bluuebunny/crossref_metadata_2025 huggingface dataset:
Further Studies of a Simian Virus 40-Like Virus Isolated from Human Brain
Authors: Weiner L. P. , Herndon R. M. , Narayan O. , Johnson R. T.
Published: January 2020

A virus similar to simian virus 40 was reisolated from brain homogenates of a patient with progressive multifocal leukoencephalopathy onto cultures of human fetal brain cells.
Temperature-Dependent Inhibition of Fusion from Without
Authors: Gallaher William R. , Bratt Michael A.
Published: January 2020

Fusion from without by Newcastle disease virus is inhibited by incubation at 23 C. The inhibitory effect is exerted at a step after viral attachment and is not reversed by subsequent incubation at higher temperatures.
Host-Virus Interactions in
Escherichia coli
: Effect of Stationary Phase on Viral Release from MS2-Infected Bacteria
Authors: Ricciuti C. Propst
Published: January 2020

Infection of stationary-phase
Escherichia coli
with MS2 bacteriophage results in the production, but not the release, of progeny virus by the host. Substantial protein synthesis in stationary-phase cells indicates that general protein synthesis is not sufficient to assure cell lysis or viral release.
Protein Kinase and Specific Phosphate Acceptor Proteins Associated with Vaccinia Virus Cores
Authors: Paoletti Enzo , Moss Bernard
Published: January 2020

Incubation of purified vaccinia virus with γ-
32
P-adenosine triphosphate resulted in the incorporation of
32
P into hot trichloroacetic acid-insoluble material. Enzymatic activity was completely dependent on the addition of divalent cations and was stimulated by nonionic detergents and dithiothreitol. Chemical studies demonstrated that serine and threonine residues of 15,000 molecular weight viral polypeptides were phosphorylated. In contrast, the major structural proteins were not phosphorylated or were phosphorylated to a much lesser extent. Added histones and protamine, but not serum albumin, casein, or phosvitin were phosphorylated by the partially disrupted vaccinia virus preparations. The protein kinase was tightly associated with vaccinia virus particles since the specific enzymatic activity remained constant during the final steps of virus purification, the specific activities of many different preparations of virus were similar, and the enzymatic activity cosedimented with vaccinia virus during rate zonal sucrose gradient and potassium tartrate gradient equilibrium centrifugations. Controlled degradation of vaccinia virus, with nonionic detergents and dithiothreitol, indicated that both the protein kinase and the specific phosphate acceptor proteins were located in the virus core.
Biophysical and Biochemical Heterogeneity of Purified Hepatitis B Antigen
Authors: Dreesman G. R. , Hollinger F. B. , Suriano J. R. , Fujioka R. S. , Brunschwig J. P. , Melnick J. L.
Published: January 2020

Hepatitis B antigen of the D (a+, d+, y−) subtype was purified from plasma of apparently healthy persons and from hepatitis patients. The original samples contained 20- and 42-nm particles and tubular forms (20-nm diameter). Ultracentrifugation during the purification procedure yielded pellets which were then treated at
p
H 2.4. Both the large, 42-nm Dane particles and the tubular forms were lost during the acid treatment of the pelleted particles, yielding a preparation containing a mixture of particles approximately 20 and 25 nm in diameter. This difference in size was substantiated in that two distinct molecular weights were calculated from high-speed equilibrium data, 3.6 × 10
6
and 4.5 × 10
6
. Further heterogeneity was observed in that hepatitis B antigenic activity was present in purified particles with an isoelectric
p
H of 4.0 and also in those with a
p
H of 4.4. No significant differences were observed in the gross amino acid composition of purified antigen obtained from plasma of three different persons.
125
I-labeled, purified antigen was found to contain six distinct polypeptides with molecular weights ranging from 10,000 to 39,000.
Specific Membranous Structures Associated with the Replication of Group A Arboviruses
Authors: Grimley Philip M. , Levin Judith G. , Berezesky Irene K. , Friedman Robert M.
Published: January 2020

Intracytoplasmic membranous structures of a unique type were associated with the replication of three group A arboviruses: Semliki Forest virus (SFV), Sindbis virus, or Western equine encephalomyelitis virus. The structures, referred to as type 1 cytopathic vacuoles (CPV-1), were membrane-limited and characteristically lined by regular membranous spherules measuring 50 nm in diameter. The membranous spherules typically contained a fine central density, but were neither virus cores nor virions. Detection of CPV-1 by electron microscopy at 3 to 6 hr postinfection coincided with the time of rapid virus growth and preceded the accumulation of virus nucleocapsids. A range of 20 to 100 CPV-1 profiles were counted per 100 ultrathin cell sections at 6 to 9 hr postinfection when viruses were grown in chick embryo, baby hamster kidney, or mouse L cells. Maximum counts remained in the same range even when the multiplicity of infection was varied over 100-fold. Inhibition of cellular ribonucleic acid (RNA) and protein synthesis by actinomycin D during SFV infection did not decrease the counts of CPV-1; however, biogenesis of CPV-1 was decreased when viral replication was limited by inhibitors of viral RNA synthesis (guanidine) or of viral protein synthesis (cycloheximide). On the basis of present and earlier findings, we concluded that formation of CPV-1 must result from a virus-specified modification of pre-existing host cell macromolecules.
Bacteriophage T4 Head Morphogenesis IV. Comparison of Gene 16-, 17-, and 49-Defective Head Structures
2
Authors: Luftig Ronald B. , Ganz Carol
Published: January 2020

