Isolation and Characterization of Temperature-sensitive Mutants of Abelson Murine Leukaemia Virus that Exhibit Dissociation among Morphological Transformation, Soft Agar Colony-forming Ability and Tyrosine Kinase Activity

Seven temperature-sensitive (ts) mutants of Abelson murine leukaemia virus (A-MuLV) were isolated on the basis of the temperature dependence of their soft agar colony-forming ability. These seven ts mutants exhibited similar characteristics and were not ts for morphological transformation and autophosphorylation of P120^gag-abl protein. The dissociation of the properties of morphology, soft agar colony formation and tyrosine kinase activity might suggest that the v-abl product has more than one primary intracellular target.