bluuebunny/crossref_metadata_2025 huggingface dataset:
Deoxyribonucleic Acid of Marek's Disease Virus in Virus-Induced Tumors
Authors: Nazerian K. , Lindahl T. , Klein G. , Lee L. F.
Published: January 2020

DNA was extracted from [
3
H]thymidine-labeled Marek's disease virus (MDV) and purified by two cycles of CsCl gradient centrifugation in a fixed-angle rotor. The DNA was transcribed in vitro into
32
P-labeled complementary RNA (cRNA). MDV cRNA did not hybridize with DNA from chicken embryo fibroblast cultures or from chicken spleen, but hybridized efficiently with DNA from MDV particles or MDV-infected cell cultures. Five Marek's disease tumors from different chickens and different organs (ovary, liver, testis) were all found to contain MDV DNA sequences. The relative amount of MDV DNA varied from tumor to tumor and was between 3 and 15 virus genome equivalents per cell. The content of virus DNA per cell in spleens from tumor-bearing chickens was much lower than in tumors from the same animals. MDV-infected cell cultures contained a large proportion (28-59%) of virus antigen-positive cells, as measured by immunofluorescence, but tumor cells were negative in this respect (<0.02% positive cells). These data indicate that MDV is present in a provirus form in tumor cells.
Bacteriophage T7 DNA Synthesis in Isolated DNA-Membrane Complexes
Authors: Center Melvin S.
Published: January 2020

A DNA-membrane complex isolated from
Escherichia coli
infected with bacteriophage T7 contains newly synthesized T7 DNA and the T7 DNA polymerase (gene 5 product). The DNA present in the complex appears to exist as a concatemer which contains single-strand breaks and possibly internal single-stranded regions (gaps). The complex is capable of synthesizing T7 DNA by using endogenous template, and part of the DNA is made by a semiconservative mechanism. A portion of the in vitro synthesized DNA sediments in alkaline sucrose as 10-11
S
material. This DNA is converted to a larger-molecular-weight material after treatment with T4 polynucleotide ligase and
E. coli
DNA polymerase I.
Transcription Units in Bacteriophage T4
Authors: Hercules Kathleen , Sauerbier Walter
Published: January 2020

We have investigated the possibility of assigning genes of T4 bacteriophage to their units of transcription (scriptons) by studying gene expression from UV-irradiated DNA templates. Since RNA chains are prematurely terminated on UV-irradiated DNA templates and since the promotor distal part of the RNA chain is deleted, the expression of any gene is inversely proportional to the distance between the promotor and the promotor distal end of the gene. We find that the early genes, 43, 45 and rIIB, are promotor proximal. Since at least genes 43 and rIIB are classified as delayed early genes, these results suggest that their synthesis may require the recognition of new promotors. Additional early genes (44, 62, 42, 46, 47, 55, and rIIA) and some late genes (34, 37, and 38) have also been assigned positions relative to their promotors.
Properties of Noninfectious and Transforming Viruses Released by Murine Sarcoma Virus-Induced Hamster Tumor Cells
Authors: Gazdar A. F. , Russell E. , Sarma P. S. , Sarin P. S. , Hall W. , Chopra H. C.
Published: January 2020

The cell culture lines HTG2 and HTG3 were established from a transplantable hamster tumor induced by a murine sarcoma virus (strain Gz-MSV) after 17 and 60 in vivo passages, respectively. The viruses released by these two cell lines markedly differ in morphology, antigenic composition, infectivity, transforming ability, and enzymatic activity. HTG2 virions contained the sarcoma genome but were noninfectious for mouse and hamster cells (S+H-virus). HTG3 virions transformed hamster but not mouse cells. Whereas HTG2 cells and its virus contained murine type C virus gs-1 antigen, all HTG3 clonal lines expressed both murine and hamster type C virus gs-1 antigens. The RNA-dependent DNA polymerase activity of HTG2 virus was very low, whereas that of HTG3 virus was relatively high. HTG2 virions contained electron-lucent centers only. HTG3 virus consisted of the expected mixture of virions with electron-dense and electron-lucent centers. Many broken or incomplete virions were present in both viruses. HTG2 virus is a noninfectious “defective” sarcoma virus without detectable helper virus. Data obtained in these experiments suggest that HTG3 virus is a hamster type C virus pseudotype of Gz-MSV (Gz-MSV [HaLV]). The genome of Gz-MSV is capable of antigenic expression in heterologous cells and in the presence of heterologous viruses. Attempts to chemically activate hamster type C virus (HaLV) from HTG2 cells were unsuccessful. The HTG1 cell culture line, established from another Gz-MSV-induced hamster tumor, initially released a virus indistinguishable from the HTG2 virus. After in vitro passage, spontaneous activation of HaLV occurred in HTG1 cells, and the resultant Gz-MSV (HaLV) had properties similar to those of the HTG3 virus.
Cell-Free Translation of Paramyxovirus Messenger RNA
Authors: Kingsbury D. W.
Published: January 2020

Polypeptides corresponding in electrophoretic mobility to virion polypeptides 1, 3, and 5 were made in a reticulocyte cell-free system to which 18
S
RNA from Sendai virus-infected cells was added. Immune precipitation was used to select relevant polypeptides from endogenous products. The cell-free product corresponding to virion polypeptide 3 (the nucleocapsid structure unit) was the most abundant; its tryptic peptides comigrated electrophoretically with tryptic peptides of polypeptide 3 isolated from virions. Other sedimenting classes of RNA from infected cells were tested; only the 28
S
fraction showed slight activity. Virion 50
S
RNA was inactive. These findings support the hypothesis that complementary RNA transcripts of paramyxovirion RNA are the templates for viral proteins.
RNA-Dependent RNA Polymerase in Nuclei of Cells Infected with Influenza Virus
Authors: Hastie N. D. , Mahy B. W. J.
Published: January 2020