Defective heads present in extracts of bacteriophage T4 gene 16, 17, or 49 mutant-infected cells have been characterized. All appeared as empty shells when examined by negative-stain electron microscopy and showed essentially the same polypeptide pattern on sodium dodecyl sulfate-acrylamide gels. However, when analyzed by several other methods, gene 16- and 17-defective heads were shown to differ markedly from phage heads present in gene 49-defective extracts. First, the gene 16- and 17-defective structures were found to possess a large number of attached tails (50%, rather than about 5%). Second, they contained less nuclease-resistant deoxyribonucleic acid (DNA) (3 versus 18% of a phage equivalent), had a smaller sedimentation coefficient (240 versus 315
S
), and a lighter density (1.31 vs. 1.34 g/ml) than gene 49-defective heads. Third, they were not attached to the intracellular DNA pool through a deoxyribonuclease-sensitive linkage. Finally, 8-nm diameter capsomers were clearly revealed on the surface of many gene 16- and 17-defective structures. There was a total of 305 ± 25 capsomers per particle, which yielded an approximate molecular weight of 84 × 10
6
for these heads. The capsomers were presumably not seen on gene 49-defective heads because of the large amount (18%) of associated DNA.

These results support the contention that gene 16- and 17-defective heads, in contrast to gene 49-defective structures, represent abortive rather than intermediate structures in T4 head morphogenesis.
Simian Virus 40 Deoxyribonucleic Acid Synthesis: the Viral Replicon
Authors: Tegtmeyer Peter
Published: January 2020

Three temperature-sensitive (ts) mutants of simian virus 40 (SV40) in complementation group A (tsA7, tsA28, tsA30) have been isolated and characterized in permissive and restrictive host cells. At 41 C in the AH line of African green monkey kidney cells, the mutants are deficient in an early function required to produce infectious viral deoxyribonucleic acid (DNA). Temperature-shift experiments and analysis of SV40 viral DNA replication by gel electrophoresis have provided strong evidence that the ts gene product of the three mutants is directly required to initiate each new round of viral DNA replication but is not required to complete a cycle which has already begun. The synthesis of mutant DNA molecules themselves can be initiated by a nonmutant gene product in viral complementation studies at 41 C. The cell, however, cannot substitute a host function to provide the initiator required for the replication of free viral DNA. The viral initiator is also required to establish the stable transformation of 3T3 cells.
Reovirus Replicase-Directed Synthesis of Double-Stranded Ribonucleic Acid
Authors: Sakuma S. , Watanabe Y.
Published: January 2020

After the incubation of reovirus replicase reaction mixtures (containing labeled ribonucleoside triphosphates), partially double-stranded ribonucleic acid (pdsRNA) products were isolated by cellulose column chromatography followed by precipitation with 2
m
NaCl. The pulse-labeled reaction product contained a significantly large amount of pdsRNA that became complete dsRNA as reaction time increased, indicating that pdsRNA was an intermediate of the replicase reaction. The newly synthesized RNA strand (
3
H-labeled) of the pdsRNA was resistant to ribonuclease digestion, suggesting that single-stranded RNA regions were part of a preexistent unlabeled RNA template. These observations, together with the electrophoretic behavior of the pdsRNA in polyacrylamide gel, are consistent with the hypothesis that dsRNA is synthesized by the elongation of a complementary RNA strand upon a preexistent template of single-stranded RNA (i.e., messenger RNA). The direction of the RNA strand elongation was determined by carrying out the replicase reaction in the presence of
3
H-cytidine triphosphate (or
3
H-uridine triphosphate) and adenine triphosphate-α-
32
P
followed by a chase with excess unlabeled cytidine triphosphate (or uridine triphosphate). The dsRNA product was digested with T1 ribonuclease and the resulting 3′-terminal fragments were isolated by chromatography on a dihydroxyboryl derivative of cellulose. Examination of the ratio of
3
H to
32
P in these fragments indicated that RNA synthesis proceeded from the 5′ to 3′ terminus.
Transcription of the Herpes Simplex Virus Genome in Human Cells
Authors: Wagner Edward K. , Swanstrom Ronald I. , Stafford Marvin G.
Published: January 2020

We have examined the details of the transcription of the herpes simplex virus (HSV) genome in HeLa cells using deoxyribonucleic acid-ribonucleic acid (DNA-RNA) hybridization. The following findings are reported. (i) Virus-specific RNA (vRNA) synthesized following onset of HSV-DNA replication (L-vRNA) is complementary to as much as 90% of the HSV genome. (ii) There is no significant class of virus-specific RNA synthesized later than L-vRNA. (iii) The vRNA synthesized prior to HSV-DNA replication (E-vRNA) is composed of two classes; one class comprising 75% of the total E-vRNA is found in large amounts as early as 45 min after infection, whereas the other class making up the other 25% of E-vRNA is found in only small amounts at 1.5 hr after infection. This second class of E-vRNA is found in amounts comparable to the first by 3.5 hr after infection. (iv) Inhibition of HSV-DNA synthesis results in the continued synthesis of E-vRNA, but there is no synthesis of L-vRNA. (v) Finally, there is no class of vRNA found in the nucleus that is not found associated with cytoplasmic polyribosomes either early or late after infection.
Major Group-Specific Protein of Rat Type C Viruses
Authors: Oroszlan S. , Bova D. , Huebner R. J. , Gilden R. V.
Published: January 2020

