PMID: 5630381Apr 1, 1967

Cytoplasmic fractions associated with Semliki Forest virus ribonucleic acid replication

Journal of Virology
R M Friedman, I K Berezesky


When actinomycin D-treated chick fibroblasts were labeled with (3)H-uridine for varying periods during the log phase of Semliki Forest virus infection, radioactivity was found associated with different cytoplasmic fractions. After a 1-min period of labeling, it appeared in a large cytoplasmic structure which was seen in electron micrographs of infected cells. Sediments of sucrose density gradients of cytoplasmic extracts of these cells also contained these structures. Three forms of viral ribonucleic acid (RNA) were associated with this cytoplasmic structure: a ribonuclease-sensitive 42S form identical to the RNA of the mature virus, a ribonuclease-sensitive 26S form, and a ribonuclease-resistant 20S form. After a 5- to 10-min labeling period, radioactivity was associated with a ribonuclease-sensitive 65S cytoplasmic fraction which contained only the 26S RNA form. Finally, after a 1-hr labeling period, a 140S ribonuclease-resistant particle was the most prominent radioactive structure in the cytoplasm. This particle contained only 42S viral RNA. Negative-contrast electron micrographs of the 140S particle and the virion demonstrated structural differences between them. The base compositions of the 42S and 26S viral RNA forms wer...Continue Reading


Feb 1, 1974·Acta Pathologica Et Microbiologica Scandinavica. Section B: Microbiology and Immunology·H Söderlund, L Kääriäinen
Jan 1, 1971·Archiv für die gesamte Virusforschung·L V UryvayevA F Bykovsky
Jul 1, 1971·Japanese Journal of Microbiology·C Nishimura, H Tsukeda
Jan 1, 1992·Archives of Virology·J Y LeeD S Bowden
Jan 1, 1972·Archiv für die gesamte Virusforschung·Y Nagatomo
Jan 1, 1972·Acta Pathologica Et Microbiologica Scandinavica. Section B: Microbiology and Immunology·C H von Bonsdorff
Jan 1, 1973·Archiv für die gesamte Virusforschung·C Gil-FernándezM Rubio-Huertos

Related Concepts

Centrifugation, Density Gradient
Chick Embryo
Electron Microscopy
Phosphorus Isotopes
RNA, Viral
Semliki forest virus

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