Morphologic alterations in the parietal yolk-sac of the rat from the 12th to the 19th day of gestation

Development ◽  
1977 ◽  
Vol 39 (1) ◽  
pp. 9-21
Author(s):  
R. P. Jensh ◽  
T. R. Koszalka ◽  
M. Jensen ◽  
L. Biddle ◽  
R. L. Brent
Keyword(s):  
Epithelial Cells ◽  
Experimental Models ◽  
Yolk Sac ◽  
Basement Membranes ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
En Face ◽  
Pas Staining ◽  
Reichert's Membrane ◽  
Histologic Changes

The rat parietal yolk-sac and its adherent epithelial cells were examined at various stages of gestation using an en face technique. Specimens were observed at both the light and electron microscopic level. Diastase pretreatment and PAS-staining were used to determine the presence of glycogen. As early as the 12th day of gestation the cytoplasm of the parietal yolk-sac cells contained numerous ribosomes and mitochondria and a large amount of endoplasmic reticulum. The glycogen content of the epithelial cells increased from the 12th day of gestation and accumulated in large quantities by the 16th day. By the 17th day many cells exhibited variable degrees of degeneration. Cellular elements of degenerating cells appeared to be trapped within Reichert's membrane. Contrary to the reports of other investigators, the present study indicates that the capsular portion of the parietal yolk-sac consisting of Reichert's membrane and its adherent epithelial cells remained intact until at least the 18th day of gestation. Some of the unique characteristics of the parietal yolk-sac provide experimental models to study the effects of environmental factors on (1) the synthesis of basement membranes, (2) the ageing of cells and (3) the correlation of these histologic changes with the functions of the parietal yolk-sac.

scholarly journals THE HISTOGENESIS OF BASEMENT MEMBRANES

1963 ◽  
Vol 117 (3) ◽  
pp. 339-348 ◽  
Author(s):  
G. B. Pierce ◽  
A. R. Midgley ◽  
J. Sri Ram
Keyword(s):  
Epithelial Cells ◽  
Connective Tissue ◽  
Basement Membrane ◽  
Yolk Sac ◽  
Basement Membranes ◽  
Ground Substance ◽  
Epithelial Secretion ◽  
Reichert's Membrane ◽  
Yolk Sac Cells

A parietal yolk sac carcinoma of the mouse that secretes large quantities of basement membrane-like material has been used to study the formation of basement membranes. Suitably characterized fluorescein-labeled antibodies against this material stained basement membranes of epithelial structures and vessels, as well as reticulin. When absorbed with reticulin and vascular basement membranes of the spleen until these structures no longer fluoresced, the antibody still stained the basement membrane-like material of the tumor, its normal embryonic counterpart (Reichert's membrane), and the basement membranes at the bases of epithelial cells. The observation made previously that parietal yolk sac cells secreted, in the absence of connective tissue and reticulin, the basement membrane (Reichert's membrane) upon which they rested has been confirmed through the localization of ferritin-labeled antibody to the endoplasmic reticulin of the secreting cells. Since a basement membrane proven to be an epithelial secretion is antigenically similar to basement membranes at the bases of all epithelial cells studied but antigenically different from connective tissue elements, it is postulated that the basement membranes at the bases of epithelial cells in general are an epithelial secretion, and are not a condensation of ground substance as is commonly believed.

Ultrastructure of Major Conducting Airway Epithelium in the Guinea Pig

1985 ◽  
Vol 43 ◽  
pp. 566-567
Author(s):  
M. L. Davis ◽  
J. O. Ford ◽  
R. F. Dodson
Keyword(s):  
Airway Epithelium ◽  
Guinea Pigs ◽  
Experimental Studies ◽  
Experimental Models ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Conducting Airway ◽  
Baseline Information ◽  
Epithelial Structure ◽  
Asbestos Related Disease

Guinea pigs have served as experimental models in a variety of pulmonary research including that concerned with asbestos related disease which is of particular interest in our laboratory. A search of the literature revealed several papers concerned with various characteristics of airway epithelium in both normal and experimentally manipulated guinea pigs, yet no studies could be found which systematically addressed the epithelial structure and organization in major airways. The present study was undertaken to fully characterize these areas at the electron microscopic level in order to provide data from healthy animals which can act as baseline information in experimental studies of airway epithelium. Initial findings from the trachea and main bronchi are presented here.

