Comparison of microtubules and microfilaments in Tipula iridescent virus-infected and uninfected cells

1985 ◽  
Vol 63 (6) ◽  
pp. 543-552 ◽  
Author(s):  
Robert W. Seagull ◽  
Peter E. Lee ◽  
Monica Frosch
Keyword(s):  
Virus Assembly ◽  
Electron Microscopic ◽  
Iridescent Virus ◽  
Initial Stage ◽  
Large Virus ◽  
Infected Cells ◽  
Specific Association ◽  
Globular Cells ◽  
Cytoskeletal Elements ◽  
Microscopic Techniques

Microfilaments and microtubules were detected in Estigmene acrea virus-infected cells using fluorescent immunochemistry and in sections by electron microscopy. Twelve hours following infection of cells with Tipula iridescent virus, large virus assembly sites developed in the cytoplasm. The majority of infected cells exhibit no detectable changes in the cytoskeleton during the initial stage of infection, when virus assembly sites are forming. Actin was localized either in cytoplasmic spikes or in patches at the cell surface. Microtubules were parallel to the long axis of elongate cells or randomly distributed in globular cells. Intermediate filaments were not detected using either immunofluorscent or electron microscopic techniques. In later stages of infection some cells exhibit a specific association between actin and the virus assembly site. The significance of this observation remains unclear since only a portion of the population exhibits this change. From this study, it does not appear that cytoskeletal elements are of importance in the formation or maintenance of the membrane-free cytoplasmic virus assembly sites.

scholarly journals ELECTRON MICROSCOPIC STUDY ON ENLARGED CELLS OF RED SEA BREAM, Pagrus major INFECTED BY THE RED SEA BREAM IRIDOVIRUS (RSIV, GENUS Megalocytivirus, FAMILY Iridoviridae)

2009 ◽  
Vol 4 (1) ◽  
pp. 53
Author(s):  
Ketut Mahardika
Keyword(s):  
Electron Microscope ◽  
Inclusion Body ◽  
Red Sea ◽  
Virus Assembly ◽  
Infected Fish ◽  
Sea Bream ◽  
Red Sea Bream ◽  
Electron Microscopic ◽  
Target Organs ◽  
Infected Cells

Most histopathologycal studies of the red sea bream iridovirus (RSIV) disease in red sea bream have been performed by studying enlarged cells as well as necrotized cells in the spleen and other organs. These enlarged cells have been named as inclusion body bearing cells (IBCs). However, few information is available about detail of ultrastructural features of IBCs produced in the target organs of RSIV-infected fish. In the present study, details of ultrastructural features of IBCs that were produced in the spleen tissue of naturally RSIV-infected red sea bream were investigated under electron microscope. Under electron microscope, RSIV-infected red sea bream had the presence of two types of IBCs: typical IBCs allowing virus assembly within viral assembly site (VAS), and atypical IBCs which degenerate organelles without virus assembly. Other infected-cells were observed as necrotized cells forming intracytoplasmic VAS with large numbers of virions, but without the formation of the distinct inclusion body. Morphogenesis steps on RSIV-infected red sea bream were observed as filamentous-filed virions, partially-filled virions and complete virions with 145-150 nm in size. These findings confirmed that RSIV-infected red sea bream were characterized by formation of typical and atypical IBCs as well as necrotized cells.

Chlamydia psittaci: inclusion vacuole ultrastructure

1980 ◽  
Vol 26 (3) ◽  
pp. 396-401 ◽  
Author(s):  
Gerald V. Stokes
Keyword(s):  
Cytoplasmic Inclusion ◽  
Chlamydia Psittaci ◽  
Host Cells ◽  
Infected Host ◽  
Electron Microscopic ◽  
Infected Cells ◽  
Microscopic Techniques

The inclusion ultrastructure of fibroblasts infected with Chlamydia psittaci (6BC) was studied. Electron microscopic techniques were used which permitted the observation of whole infected host cells and 1.0-μm sectioned preparations. It was shown that the cytoplasmic inclusion vacuoles of infected cells contained interconnecting structures within which chlamydiae reproduce.

