scholarly journals Cytopathological characterization of Mal de Río Cuarto virus in corn, wheat and barley

2002 ◽  
Vol 27 (3) ◽  
pp. 298-302 ◽  
Author(s):  
JOEL D. ARNEODO ◽  
EUGENIA LORENZO ◽  
IRMA G. LAGUNA ◽  
GUILLERMINA ABDALA ◽  
GRACIELA A. TRUOL
Keyword(s):  
Virus Particles ◽  
Dispersed Particles ◽  
Transmission Electron ◽  
Infected Cells ◽  
Tubular Inclusions ◽  
Delphacodes Kuscheli ◽  
Corn Plants ◽  
Dark Green ◽  
Cereal Plants

The Mal de Río Cuarto disease is caused by Mal de Río Cuarto virus (MRCV) transmitted by Delphacodes kuscheli. Comparative studies were carried out on the cytopathological alterations produced by MRCV in corn (Zea mays), wheat (Triticum aestivum) and barley (Hordeum vulgare), as seen with a transmission electron microscope. Corn plants were infected with viruliferous D. kuscheli collected from the endemic disease area (i.e. Río Cuarto County, Córdoba, Argentina). For the viral transmission to small grain cereal plants, laboratory rared insects were used. In this case, the inoculum source was wheat and barley plants infected with MRCV isolate grown in a greenhouse. Leaf samples with conspicuous symptoms were collected: enations and size reduction in corn; crenatures, swelling veins and dark green color in small grain cereals. Viral infection was corroborated by DAS-ELISA. Viroplasms containing complete and incomplete virus particles and fibrillar material were found in the cytoplasm of infected cells in all species. Mature virions were between 60 and 70 nm diameter. In wheat and barley, viroplasms and dispersed particles were observed only in phloem, while in corn virions were also found in cells of the bundle sheath. Crystalline arrays of particles were detected in corn enation constitutive cells. Tubular inclusions were found only in wheat samples. The three species showed abnormalities in the chloroplasts of affected cells. The results showed that MRCV cytopathology has similarities with other viruses from the genus Fijivirus, family family Reoviridae, but slight differences depending upon the host plant.

scholarly journals Particle Assembly and Ultrastructural Features Associated with Replication of the Lytic Archaeal Virus Sulfolobus Turreted Icosahedral Virus

2009 ◽  
Vol 83 (12) ◽  
pp. 5964-5970 ◽  
Author(s):  
Susan K. Brumfield ◽  
Alice C. Ortmann ◽  
Vincent Ruigrok ◽  
Peter Suci ◽  
Trevor Douglas ◽  
...  
Keyword(s):  
Time Course ◽  
Plaque Assay ◽  
Ultrastructural Changes ◽  
Progeny Virus ◽  
Particle Assembly ◽  
Virus Particles ◽  
Transmission Electron ◽  
Archaeal Viruses ◽  
Infected Cells ◽  
Sulfolobus Turreted Icosahedral Virus

ABSTRACT Little is known about the replication cycle of archaeal viruses. We have investigated the ultrastructural changes of Sulfolobus solfataricus P2 associated with infection by Sulfolobus turreted icosahedral virus (STIV). A time course of a near synchronous STIV infection was analyzed using both scanning and transmission electron microscopy. Assembly of STIV particles, including particles lacking DNA, was observed within cells, and fully assembled STIV particles were visible by 30 h postinfection (hpi). STIV was determined to be a lytic virus, causing cell disruption beginning at 30 hpi. Prior to cell lysis, virus infection resulted in the formation of pyramid-like projections from the cell surface. These projections, which have not been documented in any other host-virus system, appeared to be caused by the protrusion of the cell membrane beyond the bordering S-layer. These structures are thought to be sites at which progeny virus particles are released from infected cells. Based on these observations of lysis, a plaque assay was developed for STIV. From these studies we propose an overall assembly model for STIV.

scholarly journals Characterization of a novel alloherpesvirus from Atlantic cod (Gadus morhua)

2011 ◽  
Vol 24 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Mar Marcos-Lopez ◽  
Thomas B. Waltzek ◽  
Ronald P. Hedrick ◽  
Dolores V. Baxa ◽  
Amber F. Garber ◽  
...  
Keyword(s):  
Gadus Morhua ◽  
Virus Isolation ◽  
Atlantic Cod ◽  
International Committee ◽  
Atpase Subunit ◽  
Transmission Electron ◽  
Viral Particles ◽  
Infected Cells