Cell-to-cell adherens junction formation and actin filament organization: similarities and differences between non-polarized fibroblasts and polarized epithelial cells

1995 ◽  
Vol 108 (1) ◽  
pp. 127-142 ◽  
Author(s):  
S. Yonemura ◽  
M. Itoh ◽  
A. Nagafuchi ◽  
S. Tsukita
Keyword(s):  
Epithelial Cells ◽  
Early Stage ◽  
Light And Electron Microscopy ◽  
Adherens Junction ◽  
Cell Polarization ◽  
Stress Fiber ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Similarities And Differences ◽  
Polarized Epithelial Cells

Cadherin has an intimate spatial relationship with actin filaments (AF) in various types of cells, forming the cell-to-cell adherens junction (AJ). We compared the AJ/AF relationship between non-polarized fibroblasts (NRK cells) and polarized epithelial cells (MTD-1A cells). E/P-cadherin, alpha-catenin, ZO-1 and vinculin were localized with reference to AF in these cells using laser scan microscopy as well as conventional light and electron microscopy. NRK cells adhered to each other at the tips of thin cellular processes, where spot-like AJ were formed, where P-cadherin, alpha-catenin, ZO-1 and vinculin were concentrated. Some stress-fiber-like AF bundles ran axially in these processes and terminated at spot-like AJ on their tips. At the electron microscopic level these spot-like AJ were seen as aggregates of small ‘units’ of AJ, where AF were densely and perpendicularly associated with the plasma membrane. In MTD-1A cells, the AJ/AF relationship was investigated during the cell polarization process after replating or wounding. At the early stage, the AJ/AF relationship was quite similar to that in NRK cells. As polarization proceeded, the spot-like AJs were gradually fused side by side with the concomitant shortening of the associated stress-fiber-like AF bundles. Finally, the belt-like AJ was established, which was lined with circumferential AF bundles. The similarities and differences in the AJ/AF relationship between non-polarized fibroblasts and polarized epithelial cells are discussed.

scholarly journals Intracellular localization of thymosin alpha 1 by immunoelectron microscopy using a monoclonal antibody.

1987 ◽  
Vol 35 (2) ◽  
pp. 181-187 ◽  
Author(s):  
C Auger ◽  
C Stahli ◽  
N Fabien ◽  
J C Monier
Keyword(s):  
Monoclonal Antibody ◽  
Epithelial Cells ◽  
Intracellular Localization ◽  
Immunofluorescence Assay ◽  
Secretory Process ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Thymic Hormone ◽  
Thin Sections ◽  
Thymosin Alpha 1

Distribution of thymosin alpha 1 in normal mice (OF1) or autoimmune mice (NZB) was investigated using immunocytochemical techniques on sections of GMA- and Epon-embedded mouse thymuses. A monoclonal antibody directed against synthetic thymosin alpha 1 was used. With the immunofluorescence assay, patchy staining of thymosin alpha 1 was found in the cytoplasm of epithelial cells of the subcapsullary and medullary zones of OF1 thymus. In NZB thymus, the fluorescent pattern was less precisely localized. At the electron microscopic level, immunolabeling of Epon-embedded ultra-thin sections revealed ferritin in some vacuoles of epithelial cells. Ferritin labeling in OF1 thymus was found in several small vacuoles of the same cell, but was present in large, dense vacuoles in NZB thymus. These differences might reflect differences in the secretory process of thymic hormone.

scholarly journals A Morphometric Analysis of Nucleoli in Cultured Carcinoma Cells of the Human Thyroid

1998 ◽  
Vol 16 (3) ◽  
pp. 131-140 ◽  
Author(s):  
Lars Andersen ◽  
Lars Kayser ◽  
Niels Keiding ◽  
Jens Thomsen
Keyword(s):  
Epithelial Cells ◽  
Thyroid Carcinoma ◽  
Thyroid Tissue ◽  
Microscopic Level ◽  
Carcinoma Cells ◽  
Electron Microscopic Level ◽  
Human Thyroid ◽  
Electron Microscopic ◽  
Normal Thyroid ◽  
Granular Component

Cells from 7 patients operated on for thyroid cancer were investigated. Samples of cells from the carcinoma and from the normal thyroid tissue were cultured with and without TSH stimulation. For light microscopy, serial sections of cells were cut and the size of nucleoli was measured and the number of nucleoli per cell counted. At the electron microscopic level the number and the volume of the fibrillar centres (FC) were estimated taking the Swiss cheese effect into account. The areal densities of FC, the fibrillar and granular component in nucleoli were determined by point counting. The results indicate that the malignant transformation has no influence on the size of the FC, but the observed numbers as well as the total area of FC are larger in cancer cells than in the normal thyroid epithelial cells. The nucleolar density of the fibrillar component is larger and that of the granular component is smaller in thyroid carcinoma cells than in non‐malignant thyroid epithelial cells (p= 0.0001). Thus simple morphometry at the electron microscopic level might be helpful to discriminate between thyroid epithelial cells and thyroid carcinoma cells in culture.

scholarly journals Heterogeneity of distribution pattern at the electron microscopic level of heparan sulfate in various basement membranes.

