Rat mutant cells showing temperature sensitivity for transformation by wild-type Moloney murine sarcoma virus

To clarify the cellular target(s) of onc gene products of Moloney murine sarcoma virus (Mo-MSV), we isolated seven mutant cells that exhibit temperature sensitivity for transformation by wild-type Mo-MSV from Fischer rat cell line. Five strains of these mutant cells showed normal virus production at the nonpermissive temperature when infected with Mo-MSV, suggesting that viral replication is not affected by these cellular mutations. Four of these mutants were also temperature sensitive (ts) for transformation by Kirsten murine sarcoma virus (Ki-MSV), whereas the other three mutants were not ts, suggesting that our mutants isolated with Mo-MSV can be divided into two classes as regards temperature sensitivity to transformation by Ki-MSV.