Analysis of cellular DNA synthesis during polyoma virus infection of mice: acute infection fails to induce cellular DNA synthesis.

It is widely believed that infection with various DNA viruses stimulates quiescent host cells to divide in preparation for virus replication. To examine this issue, the effects of acute polyoma virus infection on cellular DNA synthesis are observed in newborn mice. Using [3H]thymidine incorporation and fluorography of whole mouse sagittal sections, we observed clear, high-resolution images of organ-specific patterns of cellular DNA synthesis in newborn animals. No alteration in these patterns was observed during acute polyoma virus infection. Other methods, including measurements of [3H]thymidine-labeled DNA-specific activities in various tissues and in situ autoradiography, also failed to detect virus-induced alterations in cellular DNA synthesis. These results indicate that newborn animals have high endogenous levels of DNA synthesis and imply that acute polyoma virus infection may not be associated with further induced levels of cellular DNA synthesis.