This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pritchard, C. Articles by Stout, E. R. Search for Related Content PubMed PubMed Citation Articles by Pritchard, C. Articles by Stout, E. R.

 Previous Article  |  Next Article 

J Virol. 1978 October; 28(1): 20-27
Copyright © 1978 American Society for Microbiology. All Rights Reserved.

Replication of Nondefective Parvoviruses: Lack of a Virion-Associated DNA Polymerase

¹ Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061

ABSTRACT

We have examined four of the nondefective parvoviruses for an associated DNA polymerase. Virions were purified from neuraminidase-treated infected-cell lysates by isopycnic centrifugation in CsCl or from infected cell material by CaCl₂ precipitation and centrifugation through sucrose into CsCl. Preparations of bovine parvovirus or Kilham rat virus obtained by the former procedure contained DNA polymerase activity but were not free of contaminating cellular proteins. The latter method produced viral preparations free of contaminating cellular proteins, and no DNA polymerase activity was detected in light infectious particles of H-1, LuIII, bovine parvovirus, or Kilham rat virus. Examination of levels of each cellular DNA polymerase in these preparations from each step of both purification procedures revealed that DNA polymerase ß had a greater tendency to copurify with bovine parvovirus and Kilham rat virus than did DNA polymerases or . Disruption of infectious virions obtained by the second purification method with detergents and sonic treatment did not result in the detection of a DNA polymerase activity. The biological activity and purity of each of the four different viruses obtained by the latter procedure were determined by hemagglutination and infectivity assays, polyacrylamide gel electrophoresis, and electron microscopy. In each case, the virions banding at a density of 1.39 to 1.41 g/cm² in CsCl were infectious and contained only the virion structural proteins. DNA polymerase activity was not detected in any of these preparations, and we have concluded that a virion-associated DNA polymerase is not required for productive infection with the nondefective parvoviruses.