Nuclei purified from chicken embryo fibroblast cells infected with influenza (fowl plague) virus contain an RNA-dependent RNA polymerase. The in vitro activity of this enzyme is insensitive to actinomycin D, and is completely destroyed by preincubation with ribonuclease. Enzyme induction is prevented if cells are treated with actinomycin D or cycloheximide at the time of infection. RNA-dependent RNA polymerase activity increases rapidly in cell nuclei from 1 h postinfection, reaches a maximum at 3 to 4 h, then declines; a similar RNA polymerase activity in the microsomal cell fraction increases from 2 h postinfection and reaches a maximum at 5 to 6 h. The characteristics of the nuclear and microsomal enzymes in vitro are similar with respect to pH and divalent cation requirements. The in vitro products of enzyme activity present in the nuclear and microsomal fractions of cells infected for 3 and 5 h were characterized by sucrose density gradient analysis, and annealing to virion RNA. The microsomal RNA polymerase product contained 67 and 93% RNA complementary to virion RNA at 3 and 5 h, respectively; for the nuclear RNA polymerase product these values were 40% in each case.
RD 114 Virus-Specific Sequences in Feline Cellular RNA: Detection and Characterization
Authors: Okabe Hiromi , Gilden Raymond V. , Hatanaka Masakazu
Published: January 2020

RNA extracted from cat cells contains sequences homologous to RD-114 viral RNA. The sequences are measured by molecular hybridization with a single-stranded DNA probe synthesized by the virion polymerase using the endogenous viral RNA as template. Viral-specific RNA has been detected in all cells of cat origin tested thus far, but not in cells of other animals, except for the virus-producing human rhabdomyosarcoma cell, RD-114. The extent of hybridization of the DNA probe to cellular RNA was equivalent to that obtained with viral 70
S
RNA indicating that an equal extent of viral specific sequences is present in all cat cells as well as in RD-114 cells. The amounts of this viral RNA reach approximately 100 copies per cell in cat cells, while virus-producing RD-114 cells contain about 1,000 copies per cell. The viral RNA is present in cat cells in two distinct sizes of about 35
S
and 18
S
, whereas in RD-114 cells virus-specific RNA is quite heterogeneous in size.
Structure and Infectivity of Picornaviral RNA Encapsidated by Cowpea Chlorotic Mottle Virus Protein
Authors: Black Douglas R. , Connell Carolyn J. , Merigan Thomas C.
Published: January 2020

Poliovirus and Mengo virus RNA were shown to associate efficiently with cowpea chlorotic mottle virus protein to form pseudovirions. The sedimentation coefficient for the pseudovirions was similar to that of poliovirus, and electron microscope observations showed the Mengo pseudovirions to be similar in size to Mengo virus. Such pseudovirions were infectious and were more resistant to ribonuclease than viral RNA; however, under our assay conditions, their infectivity was about equal to that of viral RNA.
Small RNAs of Rous Sarcoma Virus: Characterization by Two-Dimensional Polyacrylamide Gel Electrophoresis and Fingerprint Analysis
Authors: Sawyer Robert C. , Dahlberg James E.
Published: January 2020

Approximately 15 to 20 different species of small (4 to 7
S
) RNAs have been purified by two-dimensional polyacrylamide gel electrophoresis of RNA isolated from virions of Schmidt-Ruppin D strain of Rous sarcoma virus. Each species of small RNA has been isolated free of 70
S
RNA; nine of them, including 5
S
and 7
S
RNAs, were also found associated with the 70
S
genomic RNA. Most of the 4
S
RNAs are present at an average of less than one copy per virion. The 4
S
RNAs have T1 RNase (EC 2.7.7.26) fingerprints, which are very similar to those of tRNAs. One of the smallest 4
S
RNAs, which can act as a primer for initiation of RNA-directed DNA synthesis, is associated with the 70
S
RNA in 1 to 2 copies per complex, whereas an additional 6 to 8 copies of this molecule are free.
Template Properties of Glucose-Deficient T-Even Bacteriophage DNA
Authors: Cox G. Stanley , Conway Thomas W.
Published: January 2020

The vegetative DNA isolated from T4-infected
Escherichia coli
W4597 (UDPG PPase
-
) was about two to six times more active in stimulating protein synthesis in cell-free extracts than that isolated from T4-infected
E. coli
B06. This suggested that nonglucosylated vegetative DNA may be a better template than the glucosylated form. This view was supported by experiments measuring RNA synthesis on mature T-even DNAs with a range of glucose contents. The extent of
14
C-GTP polymerization was inversely proportional to the glucose content of the DNA. Differences were also observed in both the kind and quantity of polypeptides produced in response to these DNAs.
Cold-Sensitive
Pseudomonas
RNA Polymerase I. Characterization of the Host Dependent Cold-Sensitive Restriction of Phage CB3
Authors: Sobieski Rodney J. , Olsen Ronald H.
Published: January 2020

Analysis of bacteriophage CB3 infection of
Pseudomonas aeruginosa
strain PAT2 establishes that phage induced changes in net macromolecular synthesis are absent at nonpermissive phage growth temperatures (32 C). Alterations which are evident in the PAT2 strain at 37 C or in the fully permissive strain, PAO1C, at either warm or cold temperatures do not occur in PAT2 at low temperatures. CB3 DNA synthesis and the degradation of host DNA to approximately 78
S
components occur at 37 C, but are absent in PAT2 at 20 C. Nevertheless, attachment of phage DNA to host cytoplasmic material occurs under permissive and nonpermissive conditions. This binding of phage DNA at 20 C is identical in nature to phage DNA bound at 37 C. Thus, the conditional cold-sensitive PAT2 host function in the growth of CB3 is expressed subsequent to membrane binding of the infecting genomes but prior to the onset of the initiation of CB3 DNA synthesis, the inhibition of host DNA synthesis, and the transient depression in RNA synthesis which occurs in permissive cells.
Cold-Sensitive
Pseudomonas
RNA Polymerase II. Cold-Promoted Restriction of Bacteriophage CB3 and the Lack of Host-Dependent Bacteriophage-Specific RNA Transcription
Authors: Sobieski Rodney J. , Olsen Ronald H.
Published: January 2020