The major internal protein of a rat type C virus pseudotype of murine sarcoma virus, MSV(RaLV), was purified by isoelectric focusing (pI = 8.6) and used to prepare antibody in guinea pigs. The protein was identified by its reaction with antisera reactive with the mammalian type C virus group-specific (gs) antigenic determinant, gs-3. The guinea pig antisera mainly contained species-specific (gs-1) antibody for reactions in gel diffusion with other type C viruses were limited to those of rat origin, whereas in complement fixation tests heterologous reactions could be eliminated by use of appropriate antiserum concentrations without affecting homologous reactions. Guinea pig antisera against mouse, hamster, or cat gs-1 determinants did not react with MSV(RaLV) purified gs protein or with any of several other rat type C viruses.
Inhibition of Cleavage of Large Poliovirus-Specific Precursor Proteins in Infected HeLa Cells by Inhibitors of Proteolytic Enzymes
Authors: Summers Donald F. , Shaw Elliott N. , Stewart Margaret L. , Maizel Jacob V.
Published: January 2020

Inhibitors of chymotrypsin interfere with the post-translational cleavage of large poliovirus-specific polypeptides in the molecular weight range of 100,000 to 250,000 in infected HeLa cells.
T-Even Bacteriophage-Tolerant Mutants of
Escherichia coli
B III. Nature of the
tet
Defect
Authors: Hewlett Martinez J. , Mathews Christopher K.
Published: January 2020

T-even phage-tolerant (
tet
) mutants of
Escherichia coli
B are shown to lack the enzyme uridine diphosphoglucose pyrophosphorylase and thus produce nonglucosylated progeny phage deoxyribonucleic acid.
Analysis of High-Molecular-Weight Ribonucleic Acid Associated with Intracisternal A Particles
Authors: Yang Stringner Sue , Wivel Nelson A.
Published: January 2020

Intracisternal A particles, known primarily for their association with various tumors, have been shown to contain high-molecular-weight (HMW) ribonucleic acid (RNA) by velocity centrifugation, using linear glycerol gradients. This HMW RNA is sensitive to ribonuclease digestion and alkali treatment but is resistant to Pronase treatment. By a double-labeling experiment, HMW RNA was shown to be intrinsic to intracisternal A particles and not to have resulted from cytoplasmic polysomal RNA aggregation. By a reconstitution experiment, it was determined that the results were not due to C-type virus contamination. The synthesis of HMW RNA in intracisternal A particles is inhibited by actinomycin D and ethidium bromide. These observations emphasize that there are probably some taxonomic relationships between intracisternal A particles and oncogenic RNA viruses.
Growth of Bacteriophage H on Male and Female Strains of
Escherichia coli
Authors: Duberstein Ronnie , Oeschger Max P.
Published: January 2020

Phage H propagated on
Yersinia pestis
was reported by Molnar and Lawton to be rapidly adsorbed to female but not to male strains of
Escherichia coli.
In contrast, we find phage H adsorbs to all
E. coli
strains tested (both male and female) and forms plaques on a wide variety of male strains. Phage H appears to be related to the T3-T7 group of coliphages.
Bacteriophage Tail Components IV. Pteroyl Polyglutamate Synthesis in T4D-Infected
Escherichia coli
B
Authors: Kozloff Lloyd M. , Lute Murl
Published: January 2020

The nature of pteroyl polyglutamates in uninfected and T4D bacteriophage-infected
Escherichia coli
B has been examined.
3
H-
p
-aminobenzoic acid has been used to label the folate compounds and gel permeation chromatography on glass beads to separate the folate compound by molecular size. It has been found that, although the major folate compound in uninfected bacteria is pteroyl triglutamate,
E. coli
B cells also contain folate compounds having as many as six glutamate residues. Infection with T4D stimulated the addition of glutamate residues to the lower-molecular-weight host pteroyl compounds, resulting in the conversion of the host compounds into the hexaglutamate form. This viral-induced conversion is chloramphenicol sensitive and appears to be due to a late phage gene product. The phage gene responsible for this conversion has not been identified. In cells infected with a T4D mutant defective in gene 28, there was an apparent production of the large pteroyl polyglutamates equivalent in size to
pte
(
glu
)
9-12
. These high-molecular-weight forms were converted into
pte
(
glu
)
6
by incubation with bacterial extracts made after infection with T4D 28
+
. Apparently, the product of T4D gene 28
+
is capable of specifically cleaving the high-molecular-weight polyglutamates to the form necessary for phage tail assembly.
Studies of Nondefective Adenovirus 2-Simian Virus 40 Hybrid Viruses V. Isolation of Additional Hybrids Which Differ in Their Simian Virus 40-Specific Biological Properties
Authors: Lewis Andrew M. , Levine Arthur S. , Crumpacker Clyde S. , Levin Myron J. , Samaha Richard J. , Henry Patrick H.
Published: January 2020

Four new nondefective adenovirus 2 (Ad2)-simian virus 40 (SV40) hybrid viruses have been isolated. Although these viruses (designated Ad2
+
ND
2
, Ad2
+
ND
3
, Ad2
+
ND
4
, and Ad2
+
ND
5
) were clonal derivatives of the same Ad2-SV40 hybrid population, they differ significantly from each other and from the previously isolated nondefective hybrid, Ad2
+
ND
1
, in their biological properties or in the amount of SV40-specific RNA induced during lytic infection.

