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Interactions of Polyoma and Mouse DNAs III. Mechanism of Polyoma Pseudovirion Formation

H Türler1

  • 1Department of Molecular Biology, University of Geneva, 1211 Geneva 4, Switzerland.

Journal of Virology
|May 1, 1975
PubMed

Insights

This study reveals that polyoma virus pseudovirion production is inversely related to viral DNA synthesis. Modulating DNA replication can control the proportion of pseudovirions in virus preparations.

Area of Science:

  • Virology
  • Molecular Biology
  • Cell Biology

Background:

  • Polyoma virus infection of mouse kidney cells leads to virion and pseudovirion formation.
  • Understanding the kinetics of viral and host DNA synthesis is crucial for characterizing virus production.

Purpose of the Study:

  • To investigate the intracellular events correlating with polyoma virus virion and pseudovirion production.
  • To determine the factors influencing the proportion of pseudovirions in virus harvests.

Main Methods:

  • Photometric DNA quantitation to track mouse and polyoma DNA synthesis.
  • Analysis of virus harvests at different time points for pseudovirion proportion.
  • Inhibition of DNA synthesis using mitomycin C and synchronized replication experiments.

Main Results:

  • Cellular and viral DNA synthesis rates and timing were closely linked.
  • Fragmented mouse DNA (mouse f-DNA) appeared after DNA replication onset and coincided with progeny virus appearance.
  • Pseudovirion proportion was inversely related to viral DNA synthesis, not mouse f-DNA amount.
  • Partial inhibition of DNA synthesis or specific experimental conditions increased pseudovirion proportion (2-3 fold).
  • Virus from cell monolayers consistently showed higher pseudovirion proportions than from supernatant.

Conclusions:

  • Polyoma virus pseudovirion formation is modulated by viral DNA synthesis levels.
  • Experimental conditions can be manipulated to obtain polyoma virus preparations with varying pseudovirion proportions (10-80%).

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