Cold-sensitive restriction of
Pseudomonas
phage CB3 by
Pseudomonas aeruginosa
strain PAT2 involves some aspect of CB3 specific RNA synthesis at 20 C. Experiments using chloramphenicol treatment and RNA-DNA hybridization establish that the amount of CB3 RNA present at 20 C is consistent with the known percentage of phage yielder cells at 20 C. Thus, it appears that nonyielder cells of PAT2 synthesize little or no phage-specific mRNA. Burgess technique extracted PAT2 RNA polymerase (RNAP) is cold sensitive when assayed in vitro with CB3 DNA at 20 C. However, it is not cold sensitive when either calf thymus or PAT2 DNA are the templates for transcription. Low ionic strength assay conditions eliminate the cold sensitivity of PAT2 RNAP. The effect of low ionic environments on transcription initiation along with the in vivo and in vitro suppression of cold sensitivity by host rifampin resistance suggests that the inability of CB3 to reproduce in PAT2 at 20 C is a cold-sensitive step in host RNAP initiation. Our modified RNAP extraction procedure for PAT2 and PAO1C also results in the recovery of cold-sensitive PAT2 RNAP with respect to CB3 DNA templates and points to basic enzymological differences between the two hosts. A model is presented for the unusual influence of temperature on the initiation process of both PAT2 and PAO1C on RNAP transcription.
Synthesis of Bacteriophage M13-Specific Proteins in a DNA-Dependent Cell-Free System II. In Vitro Synthesis of Biologically Active Gene 5 Protein
Authors: Konings Ruud N. H. , Jansen Josephine , Cuypers Theo , Schoenmakers John G. G.
Published: January 2020

It is shown that gene 5 protein of bacteriophage M13 is one of the major proteins synthesized in vitro under the direction of M13 replicative-form DNA. By means of DNA-cellulose chromatography, this protein has been purified to homogeneity and its biological characteristics have been compared with those of its native counterpart. Like native gene 5 protein, the purified, in vitro-synthesized protein binds tightly and selectively to single-stranded, but not to double-stranded, DNAs. These results suggest that truly functional gene 5 protein is made in the cell-free system.
Characteristics and Purification of PRR1, an RNA Phage Specific for the Broad Host Range
Pseudomonas
R1822 Drug Resistance Plasmid
Authors: Olsen Ronald H. , Thomas Deanna D.
Published: January 2020

A new drug resistance plasmid-dependent RNA containing phage resembling coliphage f2 in its particle size and density is described. The phage, PRR1, will only productively infect some R
+
hosts containing the
Pseudomonas
drug resistance plasmid R1822. The membrane filter-salt elution patterns, RNase sensitivity, inactivation in low ionic strength solutions, and host range serve to distinguish PRR1 from coliphage f2 and two other
Pseudomonas
RNA phages, 7s and PP7.
Influence of Complement on the Neutralization of Murine Cytomegalovirus by Rabbit Antibody
Authors: Kim Kwang Soo , Carp Richard I.
Published: January 2020

Antiserum against murine cytomegalovirus produced in the rabbit contained complement (C′)-requiring neutralizing (CRN) antibody. The proportion of CRN was extremely high (up to 98%) during the early portion of an immunization procedure, whereas the antisera produced late had a much lower proportion that required C′. The antiserum produced was specific for MCMV with or without C′.
Low-Molecular-Weight RNAs of Murine Sarcoma Virus: Comparative Studies of Free and 70
S
RNA-Associated Components
Authors: Emanoil-Ravicovitch R. , Larsen C. J. , Bazilier M. , Robin J. , Périès J. , Boiron M.
Published: January 2020

Several low-molecular-weight RNAs were released from mouse leukemia sarcoma virus 70
S
RNA under conditions of thermal denaturation. One of them, the 70
S
-associated 8
S
RNA, exhibits a number of structural properties characteristic of a previously described free viral 8
S
RNA. This similarity was revealed by polyacrylamide gel electrophoresis and nucleotide composition.
Location of the T4 Gene 32 Protein Binding Site on Simian Virus 40 DNA
Authors: Morrow John F. , Berg Paul
Published: January 2020

The T4 gene 32 protein, which binds to single-stranded but not duplex DNA, forms a specifically located denaturation loop in covalently closed circular simian virus 40 (SV40) DNA. Cleavage of the SV40 DNA-gene 32 protein complex with a restriction endonuclease from
Hemophilus parainfluenzae
shows the loop center to be at 0.46 on the SV40 DNA map. This is within one of the regions of SV40 DNA cleaved preferentially by the single-strand-specific nuclease S
1
.
Ultrastructural Studies of a Visna-Like Syncytia-Producing Virus from Cattle with Lymphocytosis
Authors: Boothe Arlis D. , Van Der Maaten Martin J.
Published: January 2020

A virus structurally similar to viruses associated with maedi, progressive pneumonia, and visna of sheep has been isolated from buffy coat cells of cattle with chronic lymphocytosis. Electron microscope studies revealed three variants of the virion: (i) an intracytoplasmic form 98 to 116 nm in diameter when occurring in a nonlaminated form, (ii) a budding form 120 to 130 nm in diameter, and (iii) an extracellular form 80 to 130 nm in diameter and containing a 30 to 43 nm eccentrically located electron-dense core.
In Vitro Polyoma DNA Synthesis: Studies on an Early Temperature-Sensitive Mutant
Authors: Francke Bertold , Hunter Tony
Published: January 2020