Like Ad2
+
ND
1
, Ad2
+
ND
2
, and Ad2
+
ND
4
pass serially in both human embryonic kidney (HEK) and primary African green monkey kidney cells. In contrast, Ad2
+
ND
3
and Ad2
+
ND
5
pass serially only in HEK cells. Ad2
+
ND
2
is like Ad2
+
ND
1
in that it induces the SV40 U antigen, but not SV40 T antigen; however, in contrast to the perinuclear SV40 antigen induced by Ad2
+
ND
1
, the SV40 antigen induced by Ad2
+
ND
2
is located peripherally in the cytoplasm as well as in the perinuclear region of infected cells. Ad2
+
ND
4
induces both the SV40 T and U antigens. Ad2
+
ND
3
and Ad2
+
ND
5
do not induce serologically detectable SV40 antigens and are distinguished from each other on the basis of the relative quantities of SV40-specific RNA which they induce. The induction of different SV40-specific functions suggests the incorporation of different segments of SV40 DNA within the genomes of the respective hybrid viruses.
Avian Oncornavirus Group-Specific Antigen: Detection and Quantification by Radioimmunoassay
Authors: Fritz Robert B. , Qualtiere Louis F.
Published: January 2020

A double-antibody competitive-inhibition radioimmunoassay for avian group-specific antigen is described. A viral protein preparation, consisting primarily of gs-1, was labeled with radioiodine. Hamster and rabbit antisera were reacted with the labeled antigen, and the resultant antibody-antigen complexes were precipitated with the appropriate antiglobulin. Standard curves based on the inhibition of binding of labeled antigen to antibody after preincubation with unlabeled antigen were prepared. These showed the lower limit of sensitivity to be 2 to 10 ng of unlabeled protein when labeled antigen of 2,000 to 5,000 counts per min per ng of specific activity was used in the assay. Extracts of avian oncornavirus-infected cells, likewise, were able to inhibit binding of labeled antigen. This technique will be very useful for the quantification of small amounts of oncornavirus group-specific protein.
Mechanism of Adsorption and Eclipse of Bacteriophage φX174 II. Attachment and Eclipse with Isolated
Escherichia coli
Cell Wall Lipopolysaccharide
Authors: Incardona Nino L. , Selvidge LeRoy
Published: January 2020

A mixture of aqueous phenol, choloroform, and ether extracts the lipopolysaccharides (LPS) from the φX174-sensitive strain,
Escherichia coli
C/1, and resistant strains, C/φX and K12. Interaction of the C/1 LPS with φX in a starvation buffer containing 10
−3
M CaCl
2
at 37 C, but not at 15 C, results in a first-order inactivation that is specific for C/1 LPS. After interaction for 60 min at 15 C, followed by centrifugation, 37 and 20% of a
14
C-φX preparation are bound to the C/1 and C/φX LPS pellets, respectively. The results for intact cells are 75 and 10%. Supporting the conclusion that this represents specific attachment of φX to its receptor site in the LPS is the fact that EDTA-borate buffer is required to elute 85% of the
14
C-φX from the C/1 LPS, whereas starvation buffer elutes the same amount from C/φX LPS. Moreover, 95% of the PFU are found in the C/1 LPS pellets as compared with 50% in the resistant strain LPS pellets. When the products of interaction between φX and LPS at 37 C are examined by sucrose density gradients in EDTA-borate, a single 60 to 90
S
peak is observed in the C/1 sample, and the single peak cosediments with the 120
S
marker φX in the C/φX sample. This change in
S
20, w
is very similar to that reported for the eclipse of φX in vivo. If the inactivation at 37 C is carried out on φX-LPS complexes first formed at 15 C, the first-order kinetics are biphasic and nearly identical to that observed for the eclipse kinetics of φX attached to intact cells. Thus, the φX-LPS system is suitable for in vitro studies on the early events in φX infection.
Polioviruses, Coxsackieviruses, and Echoviruses: Comparison of the Genomes by RNA Hybridization
Authors: Young Nathaniel A.
Published: January 2020

Hybridization of single-stranded RNA from virions of human enteroviruses with denatured double-stranded RNA from infected cells indicates that a minimum of about 5% of the genome is shared by these viruses. Polynucleotide sequence relationships, furthermore, are consistent with the biologic classification into polioviruses, coxsackieviruses groups A and B, and echoviruses. In general, about 30 to 50% of the nucleotide sequences are shared by different serotypes of virus within each of these major groups, whereas among different groups less than 20% homology is observed. Coxsackievirus B4 appears to be more closely related to echoviruses than to group A coxsackieviruses, whereas polioviruses are only distantly related to any of the other agents.
Replication Process of the Parvovirus H-1 I. Kinetics in a Parasynchronous Cell System
Authors: Rhode Solon L.
Published: January 2020

Parasynchronous cultures of hamster embryo cells were used to study some of the events in the replication process of the parvovirus H-1. Synthesis of viral DNA, viral hemagglutinating antigen, and infectious virus were examined. It was found that initiation of DNA synthesis, on which subsequent viral hemagglutinin synthesis was dependent, occurred at a specific time in late S-phase. Production of H-1 viral protein was shown to be sensitive to inhibition by α-amanitin. The implications of these findings are discussed.
Radioimmunoassay for Avian C-Type Virus Group-Specific Antigen: Detection in Normal and Virus-Transformed Cells
Authors: Stephenson John R. , Wilsnack Roger E. , Aaronson Stuart A.
Published: January 2020

A radioimmunoassay has been developed for detection of avian C-type virus (30,000 mol wt) group-specific (gs) antigen. The method is 10- to 1,000-fold more sensitive than immunological methods previously available. By the radioimmunoassay technique, normal chicken embryo cells, which have previously been classified as gs negative or weakly gs positive, contain clearly detectable amounts of gs antigen. The assay has been used to study the effect of chemical induction and superinfection by mammalian C-type viruses on the expression of avian gs antigen in mammalian cells nonproductively transformed by avian sarcoma viruses.
Semliki Forest Virus-Specific RNAs Synthesized In Vitro by Enzyme from Infected BHK Cells
Authors: Michel Marcel R. , Gomatos Peter J.
Published: January 2020

