scholarly journals The Development of the Cnidoblasts of Hydra

1959 ◽  
Vol 5 (3) ◽  
pp. 441-452 ◽  
Author(s):  
David B. Slautterback ◽  
Don W. Fawcett
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Interstitial Cell ◽  
Complex Cell ◽  
Electron Microscopic ◽  
Cytoplasmic Matrix ◽  
Virtual Absence ◽  
Cytological Characteristics ◽  
Mode Of Attachment

The general histological organization of Hydra is reviewed and electron microscopic observations are presented which bear upon the nature of the mesoglea, the mode of attachment of the contractile processes of the musculo-epithelial cells, and the cytomorphosis of the cnidoblasts. Particular attention is devoted to the changes in form and distribution of the cytoplasmic organelles in the course of nematocyst formation. The undifferentiated interstitial cell is characterized by a small Golgi complex, few mitochondria, virtual absence of the endoplasmic reticulum, and a cytoplasmic matrix crowded with fine granules presumed to be ribonucleoprotein. These cytological characteristics persist through the early part of the period of interstitial cell proliferation which leads to formation of clusters of cnidoblasts. With the initiation of nematocyst formation in the cnidoblasts, numerous membrane-bounded vesicles appear in their cytoplasm. These later coalesce to form a typical endoplasmic reticulum with associated ribonucleoprotein granules. During the ensuing period of rapid growth of the nematocyst the reticulum becomes very extensive and highly organized. Finally, when the nematocyst has attained its full size, the reticulum breaks up again into isolated vesicles. The Golgi complex remains closely applied to the apical pole of the nematocyst throughout its development and apparently contributes to its enlargement by segregating formative material in vacuoles whose contents are subsequently incorporated in the nematocyst. The elaboration of this complex cell product appears to require the cooperative participation of the endoplasmic reticulum and the Golgi complex. Their respective roles in the formative process are discussed.

scholarly journals Endoplasmic reticulum-to-Golgi transitions upon herpes virus infection

F1000Research ◽  
2018 ◽  
Vol 6 ◽  
pp. 1804 ◽  
Author(s):  
Peter Wild ◽  
Andres Kaech ◽  
Elisabeth M. Schraner ◽  
Ladina Walser ◽  
Mathias Ackermann
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Golgi Complex ◽  
Nuclear Membrane ◽  
Progeny Virus ◽  
Cytoplasmic Matrix ◽  
Outer Nuclear Membrane ◽  
Nuclear Membranes ◽  
Perinuclear Space ◽  
Hsv 1

Background: Herpesvirus capsids are assembled in the nucleus, translocated to the perinuclear space by budding, acquiring tegument and envelope, or released to the cytoplasm via impaired nuclear envelope. One model proposes that envelopment, “de-envelopment” and “re-envelopment” is essential for production of infectious virus. Glycoproteins gB/gH were reported to be essential for de-envelopment, by fusion of the “primary” envelope with the outer nuclear membrane. Yet, a high proportion of enveloped virions generated from genomes with deleted gB/gH were found in the cytoplasm and extracellular space, suggesting the existence of alternative exit routes.Methods: We investigated the relatedness between the nuclear envelope and membranes of the endoplasmic reticulum and Golgi complex, in cells infected with either herpes simplex virus 1 (HSV-1) or a Us3 deletion mutant thereof, or with bovine herpesvirus 1 (BoHV-1) by transmission and scanning electron microscopy, employing freezing technique protocols.Results:  The Golgi complex is a compact entity in a juxtanuclear position covered by a membrane on thecisface. Golgi membranes merge with membranes of the endoplasmic reticulum forming an entity with the perinuclear space. All compartments contained enveloped virions. After treatment with brefeldin A, HSV-1 virions aggregated in the perinuclear space and endoplasmic reticulum, while infectious progeny virus was still produced.Conclusions: The data suggest that virions derived by budding at nuclear membranes are intraluminally transported from the perinuclear space via Golgi -endoplasmic reticulum transitions into Golgi cisternae for packaging. Virions derived by budding at nuclear membranes are infective like Us3 deletion mutants, which  accumulate in the perinuclear space. Therefore, i) de-envelopment followed by re-envelopment is not essential for production of infective progeny virus, ii) the process taking place at the outer nuclear membrane is budding not fusion, and iii) naked capsids gain access to the cytoplasmic matrix via impaired nuclear envelope as reported earlier.

