21.
Morphogenesis of Bittner Virus
- Gay, Frederick W.; Clarke, John K.; Dermott, Evelyn
The morphogenesis of Bittner virus (mouse mammary tumor virus) was studied in sectioned mammary tumor cells. Internal components of the virus (type A particles) were seen being assembled in virus factories close to the nucleus and were also seen forming at the plasma membrane. The particles in virus factories became enveloped by budding through the membrane of cytoplasmic vacuoles which were derived from dilated endoplasmic reticulum. Complete virus particles were liberated from these vacuoles by cell lysis. Particles budding at the plasma membrane were released into intercellular spaces. Maturation of enveloped virus occurred after release, but mature internal components were...
22.
Morphogenesis of Bittner Virus
- Gay, Frederick W.; Clarke, John K.; Dermott, Evelyn
The morphogenesis of Bittner virus (mouse mammary tumor virus) was studied in sectioned mammary tumor cells. Internal components of the virus (type A particles) were seen being assembled in virus factories close to the nucleus and were also seen forming at the plasma membrane. The particles in virus factories became enveloped by budding through the membrane of cytoplasmic vacuoles which were derived from dilated endoplasmic reticulum. Complete virus particles were liberated from these vacuoles by cell lysis. Particles budding at the plasma membrane were released into intercellular spaces. Maturation of enveloped virus occurred after release, but mature internal components were...
23.
Densonucleosis Virus Structural Proteins
- Kelly, D. C.; Moore, N. F.; Spilling, C. R.; Barwise, A. H.; Walker, I. O.
The protein coats of two densonucleosis viruses (types 1 and 2) were examined by a variety of biophysical, biochemical, and serological techniques. The viruses were 24 nm in diameter, contained at least four polypeptides, were remarkably stable to extremes of pH and denaturing agents, and were serologically closely related. The two viruses could, however, be distinguished serologically and by differences in migration of their structural polypeptides. For each virus the top component (i.e., the protein coat minus DNA, found occurring naturally in infections) appeared to have a composition identical to that of the coat of the virus and was a...
24.
Densonucleosis Virus Structural Proteins
- Kelly, D. C.; Moore, N. F.; Spilling, C. R.; Barwise, A. H.; Walker, I. O.
The protein coats of two densonucleosis viruses (types 1 and 2) were examined by a variety of biophysical, biochemical, and serological techniques. The viruses were 24 nm in diameter, contained at least four polypeptides, were remarkably stable to extremes of pH and denaturing agents, and were serologically closely related. The two viruses could, however, be distinguished serologically and by differences in migration of their structural polypeptides. For each virus the top component (i.e., the protein coat minus DNA, found occurring naturally in infections) appeared to have a composition identical to that of the coat of the virus and was a...
25.
Tutorial sobre virus
- Liane Margarida Rockenbach Tarouco
Presenta un tutorial sobre virus de ordenador, para orientar los usuarios que utilizan el ordenador como herramienta de trabajo.
26.
Photoreactivation of a Cytoplasmic Virus
- Pfefferkorn, E. R.; Boyle, Mary K.
Ultraviolet light-inactivated frog virus 3 is efficiently photoreactivated by chick embryo cells. A cellular enzyme is presumably responsible for this repair of viral deoxyribonucleic acid, for the phenomenon is insensitive to an inhibitor of protein synthesis and is not seen in mammalian cells that are known to lack photoreactivating enzyme. Since frog virus 3 is a cytoplasmic virus, functionally significant amounts of photoreactivating enzyme are probably present in the cytoplasm of chick embryo cells.
27.
Photoreactivation of a Cytoplasmic Virus
- Pfefferkorn, E. R.; Boyle, Mary K.
Ultraviolet light-inactivated frog virus 3 is efficiently photoreactivated by chick embryo cells. A cellular enzyme is presumably responsible for this repair of viral deoxyribonucleic acid, for the phenomenon is insensitive to an inhibitor of protein synthesis and is not seen in mammalian cells that are known to lack photoreactivating enzyme. Since frog virus 3 is a cytoplasmic virus, functionally significant amounts of photoreactivating enzyme are probably present in the cytoplasm of chick embryo cells.