When Semliki Forest virus (SFV)-infected BHK cells were disrupted 4 h after infection, 75 to 90% of the total virus-specific RNA synthesizing enzyme was found in the large particle fraction, along with 75 to 90% of the in vivo-synthesized double-stranded RNAs. The RNA products of this enzyme-template complex in an in vitro system were double-stranded RNAs sedimenting predominantly at 18
S
, and single-stranded RNAs sedimenting at 42
S
, 26
S
, and 22
S
. The various virus-specific SFV RNAs synthesized in vitro were associated with different sized structures, and thus each was separable by differential centrifugation. Kinetic and pulse-chase experiments showed that the double-stranded RNAs were the precursors to the single-stranded RNAs. There were several double-stranded RNAs identified both in the in vitro product and also in extracts from infected cells. The major replicative form had a molecular weight of 4.4 × 10
6
.
Phosphoprotein Component of Vaccinia Virions
Authors: Rosemond Hortencia , Moss Bernard
Published: January 2020

The recent discovery of a protein kinase activity in vaccinia virions led us to search for a viral protein which is phosphorylated in vivo. Vaccinia virus was radioactively labeled by infecting cells in the presence of
32
P
1
. A phosphoprotein was isolated from purified delipidated virions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The phosphoprotein appeared to be a specific viral component induced after infection. More than 60% of the phosphoprotein was associated with viral cores. The electrophoretic mobility of the protein suggested that it has a molecular weight of 11,000 to 12,000. Phosphoserine was liberated by acid hydrolysis and identified by electrophoresis with known standards. Tryptic digests of the purified phosphoprotein were analyzed by two-dimensional electrophoresis and chromatography on thin-layer cellulose plates, and a single major phosphopeptide was resolved. The high selectivity of phosphorylation suggested that the process has a specific function.
RNA Synthesis by Vesicular Stomatitis Virus and a Small Plaque Mutant: Effects of Cycloheximide
Authors: Wertz Gail W. , Levine Myron
Published: January 2020

The synthesis of viral RNA by wild-type vesicular stomatitis virus (L
1
VSV) and a small, plaque-size mutant (S
2
VSV) was studied in vitro and in chicken embryo (CE) and mouse L-cell cultures. Virus-specific RNA synthesized in CE or L cells infected with either L
1
or S
2
VSV at low multiplicity was of the same size classes, 12 to 15
S
, 28
S
, and 38
S
. The major differences were in the proportion of RNA produced of each size class. L
1
VSV always synthesized larger proportions of 38
S
RNA, and S
2
VSV produced larger proportions of 12 to 15
S
RNA. Both S
2
and L
1
VSV exhibited RNA transcriptase activity in vitro and in cell culture. The products of the in vitro reaction were the same, 12 to 15
S
for both. The products of the virion-associated transcriptase in CE or L-cell cultures in the presence of cycloheximide were also the same for both viruses but differed from the in vitro products in that 28
S
and 12 to 15
S
RNA were made. The effects of addition of cycloheximide at various times after infection demonstrated that new protein synthesis is required early (0-2 h) for both S
2
and L
1
VSV to initiate and maintain the normal rate of viral RNA synthesis. However, the overall rate of RNA synthesis in L
1
VSV infections became independent of protein synthesis after 2 h whereas the rate in S
2
VSV infections did not. With either virus, synthesis of 38
S
RNA did not occur in the absence of protein synthesis. Moreover, continuous 38
S
RNA production required continuous protein synthesis. Production of 38
S
RNA ceased within 30 min after addition of cycloheximide to S
2
−
or L
1
VSV-infected CE or L cells that had already begun to synthesize the 38
S
form. The cycloheximide-induced cessation of 38
S
RNA synthesis was accompanied by a marked increase in production of 12 to 15
S
and 28
S
RNA in L
1
VSV-infected cells, but no increase in synthesis of small RNA species occurred in S
2
VSV-infected cells.
“Reversion” of a Less Tumorigenic
cyt
Mutant of Adenovirus 12 in Induction of the Cell Surface Change
Authors: Yamamoto Hiroshi , Shimojo Hiroto
Published: January 2020

Five out of 120 clones of a
cyt
mutant of adenovirus 12 were not defective in induction of the cell surface change and in tumorigenicity.
Control of Gene Function in Bacteriophage T4 IV. Post-Transcriptional Shutoff of Expression of Early Genes
Authors: Sauerbier Walter , Hercules Kathleen
Published: January 2020

The selective and sequential shutoff of synthesis of early T4 proteins in bacteria infected with DNA-negative mutants is under the active control of one or more T4-induced proteins. Selective shutoff of synthesis of early T4 proteins is accompanied by a selective degradation of distinct species of T4 mRNA. We present circumstantial evidence that selective degradation of mRNA is the cause, and not the consequence, of selective termination of expression of early T4 genes. The mutation sp62 inactivates the shutoff mechanism and prevents the selective degradation of distinct species of T4 mRNA.
Requirement of a Functional Gene 32 Product of Bacteriophage T4 in UV Repair
Authors: Wu Jen-Ren , Yeh Yun-Chi
Published: January 2020

A temperature-sensitive mutation in gene 32 was used to study the role of gene 32 protein in the repair of UV-damaged DNA of bacteriophage T4. It was possible to distinguish between repair and replication of DNA at 33 C. At this temperature, DNA replication continued, and the intracellular DNA was stable. In contrast, no significant repair of UV-damaged DNA was observed even 40 min after the irradiation. Therefore, it was concluded that the defect in the repair mechanism at this temperature is not a simple consequence of the defect in DNA replication but that gene 32 apparently has an independent role for DNA repair. It was reported previously that gene 32 product is required for both T4 DNA replication and genetic recombination. In addition to these findings, this study has given direct evidence that, in vivo, this protein is also essential for the UV repair mechanism.
Association of Replicating Bacteriophage T7 DNA with Bacterial Membranes
Authors: Pacumbaba Rodulfo P. , Center Melvin S.
Published: January 2020