1990 ◽  
Vol 38 (10) ◽  
pp. 1459-1467 ◽  
Author(s):  
Y Kogaya ◽  
S Kim ◽  
S Haruna ◽  
T Akisaka
Keyword(s):  
Heparan Sulfate ◽  
Distribution Pattern ◽  
Staining Technique ◽  
Enzymatic Digestion ◽  
Basement Membranes ◽  
Electron Microscopic Level ◽  
Oral Epithelium ◽  
Lamina Densa ◽  
Electron Microscopic ◽  
Oral Epithelial

Using the high-iron diamine thiocarbohydrazide silver proteinate (HID-TCH-SP) staining technique and enzymatic digestion, we investigated the ultrastructural distribution pattern of heparan sulfate side chains of heparan sulfate proteoglycan (HSPG) in various basement membranes (nerve, capillary, oral epithelial, muscle, and dental basement membranes). Four different distribution patterns of stain deposits were identified as heparan sulfate on the basis of enzymatic degradation by heparitinase. In some basement membranes associated with tooth germs and oral epithelium, HID-TCH-SP stain deposits were regularly located at both sides of the lamina densa, but few were observed in the lamina densa itself. In nerve, muscle, and capillary basement membranes, the stain deposits were localized at the external side of the lamina densa adjacent to the underlying connective tissue, but were not found in the laminae lucida and densa. In the internal basal lamina of junctional epithelium of gingiva, the stain deposits were detected mainly in the lamina lucida region. Finally, in some dental and oral epithelial basement membranes, the stain deposits were randomly distributed throughout both laminae lucida and densa. Thus, the present study demonstrated distinct differences in heparan sulfate distribution pattern among various basement membranes, suggesting their architectural heterogeneity.

scholarly journals Heparan sulfate proteoglycan is present in basement membrane as a double-tracked structure.

1989 ◽  
Vol 37 (5) ◽  
pp. 597-602 ◽  
Author(s):  
S Inoue ◽  
D Grant ◽  
C P Leblond
Keyword(s):  
Basement Membrane ◽  
Heparan Sulfate ◽  
Core Protein ◽  
Heparan Sulfate Proteoglycan ◽  
Basement Membranes ◽  
Sulfate Proteoglycan ◽  
Electron Microscopic ◽  
Gold Particles ◽  
Parallel Lines ◽  
Reichert's Membrane

Basement membranes contain 4.5-nm wide sets of two parallel lines, along which short prongs called "spikes" occur at regular intervals. The nature of this structure, referred to as "double tracks," was investigated in Lowicryl sections of mouse kidney and rat Reichert's membrane immunolabeled for basement membrane components using secondary antibodies conjugated to 5-nm gold particles. When the mouse glomerular basement membrane and rat Reichert's membrane were exposed to antibodies directed to the core protein of heparan sulfate proteoglycan, 95% or more of the gold particles were over double tracks, whereas after exposure of Reichert's membrane to antisera against laminin, collagen IV, or entactin, labeling of the double tracks remained at the random level. When heparan sulfate proteoglycan was incubated in Tris buffer, pH 7.4, at 35 degrees C for 1 hr, a precipitate resulted which, on electron microscopic examination, was found to consist of 5- to 6-nm wide sets of two parallel lines along which densities were observed. Immunolabeling confirmed the presence of the proteoglycan's core protein in the sets. Since double tracks were closely similar to this structure and were labeled with the same antibodies, they were likely to be also composed of heparan sulfate proteoglycan.

scholarly journals Studies on the localization of the glycoprotein GP-2 within the renal glomerulus in vivo and in cultured kidney cell strains in vitro.