scholarly journals ELECTRON MICROSCOPY OF THE BURSA OF FABRICIUS OF THE EMBRYONIC CHICK WITH PARTICULAR REFERENCE TO THE LYMPHO-EPITHELIAL NODULES

1962 ◽  
Vol 13 (1) ◽  
pp. 127-146 ◽  
Author(s):  
G. Adolph Ackerman
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Embryonic Development ◽  
Golgi Complex ◽  
Bursa Of Fabricius ◽  
Cortical Region ◽  
Electron Microscopic ◽  
Submicroscopic Structure ◽  
Microscopic Studies ◽  
Pass Through

Electron microscopic studies of the bursa of Fabricius during the 15th and 16th day of embryonic development in the chick have shown the following findings in the submicroscopic structure of the cellular elements of the lympho-epithelial follicles. In the medulla, basal endodermal epithelial cells undergo mitosis and differentiation into lymphoblasts. During this transformation, there is a reduction in the amount of rough endoplasmic reticulum, an increase in the number or ribosomes, and frequently an enlargement of the Golgi complex. As lymphoblasts differentiate into medium lymphocytes there is a loss of endoplasmic reticulum, a reduction in the number of ribosomes and in the size of the Golgi complex, as well as a decrease in the number and size of mitochondria and in the size of the cell and nucleus. Cytoplasmic processes of reticular-epithelial cells extend between proliferating lymphocytic cells. Desmosomes connect stellate reticular-epithelial and basal epithelial cells but are not present in lymphocytic cells. Nuclear blebbing and vesiculation are frequently observed in the various cell forms of the developing lympho-epithelial nodules. Although lymphocytes and lymphocytopoietic activities in the cortex are sparse during this stage of embryonic development of the bursa, transitional forms between mesenchymal cells and lymphoblasts have been encountered. In addition, lymphoblasts and/or undifferentiated epithelial cells occasionally may pass through the basement membrane from the medulla into the cortical region of the developing nodule. That lymphocytes in the bursa of Fabricius originate from both endodermal and mesodermal derivatives during embryonic development appears to be consistent with both light and electron microscopic observations.

Disorganization of the Golgi complex and the cytoplasmic microtubule system in CHO cells exposed to okadaic acid

1992 ◽  
Vol 103 (4) ◽  
pp. 1167-1175 ◽  
Author(s):  
J. Thyberg ◽  
S. Moskalewski
Keyword(s):  
Endoplasmic Reticulum ◽  
Okadaic Acid ◽  
Golgi Complex ◽  
Cho Cells ◽  
Protein Phosphatase ◽  
Specific Inhibitor ◽  
Electron Microscopic ◽  
Cytoplasmic Microtubule ◽  
Low Concentrations ◽  
Increased Sensitivity

A combination of immunocytochemical and electron microscopic methods was used to study the effects of okadaic acid, a specific inhibitor of protein phosphatase types 1 and 2A, on the Golgi complex and the microtubule system of interphase CHO cells. At a concentration of 0.25 microM and within 2–3 h of exposure, okadaic acid caused a reversible disorganization of the Golgi complex, observed as a disintegration of the stacks of cisternae and formation of clusters of tubules and vesicles dispersed in the cytoplasm. At the same time, staining for mannosidase II was shifted from the Golgi stacks to the endoplasmic reticulum, whereas the clusters of tubules and vesicles for the main part were negative. This change in localization of the enzyme was not blocked by cycloheximide and thus not dependent on ongoing protein synthesis. The changes in the morphology of the Golgi complex were coordinated in time with a remodelling of the microtubule system, observed as a reduction in the number of microtubules, a tendency of the remaining microtubules to arrange in an aster-like pattern, and an increased sensitivity to low concentrations of the microtubule-disruptive drug nocodazole. After removal of the drug, the microtubule system was rapidly normalized (1-2 h) and subsequently also the Golgi complex (4-8 h). The results suggest that okadaic acid induces a redistribution of the Golgi stacks into the endoplasmic reticulum, leaving the trans-most elements behind as tubules and vesicles.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural Changes in Pig Hepatocytes During the Transitional Period from Late Foetal to Early Neonatal Life