Infection of
Escherichia coli
with bacteriophage T7 leads to the formation of an association between host membranes and newly synthesized T7 DNA. Evidence for this conclusion is suggested by the findings that replicating T7 DNA cosediments with host membranes in sucrose and cesium chloride density gradients. Furthermore, the sedimentation rate of T7 DNA is dependent on the integrity of membrane structure. Finally, an association between DNA and membranes can be demonstrated by electron microscope studies.
Polyamine Synthesis and Accumulation in
Escherichia coli
Infected with Bacteriophage R17
Authors: Fukuma Isamu , Cohen Seymour S.
Published: January 2020

We have studied the biosynthesis of polyamines during the multiplication of the RNA bacteriophage R17. R17-sensitive strains of
Escherichia coli
were derived from the stringent CP78 and the relaxed mutant derivative CP79. The cells were infected with R17 in the presence or absence of arginine, a required amino acid, and both the RNA and polyamine contents of the bacteria were determined before and after the infection. The uninfected CP79
rel
derivative accumulated RNA and spermidine in the absence of arginine, unlike the stringent organism that accumulated neither under these conditions. After R17 infection, the stringent strain accumulated RNA and spermidine in the presence or absence of arginine. The data indicate a close correlation between the synthesis of RNA and spermidine, suggesting a significant role for this polyamine in the multiplication of phage R17.
Replication of the Parvovirus MVM II. Isolation and Characterization of Intermediates in the Replication of the Viral Deoxyribonucleic Acid
Authors: Tattersall Peter , Crawford Lionel V. , Shatkin Aaron J.
Published: January 2020

The time course of the appearance of intracellular viral DNA has been studied in mouse L cells infected with the single-stranded DNA virus MVM (minute virus of mice) by using a selective extraction procedure. Approximately half of this DNA elutes from hydroxyapatite as single-stranded DNA. It is sensitive to
Escherichia coli
exonuclease I and shows a sedimentation profile similar to DNA from the virus, suggesting that it is progeny viral DNA. The remainder of the selectively extracted DNA elutes from hydroxyapatite in the position of double-stranded DNA and is resistant to exonuclease I. Most of this DNA has a sedimentation coefficient of 14 to 16
S
, indicating that its molecular weight is twice that of the viral DNA. Denaturation renders the majority of the double-stranded DNA sensitive to exonuclease I, but a significant fraction renatures spontaneously in a monomolecular fashion, indicating that it has a cross-linked or hairpin structure. Chromatography of the double-stranded DNA on benzoylated diethylaminoethyl cellulose resolves two components, one with duplex structure and one which contains single-stranded regions. A short pulse label late in infection predominantly labels the latter class of DNA, suggesting that it contains replicating intermediates. The possible roles of these various forms of DNA in the replication of the viral genome are discussed.
Development of Bdellophage VL-1 in Parasitic and Saprophytic Bdellovibrios
Authors: Kessel Martin , Varon Mazal
Published: January 2020

Ultrastructure was correlated with growth kinetics of bdellophage VL-1 infecting host-dependent (“parasitic”)
Bdellovibrio bacteriovorus
109J in its
Escherichia coli
B host (the three-membered system), as well as in the host-independent (“saprophytic”) derivative of the
Bdellovibrio.
Electron microscope observations showed the arrested growth of the phage-infected bdellovibrios, polar localization of the phage progeny, and stages in their release. Present evidence indicates that bdellophage DNA is derived from both the
Bdellovibrio
and its host cell.
Morphological Variants of Sindbis Virus Obtained from Infected Mosquito Tissue Culture Cells
Authors: Brown Dennis T. , Gliedman Jeffrey B.
Published: January 2020

Tissue-cultured
Aedes albopictus
cells infected with morphologically homogeneous Sindbis virus were found to produce progeny virions which could be divided into three classes based on size. The thickness of the envelope was constant on all three sizes of progeny virions suggesting that the variability in size rested with the viral nucleocapsid. It is suggested that the three classes of virions have icosahedral nucleocapsids composed of common subunits organized in decreasing triangulation numbers.
Proteins Specified by Herpes Simplex Virus X. Staining and Radiolabeling Properties of B Capsid and Virion Proteins in Polyacrylamide Gels
Authors: Gibson Wade , Roizman Bernard
Published: January 2020

Analyses of the structural proteins of herpes simplex virions and of capsids containing viral DNA (B capsids), after electrophoresis in polyacrylamide gels, revealed considerable variability in their properties with respect to: (i) retention of Coomassie brilliant blue (CBB) and fast green stains during destaining, (ii) relative optical absorbance of the CBB-protein complex at different wavelengths, (iii) relative efficiency with which
14
C-amino acids are incorporated during early and late periods of the infection cycle, and (iv) capacity to be phosphorylated in vivo. In addition, it was found that protein 22a of B capsids, which does not have an electrophoretically identical counterpart in virions, shares a relatively unique set of staining and radiolabeling properties with virion protein 22, which has a slightly more rapid electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels.
Phosphorylated Proteins of Sindbis Virus
Authors: Waite Marilynn R. F. , Lubin Martin , Jones Kenneth J. , Bose Henry R.
Published: January 2020

The capsid and two membrane proteins of Sindbis virus, grown in chicken cells, contain 0.03 to 0.1 mol of phosphate per mol of protein.
Isolation and Characterization of Sendai Virus Temperature-Sensitive Mutants
Authors: Portner Allen , Marx Preston A. , Kingsbury D. W.
Published: January 2020

