In mouse oocytes the mitochondrion-originated germinal body-like structures accumulate mouse Vasa homologue (MVH) protein

Zygote ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 501-506 ◽  
Author(s):  
Arkadiy A. Reunov ◽  
Yulia A. Reunova
Keyword(s):  
Electron Microscopy ◽  
Germ Plasm ◽  
Mouse Oocytes ◽  
Mitochondrial Origin ◽  
Conventional Electron Microscopy

SummaryMouse Vasa homologue (MVH) antibodies were applied to mouse Graafian oocytes to clarify if mitochondrion-originated germinal body-like structures, described previously by conventional electron microscopy, were associated with the germ plasm. It was found that both the mitochondrion-like structures with cristae and the germinal body-like structures that lacked any signs of cristae were labelled specifically by the anti-MVH antibody. Moreover, some granules were MVH-positive ultrastructural hybrids of the mitochondria and germinal body-like structures, the presence of which clearly supported the idea of a mitochondrial origin for the germinal body-like structures. This finding is the first evidence that mitochondrion-originated germinal body-like granules represent mouse germ plasm.

Examination of Schistosome Cercariae and Schistosomules by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 50-51
Author(s):  
D. Johnson ◽  
P. Moriearty
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Light Microscopy ◽  
Surface Structure ◽  
Extensive Study ◽  
Scanning Microscopy ◽  
Host Parasite ◽  
Conventional Electron Microscopy ◽  
Scanning Electron

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.

Use of human autoantibodies and immunoelectron microscopy to study structure and function of the nucleolus and nuclear bodies

1992 ◽  
Vol 50 (1) ◽  
pp. 506-507
Author(s):  
Robert L. Ochs
Keyword(s):  
Electron Microscopy ◽  
Structure And Function ◽  
Nuclear Bodies ◽  
Nuclear Interior ◽  
Coiled Bodies ◽  
Interchromatin Granules ◽  
And Function ◽  
Conventional Electron Microscopy ◽  
Perichromatin Granules ◽  
Perichromatin Fibrils

By conventional electron microscopy, the formed elements of the nuclear interior include the nucleolus, chromatin, interchromatin granules, perichromatin granules, perichromatin fibrils, and various types of nuclear bodies (Figs. 1a-c). Of these structures, all have been reasonably well characterized structurally and functionally except for nuclear bodies. The most common types of nuclear bodies are simple nuclear bodies and coiled bodies (Figs. 1a,c). Since nuclear bodies are small in size (0.2-1.0 μm in diameter) and infrequent in number, they are often overlooked or simply not observed in any random thin section. The rat liver hepatocyte in Fig. 1b is a case in point. Historically, nuclear bodies are more prominent in hyperactive cells, they often occur in proximity to nucleoli (Fig. 1c), and sometimes they are observed to “bud off” from the nucleolar surface.

Cytochalasin B-induced pseudo-cleavage of mouse oocytes in vitro. II. Studies of the mechanism and morphological consequences of pseudocleavage

1977 ◽  
Vol 26 (1) ◽  
pp. 323-337
Author(s):  
P.M. Wassarman ◽  
T.E. Ukena ◽  
W.J. Josefowicz ◽  
G.E. Letourneau ◽  
M.J. Karnovsky
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cytochalasin B ◽  
Oocyte Size ◽  
Contractile Ring ◽  
Subsequent Formation ◽  
Mouse Oocytes ◽  
Meiotic Competence ◽  
Scanning Electron

Mouse oocytes are induced by cytochalasin B to undergo ‘pseudocleavage’ in vitro into 2 compartments, only one of which possesses microvilli. It has been found that this particular response to cytochalasin B is related to oocyte size and, possibly, to the acquisition of meiotic competence by the oocyte during its growth phase. Certain of the morphological events which characterize pseudocleavage have been determined using transmission and scanning electron microscopy. These events include: (i) an initial withdrawal of microvilli from the surface of the oocyte, together with the concomitant disappearance of microfilaments normally associated with the microvilli; (ii) the subsequent formation of a pseudocleavage furrow and contractile ring; and (iii) the reappearance of microvilli and associated microfilaments in one of the two resulting oocyte compartments. These changes in surface architecture are reflected in the distribution of fluorescein-conjugated lectins bound to the oocyte surface during pseudocleavage.

Microstructure of epitaxial VO2 thin films deposited on (1120) sapphire by MOCVD

1994 ◽  
Vol 9 (9) ◽  
pp. 2264-2271 ◽  
Author(s):  
H. Zhang ◽  
H.L.M. Chang ◽  
J. Guo ◽  
T.J. Zhang
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Deposition Temperature ◽  
Room Temperature ◽  
High Resolution Electron Microscopy ◽  
Sapphire Substrates ◽  
Resolution Electron ◽  
Initial Nucleation ◽  
Vo2 Thin Films ◽  
Conventional Electron Microscopy

Epitaxial VO2 thin films grown on (1120) sapphire (α-Al2O3) substrates by MOCVD at 600 °C have been characterized by conventional electron microscopy and high resolution electron microscopy (HREM). Three different epitaxial relationships between the monoclinic VO2 films and sapphire substrates have been found at room temperature: I. (200) [010] monoclinic VO2 ‖ (1120) [0001] sapphire, II. (002) [010] monoclinic VO2 ‖ (1120) [0003] sapphire, and III. (020) [102] monoclinic VO2 ‖ (1120) [0001] sapphire. Expitaxial relationships II and III are equivalent to each other when the film possesses tetragonal structure at the deposition temperature; i.e., they can be described as (010) [100] tetragonal VO2 ‖ (1120) [0001] sapphire and (100) [010] tetragonal VO2 ‖ (1120) [0001] sapphire. HREM image shows that the initial nucleation of the film was dominated by the first orientation relationship, but the film then grew into the grains of the second and the third (equivalent to each other at the deposition temperature) epitaxial relationships. Successive 90°transformation rotational twins around the a-axis are commonly observed in the monoclinic films.