The polyoma ts-a function was investigated by using an in vitro DNA-synthesizing system. A comparison of systems derived from ts25 (a ts-a group mutant)-and ts1260 (a late group mutant)-infected cells showed that the activation energies for DNA chain elongation and the mechanisms of discontinous growth were identical for both mutants.
Location of the Transcription Defect in Group I Temperature-Sensitive Mutants of Vesicular Stomatitis Virus
Authors: Hunt D. Margaret , Wagner Robert R.
Published: January 2020

The ribonucleoprotein-dependent RNA transcriptase in vesicular stomatitis B virions of four temperature-sensitive (
ts
) mutants belonging to complementation group I was analyzed in vitro at permissive (31 C) and restrictive (39 C) temperatures. The RNA-synthesizing activity of all four
ts
mutants was more labile at 39 C than was the transcriptive activity of wild-type (
wt
) virions. In order to locate the temperature-sensitive transcription defect in the mutants,
wt
and
ts
mutant virions were fractionated by Triton X-100-high salt solubilizer into a sedimentable ribonucleoprotein template and a nonsedimentable enzyme fraction, each of which alone had little or no transcriptive activity. The template- and enzyme-containing fractions of
wt
virions were then tested for their capacity to restore transcriptive activity at 39 C to corresponding template and enzyme preparations of
ts
mutant virions. Recombination of
wt
template and
ts
enzymes resulted in no significant restoration of capacity to synthesize RNA at restrictive temperature. In contrast, transcriptive function at 39 C was reconstituted by recombining the
wt
enzyme with the template component of
ts
mutants. It appears, therefore, that the enzyme, rather than the template, is the temperature-sensitive component of the transcription complex of group I vesicular stomatitis virus mutants.
Inhibition of Protein Synthesis in Cell-Free Systems from Interferon-Treated, Infected Cells: Further Characterization and Effect of Formylmethionyl-tRNA
F
Authors: Kerr Ian M. , Friedman R. M. , Brown R. E. , Ball L. A. , Brown J. C.
Published: January 2020

The translation of encephalomyocarditis virus (EMC) RNA is markedly inhibited in cell-free systems from interferon-treated, vaccinia virus-infected L-cells (10, 11). The polypeptide products synthesized in response to EMC RNA in cell-free systems from these and untreated infected cells have been analyzed by electrophoresis on polyacrylamide gels. Qualitatively, the same EMC-specific polypeptides were synthesized throughout. In experiments using preincubated microsomes from normal Krebs cells to assay cell sap from L-cells which had been exposed to interferon prior to infection, only the amount of the EMC-specific polypeptide products was reduced. This result suggests that there is an inhibition very early in translation in interferon-treated, infected cells. Initiation seems a priori the more attractive site for this inhibition, but an effect shortly after initiation cannot be excluded. With unfractionated cell-free systems from interferon-treated infected L-cells, however, there appeared to be an additional minor inhibitory effect on polypeptide chain elongation, in that the EMC-specific polypeptides synthesized showed not only a reduction in amount but also a bias towards lower molecular weight. The formylated methionyl initiator tRNA (Fmet-tRNA
F
) was used as a further probe into the apparent effect on intiation. With this reagent we have confirmed that there is one major initiation site for the translation of EMC RNA in these cell-free systems. In addition, the results have shown that EMC-specific polypeptide chains initiated with Fmet escape the major interferon-mediated inhibition at or shortly after initiation.
Bacteriophage f1 Infection: Fate of the Parental Major Coat Protein
Authors: Smilowitz Henry
Published: January 2020

The major coat protein of infecting f1 phage is incorporated into the inner membrane of the host cell, even in the absence of phage f1DNA penetration and replication. The major coat protein monomers are reutilized in the assembly of new phage. They are not conserved as a single unit but behave as independent units which are slowly incorporated into newly manufactured phage.
Evidence for the Presence of Nontranslated T7 Late mRNA in Infected F′(PIF
+
) Episome-Containing Cells
Authors: Blumberg Daphne D. , Malamy Michael H.
Published: January 2020

The inability of T7 to develop in cells of
Escherichia coli
containing F
+
or substituted F′ episomes is a result of the failure to synthesize late proteins; no in vivo translation of mRNA species synthesized by the T7 RNA polymerase occurs. Further experiments have been performed to measure the amount of late mRNA in T7-infected F′(PIF
+
) cells. (We have designated the property of phage inhibition of F factors as PIF; the wild-type episome is therefore F′[PIF
+
].) T7 late proteins were synthesized in vitro by using a system programed with RNA extracted from T7-infected F
−
and F′(PIF
+
) cells. The T7 lysozyme, product of gene 3.5, and the gene 10 head protein were assayed. The following results were obtained: (i) mRNA capable of supporting in vitro synthesis of lysozyme and the gene 10 head protein is present in T7-infected F′(PIF
+
) cells; (ii) lysozyme mRNA extracted from T7-infected F′(PIF
+
) cells is present at 70 to 75% of the level found in T7-infected F
−
cells; (iii) gene 10 mRNA is present at 35 to 78% of the level found in T7-infected F
−
cells. No in vivo synthesis of either lysozyme or gene 10 protein can be detected in T7-infected F′(PIF
+
) cells although normal synthesis of these proteins occurs in F
−
cells. These findings confirm that the block in T7 development in F′(PIF
+
) cells results from the failure to translate late classes of T7 RNA.
Temperature-Sensitive Formation of the DNA Replication Complex in Adenovirus 31-Infected Cells
Authors: Suzuki Eiko , Shimojo Hiroto
Published: January 2020

A temperature-sensitive mutant of adenovirus 31 was defective in formation of the DNA replication complex, suggesting the existence of a virus-coded protein necessary for the complex-formation.
Protease-Sensitive Transfection of
Bacillus subtilis
with Bacteriophage GA-1 DNA: a Probable Case of Heterologous Transfection
Authors: Arwert Fré , Venema Gerard
Published: January 2020

