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Biomedical subjects

H Okabe

Publications and source records attributed to H Okabe.

At least 577 records · Page 32Linked to original sources
PubMed1974

Specificity of the DNA product of RNA-dependent DNA polymerase in type C viruses: 3. Analysis of viruses derived from Syrian hamsters.

DNA transcripts were prepared from three related viruses of hamster and analyzed by interviral hybridization and by reaction with cellular DNA. A virus (G-HaLV), isolated from a dimethylbenzanthraceneinduced tumor cell in Graffi hamsters, contained nucleic acid sequences highly specific for hamster cell DNA and did not react with mouse cell DNA nor did its transcript show homology (<5%) with mouse or rat viral RNAs. The hamster-specific sarcoma virus, B-34, isolated by Bassin and coworkers from tumors induced by the Harvey strain of murine sarcoma virus, contained mouse-, hamster-, and possibly rat-specific sequences. B-34 transcripts were predominantly mouse-specific. GLOH(-), a lymphomagenic virus derived by dilution beyond the transforming endpoint of a hamster-specific sarcoma virus obtained from tumors induced by the Gross pseudotype of murine sarcoma virus, also contained hamster- and mouse-specific sequences. Only a portion of its hamster sequence (about 50%) was shared with B-34 and G-HaLV viruses. As expected, transcripts of GLOH(-) virus were reactive with mouse and hamster cellular DNA.

Animals↗
PubMed1973

Specificity of the DNA product of RNA-dependent DNA polymerase in type C viruses. II. Quantitative analysis.

A number of mammalian Type C viruses were analyzed for relatedness by the technique of DNA.RNA hybridization. Viral DNAs were prepared in single-stranded form from complexes with 70S viral RNA formed during endogenous polymerase reactions. Extent of hybridization was assayed with the single-strand nuclease (S-1) from Aspergillus oryzae. Results obtained indicated a high degree of viral specificity, with significant cross-reactions being observed only with viruses obtained from within a species, as in the case of mouse and cat viruses, or in the special case of woolly monkey-gibbon comparisons. Comparisons of RD-114 virus, recently determined to be of feline origin, and conventional feline Type C viruses (FeLV), revealed minimal relatedness, especially when feline virus was grown on human cells, thus indicating the possibility of coexistence of greatly disparate Type C viruses within one species. A rat-specific virus, recovered from tumors induced by murine sarcoma virus, was found to contain genetic material common to both the original mouse virus and viruses indigenous to the rat, even though only rat-specific proteins have been detected during infection by this virus.

Animals↗
PubMed1973

RD 114 virus-specific sequences in feline cellular RNA: detection and characterization.

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 70S 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 35S and 18S, whereas in RD-114 cells virus-specific RNA is quite heterogeneous in size.

Animals↗