The fate of polyoma virus in hamster, mouse, and human cells

The interactions of hamster, mouse, and human tissue culture cells with P 32-labeled polyoma virus were studied. Approximately one-third of the radioactive material that became firmly attached and probably entered the cytoplasm of the cells was degraded within the 24 hours following infection and appeared in the medium as acid-soluble material. Most of the radioactivity remaining acid insoluble retained the physical characteristics of intact virus particles and was lost from the cytoplasm (1) by rejection into the medium and (2) by association with the nuclear fraction. In hamster cells the nuclear-associated radioactivity remained constant for at least 4 and probably 6 days, while the cells were actively dividing.