The genome of Bluegill virus

1982 ◽  
Vol 28 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Jean Robin ◽  
Claude Dery
Keyword(s):  
Molecular Weight ◽  
Nucleic Acid ◽  
Base Composition ◽  
Viral Infectivity ◽  
Percoll Gradient ◽  
Host Proteins ◽  
Virus Particles ◽  
Fish Virus ◽  
Intact Virus ◽  
Isopycnic Centrifugation

The EFDL strain of Bluegill virus, a fish virus, was grown in a Bluegill Fry cell line (BF-2) in medium containing [3H]uridine or [32P]orthophosphate. This virus was purified from the cellular material by precipitation with PEG 6000 followed by isopycnic centrifugation in a Percoll gradient. As calculated from reconstruction experiments, only 8.5 and 0.5%, respectively, of the host proteins and the host RNA were recovered with the viral band, whereas the recovery of viral infectivity was approximately 20%. Electron microscopy of the viral band showed mostly intact virus particles. The nucleic acid extracted from purified virus was found to have the following properties: (i) it migrated homogeneously during electrophoresis at the rate expected from a single-stranded nucleic acid of molecular weight 2.17 × 106, (ii) it sedimentated as a single molecular species when analyzed by velocity centrifugation in sucrose gradients,(iii) it banded in a neutral Cs2SO4 gradient at a density of 1.69 g/cm3 as expected for single-stranded RNA, (iv) its base composition is that of a single-stranded RNA molecule: 14.89% C, 12.77% A, 37.03% U, and 35.23% G. The nucleic acid of Bluegill virus thus appears to be a single-stranded RNA molecule of approximately 2.17 × 106 molecular weight.

scholarly journals The Disintegration of Influenza Virus Particles on Entry into the Host Cell. Studies with Virus Labelled with Radiophosphorus

1955 ◽  
Vol 53 (4) ◽  
pp. 474-486 ◽  
Author(s):  
L. Hoyle ◽  
W. Frisch-Niggemeyer
Keyword(s):  
Molecular Weight ◽  
Influenza Virus ◽  
Nucleic Acid ◽  
Host Cell ◽  
Virus Particle ◽  
Physiological Saline ◽  
Close Relation ◽  
Nuclear Material ◽  
Small Molecular Weight ◽  
Virus Particles

SummaryInfluenza A virus labelled with radiophosphorus was introduced as a primary inoculum into the allantoic sac of fertile eggs. Virus so introduced enters the cells of the chorio-allantoic membrane, and a study has been made of the chemical state of 32P present in the membranes 1½ hr. after inoculation.It was found that on entry into the host cell the virus particle disintegrates probably as a result of destruction of its phospholipid. Radiophosphorus derived from the virus phospholipid can be recovered from the infected membranes by extraction with physiological saline in the form of compounds of small molecular weight which are not precipitated by protein precipitants and are not sedimentable at a centrifugal force of 100,000 g.Saline extracts of the infected membranes also contain labelled nucleic acid which appears to be derived from the virus nucleoprotein.A large part of the nucleoprotein phosphorus of the inoculated labelled virus cannot be recovered from the infected membranes by extraction with physiological saline but can be recovered if the cell nuclear material is dissolved in molar sodium chloride. The 32P in such molar chloride extracts is partly precipitated with the deoxyribonucleoprotein on dilution with water, and is partly present as free nucleic acid.It is suggested that on entry into the host cell the virus particle is broken down, the phospholipid being destroyed and the nucleoprotein disintegrated with the release of free nucleic acid which enters into a close relation with the cell nuclear material.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

scholarly journals Coat protein and RNAs of Cole latent virus are not present within chloroplasts of Chenopodium quinoa-infected cells

2003 ◽  
Vol 28 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Priscila Belintani ◽  
José O. Gaspar
Keyword(s):  
Electron Microscopy ◽  
Coat Protein ◽  
Chenopodium Quinoa ◽  
Latent Virus ◽  
Percoll Gradient ◽  
Northern Blots ◽  
Virus Particles ◽  
Ultrastructural Studies ◽  
Particle Aggregates ◽  
Infected Cells

Cole latent virus (CoLV), genus Carlavirus, was studied by electron microscopy and biochemical approaches with respect both to the ultrastructure of the Chenopodium quinoa infected cells and to its association with chloroplasts. The CoLV was observed to be present as scattered particles interspersed with membranous vesicles and ribosomes or as dense masses of virus particles. These virus particles reacted by immunolabelling with a polyclonal antibody to CoLV. Morphologically, chloroplasts, mitochondria and nuclei appeared to be unaltered by virus infection and virus particles were not detected in these organelles. However, virus particle aggregates were frequently associated with the outer membrane of chloroplasts and occasionally with peroxisomes. Chloroplasts were purified by Percoll gradient, and the coat protein and virus-associated RNAs were extracted and analyzed by Western and Northern blots respectively. Coat protein and CoLV-associated RNAs were not detected within this organelle. The results presented in this work indicate that the association CoLV/chloroplasts, observed in the ultrastructural studies, might be a casual event in the host cell, and that the virus does not replicate inside the organelle.

scholarly journals Properties of virus particles, nucleic acid and coat protein of cycas necrotic stunt virus.

