Behavior of tissue culture cells infected with polyoma virus

Infection of tissue culture cells with the oncogenic polyoma virus, or its temperature-sensitive mutant Ts-a, causes several changes other than the previously known induction of cellular DNA synthesis. Cellular movement, survival, and mitotic rate are enhanced in low-serum medium, and morphology is changed; the cellular growth parameters, wound serum requirement, and topoinhibition are markedly decreased. The changes are similar to those that occur in cell transformation and are produced by viral functions known to be expressed in transformed cells. Clues as to the possible mechanisms of all these changes are analyzed and a possible mechanism is discussed.