1969 ◽  
Vol 4 (2) ◽  
pp. 381-395
Author(s):  
M. B. BISCHOFF ◽  
W. R. RICHTER ◽  
R. J. STEIN
Keyword(s):  
Endoplasmic Reticulum ◽  
Microscopic Study ◽  
Golgi Complex ◽  
Structural Changes ◽  
Bile Canaliculus ◽  
Transitional Period ◽  
Ultrastructural Changes ◽  
Synthetic Activity ◽  
Electron Microscopic ◽  
Neonatal Life

A light-and electron-microscopic study of pig hepatocytes from late prenatal to early neonatal animals shows changes which reflect an increasing rate of synthetic activity. The granular endoplasmic reticulum (ER) in the prenatal pig hepatocyte is situated along the periphery of the cytoplasm and in the region immediately surrounding the nucleus. Mitochondria are most abundant in the area adjacent to the nucleus, while the Golgi complex is generally located in the region of the bile canaliculus. The remaining portion of the hepatocyte is occupied with glycogen. A few hours after birth the hepatocyte increases about twofold in size with the nucleus shifting from a peripheral to a more centrally located position. The glycogen decreases quickly coincident with a rapid increase in the amount of granular ER and the dispersion of the mitochondria throughout the cell. The Golgi complex becomes distended and numerous vesicles appear in its immediate vicinity containing a moderately dense material. Numerous peribiliary inclusions appear during the second postnatal day. These structural changes are an indication of the increased synthetic activity occurring within the hepatocytes of rapidly developing animals.

scholarly journals ELECTRON MICROSCOPIC OBSERVATIONS ON ANTIBODY-PRODUCING CELLS IN LYMPH AND BLOOD

1966 ◽  
Vol 124 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Klaus Hummeler ◽  
T. N. Harris ◽  
Natale Tomassini ◽  
Maureen Hechtel ◽  
Miriam B. Farber
Keyword(s):  
Endoplasmic Reticulum ◽  
Thoracic Duct ◽  
Peripheral Blood ◽  
Lymphatic Vessels ◽  
Spherical Shape ◽  
Golgi Body ◽  
Central Position ◽  
Electron Microscopic ◽  
Cytoplasmic Matrix ◽  
Relative Scarcity

Antibody-producing cells have been identified among cells obtained from efferent lymphatic vessels, the thoracic duct, and peripheral blood. These cells, which produced plaques of hemolysis and which were quite rare (20 to 50 per million), due in most instances to 19S antibody, were located and studied by electron microscopy. Of the antibody-producing cells found in these three sites there were several features common to all: small size (5 to 8 µ), generally spherical shape, approximately central position of the nucleus, and retention in the nucleus of the condensations of chromatin characteristic of the lymphocyte. The differences among the cells of these sources were largely in the relative amount and state of organization of the organelles of the cytoplasm. In cells of the efferent lymphatic vessel and the thoracic duct, the endoplasmic reticulum showed a range from relative scarcity to considerable numbers of well organized channels. Between these extremes were cells with a considerable amount of endoplasmic reticulum, the channels disorganized and sectioned at various angles. The cytoplasmic matrix of all of these contained a profusion of polyribosomes. Antibody-producing cells obtained from peripheral blood showed, around the roughly spherical nucleus, a ring of cytoplasm which was narrow, but wholly organized into parallel lamellae of endoplasmic reticulum, with many polyribosomes between these, and a large Golgi body. Some similarities and some differences of these cells, in comparison with antibody-producing cells obtained from lymph nodes, have been indicated.

scholarly journals Immunocytochemical localization of BiP to the rough endoplasmic reticulum: evidence for protein sorting by selective retention.