28.
Virus Replication in Enucleate Cells: Vesicular Stomatitis Virus and Influenza Virus
- Follett, E. A. C.; Pringle, C. R.; Wunner, W. H.; Skehel, J. J.
The requirement of the presence of a nucleus for the replication of vesicular stomatitis virus and influenza virus has been examined by following the growth and development of these viruses in enucleate BS-C-1 cells. Vesicular stomatitis virus replicates normally in enucleate cells with the rate of production of infectious virus, the amount of virus-specific protein synthesis, and the type of proteins produced being essentially the same in nucleate and enucleate cells. Influenza virus does not replicate in enucleate cells, no virus gene products can be detected, and there is no inhibition of cellular protein synthesis.
29.
Virus Replication in Enucleate Cells: Vesicular Stomatitis Virus and Influenza Virus
- Follett, E. A. C.; Pringle, C. R.; Wunner, W. H.; Skehel, J. J.
The requirement of the presence of a nucleus for the replication of vesicular stomatitis virus and influenza virus has been examined by following the growth and development of these viruses in enucleate BS-C-1 cells. Vesicular stomatitis virus replicates normally in enucleate cells with the rate of production of infectious virus, the amount of virus-specific protein synthesis, and the type of proteins produced being essentially the same in nucleate and enucleate cells. Influenza virus does not replicate in enucleate cells, no virus gene products can be detected, and there is no inhibition of cellular protein synthesis.
30.
Separation of Reticuloendotheliosis Virus from Avian Tumor Viruses
- Maldonado, R. L.; Bose, H. R.
Velocity sedimentation and isopycnic density gradient centrifugation indicate that reticuloendotheliosis virus has a different mass and buoyant density than members of the avian tumor virus group. The group-specific antigen of the avian tumor virus group was not detected in concentrated and purified reticuloendotheliosis virus preparations.
31.
Separation of Reticuloendotheliosis Virus from Avian Tumor Viruses
- Maldonado, R. L.; Bose, H. R.
Velocity sedimentation and isopycnic density gradient centrifugation indicate that reticuloendotheliosis virus has a different mass and buoyant density than members of the avian tumor virus group. The group-specific antigen of the avian tumor virus group was not detected in concentrated and purified reticuloendotheliosis virus preparations.
32.
Infective Virus Substructure from Vesicular Stomatitis Virus
- Brown, F.; Cartwright, B.; Crick, Joan; Smale, C. J.
Treatment of suspensions of vesicular stomatitis virus with Tween-ether results in a rapid and considerable loss of infectivity (ca. 4 logs in 2 min), but the residual infectivity is comparatively stable to further treatment with ether. The infectivity remaining after the short exposure to Tween-ether is not due to virus for the following reasons. (i) It is much less infective for tissue cultures than for mice, whereas the intact virion is equally infective for both hosts. (ii) The residual infectivity is much less stable than virus infectivity in both sucrose and tartrate gradients. (iii) Virus immune serum does not neutralize...
33.
Infective Virus Substructure from Vesicular Stomatitis Virus
- Brown, F.; Cartwright, B.; Crick, Joan; Smale, C. J.
Treatment of suspensions of vesicular stomatitis virus with Tween-ether results in a rapid and considerable loss of infectivity (ca. 4 logs in 2 min), but the residual infectivity is comparatively stable to further treatment with ether. The infectivity remaining after the short exposure to Tween-ether is not due to virus for the following reasons. (i) It is much less infective for tissue cultures than for mice, whereas the intact virion is equally infective for both hosts. (ii) The residual infectivity is much less stable than virus infectivity in both sucrose and tartrate gradients. (iii) Virus immune serum does not neutralize...
34.
Morphogenesis of Aura Virus
- Lascano, Eduardo F.; Berría, María I.; Oro, Julio G. Barrera
Aura virus, a member of the Western equine-encephalitis-Whataroa subgroup of group A arboviruses, was studied by electron microscopy in suckling mouse brain and chick embryo cultured cells. Virus precursors, budding particles, and complete virus particles were first detected 10 hr after infection in chick embryo cells and 24 hr after inoculation in mouse brain. Virus precursors were generally seen aligned along cytomembranes, and were less frequently seen closely associated with viroplasm-like foci, tubular aggregates, or scattered in the cytoplasmic matrix without an apparent connection to any other structure. The assembly of mature virus was observed to take place by a...
