scholarly journals Nuclear lipid droplets identified by electron microscopy of serial sections

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Rustem Uzbekov ◽  
Philippe Roingeard
Keyword(s):  
Electron Microscopy ◽  
Lipid Droplets ◽  
Serial Sections

Microstructure of Female Reproductive System of Phenacoccus fraxinus Tang (Hemiptera: Coccoidea: Pseudococcidae)

2008 ◽  
Vol 43 (4) ◽  
pp. 362-372 ◽  
Author(s):  
Xiaohong Fu ◽  
Yingping Xie ◽  
Xiaomin Zhang ◽  
Weimin Liu
Keyword(s):  
Electron Microscopy ◽  
Reproductive System ◽  
Lipid Droplets ◽  
Nurse Cells ◽  
Serial Sections ◽  
Female Reproductive System ◽  
Follicular Cells ◽  
Yolk Lipid ◽  
Egg Chamber ◽  
Scanning Electron

The structure of the female reproductive system of the mealybug, Phenacoccus fraxinus Tang (Hemiptera: Coccoidea: Pseudococcidae), was studied using standard histological examination of serial sections of tissues embedded in paraffin and by scanning electron microscopy. Our studies revealed that the ovary of P. fraxinus has paired lateral oviducts comprised of numerous short ovarioles. Each ovariole consists of 1 trophic chamber, 1 egg chamber and 1 pedicel which connect to the bottom of the egg chamber. Three nurse cells were observed in the trophic chamber, whereas yolk, lipid droplets and an oocyte were seen in the egg chamber. Follicular cells were arranged along the wall of the egg chamber and extended to form the pedicel. Many tracheae and tracheoles of various thicknesses were observed innervating the clusters of ovaries.

scholarly journals Anatomical basis for cell transplantation into mouse seminiferous tubules

Reproduction ◽  
2012 ◽  
Vol 144 (3) ◽  
pp. 385-392 ◽  
Author(s):  
Unai Silván ◽  
Juan Aréchaga
Keyword(s):  
Electron Microscopy ◽  
Cell Transplantation ◽  
Soft Tissues ◽  
Partial Information ◽  
Three Dimensional ◽  
Seminiferous Tubules ◽  
Serial Sections ◽  
Pathological Conditions ◽  
Anatomical Basis ◽  
Scanning Electron

Cell transplantation into the seminiferous tubules is a useful technique for the study of physiological and pathological conditions affecting the testis. However, the precise three-dimensional organization and, particularly, the complex connectivity of the seminiferous network have not yet been thoroughly characterized. To date, the technical approaches to address these issues have included manual dissection under the stereomicroscope, reconstruction of histological serial sections, and injection of contrast dyes, but all of them have yielded only partial information. Here, using an approach based on the microinjection of a self-polymerizing resin followed by chemical digestion of the surrounding soft tissues, we reveal fine details of the seminiferous tubule scaffold and its connections. These replicas of the testis seminiferous network were studied by scanning electron microscopy. The present results not only establish a morphological basis for more precise microinjection into the mouse seminiferous tubules but also enable a more profound investigation of physiological and embryological features of the testis.

A systematic approach to reconstructing microcircuitry by electron microscopy of serial sections

1980 ◽  
Vol 2 (1-3) ◽  
pp. 265-293 ◽  
Author(s):  
John K. Stevens ◽  
Thomas L. Davis ◽  
Neil Friedman ◽  
Peter Sterling
Keyword(s):  
Electron Microscopy ◽  
Systematic Approach ◽  
Serial Sections

Rehydration of freeze substituted brain tissue for preembedding immuno-electron microscopy

2021 ◽  
Author(s):  
Linnaea E Ostroff ◽  
Janeth Perez-Garza ◽  
Emily Parrish ◽  
Zachary Deane
Keyword(s):  
Electron Microscopy ◽  
Full Potential ◽  
Serial Sections ◽  
Volume Reconstruction ◽  
Additional Advantage ◽  
Brain Circuits ◽  
Immuno Electron Microscopy ◽  
Neuronal Processes ◽  
Molecular Information ◽  
Antibody Labeling