1989 ◽  
Vol 37 (12) ◽  
pp. 1817-1823 ◽  
Author(s):  
D G Bole ◽  
R Dowin ◽  
M Doriaux ◽  
J D Jamieson
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Membrane System ◽  
Myeloma Cell ◽  
Secretory Protein ◽  
Electron Microscopic Level ◽  
Immunoperoxidase Staining ◽  
Secretory Proteins ◽  
Electron Microscopic ◽  
Exocytic Pathway

Immunoglobulin heavy chain binding protein (BiP) (also known as GRP 78) is a protein of the endoplasmic reticulum (ER) which has been shown to be involved in post-translational processing of nascent membrane and secretory proteins. To determine BiP's location in the exocytic pathway, we localized BiP at the electron microscopic level in mouse myeloma cell lines by immunoperoxidase cytochemistry. BiP was found to be present within the cisternal spaces of the RER and nuclear envelope but was not detected in the cisternae of the Golgi complex. BiP reaction product was also found within transitional elements of the RER but was absent from smooth-surfaced vesicles found between the ER and the Golgi complex. Immunoperoxidase staining of BiP was reduced or absent in regions of a smooth ER membrane system in myelomas that contained endogenous murine retrovirus A particles. All compartments of the exocytic pathway, including the virus-containing smooth ER, stained for IgG, a secretory protein. These observations suggest that BiP is selectively retained in the cisternae of the ER and is not free to enter Golgi-directed transport vesicles. These studies suggest that BiP's subcellular localization may occur by selective interaction with component(s) of the ER.

OBSERVATIONS ON THE LOCALIZATION OF RECENTLY SYNTHESIZED CATECHOLAMINES IN CHROMAFFIN CELLS AFTER THE INJECTION OF l-[2,5,6-3H]DOPA

1976 ◽  
Vol 69 (1) ◽  
pp. 139-NP ◽  
Author(s):  
R. E. COUPLAND ◽  
S. KOBAYASHI ◽  
CHRISTINE KENT
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Chromaffin Cells ◽  
Intracellular Localization ◽  
Chromaffin Granules ◽  
Electron Microscopic ◽  
Electron Microscopic Autoradiography ◽  
Metabolic Products ◽  
Noradrenaline And Adrenaline

SUMMARY The fate of l-[2,5,6-3H]DOPA, and the intracellular localization of its metabolic products dopamine, noradrenaline and adrenaline, have been determined by the simultaneous use of assay techniques following separation of amines by chromatography and light and electron microscopic autoradiography. During the first 24 h after i.v. or i.p. injection of [3H]DOPA, synthesis of the above catecholamines occurred. Throughout this time the labelled amines were associated with chromaffin granules or immediately adjacent cytosol and not with either the Golgi complex or rough endoplasmic reticulum. Labelling of chromaffin granules occurred simultaneously throughout the cell and there was no evidence of regions containing recently labelled granules and others containing previously charged (older) granules. Adrenaline-storing cells took up [3H]DOPA and its products more rapidly and lost recently synthesized adrenaline more rapidly than noradrenaline-storing cells took up and stored their equivalent amines. This was in keeping with a more rapid turnover of catecholamines in adrenaline-storing elements.

scholarly journals ELECTRON MICROSCOPY OF HELA CELLS AFTER THE INGESTION OF COLLOIDAL GOLD

1957 ◽  
Vol 3 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Carl G. Harford ◽  
Alice Hamlin ◽  
Esther Parker
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Cell Membrane ◽  
Golgi Complex ◽  
Hela Cells ◽  
Colloidal Gold ◽  
Tissue Cultures ◽  
Cytoplasmic Matrix ◽  
Gold Particles ◽  
Dense Granules

Tissue cultures of HeLa cells were grown in media containing colloidal gold, and after various intervals, the cells were fixed, embedded, and sectioned for electron microscopy. Uncoated grids with small holes were used in many of the experiments. Intracellular particles of gold were identified in areas surrounded by single membranes, in moderately dense granules, in globoid bodies, and in the cytoplasmic matrix. Gold particles were not found in typical mitochondria, Golgi complex, ergastoplasm (granular forms of endoplasmic reticulum), or nuclei. The phenomenon of pinocytosis was considered to be the most likely means by which the gold particles were ingested, and the locations of gold particles appeared to have significance concerning theories that membranous organelles of the cytoplasm may be derived from the cell membrane.

scholarly journals Aminoglycoside antibiotics traffic to the Golgi complex in LLC-PK1 cells.