Ten temperature-sensitive mutants of Sendai virus, a paramyxovirus, were isolated and partially characterized. The mutants replicated in chicken embryo lung cells at 30 C, but not at 38 C; wild-type virus grew equally well at both temperatures. Complementation tests divided the mutants into seven groups. Six groups synthesized neither infectious virus nor RNA when incubated at 38 C from the beginning of infection. Temperature shift-up experiments demonstrated that three of these complementation groups were blocked in early steps required for RNA synthesis, but these gene functions were not needed throughout the replicative cycle. In contrast, the other three RNA-negative complementation groups were defective throughout the replicative cycle in functions required for virus-specific RNA synthesis. Only one mutant, which complemented all of the above, synthesized RNA but not infectious virus when placed at 38 C; the hemagglutinin of this mutant functioned only at the permissive temperature.
Spackle and Immunity Functions of Bacteriophage T4
Authors: Cornett James B.
Published: January 2020

Cells of
Escherichia coli
B infected with the immunity-negative (
imm
2) mutant of bacteriophage T4 are able to develop a substantial level of immunity to superinfecting phage ghosts if the ghost challenge is made late in infection. This background immunity is not seen in infections with phage carrying the spackle (
s
) mutation in addition to the
imm
2 lesion. The level of immunity in
s
−
infections is intermediate between that of
imm
−
and wild-type infections under standard assay conditions. With respect to genetic exclusion of superinfecting phage, cells infected with
imm
−
phage are completely deficient, whereas infections with the
s
−
phage are only partially deficient compared to wild-type infections. Whereas
s
−
-infected cells are unable to resist lysis from without by a high multiplicity of infection (MOI) of superinfecting phage, cells infected with
imm
−
phage show less than wild-type levels of resistance and the majority of cells remaining intact are unable to incorporate leucine or form infective centers. Under conditions of superinfection by low MOI of homologous phage,
imm
−
-infected cells are lysis inhibited, whereas
s
−
-infected cells do not show this property. Superinfecting phage inject their DNA into
imm
−
-infected cells with the same efficiency as seen in wild-type infections, but this efficiency is reduced when the cells are first infected with
s
−
phage. The
s
function of T4 appears not only to affect the host cell wall as previously postulated by Emrich, but may also affect the junctures of cell wall and membrane with consequences similar to those of the
imm
function.
Genetic Recombination for Antigenic Markers of Antigenically Different Strains of Influenza B Virus
Authors: Tobita K. , Kilbourne E. D.
Published: January 2020

Incorporation of trypsin in agar overlay or fluid maintenance media resulted in enhancement of plaquing efficiency and replication of influenza B viruses in primary chicken embryo fibroblasts. Using this improved technique, recombination was attempted with two serologically distinct strains of influenza B virus, B/Lee/40 and B/Massachusetts/1/71. After mixed infection, two virus clones were selected and characterized in detail. Hemagglutination inhibition and neuraminidase inhibition tests showed that these viruses are reciprocal antigenic recombinants with hemagglutinin derived from one parent and neuraminidase from the other. Serological examinations of the antisera to these recombinants confirmed the results. The frequency of recombination was high in the present system and 64% of the virus clones isolated without selection from the mixed yield were recombinants. This high recombination frequency is consistent with the genomic reassortment that is characteristic of recombination of influenza A viruses.
Structure of the Mouse Mammary Tumor Virus: Polypeptides and Glycoproteins
Authors: Teramoto Yoshio A. , Puentes Manuel J. , Young Lawrence J. T. , Cardiff Robert D.
Published: January 2020

The polypeptide and glycoprotein compositions of the mouse mammary tumor virus virion from primary monolayer cultures of BALB/cfC3H mouse mammary tumor cells were studied by polyacrylamide gel electrophoresis by using internal and external labeling and Coomassie blue and periodic acid Schiff (PAS) staining. Twelve polypeptides were reproducibly resolved by the combined methods. Five major polypeptides were demonstrable with estimated molecular weights of 52,000, 36,000, 28,000, 14,000, and 10,000. Seven minor polypeptides were also consistently detected and had estimated molecular weights of 70,000, 60,000, 46,000, 38,000, 30,000, 22,000, and 17,000. Carbohydrate was associated with five of these polypeptides as measured by PAS stain or [
3
H] glucosamine labeling, or both. These glycoproteins had estimated molecular weights of 70,000, 60,000, 52,000, 36,000 and 10,000. The majority of the PAS stain and glucosamine was found in the 52,000 and 36,000 dalton peaks.
Effects of
l
-Glutamine Deprivation on Growth of HVJ (Sendai Virus) in BHK Cells
Authors: Ito Yasuhiko , Kimura Yoshinobu , Nagata Ikuya , Kunii Akira
Published: January 2020

l
-Glutamine requirement for viral maturation was found in BHK-HVJ cells, a cell line of baby hamster kidney cells persistently infected with HVJ (Sendai virus). Synthesis of envelope protein in BHK-HVJ cells was markedly suppressed by deprivation of
l
-glutamine, whereas development of nucleocapsid (S) antigen was less affected. More detailed examination of this phenomenon was carried out by using a cytolytic system. Growth of HVJ in BHK cells cultured in media deprived of various amino acids was investigated, and omission of
l
-glutamine from culture medium resulted in a marked inhibitory effect on the release of infectious virus and synthesis of envelope protein, although synthesis of virus-specific RNA and nucleocapsid antigen in the cells was readily detected. When
l
-glutamine was restored to the culture medium, infectious virus and envelope protein could be detected.
l
-Glutamic acid,
l
-aspartic acid, or
l
-alanine could be substituted for
l
-glutamine. Effects of
l
-glutamine deprivation on HVJ growth in several other cells were also investigated. The growth of HVJ in the cells other than BHK and FL cells was not suppressed by lack of
l
-glutamine. Growth of Sindbis virus in BHK cells was also markedly retarded in the absence of
l
-glutamine.
Polyoma Viral DNA Replicated as a Nucleoprotein Complex in Close Association with the Host Cell Chromatin
Authors: Seebeck Thomas , Weil Roger
Published: January 2020