Electron microscopy (EM) volume reconstruction is a powerful tool for investigating the fundamental structure of brain circuits, but the full potential of this technique is limited by the difficulty of integrating molecular information. High quality ultrastructural preservation is necessary for EM reconstruction, and intact, highly contrasted cell membranes are essential for following small neuronal processes through serial sections. Unfortunately, the antibody labeling methods used to identify most endogenous molecules result in compromised morphology, especially of membranes. Cryofixation can produce superior morphological preservation and has the additional advantage of allowing indefinite storage of valuable samples. We have developed a method based on cryofixation that allows sensitive immunolabeling of endogenous molecules, preserves excellent ultrastructure, and is compatible with high-contrast staining for serial EM reconstruction.

scholarly journals A conserved family of proteins facilitates nascent lipid droplet budding from the ER

2015 ◽  
Vol 211 (2) ◽  
pp. 261-271 ◽  
Author(s):  
Vineet Choudhary ◽  
Namrata Ojha ◽  
Andy Golden ◽  
William A. Prinz
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Lipid Metabolism ◽  
Caenorhabditis Elegans ◽  
Lipid Droplet ◽  
Lipid Droplets ◽  
De Novo ◽  
Fat Storage ◽  
Higher Eukaryotes ◽  
Er Membrane

Lipid droplets (LDs) are found in all cells and play critical roles in lipid metabolism. De novo LD biogenesis occurs in the endoplasmic reticulum (ER) but is not well understood. We imaged early stages of LD biogenesis using electron microscopy and found that nascent LDs form lens-like structures that are in the ER membrane, raising the question of how these nascent LDs bud from the ER as they grow. We found that a conserved family of proteins, fat storage-inducing transmembrane (FIT) proteins, is required for proper budding of LDs from the ER. Elimination or reduction of FIT proteins in yeast and higher eukaryotes causes LDs to remain in the ER membrane. Deletion of the single FIT protein in Caenorhabditis elegans is lethal, suggesting that LD budding is an essential process in this organism. Our findings indicated that FIT proteins are necessary to promote budding of nascent LDs from the ER.

Ultrastructure of region of a low safety factor in inhomogeneous giant axon of the cockroach

1976 ◽  
Vol 39 (4) ◽  
pp. 900-908 ◽  
Author(s):  
M. Castel ◽  
M. E. Spira ◽  
I. Parnas ◽  
Y. Yarom
Keyword(s):  
Electron Microscopy ◽  
Glial Cells ◽  
Extracellular Space ◽  
Light And Electron Microscopy ◽  
Giant Axon ◽  
Serial Sections ◽  
Giant Axons ◽  
Chemical Synapses ◽  
Cytoplasmic Processes ◽  
Periaxonal Space

1. The structure of the ventral giant axons of the cockroach at the level of ganglion T3 was studied by means of light and electron microscopy. 2. From serial sections and cobalt injections, the axons diameter was found to range between 40 and 60 mum at the caudal end of ganglion T3; toward the center of T3 they narrow to 20-40 mum, and again expand to 30-45 mum anteriorly in ganglion T3. 3. Each giant axon sends off several branches, 1-15 mum in diameter, into the neuropil. The giant axons and the bases of their branches are enveloped by cytoplasmic processes of glial cells. The periaxonal space is about 100-200 A. 4. Distally the branches are devoid of glial envelopes and the extracellular space between the branches and other axonal profiles is about 200 A. Terminals with presumptive chemical synapses on the giant axon branches were found. Clear vesicles, 300-400 A in diameter, are seen clustered together. The width of the supposedly synaptic gap is about 100 A. 5. In some areas the branches and other axonal profiles form close appositions.

Elektronenmikroskopische Untersuchungen über die Eizellbildung und Eizellreifung des Lebermooses Sphaerocarpus donnellii Aust.