The host bacterium of bacteriophage GA-1,
Bacillus
sp. G1R, was compared with respect to its taxonomic relationship to
Bacillus subtilis, B. licheniformis
, and
B. pumilis.
The physiological-biochemical properties of
Bacillus
sp. G1R are equal to those of
B. licheniformis
, but the thermal denaturation midpoint of G1R DNA differs by 3 C and the buoyant density by 0.005 g/cm
3
from that of
B. licheniformis.
Transformation with G1R donor DNA was neither observed in
B. licheniformis
nor in
B. subtilis
-competent recipients. Bacteriophage GA-1 shows neither infectivity on
B. licheniformis
nor on
B. subtilis.
However, infection of competent
B. subtilis
cultures with phenol-extracted GA-1 DNA results in the production of infective GA-1 particles. The transfecting activity of GA-1 DNA is destroyed by treatment with proteolytic enzymes. Resistance of transfecting DNA to inactivation by trypsin develops earlier than that to inactivation by DNase. Protease-treated GA-1 DNA competes with transforming DNA to approximately the same extent as does untreated GA-1 DNA, suggesting that uptake of GA-1 DNA is not affected by protease treatment. CsCl density gradient centrifugation reveals that the density of trypsinized GA-1 DNA is 0.004 g/cm
3
greater than that of untreated DNA.
RNA Transcription by the Virion Polymerases of Five Rhabdoviruses
Authors: Chang S. H. , Hefti Elizabeth , Obijeski J. F. , Bishop D. H. L.
Published: January 2020

The presence of a virion-associated RNA-dependent RNA polymerase in five serologically distinct rhabdovirus isolates (vesicular stomatitis virus [VSV] Indiana, VSV New Jersey, Cocal, Chandipura, and Piry viruses) has been demonstrated. The enzyme for each virus has been shown to be a transcriptase capable of synthesizing in vitro RNA which is complementary to the viral genome. By sequence analyses it has been shown that, for each rhabdovirus, transcription is multiply initiated with specific 5′ nucleotide sequences. The results indicate that, for all five viruses, the initiation of transcription involves similar sequences (e.g., pppApCpGp..., pppGpCp..., and possibly one or two other sequences), suggesting relatedness and some genome conservation among these viruses.
Bacteriophage DNA: Correlation of Buoyant Density, Melting Temperature, and the Chemically Determined Base Composition
Authors: Kropinski Andrew M.
Published: January 2020

The mathematical relationships between the buoyant density, melting temperature, and chemically determined base composition of bacteriophage DNA are described and compared with regression equations derived from studies with bacterial DNA.
Nucleotide Sequence Relationships of Avian RNA Tumor Viruses: Measurement of the Deletion in a Transformation-Defective Mutant of Rous Sarcoma Virus
Authors: Neiman P. E. , Wright S. E. , McMillin C. , MacDonnell D.
Published: January 2020

Stocks of cloned helper-independent Rous sarcoma virus (RSV) spontaneously segregate transformation-defective (
td
) mutants that appear to have an RNA genome composed of smaller subunits than those of the patent virus. Differential hybridization and competitive hybridization techniques involving reactions between viral RNA and proviral sequences in host cell DNA (under conditions of initial DNA excess) were used to measure the extent of the deletion in a
td
mutant of Prague strain (Pr) of RSV (Pr RSV-C). Viral 60 to 70
S
RNA sequences labeled to 1 to 5 × 10
7
counts per min per μg with
125
I were characterized with respect to their properties in hybridization reactions and used to reinforce data obtained with [
3
H]RNA of lower specific activity. By these techniques, about 13% ± 3% of the sequences Pr RSV-C that formed hybrids with DNA from virus-induced sarcomas appeared to be deleted from the genome of
td
Pr RSV-C. Studies comparing hybridization of RNA from Pr RSV-C and
td
Pr RSV-C with RSV-related sequences in normal cells, and competition experiments with RNA from the endogenous chicken oncornavirus Rous-associated virus type 0 (RAV-0) provided evidence that the majority, if not all, of the RNA sequences of Pr RSV-C deleted from its transformation-defective mutant are not represented in normal chicken DNA. Competition studies with a leukosis virus, RAV-7, indicated this virus also lacks a genome segment of about the same size as the deletion in the
td
mutant. Finally, the genome of all three “exogenous” viruses was found to lack a small segment (about 12%) of sequences present in the endogenous provirus of RAV-O.
DNA Configuration in the Core of Marek's Disease Virus
Authors: Nazerian K.
Published: January 2020

Marek's disease virus DNA appears to be wound around a central structure connecting the two inner poles of the capsid. Based on electron micrographs of Marek's disease virions, a diagram of spatial configuration of virus DNA is presented. This diagram may explain the pleomorphic character of the herpesvirus core observed with the electron microscope.
Isolation of Bacteriophage for
Caryophanon latum
Authors: Nauman R. K. , Wilkie E. F.
Published: January 2020

Bacteriophage which produce either clear or turbid center plaques have been isolated for native isolates of
Caryophanon latum.
Photodynamic Inactivation of Antigenic Determinants of Single-Stranded DNA Bacteriophage φX174
Authors: Khan Narayan C. , Poddar Ramendra K.
Published: January 2020

Bacteriophage φX174 when photodynamically inactivated (i.e., when rendered unable to produce plaques as a result of exposure to visible light in air in the presence of proflavine) progressively lost their capacity to bind efficiently with homologous antiserum. Such loss of serum-blocking power was evident with heat-inactivated but not with UV-irradiated phage. The ability of the phages to adsorb to host cells, however, remained practically unaltered even after photodynamic inactivation. It thus appears that photodynamic damages in the so-called “jacket” component of the φX174 coat proteins are partly responsible for the loss of plaque-forming ability, whereas the “spikes” are either poor antigens or insensitive to photodynamic treatment.
Cell-Cycle Dependent Appearance of Murine Leukemia-Sarcoma Virus Antigens
Authors: Panem Sandra , Schauf Victoria
Published: January 2020