Alloherpesviruses affect freshwater and marine fish species. The aim of the current study was to characterize a novel alloherpesvirus in Atlantic cod ( Gadus morhua). Samples were processed for histopathology, transmission electron microscopy (TEM), virus isolation, molecular characterization, and in situ hybridization (ISH). Histopathology revealed that the infection was restricted to the gills and that it induced cytomegaly in infected cells. By TEM, numerous viral particles with morphology compatible with a herpesvirus were observed inside the cytomegalic cells. To characterize this new agent, polymerase chain reaction amplified regions of the ATPase subunit of the terminase, and DNA polymerase genes were sequenced. Phylogenetic analysis revealed strongest similarity with alloherpesviruses belonging to the genus Ictalurivirus and Salmonivirus. The ISH showed specific labeling of nuclear inclusions in the cytomegalic cells. While virus isolation was unsuccessful, the results obtained through different diagnostic tests in the present study confirm the discovery of a new alloherpesvirus affecting Atlantic cod. The authors propose the formal species designation Gadid herpesvirus 1 (GaHV-1) to be considered for approval by the International Committee on the Taxonomy of Viruses.

scholarly journals Incorporation of Three Endocytosed Varicella-Zoster Virus Glycoproteins, gE, gH, and gB, into the Virion Envelope

2005 ◽  
Vol 79 (2) ◽  
pp. 997-1007 ◽  
Author(s):  
Lucie Maresova ◽  
Tracy Jo Pasieka ◽  
Elizabeth Homan ◽  
Erick Gerday ◽  
Charles Grose
Keyword(s):  
Varicella Zoster Virus ◽  
Virion Assembly ◽  
Varicella Zoster ◽  
Virus Particles ◽  
Transmission Electron ◽  
Cleavage Assay ◽  
Viral Glycoproteins ◽  
Cytoplasmic Tails ◽  
Virion Envelope ◽  
Infected Cells

ABSTRACT The cytoplasmic tails of all three major varicella-zoster virus (VZV) glycoproteins, gE, gH, and gB, harbor functional tyrosine-based endocytosis motifs that mediate internalization. The aim of the present study was to examine whether endocytosis from the plasma membrane is a cellular route by which VZV glycoproteins are delivered to the final envelopment compartment. In this study, we demonstrated that internalization of the glycoproteins occurred in the first 24 h postinfection but was reduced later in infection. Using surface biotinylation of VZV-infected cells followed by a glutathione cleavage assay, we showed that endocytosis was independent of antibody binding to gE, gH, and gB. Subsequently, with this assay, we demonstrated that biotinylated gE, gH, and gB retrieved from the cell surface were incorporated into nascent virus particles isolated after density gradient sedimentation. To confirm and extend this finding, we repeated the above sedimentation step and specifically detected envelopes decorated with Streptavidin-conjugated gold beads on a majority of complete virions through examination by transmission electron microscopy. In addition, a gE-gI complex and a gE-gH complex were found on the virions. Therefore, the above studies established that VZV subsumed a postendocytosis trafficking pathway as one mechanism by which to deliver viral glycoproteins to the site of virion assembly in the cytoplasm. Furthermore, since a recombinant VZV genome lacking only endocytosis-competent gE cannot replicate, these results supported the conclusion that the endocytosis-envelopment pathway is an essential component of the VZV life cycle.

scholarly journals Detection of Poinsettia mosaic virus Infecting Poinsettias (Euphorbia pulcherrima) in Venezuela

Plant Disease ◽  
2001 ◽  
Vol 85 (11) ◽  
pp. 1208-1208 ◽  
Author(s):  
O. Carballo ◽  
M. L. Izaguirre ◽  
E. Marys
Keyword(s):  
Mosaic Virus ◽  
Leaf Tissue ◽  
Enzyme Linked Immunosorbent Assay ◽  
Euphorbia Pulcherrima ◽  
Leaf Extracts ◽  
Thin Sections ◽  
Virus Particles ◽  
Transmission Electron ◽  
Rugose Mosaic ◽  
Infected Cells

Poinsettia mosaic virus (PnMV), a putative member of the tymoviruses, was detected in several cultivars of vegetatively propagated poinsettias grown in commercial nurseries in Estado Miranda, Venezuela. Symptoms associated with the affected plants consisted of severe mottling and distortion of leaves and bracteoles. The suspect virus was mechanically transmitted to Nicotiana benthamiana. Leaf extracts and thin sections of affected leaf tissue were analyzed by transmission electron microscopy. Spherical virus particles (30 nm diameter) were observed in samples from symptomatic poinsettia plants. Ultrastructural analyses of virus-infected cells revealed aggregates of virus particles in the cytoplasm and central vacuole. The virus was purified twice from infected N. benthamiana, resulting in yields as high as 12 mg/100 g. Dissociated coat protein contained a single 24-kDa protein species. The virus was not serologically related to Carnation mottle, Bean rugose mosaic, Cowpea mosaic, Cucumber mosaic, Pea enation mosaic, Prunus necrotic ringspot, Apple mosaic, Tobacco streak, Maize rayado fino, Tomato ringspot, Bean southern mosaic, Sowbane mosaic, Andean potato latent, Belladona mottle, Scrophularia or Turnip yellow mosaic viruses, but did react positively in enzyme-linked immunosorbent assay and western blot analysis with antiserum (ATCC PVAS-476) to PnMV. Based on these results, the virus is considered to be PnMV. To our knowledge, this is the first report of PnMV infecting poinsettias in Venezuela.

