Abstract
Supercoiled DNA molecules purified from mouse cells infected with high-multiplicity-passaged polyoma virus has a broader size distribution and sediments more slowly than DNA derived from low-multiplicity-passaged virus. The shorter DNA molecules are predominately noninfectious. Virus populations containing distinct size classes of defective virus DNA were isolated by growing virus from single cells infected by a defective and nondefective helper virus (infectious center). This technique probably results in the cloning of defective virus particles. By applying the infectious center method to DNA from various fractions of sucrose gradients it has been possible to obtain shorter circular DNA molecules ranging in size from 50 to 95% of the unit-length polyoma DNA molecule. The shorter molecules in any one preparation are homogeneous in size. This class size is retained upon repeated passage of crude viral lysates at high multiplicity. Thus far, all the purified shorter DNA molecules tested appear to be noninfectious and largely resistant to cleavage by the R1 restriction enzyme. Some of the purified defective molecules have been found to interfere with the production of infectious virus upon co-infection with unit-length infectious polyoma DNA.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Blackstein M. E., Stanners C. P., Farmilo A. J. Heterogeneity of polyoma virus DNA: isolation and characterization of non-infectious small supercoiled molecules. J Mol Biol. 1969 Jun 14;42(2):301–313. doi: 10.1016/0022-2836(69)90045-x. [DOI] [PubMed] [Google Scholar]
- Cuzin F., Vogt M., Dieckmann M., Berg P. Induction of virus multiplication in 3T3 cells transformed by a thermosensitive mutant of polyoma virus. II. Formation of oligometric polyoma DNA molecules. J Mol Biol. 1970 Feb 14;47(3):317–333. doi: 10.1016/0022-2836(70)90305-0. [DOI] [PubMed] [Google Scholar]
- FRIED M. ISOLATION OF TEMPERATURE-SENSITIVE MUTANTS OF POLYOMA VIRUS. Virology. 1965 Apr;25:669–671. doi: 10.1016/0042-6822(65)90098-x. [DOI] [PubMed] [Google Scholar]
- Fried M. Characterization of a temperature-sensitive mutant of polyoma virus. Virology. 1970 Mar;40(3):605–617. doi: 10.1016/0042-6822(70)90205-9. [DOI] [PubMed] [Google Scholar]
- Hirt B. Selective extraction of polyoma DNA from infected mouse cell cultures. J Mol Biol. 1967 Jun 14;26(2):365–369. doi: 10.1016/0022-2836(67)90307-5. [DOI] [PubMed] [Google Scholar]
- Radloff R., Bauer W., Vinograd J. A dye-buoyant-density method for the detection and isolation of closed circular duplex DNA: the closed circular DNA in HeLa cells. Proc Natl Acad Sci U S A. 1967 May;57(5):1514–1521. doi: 10.1073/pnas.57.5.1514. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tai H. T., Smith C. A., Sharp P. A., Vinograd J. Sequence heterogeneity in closed simian virus 40 deoxyribonucleic acid. J Virol. 1972 Feb;9(2):317–325. doi: 10.1128/jvi.9.2.317-325.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thorne H. V. Detection of size heterogeneity in the supercoiled fraction of Polyoma virus DNA. J Mol Biol. 1968 Jul 14;35(1):215–226. doi: 10.1016/s0022-2836(68)80049-x. [DOI] [PubMed] [Google Scholar]
- Thorne H. V., Evans J., Warden D. Detection of biologically defective molecules in component I of polyoma virus DNA. Nature. 1968 Aug 17;219(5155):728–730. doi: 10.1038/219728a0. [DOI] [PubMed] [Google Scholar]
- Vogt M. Induction of virus multiplication in 3T3 cells transformed by a thermosensitive mutant of polyoma virus. I. Isolation and characterization of Ts-a-3T3 cells. J Mol Biol. 1970 Feb 14;47(3):307–316. doi: 10.1016/0022-2836(70)90304-9. [DOI] [PubMed] [Google Scholar]
- Yoshiike K., Furuno A. Heterogeneous DNof simian virus 40. Fed Proc. 1969 Nov-Dec;28(6):1899–1903. [PubMed] [Google Scholar]
- Yoshiike K. Studies on DNA from low-density particles of SV40. I. Heterogeneous defective virions produced by successive undiluted passages. Virology. 1968 Mar;34(3):391–401. doi: 10.1016/0042-6822(68)90059-7. [DOI] [PubMed] [Google Scholar]
- Yoshike K. Studies on DNA from low-density particles of SV40. II. Noninfectious virions associated with a large-plaque variant. Virology. 1968 Mar;34(3):402–409. doi: 10.1016/0042-6822(68)90060-3. [DOI] [PubMed] [Google Scholar]