A Comparison of Calculated Images Generated by Six Modes of Transmission Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 368-369
Author(s):  
A. Engel ◽  
J. W. Wiggins ◽  
David Woodruff
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Phase Plate ◽  
Modes Of Transmission ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Detector ◽  
Conventional Electron Microscopy

Six modes of transmission electron microscopy are compared by a numerical simulation of the image formation assuming perfectly coherent illumination and ignoring the influence of radiation damage and noise. The comparison includes five modes of conventional electron microscopy (CEM): axial bright field, Unwin's phase plate, central stop dark field, tilted-beam dark field and conical illumination dark field, and the annular detector mode of the scanning transmission electron microscope (STEM).

Ultrastructural Study of Peroxisome Proliferation in Hepatocytes by Quick-Freezing and Deep-Etching Method

1988 ◽  
Vol 46 ◽  
pp. 258-259
Author(s):  
S. Ohno
Keyword(s):  
Electron Microscopy ◽  
Liquid Nitrogen ◽  
Ultrastructural Study ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferation ◽  
Solution Ph ◽  
Deep Etching ◽  
Quick Freezing ◽  
Ethylhexyl Phthalate ◽  
Conventional Electron Microscopy

It had been emphasized that luminar continuities between sER and peroxisomes were detected by conventional electron microscopy. However, recent studies ruled out the luminar continuities between sER and peroxisomes. Lazarow et al. reported that peroxisomal proteins were synthesized on free ribosomes and postulated the existence of “peroxisomal reticulum” distinct from the ER. The object of this study is to clarify the proliteration mechanism of peroxisomes after administration of a peroxisome proliferator, DEHP (di-2- ethylhexyl phthalate).Mice treated with 2% DEHP for 1, 3, 5 and 7 days and normal mice were perfused with 2% paraformaldehyde in 0.1M phosphate buffered solution, pH 7.4, (PB) for 5 min. The livers were cut into small pieces, washed in PB to remove cytoplasmic soluble proteins and were fixed again with 2% paraformaldehyde-0.25% glutaraldehyde for 30 min. They were quickly frozen in isopentane-propane mixture (around -190 C) and fractured in liquid nitrogen to remove the damaged surface tissues. They were deeply etched in Eiko FD-3S machine (-95°C, 2-6xl0-7 Torr) and rotary shadowed with platinum.

An Intranuclear Fibrillar Lattice in Neurons

1966 ◽  
Vol 1 (3) ◽  
pp. 283-286
Author(s):  
R. L. CHANDLER ◽  
R. WILLIS
Keyword(s):  
Electron Microscopy ◽  
Mouse Brain ◽  
Basic Component ◽  
Conventional Electron Microscopy

A new intranuclear structure has been demonstrated in neurons of rat and mouse brain, and studied using conventional electron microscopy and electron stereoscopy techniques. The structure has a crystalline appearance and a variety of profiles was seen in the sections, some showing curvature and one showing ellipticity. The basic component consisted of planes of parallel fibrils; layers of these arrays, usually two in number, crossed each other at an angle, resulting in the appearance of a lattice.

scholarly journals Ageing-induced changes in the cortical granules of mouse eggs

Zygote ◽  
2004 ◽  
Vol 12 (2) ◽  
pp. 95-103 ◽  
Author(s):  
Hugo Díaz ◽  
Pedro Esponda
Keyword(s):  
Electron Microscopy ◽  
Cortical Granules ◽  
Young Females ◽  
Dense Granules ◽  
Fertilization Rates ◽  
Mouse Oocytes ◽  
Induced Changes ◽  
Mouse Eggs ◽  
Old Females

The cortical cytoplasm and cortical granules (CGs) of mouse oocytes were analysed by electron microscopy. Oocytes were collected soon and 20 h after ovulation from adult young females (3–4 months old). In addition, gametes collected soon after ovulation from 12- to 14-month-old females were used. Ultrastructural analyses were undertaken using the conventional procedures and the alcoholic PTA method. PTA selectively stains the CGs indicating the presence of lysine-rich proteins in these granules. Oocytes from young females showed CGs as dense granules 300–500 nm in diameter linearly arranged under the oolemma. In oocytes recovered 20 h after ovulation 24.31% of CGs appeared vacuolated and 38.40% internalized in the cytoplasm. In gametes collected from old females several changes were observed in the cortical cytoplasm: (a) CGs appeared concentrated in some areas while others regions were devoid of granules; (b) groups of CGs appeared internalized in the egg cytoplasm; (c) the CG contents had swollen and changed, showing dense and clear areas; (d) numerous dense structures and vesicles (lysosome-like vesicles) were present; (e) cytoplasmic fragmentation was frequently seen. Fragments contained CGs, dense structures and vacuoles. These changes are closely related to the low fertilization rates shown by these oocytes when they were used for in vitro fertilization procedures.

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