The Distribution and Ultrastructural Effects of Passionfruit Woodiness Virus in Bean Leaves

1975 ◽  
Vol 23 (6) ◽  
pp. 905 ◽  
Author(s):  
RD Pares ◽  
JK Mcgechan
Keyword(s):  
French Bean ◽  
Phaseolus Vulgaris L ◽  
Microscope Examination ◽  
Mesophyll Cells ◽  
Virus Particles ◽  
Vein Clearing ◽  
Green Areas ◽  
Infected Cells ◽  
Dark Green ◽  
Bean Leaves

An electron microscope examination was made of mesophyll cells in the leaves of French bean (Phaseolus vulgaris L.) cv. Cherokee Wax infected with passionfruit woodiness virus (PWV). Virus particles and virus-induced inclusions were found in the mesophyll cells of yellow areas of inoculated leaves, leaves with vein clearing, and yellow areas of leaves with systemic mosaic symptoms, but not in the green areas of inoculated leaves and only occasionally in dark green areas of leaves with systemic mosaic symptoms. Virus-induced inclusions were confined to the cytoplasm and were frequently associated with cell membranes. Chloroplasts in infected cells had an increased tendency to invagination of the limiting membranes, and the invaginated portion frequently contained a mitochondrion. Some effects were recorded on the numbers of starch grains per chloroplast.

scholarly journals Purification and Characterization of Peach Mosaic Virus

Plant Disease ◽  
1998 ◽  
Vol 82 (8) ◽  
pp. 905-908 ◽  
Author(s):  
Carmen Gispert ◽  
Thomas M. Perring ◽  
Rebecca Creamer
Keyword(s):  
Electron Microscopy ◽  
Mosaic Virus ◽  
Average Length ◽  
Rabbit Antiserum ◽  
Purification And Characterization ◽  
Chenopodium Amaranticolor ◽  
Virus Particles ◽  
Transmission Electron ◽  
Polyclonal Rabbit Antiserum

Virus particles were observed by transmission electron microscopy in preparations extracted from symptomatic leaves of Chenopodium amaranticolor that had been mechanically inoculated with peach mosaic virus. The particles were long, flexuous, filamentous rods with an average length of 888 nm. Purified preparations had an A 260/280 nm ratio of 1.25. RNA extracted from purified virus was approximately 8.1 kilobases, and a capsid protein of approximately 27 kDa was found. Polyclonal rabbit antiserum, produced against purified virus, reacted with samples from peach mosaic and cherry mottle leaf-infected plants when used in Western blot analysis.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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.

An Electron Microscope Study of Interdiffusion and Compound Formation in Ta-Au Thin Films

1973 ◽  
Vol 31 ◽  
pp. 32-33 ◽  
Author(s):  
T. C. Tisone ◽  
S. Lau
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Thermally Grown Oxide ◽  
Ion Milling ◽  
Compound Formation ◽  
Technology Application ◽  
Transmission Electron ◽  
Before And After ◽  
Au Thin Films

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.

Electron Microscope Study of RNA's of Paramyxoviruses

1972 ◽  
Vol 30 ◽  
pp. 196-197
Author(s):  
Ruchama Baum ◽  
J.T. Seto
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Microscope Study ◽  
Sendai Virus ◽  
Sodium Dodecyl ◽  
Rna Molecules ◽  
Virus Particles ◽  
Molecular Weights ◽  
Length Measurements

The ribonucleic acid (RNA) of paramyxoviruses has been characterized by biochemical and physiochemical methods. However, paramyxovirus RNA molecules have not been studied by electron microscopy. The molecular weights of these single-stranded viral RNA molecules are not known as yet. Since electron microscopy has been found to be useful for the characterization of single-stranded RNA, this investigation was initiated to examine the morphology and length measurements of paramyxovirus RNA's.Sendai virus Z strain and Newcastle disease virus (NDV), Milano strain, were used. For these studies it was necessary to develop a method of extracting RNA molecules from purified virus particles. Highly purified Sendai virus was treated with pronase (300 μg/ml) at 37°C for 30 minutes and the RNA extracted by the sodium dodecyl sulfate (SDS)-phenol procedure.

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