1965 ◽  
Vol 20 (8) ◽  
pp. 795-801 ◽  
Author(s):  
Lothar Diers
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Phase Contrast ◽  
Lipid Droplets ◽  
Unit Membrane ◽  
Light Phase ◽  
Lamellar System ◽  
Small Bodies ◽  
Canal Cell ◽  
Ventral Canal

The formation and maturation of the egg of the liverwort, Sphaerocarpus donnellii, was investigated by light, phase contrast and particularly by electron microscopy. The division of the central cell into the egg and the ventral canal cell, and the maturation of the egg, is completed within four days. All stages of this formation and maturation were examined under the electron microscope after fixation in KMnO4 or OsO4. — In the maturing egg there always occur the endoplasmic reticulum, well recognisable plastids with a poorly developed lamellar system, numerous mitochondria and dictyosomes, a rising number of lipid droplets, unknown small bodies limited by a unit membrane, and numerous ribosomes. During maturation the nucleus considerably enlarges and forms evaginations into the cytoplasm. Starch is increasingly deposited in the plastids. A degeneration of plastids has not been found.

scholarly journals Studies of the Interaction of Cardiac Lipid Droplets with Mitochondria Using Electron Microscopy

2014 ◽  
Vol 20 (S3) ◽  
pp. 1376-1377
Author(s):  
Johanna Sotiris ◽  
John Strong ◽  
Carole Sztalryd ◽  
Ru-ching Hsia
Keyword(s):  
Electron Microscopy ◽  
Lipid Droplets ◽  
Cardiac Lipid

scholarly journals Metabolism of cationized lipoproteins by human fibroblasts: biochemical and morphologic correlations

1977 ◽  
Vol 74 (1) ◽  
pp. 119-135 ◽  
Author(s):  
SK Basu ◽  
RGW Anderson ◽  
JL Goldstein ◽  
MS Brown
Keyword(s):  
Electron Microscopy ◽  
Cholesteryl Ester ◽  
Lipid Droplets ◽  
Human Fibroblasts ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Turnover Time ◽  
Cholesteryl Esters ◽  
Light Microscope Level ◽  
Cellular Content

Human plasma low density lipoprotein (LDL) that had been rendered polycationic by coupling with N, N-dimethyl-1, 3-propanediamine (DMPA) was shown by electron microscopy to bind in clusters to the surface of human fibroblasts. The clusters resembled those formed by polycationic ferritin (DMPA-feritin), a visual probe that binds to anionic site on the plasma membrane. Biochemical studies with (125)I-labeled DMPA-LDL showed that the membrane-bound lipoprotein was internalized and hydrolyzed in lysosomes. The turnover time for cell bound (125)I-DMPA-LDL, i.e., the time in which the amount of (125)I-DMPA-LDL degraded was equal to the steady-state cellular content of the lipoprotein, was about 50 h. Because the DMPA-LDL gained access to fibroblasts by binding nonspecifically to anionic sites on the cell surface rather than by binding to the physiologic LDL receptor, its uptake failed to be regulated under conditions in which the uptake of native LDL was reduced by feedback suppression of the LDL receptor. As a result, unlike the case with native LDL, the DMPA-LDL accumulated progressively within the cell, and this led to a massive increase in the cellular content of both free and esterified cholesterol. Studies with (14)C-oleate showed that at least 20 percent of the accumulated cholesteryl esters represented cholesterol that had been esterified within the cell. After 4 days of incubation with 10 μg/ml of DMPA-LDL, fibroblasts had accumulated so much cholesteryl ester that neutral lipid droplets were visible at the light microscope level with Oil Red O staining. By electron microscopy, these intracellular lipid droplets were observed to lack a tripartite limiting membrane. The ability to cause the overaccumulation of cholesteryl esters within cells by using DMPA-LDL provides a model system for study of the pathologic consequences at the cellular level of massive deposition of cholesteryl ester.

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