1981 ◽  
Vol 29 (11) ◽  
pp. 1237-1242 ◽  
Author(s):  
T D Oberley ◽  
A E Chung ◽  
J E Murphy-Ullrich ◽  
D F Mosher
Keyword(s):  
Basement Membrane ◽  
Basement Membranes ◽  
Molecular Organization ◽  
Electron Microscopic Level ◽  
Positive Staining ◽  
Electron Microscopic ◽  
Antibody Technique ◽  
Glomerular Cell ◽  
Kidney Glomerulus

Positive staining for the glycoprotein GP-2 was demonstrated in the kidney glomerulus by use of the indirect peroxidase-labeled antibody technique. At the ultrastructural level, heaviest staining for GP-2 was demonstrated along the lamina rara externa and lamina rara interna of the glomerular and tubular basement membranes, demonstrating definite molecular organization for structures which appear amorphous even at the electron microscopic level. However, GP-2 was also present in the lamina densa of the glomerular basement membrane, but not of the tubular basement membrane. The staining for GP-2 is in contrast to the predominantly mesangial staining for fibronectin. Using the indirect immunoperoxidase techniques for kidney cells cultured in vitro, it was demonstrated that cell surfaces of specific subpopulations of glomerular cells stained heavily for both fibronectin and GP-2, while renal medullary cells did not stain at all using specific antiserum to these molecules. GP-2 was present extracellularly and showed moderate staining in glomerular cell culture, while fibronectin showed heavy staining in this location.

scholarly journals Centriolar Satellites

1999 ◽  
Vol 147 (5) ◽  
pp. 969-980 ◽  
Author(s):  
Akiharu Kubo ◽  
Hiroyuki Sasaki ◽  
Akiko Yuba-Kubo ◽  
Shoichiro Tsukita ◽  
Nobuyuki Shiina
Keyword(s):  
Epithelial Cells ◽  
Live Cells ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Respiratory Epithelial Cells ◽  
Dense Granules ◽  
Pericentriolar Material ◽  
Respiratory Epithelial ◽  
Ciliated Epithelial Cells

We identified Xenopus pericentriolar material-1 (PCM-1), which had been reported to constitute pericentriolar material, cloned its cDNA, and generated a specific pAb against this molecule. Immunolabeling revealed that PCM-1 was not a pericentriolar material protein, but a specific component of centriolar satellites, morphologically characterized as electron-dense granules, ∼70–100 nm in diameter, scattered around centrosomes. Using a GFP fusion protein with PCM-1, we found that PCM-1–containing centriolar satellites moved along microtubules toward their minus ends, i.e., toward centrosomes, in live cells, as well as in vitro reconstituted asters. These findings defined centriolar satellites at the molecular level, and explained their pericentriolar localization. Next, to understand the relationship between centriolar satellites and centriolar replication, we examined the expression and subcellular localization of PCM-1 in ciliated epithelial cells during ciliogenesis. When ciliogenesis was induced in mouse nasal respiratory epithelial cells, PCM-1 immunofluorescence was markedly elevated at the apical cytoplasm. At the electron microscopic level, anti–PCM-1 pAb exclusively labeled fibrous granules, but not deuterosomes, both of which have been suggested to play central roles in centriolar replication in ciliogenesis. These findings suggested that centriolar satellites and fibrous granules are identical novel nonmembranous organelles containing PCM-1, which may play some important role(s) in centriolar replication.

scholarly journals Nidogen-1: Expression and Ultrastructural Localization During the Onset of Mesoderm Formation in the Early Mouse Embryo

2000 ◽  
Vol 48 (2) ◽  
pp. 229-237 ◽  
Author(s):  
Nicolai Miosge ◽  
Fabio Quondamatteo ◽  
Christina Klenczar ◽  
Rainer Herken
Keyword(s):  
Basement Membrane ◽  
Collagen Type ◽  
Mesenchymal Cells ◽  
Basement Membranes ◽  
Electron Microscopic Level ◽  
Collagen Type Iv ◽  
Electron Microscopic ◽  
Type Iv ◽  
Mesoderm Formation ◽  
Nidogen 1

Nidogen-1, a key component of basement membranes, is considered to function as a link between laminin and collagen Type IV networks and is expressed by mesenchymal cells during embryonic and fetal development. It is not clear which cells produce nidogen-1 in early developmental stages when no mesenchyme is present. We therefore localized nidogen-1 and its corresponding mRNA at the light and electron microscopic level in Day 7 mouse embryos during the onset of mesoderm formation by in situ hybridization, light microscopic immunostaining, and immunogold histochemistry. Nidogen-1 mRNA was found not only in the cells of the ectoderm-derived mesoderm but also in the cytoplasm of the endoderm and ectoderm, indicating that all three germ layers express it. Nidogen-1 was localized only in fully developed basement membranes of the ectoderm and was not seen in the developing endodermal basement membrane or in membranes disrupted during mesoderm formation. In contrast, laminin-1 and collagen Type IV were present in all basement membrane types at this developmental stage. The results indicate that, in the early embryo, nidogen-1 may be expressed by epithelial and mesenchymal cells, that both cell types contribute to embryonic basement membrane formation, and that nidogen-1 might serve to stabilize basement membranes in vivo.

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