Further Observations on the Virus of Epizootic Diarrhea of Infant Mice. An Electron Microscopic Study

1967 ◽  
Vol 25 ◽  
pp. 110-111
Author(s):  
W. G. Banfield ◽  
G. Kasnic ◽  
J. H. Blackwell
Keyword(s):  
Electron Microscope ◽  
Infected Cell ◽  
Microscopic Study ◽  
Intestinal Epithelium ◽  
Ultrastructural Study ◽  
Osmium Tetroxide ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Virus Particles ◽  
Infected Cells

An ultrastructural study of the intestinal epithelium of mice infected with the agent of epizootic diarrhea of infant mice (EDIM virus) was first performed by Adams and Kraft. We have extended their observations and have found developmental forms of the virus and associated structures not reported by them.Three-day-old NLM strain mice were infected with EDIM virus and killed 48 to 168 hours later. Specimens of bowel were fixed in glutaraldehyde, post fixed in osmium tetroxide and embedded in epon. Sections were stained with uranyl magnesium acetate followed by lead citrate and examined in an updated RCA EMU-3F electron microscope.The cells containing virus particles (infected) are at the tips of the villi and occur throughout the intestine from duodenum through colon. All developmental forms of the virus are present from 48 to 168 hours after infection. Figure 1 is of cells without virus particles and figure 2 is of an infected cell. The nucleus and cytoplasm of the infected cells appear clearer than the cells without virus particles.

Polarity Determination in Sphalerite and Wurtzite Structures

1990 ◽  
Vol 48 (2) ◽  
pp. 500-501
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Opposite Polarity ◽  
Single Domain ◽  
Polar Material ◽  
Electron Microscopic ◽  
Dynamical Interaction ◽  
X Ray ◽  
Polarity Determination ◽  
The Absolute ◽  
Microscopic Techniques

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

Ultrastructural Immunocytochemistry of Five Rat Pituitary Adenomas

1980 ◽  
Vol 38 ◽  
pp. 724-725
Author(s):  
D. J. McComb ◽  
N. Ryan ◽  
E. Horvath ◽  
K. Kovacs ◽  
E. Nagy ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Pituitary Tumors ◽  
Electron Microscopic ◽  
Electron Microscopic Immunocytochemistry ◽  
Transmission Electron ◽  
Rat Pituitary ◽  
Radiation Induced ◽  
Group 5 ◽  
Group 2 ◽  
Microscopic Techniques

Conventional light and electron microscopic techniques failed to clarify the cellular composition and derivation of spontaneous and induced, intrasellar and transplanted pituitary adenomas in rats (1). In the present work, electron microscopic immunocytochemistry was applied to evaluate five adenohypo-physial tumors using a technique described by Moriarty and Garner (2). Spontaneously occurring pituitary adenomas (group 1) were harvested from aging female Long-Evans rats. R-Amsterdam rats were treated with 2 x 1.0 mg estrone acetate (HogivaI) s.c. weekly for 6 months. Pituitary adenomas in excess of 30 mg were removed from these animals to make up the tumors of group 2. Groups 3 and 4 consisted of estrogen-induced autonomous transplan¬ted pituitary tumors MtT.WlO and MtT.F4. Group 5 was a radiation-induced transplanted autonomous pituitary tumor MtT.W5. The tumors of groups 3,4 and 5 were allowed to proliferate in host rats 6-8 weeks prior to removal for processing. Tissue was processed for transmission electron microscopy (glutaraldehyde fixation, OsO4 postfixation and epoxy resin embedding), and electron microscopic immunocytochemistry (3% paraformaldehyde fixation and Araldite embedding).

scholarly journals Zika virus replication in glioblastoma cells: electron microscopic tomography shows 3D arrangement of endoplasmic reticulum, replication organelles, and viral ribonucleoproteins

