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Radiobiological and Biochemical Investigations of Polyoma Virus-Cell Interactions


Benjamin, Thomas Livingston (1966) Radiobiological and Biochemical Investigations of Polyoma Virus-Cell Interactions. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/BBKM-MN37.


The cytolytic interaction of Polyoma virus with mouse embryo cells has been studied by radiobiological methods known to distinguish temperate from virulent bacteriophage. No evidence for "temperate" properties of Polyoma was found. During the course of these studies, it was observed that the curve of inactivation of Polyoma virus by ultraviolet light had two components - a more sensitive one at low doses, and a less sensitive one at higher doses. Virus which survives a low dose has an eclipse period similar to that of unirradiated virus, while virus surviving higher doses shows a significantly longer eclipse period. If Puromycin is present during the early part of the eclipse period, the survival curve becomes a single exponential with the sensitivity of the less sensitive component. These results suggest a repair mechanism in mouse cells which operates more effectively if virus development is delayed.

A comparison of the rates of inactivation of the cytolytic and transforming abilities of Polyoma by ultraviolet light, X-rays, nitrous acid treatment, or the decay of incorporated P32, showed that the transforming ability has a target size roughly 60% of that of the plaque-forming ability. It is thus concluded that only a fraction of the viral genes are necessary for causing transformation.

The appearance of virus-specific RNA in productively infected mouse kidney cells has been followed by means of hybridization between pulse-labelled RNA from the infected cells and the purified virus DNA. The results show a sharp increase in the amount of virus-specific RNA around the time of virus DNA synthesis. The presence of a small amount of virus-specific RNA in virus-free transformed cells has also been shown. This result offers strong evidence for the persistence of at least part of the viral genome in transformed cells.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Virology and Biochemistry)
Degree Grantor:California Institute of Technology
Major Option:Biology
Minor Option:Biochemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Dulbecco, Renato (advisor)
  • Attardi, Giuseppe (advisor)
  • Vinograd, Jerome Rubin (advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1965
Funding AgencyGrant Number
United States Public Health Service5 T1-GM-86
Record Number:CaltechTHESIS:09182015-084245868
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:9160
Deposited By: Benjamin Perez
Deposited On:18 Sep 2015 16:06
Last Modified:27 Feb 2024 20:27

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