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Intermolecular duplexes formed from polyadenylylated vaccinia virus RNA
Journal of Virology
|April 1, 1979
Summary
Vaccinia virus infection produces double-stranded RNA molecules from cytoplasmic RNA. This RNA exhibits symmetrical transcription across the viral genome, suggesting complex gene expression strategies.
Area of Science:
- Virology
- Molecular Biology
- RNA Biochemistry
Background:
- Vaccinia virus infection alters host cell gene expression.
- Cytoplasmic RNA plays a role in viral replication and protein synthesis.
Purpose of the Study:
- To characterize the double-stranded RNA (dsRNA) formed during vaccinia virus infection.
- To investigate the transcriptional patterns of vaccinia virus RNA.
Main Methods:
- RNA isolation and labeling post-infection.
- Characterization of dsRNA using RNase resistance, density gradient centrifugation, and base composition analysis.
- Hybridization studies with vaccinia virus DNA and restriction endonuclease fragments.
- Analysis of RNA secondary structures using sucrose gradient sedimentation and electron microscopy.
Main Results:
- Approximately 15% of late cytoplasmic polyadenylic acid-containing RNA formed dsRNA structures.
- These dsRNA regions were several hundred to over a thousand base pairs long.
- Denatured dsRNA hybridized to 25% of the vaccinia virus genome, indicating symmetrical transcription.
- dsRNA hybridized to most HindIII restriction fragments, showing symmetrical transcription is not localized.
- Early RNA showed limited self-annealing, but increased upon addition of late RNA, suggesting complementary sequences.
Conclusions:
- Vaccinia virus infection leads to the formation of significant amounts of dsRNA.
- Symmetrical transcription occurs across large portions of the vaccinia virus genome, not just specific regions.
- Late viral RNA contains sequences complementary to early viral RNA, potentially regulating gene expression.