significance of SSC's in relation to neuronal electrophysiology and metabolism is discussed.

The fine structure of the ookinete of Parahaemoproteus velans (= Haemoproteus velans Coatney and Roudabush) (Haemosporidia: Haemoproteidae)

1972 ◽  
Vol 50 (5) ◽  
pp. 477-480 ◽  
Author(s):  
Sherwin S. Desser
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Granular Endoplasmic Reticulum ◽  
Central Nucleus ◽  
Apical Region ◽  
Cylindrical Structures ◽  
Inner Surface

The ookinete of Parahaemoproteus velans is bounded externally by a trilaminar membrane, beneath which lies a fibrillar zone. Below this zone and forming the inner surface of the pellicle is a second, dense, membranelike layer. The specialized apical region of the ookinete is modified into a thickened "caplike" structure. The inner layer of the pellicle in this region is thickened and wavy in appearance. In a sub-pellicular space in the cap region lie about 27 elongate cylindrical structures, and beneath these about 50 microtubules ring the cytoplasm. Numerous dense spherical bodies are located in the anterior cytoplasm of the parasite. A large, more or less central nucleus, often containing microtubular elements, lies in a cytoplasm richly endowed with granular endoplasmic reticulum. Two or more areas containing a "crystalloid" material lie anterior and posterior to the nucleus.

The Cartilaginous Nature of the Cervine Antler

1970 ◽  
Vol 28 ◽  
pp. 154-155
Author(s):  
William J. Banks ◽  
Jennifer Neal
Keyword(s):  
Endoplasmic Reticulum ◽  
Progenitor Cells ◽  
Distal Portion ◽  
Frontal Bone ◽  
Granular Endoplasmic Reticulum ◽  
Exact Nature ◽  
Undifferentiated Cells ◽  
Hyperplastic Tissue ◽  
Ossification Process

The histomorphology and ossification process of the antler has been a subject of controversy. The exact nature of antler cartilage, based on light microscopic and limited histochemical analyses, has not been clarified. This report presents evidence that the ultrastructural features of antler progenitor cells and chondrocytes are similar to other cartilaginous systems which arise from reserve, undifferentiated cells.An extensive fibrocellular cap covered the distal portion of the growing antler and was continuous with the typical periosteum of the antler shaft and frontal bone. This hyperplastic tissue (Fig. 1) was composed of fibroblastlike cells which contained large nuclei with 1 or 2 nucleoli (N). The cytoplasm contained numerous free ribosomes and polyribosomes, as well as granular endoplasmic reticulum (ER). The latter was tubular or vesicular; some exhibited dilations.

An Electron Microscopic Study of the Human Gastric Epithelia with Special Reference to the Cardinal Morphological Changes of the Chief Cells Induced by Insulin Stimulus

1972 ◽  
Vol 30 ◽  
pp. 344-345
Author(s):  
Hiroshi Saito ◽  
Goro Asano ◽  
Kaoru Aihara ◽  
Katsunari Fukushi ◽  
Minoru Yoshida ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Morphological Changes ◽  
Regular Insulin ◽  
Endoscopic Biopsy ◽  
Granular Endoplasmic Reticulum ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Chief Cells ◽  
Microscopic Studies ◽  
The One

This short communication is dealt with the ultrastructural changes of the chief cells in insulin stimulus in chronic gastritic condition. The bio gastro-endoscopic biopsy was obtained and pepsin activity of the gastric juice was measured in respective cases. Regular insulin of 0.15U/kg was administrated intra-muscularly and in pre-administration of insulin, 10 minutes, 20 minutes and 30 minutes after administration, biopsied specimens were subjected for electron microscopic studies.In the pre-treated chief cells, extensive development of the cysternal structures of the granular endoplasmic reticulum in basal aspect of the cytoplasm and spherical or oval shaped, light homogeneous zymogen granules in supranuclear region and especially apical aspect of the cytoplasm were featured. Moreover, other type of the chief cells as the one characterized by their fragmented and saccular dilated granular endoplasmic reticulum in basal aspect of the cytoplasm, also exist.

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