Normal rat kidney (NRK) cells, NRK cells infected with Rauscher murine leukemia virus, and NRK cells infected with Kirsten murine sarcoma-leukemia virus (NRK-K) were synchronized by a double thymidine block. At intervals after release from thymidine blockage, the cells were examined for the presence of viral antigens in the cytoplasm and on the cell surface by immunofluorescent microscopy by using goat anti-Rauscher murine leukemia virus and goat anti-Moloney leukemia virus (Tween-ether disrupted) sera. Detection of viral antigens in the cytoplasm was periodic during the cell cycle. Antigens were detected first during the S phase, increased during the G2 phase, and disappeared during the M and G1 phases. A similar pattern of surface immunofluorescence was observed. Infectious virus was detected in culture fluids from synchronized cells during the M phase. Surface immunofluorescence was detected in NRK-K cells with anti-Rauscher murine leukemia virus and may represent the presence of group-specific antigens on the cell surface. Control, uninfected NRK cells, which did not normally fluoresce, showed weak immunofluorescence during the S and G2 phases after synchronization. Synchronization can be used to amplify latent oncornavirus expression.
Inhibition of the Multiplication of Vesicular Stomatitis and Newcastle Disease Virus by 2-Deoxy-
d
-Glucose
Authors: Scholtissek C. , Rott R. , Hau G. , Kaluza G.
Published: January 2020

The production of infectious vesicular stomatitis (VSV) and Newcastle disease virus can be completely inhibited by 2-deoxy-
d
-glucose in pyruvate-containing medium, if virus either grown in pyruvate-containing medium or dialyzed against phosphate-buffered saline is used for infection. Under these conditions, the synthesis of all VSV proteins is reduced. VSV RNA, which is synthesized at reduced rates, seems to be unstable. The effect is completely reversible. If virus grown in glucose-containing medium is used for infection, the production of both viruses is not significantly inhibited by 2-deoxy-
d
-glucose. Under these conditions the production of the VSV glycoprotein is specifically impaired, but does not lead to a marked reduction of the yield of infectious virus.
Structural Aberrations in T-Even Bacteriophage IV. Parameters of Induction and Formation of Lollipops
Authors: Bolin Rex W. , Cummings Donald J.
Published: January 2020

Previous results from our laboratory have shown that when a T-even bacteriophage-infected bacterial cell was exposed to
l
-canavanine followed by an
l
-arginine chase, a monster phage particle, termed a lollipop, was formed. We now describe certain parameters concerning (i) the induction and (ii) the formation of T4 lollipops. The induction step involves a T4 late function, and can require only a 3-min exposure to
l
-canavanine. Short pulses of
l
-canavanine result in the formation of shorter lollipops indicating the presence of a possible “precursor substance” which is influenced by
l
-canavanine. DNA synthesis is inhibited by
l
-canavanine but is stimulated 20 to 40 min after the addition of
l
-arginine. Chloramphenicol prevents both responses indicating a possible protein involvement. The appearance of lollipops and phage was noted only after 25 min after the addition of
l
-arginine.
Reconstitution of Infectivity and Transcriptase Activity of Homologous and Heterologous Viruses: Vesicular Stomatitis (Indiana Serotype), Chandipura, Vesicular Stomatitis (New Jersey Serotype), and Cocal Viruses
Authors: Bishop D. H. L. , Emerson Suzanne U. , Flamand Anne
Published: January 2020

RNA transcriptase activities have been reconstituted from fractionated components of four rhabdoviruses: vesicular stomatitis virus (VSV) (Indiana serotype), Cocal, VSV (New Jersey), and Chandipura viruses. Heterologous reconstitution of transcription has been observed between template and enzyme fractions of VSV Indiana and Cocal viruses but not to any significant extent between components of the other two viruses with VSV Indiana template or enzyme. Homologous reconstitution of infectivity has been obtained for each virus from their respective parts as well as heterologous reconstitution between Cocal and VSV Indiana components.
RNA Polymerase in Mumps Virion
Authors: Bernard Jacqueline P. , Northrop Robert L.
Published: January 2020

Mumps virions of the Enders' strain were examined for polymerase activity in vitro. An RNA-dependent RNA polymerase was found to be associated with the virion. The general properties of the reaction appear to be similar to those described for other paramyxoviruses.
Isolation and Partial Characterization of Bacteriophage T5 Mutants Deficient in the Ability to Induce Deoxynucleoside Monophosphate Kinase
Authors: Berget Susan M. , Warner Huber R. , McCorquodale D. James
Published: January 2020

Two mutants of bacteriophage T5 deficient in the ability to induce wild-type levels of deoxynucleoside monophosphate kinase were isolated and partially characterized. Both mutations were demonstrated to be in a structural gene for the kinase. One of the mutants, designated
dnk
10, induces no detectable levels of dCMP, dGMP, or dTMP kinase activity. Because the mutant can successfully infect nonpermissive cells, phage-induced deoxynucleoside monophosphate kinase appears to be an unessential function for phage production. DNA synthesis in
dnk
10-infected cells, however, is reduced to 30% of that observed in wild-type-infected cells; phage production is reduced by a comparable amount. The
dnk
mutation has been mapped and located on the “C” region of the T5 genetic map, 6.3 map units from the C1 locus.
Regulation of Herpesvirus Macromolecular Synthesis I. Cascade Regulation of the Synthesis of Three Groups of Viral Proteins
Authors: Honess Robert W. , Roizman Bernard
Published: January 2020

