Characterization of Virus-like Particles Released from the Hamster Cell Line CHO-K1 After Treatment with 5-Bromodeoxyuridine

• Published in: Journal of general virology Vol. 39; no. 3; pp. 505 - 517
• Main Authors: Manly, K. F, Givens, J. F, Taber, R. L, Zeigel, R. F
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01.06.1978
• Subjects: Animals; Bromodeoxyuridine - pharmacology; Cell Line; Cricetinae; Cyclic AMP - pharmacology; Hydrogen-Ion Concentration; Retroviridae - drug effects; Retroviridae - enzymology; Retroviridae - growth & development; RNA-Directed DNA Polymerase - metabolism; Templates, Genetic; Virus Replication - drug effects
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-39-3-505

Department of Medical Viral Oncology, Roswell Park Memorial Institute, Buffalo, N.Y. 14263, and Graduate Faculty in Microbiology, State University of New York at Buffalo (Roswell Park Division), U.S.A. Simple biochemical measurements have been shown to seriously overestimate the production of C-type particles by Chinese hamster ovary (CHO) cells treated with 5-bromodeoxyuridine. First, most particle-bound DNA polymerase activity released by induced cells was associated with particles which had a different density from C-type particles. Second, when labelled with radioactive uridine, induced CHO cells released small amounts of particle-bound radioactivity. Most of the radioactivity, however, was in DNA and did not sediment with the particle-bound polymerase. Thus, few particles which had RNA, an associated DNA polymerase, and the density typical of RNA tumour viruses were released by BrdUrd-induced CHO cells. In spite of this, some immature C-type forms were observed by electron microscopy in partially purified preparations of DNA polymerase-containing particles from induced CHO cells. Received 27 September 1977; accepted 23 December 1977.