| Abstract: | Formation of viral closed circular supercoiled DNA duplexes and production of progeny virus were both inhibited in cultured mouse cells treated with cycloheximide in the first 4 h of type C retrovirus infection. With different doses of cycloheximide to cause different degrees of inhibition, the number of viral supercoiled DNA duplexes detected in the cells at 11 h showed an apparent correlation with the amount of progeny virus produced in the 12- to 22-h period of infection. A slight accumulation of the full-genome linear duplex and an open circular duplex of viral DNA intermediate was observed in the cycloheximide-treated cells. Cycloheximide given to the cells during the time of conversion of viral DNA from linear to supercoiled duplex forms (6 to 11 h after virus inoculation) did not inhibit the conversion. These kinetic data suggest that a cycloheximide-sensitive metabolic process, probably early viral protein synthesis, is required for retrovirus replication and supercoiled viral DNA formation in the cell. |