Based on evidence that 50% of herpes simplex 1 DNA is transcribed in HEp-2 cells in the absence of protein synthesis we examined the order and rates of synthesis of viral polypeptides in infected cells after reversal of cycloheximide- or puromycin-mediated inhibition of protein synthesis. These experiments showed that viral polypeptides formed three sequentially synthesized, coordinately regulated groups designated α, β, and γ. Specifically: (i) The α group, containing one minor structural and several nonstructural polypeptides, was synthesized at highest rates from 3 to 4 h postinfection in untreated cells and at diminishing rates thereafter. The β group, also containing minor structural and nonstructural polypeptides, was synthesized at highest rates from 5 to 7 h and at decreasing rates thereafter. The γ group containing major structural polypeptides was synthesized at increasing rates until at least 12 h postinfection. (ii) The synthesis of α polypeptides did not require prior infected cell protein synthesis. In contrast, the synthesis of β polypeptides required both prior α polypeptide synthesis as well as new RNA synthesis, since the addition of actinomycin D immediately after removal of cycloheximide precluded β polypeptide synthesis. The function supplied by the α polypeptides was stable since interruption of protein synthesis after α polypeptide synthesis began and before β polypeptides were made did not prevent the immediate synthesis of β polypeptides once the drug was withdrawn. The requirement of γ polypeptide synthesis for prior synthesis of β polypeptides seemed to be similar to that of β polypeptides for prior synthesis of the α group. (iii) The rates of synthesis of α polypeptides were highest immediately after removal of cycloheximide and declined thereafter concomitant with the initiation of β polypeptide synthesis; this decline in α polypeptide synthesis was less rapid in the presence of actinomycin D which prevented the appearance of β and γ polypeptides. The decrease in rates of synthesis of β polypeptides normally occurring after 7 h postinfection was also less rapid in the presence of actinomycin D than in its absence, whereas ongoing synthesis of γ polypeptides at this time was rapidly reduced by actinomycin D. (iv) Inhibitors of DNA synthesis (cytosine arabinoside or hydroxyurea) did not prevent the synthesis of α, β, or γ polypeptides, but did reduce the amounts of γ polypeptides made.
Prevention of Bacteriophage Adsorption to
Staphylococcus aureus
by Immunoglobulin G
Authors: Nordström Kristina , Forsgren Arne , Cox Peter
Published: January 2020

Normal human and rabbit sera when incubated with
Staphylococcus aureus
inhibit the adsorption of bacteriophages. The bacteriophage adsorption was also inhibited by separated normal immunoglobulin M (IgM), F(ab′)
2
, and Fab-fragments of IgG. No inhibition was obtained with myeloma IgG or Fc-fragments of normal human and rabbit IgG. The results indicate that the serum inhibition of bacteriophage adsorption to
S. aureus
is not due to a binding of IgG to protein A on the surface of
S. aureus.
Reliability of the RNA-DNA Filter Hybridization for the Detection of Oncornavirus-Specific DNA Sequences
Authors: Shoyab M. , Markham P. D. , Baluda M. A.
Published: January 2020

Denatured DNA from leukemic myeloblasts or uninfected chicken embryos, immobilized on nitrocellulose filters, was hybridized to a vast excess of [
3
H]70
S
RNA from purified avian myeloblastosis virus. The viral RNA was eluted from the RNA-DNA hybrids, purified, and then rehybridized in solution to an excess of either leukemic or normal chicken embryonic DNA. This study revealed that all the slow and the fast hybridizing viral RNA sequences detectable by liquid hybridization in DNA excess had hybridized to the filter bound DNA. Both techniques also gave similar values for the number of 28
S
ribosomal RNA genes contained in a chicken cell genome: 210 by the liquid hybridization procedure and 218 by the filter hybridization technique. Therefore, filter hybridization can accurately detect DNA sequences present in relatively few numbers in the genome of higher organisms.
Characterization of Late Polyoma mRNA
Authors: Buetti Elena
Published: January 2020

Polyoma-infected mouse kidney cell cultures were labeled with [
3
H]uridine for 3 h late in the lytic cycle (26 to 29 h after infection) and RNA was extracted from cytoplasm and nuclei and from isolated polyribosomes. Sedimentation velocity analysis in sucrose gradients showed that polyoma-specific “giant” and 26
S
RNAs are present exclusively in the nucleus. RNA associated with cytoplasmic polyribosomes was analyzed by sedimentation in aqueous sucrose density gradients and dimethylsulfoxide sucrose gradients, as well as by polyacrylamide gel electrophoresis. Polyoma-specific RNA in polyribosomes consists of at least two classes, with sedimentation coefficients of 16 (major fraction) and 19
S
(minor fraction) in aqueous sucrose gradients and 15 and 17
S
, respectively, in dimethylsulfoxide gradients. Estimates based on dimethylsulfoxide gradient and analysis suggest a molecular weight of approximately 500,000 for 16
S
RNA and 700,000 for 19
S
RNA. These polyoma RNAs seem to undergo reversible conformational changes under the different conditions of analysis. We cannot exclude the possibility that they contain more than one molecular species.
Measurement of the Sequence Complexity of Cloned Moloney Murine Leukemia Virus 60 to 70
S
RNA: Evidence for a Haploid Genome
Authors: Fan Hung , Paskind Michael
Published: January 2020