35.
Morphogenesis of Aura Virus
- Lascano, Eduardo F.; Berría, María I.; Oro, Julio G. Barrera
Aura virus, a member of the Western equine-encephalitis-Whataroa subgroup of group A arboviruses, was studied by electron microscopy in suckling mouse brain and chick embryo cultured cells. Virus precursors, budding particles, and complete virus particles were first detected 10 hr after infection in chick embryo cells and 24 hr after inoculation in mouse brain. Virus precursors were generally seen aligned along cytomembranes, and were less frequently seen closely associated with viroplasm-like foci, tubular aggregates, or scattered in the cytoplasmic matrix without an apparent connection to any other structure. The assembly of mature virus was observed to take place by a...
36.
Ultrastructure of Lymphocystis Virus
- Zwillenberg, Lutz O.; Wolf, Ken
Lymphocystis virus obtained from bluegills (Lepomis macrochirus) was cultured in the permanent bluegill cell line BF-2 and examined by electron microscopy in ultrathin sections of cell cultures and in negative-contrast preparations from cells and from centrifuged culture medium. According to negative-contrast preparations, the icosahedral virions have an overall diameter close to but not exceeding 300 m?. Delicate filaments seem to issue from the vertices. In collapsed virions, an ordered array of morphological units was seen. Positively contrasted virions in ultrathin sections show a shell with three dark (heavy metal-stained) layers alternating with and separated by two clear layers. The acquisition...
37.
Ultrastructure of Lymphocystis Virus
- Zwillenberg, Lutz O.; Wolf, Ken
Lymphocystis virus obtained from bluegills (Lepomis macrochirus) was cultured in the permanent bluegill cell line BF-2 and examined by electron microscopy in ultrathin sections of cell cultures and in negative-contrast preparations from cells and from centrifuged culture medium. According to negative-contrast preparations, the icosahedral virions have an overall diameter close to but not exceeding 300 m?. Delicate filaments seem to issue from the vertices. In collapsed virions, an ordered array of morphological units was seen. Positively contrasted virions in ultrathin sections show a shell with three dark (heavy metal-stained) layers alternating with and separated by two clear layers. The acquisition...
38.
Lack of Sequence Homology Between the 70S RNA of Various RNA Tumor Viruses and the DNA of Simian Virus 40 or Polyoma Virus
- Gallagher, Robert E.; Levine, Arthur S.; Gillespie, David H.; Gallo, Robert C.
No significant hybridization was detected of DNA from simian virus 40 or polyoma virus, and of 70S RNA from avian myeloblastosis virus, murine leukemia virus (Rauscher), murine sarcoma virus (Kirsten), RD-114B, simian sarcoma virus-1, or Mason-Pfizer virus.
39.
Lack of Sequence Homology Between the 70S RNA of Various RNA Tumor Viruses and the DNA of Simian Virus 40 or Polyoma Virus
- Gallagher, Robert E.; Levine, Arthur S.; Gillespie, David H.; Gallo, Robert C.
No significant hybridization was detected of DNA from simian virus 40 or polyoma virus, and of 70S RNA from avian myeloblastosis virus, murine leukemia virus (Rauscher), murine sarcoma virus (Kirsten), RD-114B, simian sarcoma virus-1, or Mason-Pfizer virus.
40.
Infectious Rous Sarcoma Virus and Reticuloendotheliosis Virus DNAs
- Cooper, Geoffrey M.; Temin, Howard M.
An efficient and quantitative assay for infectious Rous sarcoma virus and reticuloendotheliosis virus DNAs is described. The specific infectivities of viral DNA corresponded to one infectious unit per 105 to 106 viral DNA molecules. Infection with viral DNA followed one-hit kinetics. The minimal size of infectious Rous sarcoma virus DNA was approximately 6 million daltons, whereas the minimal size of infectious reticuloendotheliosis virus DNA was larger, 10 to 20 million daltons.