2021 ◽  
Author(s):  
Johannes Wieland ◽  
Stefan Frey ◽  
Ulrich Rupp ◽  
Sandra Essbauer ◽  
Rüdiger Groß ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Line ◽  
Zika Virus ◽  
Structural Changes ◽  
Electron Tomography ◽  
Glioblastoma Cells ◽  
Electron Microscopic ◽  
N Protein ◽  
Ribonucleoprotein Complexes ◽  
Infected Cells

AbstractStructural changes of two patient-derived glioblastoma cell lines after Zika virus infection were investigated using scanning transmission electron tomography on high-pressure-frozen, freeze-substituted samples. In Zika-virus-infected cells, Golgi structures were barely visible under an electron microscope, and viral factories appeared. The cytosol outside of the viral factories resembled the cytosol of uninfected cells. The viral factories contained largely deranged endoplasmic reticulum (ER), filled with many so-called replication organelles consisting of a luminal vesicle surrounded by the ER membrane. Viral capsids were observed in the vicinity of the replication organelles (cell line #12537 GB) or in ER cisternae at large distance from the replication organelles (cell line #15747 GB). Near the replication organelles, we observed many about 100-nm-long filaments that may represent viral ribonucleoprotein complexes (RNPs), which consist of the RNA genome and N protein oligomers. In addition, we compared Zika-virus-infected cells with cells infected with a phlebovirus (sandfly fever Turkey virus). Zika virions are formed in the ER, whereas phlebovirus virions are assembled in the Golgi apparatus. Our findings will help to understand the replication cycle in the virus factories and the building of the replication organelles in glioblastoma cells.

scholarly journals Characterization of the Coronavirus Mouse Hepatitis Virus Strain A59 Small Membrane Protein E

2000 ◽  
Vol 74 (5) ◽  
pp. 2333-2342 ◽  
Author(s):  
Martin J. B. Raamsman ◽  
Jacomine Krijnse Locker ◽  
Alphons de Hooge ◽  
Antoine A. F. de Vries ◽  
Gareth Griffiths ◽  
...  
Keyword(s):  
Virus Strain ◽  
Hepatitis Virus ◽  
Expression System ◽  
Mouse Hepatitis Virus ◽  
Viral Envelope ◽  
Membrane Structures ◽  
Electron Microscopic ◽  
E Protein ◽  
Infected Cells ◽  
Virus Expression

ABSTRACT The small envelope (E) protein has recently been shown to play an essential role in the assembly of coronaviruses. Expression studies revealed that for formation of the viral envelope, actually only the E protein and the membrane (M) protein are required. Since little is known about this generally low-abundance virion component, we have characterized the E protein of mouse hepatitis virus strain A59 (MHV-A59), an 83-residue polypeptide. Using an antiserum to the hydrophilic carboxy terminus of this otherwise hydrophobic protein, we found that the E protein was synthesized in infected cells with similar kinetics as the other viral structural proteins. The protein appeared to be quite stable both during infection and when expressed individually using a vaccinia virus expression system. Consistent with the lack of a predicted cleavage site, the protein was found to become integrated in membranes without involvement of a cleaved signal peptide, nor were any other modifications of the polypeptide observed. Immunofluorescence analysis of cells expressing the E protein demonstrated that the hydrophilic tail is exposed on the cytoplasmic side. Accordingly, this domain of the protein could not be detected on the outside of virions but appeared to be inside, where it was protected from proteolytic degradation. The results lead to a topological model in which the polypeptide is buried within the membrane, spanning the lipid bilayer once, possibly twice, and exposing only its carboxy-terminal domain. Finally, electron microscopic studies demonstrated that expression of the E protein in cells induced the formation of characteristic membrane structures also observed in MHV-A59-infected cells, apparently consisting of masses of tubular, smooth, convoluted membranes. As judged by their colabeling with antibodies to E and to Rab-1, a marker for the intermediate compartment and endoplasmic reticulum, the E protein accumulates in and induces curvature into these pre-Golgi membranes where coronaviruses have been shown earlier to assemble by budding.

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