Polyoma viral DNA is shown to be replicated in close association with the mouse cell chromatin. Two virus-specific nucleoprotein complexes, designated complex A and B, can be dissociated from the isolated chromatin by gentle homogenization in 0.5 M NaCl. Complex A contains only replicating polyoma (Py) DNA whereas complex B contains only mature Py DNA I. The results show, furthermore, that complex A, containing viral DNA in different stages of replication, and complex B are both nucleoproteins with the same buoyant density. The data presently available suggest that newly synthesized stretches of Py DNA are immediately complexed with mouse cell histones and that complex B becomes the “core” of progeny Py virions. These results suggested that Py-induced replication of the mouse cell chromatin may be necessary to provide replicating Py DNA with histones.
Genetics and Physiology of Bacteriophage T4 3′-Phosphatase: Evidence for Involvement of the Enzyme in T4 DNA Metabolism
Authors: Depew Richard E. , Cozzarelli Nicholas R.
Published: January 2020

Mutants of bacteriophage T4D which fail to induce the deoxyribonucleotide-specific T4 3′-phosphatase have been isolated. These mutants (T4
pseT
) grow as well as wild-type T4 in most strains of
Escherichia coli
, but not in the T4-sensitive “Hospital Strain,” CT196, or in a derivative strain, CTr5x. Both the formation of infectious centers and the final yield of phage are reduced by 98% when CTr5x is infected by T4
pseT
mutants. The growth defects are accompanied by a 50% reduction in the rate of T4 DNA synthesis, a decrease in the single-strand length of the DNA product to about one-half the mature length, and greatly reduced packaging of DNA into phage particles. Introduction of an extra-cistronic suppressor mutation (
stp
) into T4
pseT
eliminates both the requirement for the T4 3′-phosphatase in infected CTr5x and the other observed effects of the
pseT
mutations. The
pseT
gene lies between genes 63 and 31. The
stp
gene lies in the nonessential region between
r
IIB and
ac.
Our results suggest that 3′-phosphoryl termini can disrupt T4 DNA replication to the extent that T4 3′-phosphatase becomes required for phage production.
Polyadenylation of Vesicular Stomatitis Virus mRNA
Authors: Ehrenfeld Ellie
Published: January 2020

Vesicular stomatitis virus (VSV) mRNA isolated from infected cell polysomes contains polyadenylic acid [poly(A)] sequences. Detergent-activated purified virions in vitro can transcribe complementary RNA, which has sedimentation properties similar to mRNA, and this RNA also contains poly(A) sequences. Digestion of virion RNA with U2 RNase under conditions where hydrolysis is specific for purine linkages leaves no sequences of polyuridylic acid corresponding in length to the poly(A) on the transcripts. Growth of infectious virus is not inhibited by 3-deoxyadenosine (cordycepin) under conditions in which it inhibits polyadenylation of cellular mRNA. The virus-specific mRNA produced in the presence of cordycepin has poly(A) sequences of the same size distribution as that synthesized in the absence of cordycepin.
Complementation Analysis of Simian Virus 40 Mutants
Authors: Chou Janice Yang , Martin Robert G.
Published: January 2020

Seventy six new temperature-sensitive mutants of simian virus 40 have been isolated. A simple modification of the standard plaquing technique permits complementation analyses to be performed readily. By using this technique the new mutants have been divided into four complementation groups.
DNA Polymerase I-Dependent Mutants of Coliphage Lambda
Authors: Shizuya Hiroaki , Brown Douglas , Campbell Allan
Published: January 2020

Mutagenized lysates of bacteriophage lambda were screened for mutants unable to plate on DNA polymerase I-deficient (
polA
−
) hosts. The mutants obtained were all recombination deficient (
red
−
). These mutants, like
red
−
and
gam
−
mutants previously isolated by others, grow more poorly than wild-type λ even on
polA
+
hosts (burst size 14 to 30% of wild-type λ.) In a
polA
−
host, the burst size of
red
−
and
gam
−
mutants is reduced an additional five- to tenfold, and lysis is delayed. Wild-type λ grows normally in
polA
−
hosts. Neither λ

N
−
nin

(which doesn't express
red
or
gam
) nor λ
bio
phages (from which all or part of the
red-gam
region is deleted) form plaques on
polA
−
hosts. Apparent revertants, able to plate on
polA
−
hosts, have been selected from both λ

N
−
nin

and λ
bio
. Those derived from

N
−
nin

seem to be

N
−
nin cro

−
mutants; whereas those coming from λ
bio
have a new bypass mutation (
pas
) that lies between genes
P
and
Q
.
Simian Virus 40 Transcription in Productively Infected and Transformed Cells
Authors: Weinberg Robert A. , Ben-Ishai Zvi , Newbold John E.
Published: January 2020

Several independent cell lines transformed by simian virus 40 carry a species of viral RNA of 900,000 to 1,000,000 daltons. A viral RNA species of similar size is found early in the lytic cycle. Late in the viral lytic cycle, two prominent viral RNA species of about 600,000 and 900,000 daltons are seen. The larger late species shares nucleotide sequences with, and is less stable than, the smaller. These RNA species are located in the cytoplasm of the infected cell. The regions of the viral genome coding for these RNA species are mapped by hybridization of lytic RNA species to fragments of the genome produced by cleavage with
Haemophilus aegyptius
endonuclease.