1986 ◽  
Vol 52 (3) ◽  
pp. 422-427 ◽  
Author(s):  
Kaoru HANADA ◽  
Manabu KUSUNOKI ◽  
Mitsuro IWAKI
Keyword(s):  
Nucleic Acid ◽  
Coat Protein ◽  
Virus Particles

scholarly journals Effect of kinetin on nucleic acid synthesis in senescing and young leaves in Brassica oleracea L. var. gongylodes L.

2015 ◽  
Vol 44 (4) ◽  
pp. 553-565
Author(s):  
J. Legocka ◽  
A. Szweykowska
Keyword(s):  
Molecular Weight ◽  
Nucleic Acid ◽  
Acid Synthesis ◽  
Inhibitory Effect ◽  
Rrna Synthesis ◽  
Low Molecular Weight ◽  
Chlorophyll B ◽  
Mature Leaves ◽  
Young Leaves ◽  
Brassica Oleracea L

In detached kohlrabi leaves senescing in the dark, the decrease in chlorophyll to was more pronounced than in chlorophyll a. The retardation by kinetin of the chlorophyll loss was also markedly stronger in the case of chlorophyll b. Using the fractionation of nucleic acids on polyacrylamide gels it has been shown that during leaf senescence the level of all RNA species decreased, whereas the amount of DNA was more or less constant. In the presence of kinetin, the loss of RNA was inhibited and the incorporation of precursor into the cytoplasmic rRNA as well as into low molecular weight RNA species was supported. Chloroplast rRNA synthesis has not been detected in mature leaves and kinetin showed no effect in this respect. In young expanding leaves detached and kept in light, the synthesis of cytoplasmic rRNA was strongly stimulated by kinetin, whereas in the case of Chloroplast rRNA only an inhibitory effect of kinetin could be found. The results suggest that the cytokinins are primarily involved in processes of the synthesis of cytoplasmic rRNA and low molecular RNA fractions, and in this way affect the development of plastids, in particular the course of their senescence.

DNA Synthesis in Isolated Yeast Mitochondria

1974 ◽  
Vol 52 (11) ◽  
pp. 941-949 ◽  
Author(s):  
L. Zeman ◽  
C. V. Lusena
Keyword(s):  
Molecular Weight ◽  
Mitochondrial Dna ◽  
Base Composition ◽  
Nuclear Dna ◽  
Sedimentation Velocity ◽  
Yeast Saccharomyces Cerevisiae ◽  
Denatured State ◽  
Saccharomyces Cerevisiae Mitochondria

Isolated yeast (Saccharomyces cerevisiae) mitochondria incorporate radioactive precursors into mitochondrial DNA. This in vitro labelled DNA was characterized by isopycnic and sedimentation velocity centrifugation both in the native and denatured state. The profiles of isopycnic CsCl gradients obtained by centrifugation in a fixed-angle rotor are skewed toward high density. The skew is neither due to the presence of in vitro labelled nuclear DNA nor due to random breaks in mitochondrial DNA which would reveal, then, its heterogeneity in base composition. The in vitro labelled DNA is reproducibly recovered as a class of molecules sedimenting at about 5–8 S, indicating a molecular weight of 1 × 105 – 4 × 105 daltons, while the smallest in vivo labelled fragments sediment at about 13–14 S, corresponding to 1.6 × 106 – 2.0 × 106 daltons. After denaturation, the in vitro labelled DNA molecules sediment at about 2–5 S, corresponding to a single-strand molecular weight of 1 × 104 – 7 × 104 daltons, which is about one hundred times less than the observed size of the denatured in vivo labelled molecules.

Direct Isolation of High-Quality Low Molecular Weight RNA of Pear Peel from the Extraction Mixture Containing Nucleic Acid

2009 ◽  
Vol 44 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Xin-wei Wang ◽  
Ai-sheng Xiong ◽  
Quan-hong Yao ◽  
Zhen Zhang ◽  
Yu-shan Qiao
Keyword(s):  
Molecular Weight ◽  
Nucleic Acid ◽  
Low Molecular Weight ◽  
High Quality ◽  
Extraction Mixture

Über die pH- und Temperatur-Abhängigkeit des thermischen Zerfalls von Poliovirus-Teilchen in Nucleinsäure und leere Proteinhüllen

1966 ◽  
Vol 21 (4) ◽  
pp. 357-361 ◽  
Author(s):  
O. Drees ◽  
K. D. Demme
Keyword(s):  
Heat Treatment ◽  
Initial Rate ◽  
Concentrated Suspensions ◽  
Virus Particles ◽  
Ph Values ◽  
Intact Virus ◽  
Wide Range ◽  
Ultracentrifugal Analysis ◽  
Increasing Temperature ◽  
Kinetics Of

The intact virus particles of highly purified, concentrated suspensions of poliovirus have been disintegrated into free nucleic acid and empty protein shells (78 S protein) by moderate heat treatment at various temperatures and pH values. The kinetics of this degradation has been followed by ultracentrifugal analysis.With increasing temperature between 35° and 50 °C and with increasing pH of the suspension medium between 7 and 8, the rate of degradation increased. For any particular conditions the initial rate was not maintained, and after a certain time there was little further degradation if conditions remained unaltered. Some particles with the sedimentation characteristics of poliovirus were resistant to disintegration under the same conditions which led to the breakdown of the bulk of the virus. The proportion of this “stable fraction” varied within a wide range from one preparation to another and decreased with increasing temperature and with increasing pʜ.

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