A CYTOPLASMIC POLYHEDROSIS OF HYALOPHORA CECROPIA (LINNAEUS)

1965 ◽  
Vol 11 (4) ◽  
pp. 703-707 ◽  
Author(s):  
W. A. Smirnoff
Keyword(s):  
Electron Microscope ◽  
Viral Infection ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Virus Particles ◽  
Protein Mass ◽  
Viral Particles ◽  
Polyhedrosis Virus ◽  
Hyalophora Cecropia

Hyalophora cecropia (Linnaeus) is susceptible to infection by a cytoplasmic polyhedrosis virus. Electron microscope studies showed spherical viral particles known as "cores" which remain in groups of 12 to 17 subunits. The virus particles were embedded in a protein mass located in craters of the polyhedra. Larvae of the first, second, and third instars were more susceptible to viral infection than later instars. However, up to 50% of the larvae of later instars sometimes survived. The larvae of subsequent instars and the pupa were very resistant and periodic injections of strong dosages of virus material produced no ill effect. In general, larvae infected by this cytoplasmic virus shrank to less than half normal size before death.

ON THE MORPHOLOGY AND DEVELOPMENT OF INSECT CYTOPLASMIC-POLYHEDROSIS VIRUS PARTICLES

1965 ◽  
Vol 11 (3) ◽  
pp. 497-501 ◽  
Author(s):  
F. T. Bird
Keyword(s):  
Virus Particle ◽  
Inner Core ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Virus Particles ◽  
Early Stages ◽  
Polyhedrosis Virus

The cytoplasmic-polyhedrosis virus particle is an icosahedron about 68 mμ in diameter. It consists of a capsid, made up of two concentric rings, and an inner core. The capsid has 12 projections.Large masses consisting mostly of the capsids of virus particles develop in the cytoplasm of gut cells infected with cytoplasmic-polyhedrosis virus. Cores of the virus particles are found on the outer surfaces of these masses or in material adjacent to them. The complete virus particle is assembled just before it is enveloped by protein and incorporated into a developing polyhedron.Granules, tentatively identified as lysosomes, increase in number and size during the early stages of infection. Other granules and bodies observed in the gut cells are described.

Midgut infection of Heliothis Zea (Lepidoptera: Noctuidae) by cytoplasmic polyhedrosis virus

1989 ◽  
Vol 47 ◽  
pp. 860-861
Author(s):  
C. F. J. Bong
Keyword(s):  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Heliothis Zea ◽  
Uranyl Acetate ◽  
Corn Earworm ◽  
Chronic Infections ◽  
En Bloc ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Half Strength ◽  
Polyhedrosis Virus

The cytoplasmic polyhedrosis virus (CPV, Family Reoviridae) is an entomopathogen with a very wide host range, affecting mainly lepidopterous insects. The virus often causes chronic infections in insects, infecting mainly the midgut epithelium. Detailed studies of the effects of CPV on silkworm, Bombyx mori, have been done by Japanese workers , but there is very little information on the histopathology of CPV on other insects.In this study, 5-day old corn earworm (H. zea) larvae were infected per os with CPV. Control larvae were fed sterile water. The midgut was dissected out at 20, 48 and 72h post-treatment for both SEM and TEM studies. In the SEM study the midgut was fixed in 2.5% glutaraldehyde in phosphate buffer at pH 7.2, postfixed in buffered 2% osmium tetroxide at room temperature, dehydrated in ethanol, cryofractured in liquid nitrogen, critical-point dried, mounted, coated with gold-palladium and examined in a Hitachi HHS-2R scanning electron microscope at 20 kV. In the TEM study, the tissues were fixed in half-strength Karnovsky's fixative, postfixed in buffered cold 2% osmium tetroxide, en bloc stained in aqueous 0.5% uranyl acetate, dehydrated in ethanol and embedded in Spurr resin. Ultrathin sections were cut with glass knives, sequentially stained in aqueous uranyl acetate and lead citrate, and observed in a Zeiss 109 transmission electron microscope at 50 kV or a Siemens 101 at 80 kV.

THE DEVELOPMENT OF A CYTOPLASMIC POLYHEDROSIS VIRUS IN THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEMENS)

1966 ◽  
Vol 12 (2) ◽  
pp. 337-339 ◽  
Author(s):  
F. T. Bird
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Similar Type ◽  
Dense Material ◽  
Envelop Virus ◽  
Cytoplasmic Polyhedrosis Virus ◽  
Virus Particles ◽  
Polyhedral Shape ◽  
Polyhedrosis Virus

Virus particles and polyhedra develop in patches of viroplasm in the cytoplasm of mid-gut cells of larvae of the spruce bud worm, Choristoneura fumiferana (Clemens). Normal components of the cell disintegrate as the disease spreads, and either they completely disappear or mitochondria, ribosomes, and other components form rings in the outer regions of the cell.Polyhedra develop from dense material which appears to attract and envelop virus particles. Only complete particles with large prominent cores are incorporated into growing polyhedra. As the polyhedra mature, they assume a smooth outline and polyhedral shape and either cease to attract virus particles, or their size is limited by the amount of polyhedron protein and numbers of complete virus particles produced in the cell. Although most of the virus particles not incorporated into polyhedra appear incomplete, the large masses of incomplete particles formed in a similar type of disease of another insect were not found in bud worm larvae.

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.

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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