Studies on the Cytopathic Effects of Newcastle Disease Virus: Metabolic Requirements

Abstract
Kirsten sarcoma virus induces foci of morphologically altered cells in rat, mouse, and human cells in tissue culture. The kirsten sarcoma virus stock contains two viruses; one forming foci and the other plaques on XC cells. The sarcoma virus particle transforms cells in the absence of murine leukaemia virus but requires murine leukaemia virus for its replication. The high susceptibility of human cells to transformation by kirsten sarcoma virus is related to a function provided to the sarcoma virus by murine leukaemia virus. A large number of kirsten sarcoma virus-transformed mouse and rat cell foci has been isolated, and from these many non-producer clonal lines have been derived and characterized.