摘要:

The elevation of the genus Adenovirus to a family named Adenoviridae is described. This family at the present stage contains two genera, mammalian adenoviruses – Mastadenovirus – and avian adenoviruses – Aviadenovirus. The two genera are separated primarily on the basis of differences in immunological properties of the vi

ISSN:0300-5526    

DOI:10.1159/000149945

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Evidence was presented that in adenovirus type 2, a representative of Rosen’s subgroup III, a preferential oligomer species of pentons, penton tetramers, could be detected in freshly purified penton preparation

ISSN:0300-5526    

DOI:10.1159/000149946

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Polyadenylation of cytoplasmic RNAs was investigated in L cells infected with encephalomyocarditis virus. During the early stage of infection, the mean size of newly made poly(A) chains attached to cell mRNAs decreased gradually, in parallel with the shut-off of RNA synthesis. Later on, ρoly(A) segments, an average of 50 nucleotides long, were associated with viral RNA isolated either from polysomes or whole cytoplasm. These segments seemed to be processed differently in the course of time, and RNA molecules containing short poly(A) tracts (less than 20 bases) were incorporated into the virions

ISSN:0300-5526    

DOI:10.1159/000149947

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Cytochalasin B (CB) prevents cytoplasmic cleavage without directly affecting nuclear division. Secondary cultures of mouse embryo fibroblasts or 3T3 cells show controlled nuclear division when treated with CB: only binucleated cells are formed. Many CB-treated transformed cells show uncontrolled nuclear division and become highly multi-nucleated. When CB-treated normal cells are concurrently infected with high inputs of SV40, many of these cells become highly multinucleated. It is suggested that these highly multinucleated cells represent abortively transformed cells since the actual number of transforming units (focus-forming units) of simian virus 40 (SV40) is too low to account for the appearance of these cells. Also, if the CB treatment is begun 6 days after SV40 inoculation, the large increase in highly multinucleated cells is not observed. Most cells stably transformed by SV40 or adenovirus show uncontrolled nuclear division when treated with CB. However, 3T3 cells transformed by SV40 or adenovirus and analyzed shortly after transformation are an exception and show controlled nuclear division. This property of 3T3 cells is apparently overcome by high inputs of SV40 since abortively transformed cells become highly multinucleated.

ISSN:0300-5526    

DOI:10.1159/000149948

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

Newly synthesized herpes simplex virus type 1 DNA yielded a heterogeneous sedimentation profile in neutral sucrose gradients, with the main peak occurring at approximately 40S. Components sedimenting slower than virion DNA and a rapidly sedimenting intracellular HSV DNA were also observed. Both the low-molecular weight and the rapidly sedimenting components seemed to be precursors of virion DNA: they almost completely disappeared after a 60-min chase of a 3-min pulse of 3H-thymidine, and were converted into DNA which cosedimented with virion 32P-labeled DNA. However, sedimentation analysis in alkaline sucrose gradients showed that a 60-min period was insufficient for completing the maturation of HSV DNA. Cleavage of parental DNA molecules was observed in neutral sucrose gradients after infection with 3H-thymidine-labeled virions. No evidence for the formation of covalently closed circles during the replication process was obtained. The presence of single-stranded regions in the replicative form of HSV DNA was revealed. Some of the short-pulse (30 sec) labeled HSV DNA (26.1%) was eluted from hydroxylapatite columns with the properties of single-stranded DNA, and 22% of its trichloroacetic acid precipitabüity was susceptible to single-strand specific SI nuclease treatment. Pulse-chase experiments indicated that the life-time of this single-stranded component in nascent DNA was probably not longer than 3 min. A small proportion of single-stranded regions, however, survived for longer periods. Almost all of the newly synthesized short-pulse-labeled HSV DNA exhibited an affinity for nitrocellulose filters. This affinity, which was SI nuclease-sensitive, gradually decreased with prolongation of the time of the chase. After chasing the pulse for 1 h, the attachment of newly synthesized DNA was comparable with virion DNA

ISSN:0300-5526    

DOI:10.1159/000149949

出版商:S. Karger AG    

年代:1976

数据来源: Karger

摘要:

The nucleic acid of infantile gastroenteritis virus was partially characterized. It was found to be a double-stranded RNA having a buoyant density in CS2SO4 of 1.57 g/ml.

ISSN:0300-5526    

DOI:10.1159/000149950

出版商:S. Karger AG    

年代:1976

数据来源: Karger