1998 ◽  
Vol 9 (2) ◽  
pp. 167-174
Author(s):  
R Sandoval ◽  
J Leiser ◽  
B A Molitoris
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Aminoglycoside Antibiotics ◽  
Electron Microscopic ◽  
Fluorescent Marker ◽  
Intracellular Compartments ◽  
Confocal Images ◽  
Free Media ◽  
Texas Red ◽  
H Protein

Aminoglycoside antibiotics are known to be internalized via endocytosis and have been associated with subcellular organelle dysfunction; however, the route of intracellular trafficking and their distribution remain largely unknown. To address these questions, a Texas Red conjugate of gentamicin (TRG) was synthesized for dual-labeling experiments with the endoplasmic reticulum, Golgi, and lysosomal markers DiOC6-3, C6-NBD-ceramide, and fluorescent dextrans, respectively. Confocal images were overlaid to determine areas of colocalization. Initial characterization studies of the fluorescent gentamicin analogue revealed that both internalization and accumulation were inhibited by excess unlabeled gentamicin. Furthermore, the fluorescent gentamicin label was colocalized with unlabeled gentamicin, using immunologic techniques. LLC-PK1 cells were exposed to the fluorescent gentamicin in media containing 1 mg/ml labeled gentamicin for 8 h and then either fixed or chased with gentamicin-free media for an additional 16 or 40 h (24 to 48 h total). Studies with fluorescent dextrans revealed rapid intracellular colocalization within the endosomal and lysosomal systems. Neither endoplasmic reticulum nor mitochondrial colocalization could be detected. However, Golgi colocalization was revealed using both confocal and electron microscopic techniques at 8 h of TRG incubation, and continued to be present for an additional 40 h. Protein synthetic rates were quantified and revealed decreased synthesis at the 24-h chase mark. These results suggest that TRG can serve as a fluorescent tracer for aminoglycoside trafficking within cells. The fluorescent marker remained associated with vesicular structures at all times and colocalized with the Golgi apparatus. It is postulated that this early association of gentamicin with the Golgi complex may be an avenue for delivery of aminoglycosides to other intracellular compartments.

scholarly journals Antibodies to the Golgi complex and the rough endoplasmic reticulum.

1982 ◽  
Vol 92 (1) ◽  
pp. 92-107 ◽  
Author(s):  
D Louvard ◽  
H Reggio ◽  
G Warren
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Rat Kidney ◽  
Apparent Molecular Weight ◽  
Fluorescent Labeling ◽  
Central Feature ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Culture Cells

Rabbits were immunized with membrane fractions from either the Golgi complex or the rough endoplasmic reticulum (RER) by injection into the popliteal lymph nodes. The antisera were then tested by indirect immunofluorescence on tissue culture cells or frozen, thin sections of tissue. There were may unwanted antibodies to cell components other than the RER or the Golgi complex, and these were removed by suitable absorption steps. These steps were carried out until the pattern of fluorescent labeling was that expected for the Golgi complex or RER. Electron microscopic studies, using immunoperoxidase labeling of normal rat kidney (NRK) cells, showed that the anti-Golgi antibodies labeled the stacks of flattened cisternae that comprise the central feature of the Golgi complex, many of the smooth vesicles around the stacks, and a few coated vesicles. These antibodies were directed, almost entirely, against a single polypeptide with an apparent molecular weight of 135,000. The endoplasmic reticulum (ER) in NRK cells is an extensive, reticular network that pervades the entire cell cytoplasm and includes the nuclear membrane. The anit-RER antibodies labeled this structure alone at the light and electron microscopic levels. They were largely directed against four polypeptides with apparent molecular weights of 29,000, 58,000, 66,000, and 91,000. Some examples are presented, using immunofluorescence microscopy, where these antibodies have been used to study the Golgi complex and RER under a variety of physiological and experimental condition . For biochemical studies, these antibodies should prove useful in identifying the origin of isolated membranes, particularly those from organelles such as the Golgi complex, which tend to lose their characteristic morphology during isolation.

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