The sequence complexity of the 60-70
S
RNA complex from Moloney murine leukemia virus (M-MuLV) was determined by measuring the annealing rate of radioactively labeled virus-specific DNA with M-MuLV 60-70
S
RNA in conditions of vast RNA excess. The M-MuLV RNA annealing rate, characterized by the quantity C
r
t
½
, was compared with the C
r
t
½
values for annealing of poliovirus 35
S
RNA (2.6 × 10
6
molecular weight) with poliovirus-specific DNA and Sindbis virus 42
S
RNA (4.3 × 10
6
molecular weight) with Sindbis-specific DNA. M-MuLV-specific DNA was prepared in vitro by the endogenous DNA polymerase reaction of M-MuLV virions, and poliovirus and Sindbis virus DNAs were prepared by incubation of viral RNA and DNA polymerase purified from avian myeloblastosis virus and an oligo deoxynucleotide primer. The poliovirus and Sindbis virus DNAs were sedimented through alkaline sucrose gradients, and those portions of the DNA with sizes similar to the M-MuLV DNA were selected out for the annealing measurements. M-MuLV was cloned on NIH-3T3 cells because it appeared possible that the standard source of M-MuLV for these experiments was a mixture of viruses. The annealing measurements indicated a sequence complexity of approximately 9 × 10
6
daltons for the cloned M-MuLV 60-70
S
RNA when standardized to poliovirus and Sindbis virus RNAs. This value supports the hypothesis that each of the 35
S
RNA subunits of M-MuLV 60-70
S
RNA has a different base sequence.
Separation, Isolation, and Immunological Studies of the Structural Proteins of Venezuelan Equine Encephalomyelitis Virus
Authors: Pedersen Carl E. , Eddy Gerald A.
Published: January 2020

Three viral proteins were separated from the TC-83 strain of Venezuelan equine encephalomyelitis virus by discontinuous polyacrylamide gel electrophoresis after disruption with sodium dodecyl sulfate and β-2-mercaptoethanol. These proteins were inoculated into rabbits and the resultant antisera were tested for immunological activity by gel precipitation, plaque reduction neutralization, hemagglutination inhibition (HI), complement fixation, fluorescence microscopy, and mouse protection studies. All proteins were capable of stimulating precipitating antibody in rabbits, but the largest protein (VP 1), which is contained in the envelope, stimulated the production of detectable neutralizing and HI antibody against the intact virion. The other two proteins yielded little or no neutralizing or HI antibody.
Replication of Measles Virus: Continued Synthesis of Nucleocapsid RNA and Increased Synthesis of mRNA in the Presence of Cycloheximide
Authors: Kiley Michael P. , Payne Francis E.
Published: January 2020

The effect of cycloheximide on virus specific RNA synthesis in Vero cells infected with either wild-strain (Edmonston) or subacute sclerosing panencephalitis strain measles virus was investigated. At 3 days postinfection, cells treated with cycloheximide (2.6 × 10
−4
M) and then exposed to [
3
H]uridine showed a marked increase in labeled virus-specific RNA. A major portion of this incremental labeled RNA was putative viral mRNA which sedimented at 16, 22, and 30
S
. Five distinct classes of polyribosomes, which were not evident in untreated cells, were found in cycloheximide-treated cells and each contained similar species of virus-specific RNA. Viral nucleocapsid RNA, 50 and 18
S
, was synthesized and encapsidated in the presence of cycloheximide. The latter observation is in apparent contrast to reports that cycloheximide inhibits replication of RNA of classical paramyxoviruses, and may indicate that mechanisms for replicating RNA of measles virus are different from those for replicating RNA of paramyxoviruses.
Polypeptide Composition of Urea- and Heat-Resistant Mutants of Poliovirus Types 1 and 2
Authors: Fennell Robert , Phillips Bruce A.
Published: January 2020

Five urea-resistant and two heat-resistant mutants of poliovirus types 1 and 2 were isolated and their structural and nonstructural polypeptides compared to those of their wild-type, parental strains in an attempt to correlate mutant phenotypes with alterations in specific capsid polypeptides. Four of the seven mutants were found to contain polypeptides which differed in molecular weight from their respective parental viruses. However, resistance of virions to heat- or urea-inactivation could not be attributed to changes in particular capsid polypeptides because alterations were detected in all but one of the capsid components. For two of the urea-resistant mutants and one heat-resistant mutant, no differences were found in the molecular weights of the capsid and noncapsid polypeptides. These results, and the fact that at least 12 selective treatments were required to obtain stable mutants, indicate that: (i) such phenotypes probably can be expressed by mutations affecting one or more of the larger capsid polypeptides, and (ii) such phenotypes reflect multiple mutational steps.
Use of DNA-DNA Annealing to Detect New Virus-Specific DNA Sequences in Chicken Embryo Fibroblasts After Infection by Avian Sarcoma Virus
Authors: Varmus Harold E. , Heasley Suzanne , Bishop J. Michael
Published: January 2020

Labeled, virus-specific DNA synthesized in vitro by the virion-associated polymerase of avian sarcoma virus (ASV) was used to measure virus-specific sequences in cell DNA in three ways: (i) by determining the effect of cell DNA upon the reassociation rate of double-stranded polymerase products; (ii) by measuring the kinetics of annealing of single-stranded polymerase product (cDNA) to cell DNA; or (iii) by measuring the amount of cDNA which anneals to a large excess of cell DNA. With these three assays and modifications of them, we show that fewer than five copies of ASV-specific DNA sequences are present per diploid cell in uninfected chicken embryos; that a two- to several-fold increase in copy number of viral DNA follows infection by ASV; that infection introduces to the cell viral sequences not present before infection; and that DNAs from uninfected Pekin duck and Japanese quail embryos show no homology with DNA synthesized by the ASV polymerase. Some of these results differ from data in a previous report from this laboratory (H. E. Varmus, R. A. Weiss, R. R. Friis, W. Levinson, and J. M. Bishop, 1972) and, in general, reconcile our observations with those from other laboratories.
Rhinovirus RNA Polymerase: Products and Kinetics of Appearance in Human Diploid Cells
Authors: Koliais Stephanos I. , Dimmock Nigel J.
Published: January 2020

The kinetics of appearance of an RNA-dependent RNA polymerase activity obtained from human embryo lung cells infected with rhinovirus type 2 have been followed by analysis of the RNA synthesized by the polymerase preparation in vitro. Little single-stranded RNA was synthesized and the proportion of replicative intermediate to replicative form was over threefold greater than obtained in vivo. The polymerase activity in vivo declined in the presence of cycloheximide showing that continued protein synthesis was necessary to maintain RNA replication.