title: Induction of G1- cells at high frequency.
abstract: Experimental conditions are reported on the induction of G1- cells at high frequency by ultraviolet irradiation of temperature-sensitive cells arrested in G1 phase at the restricted temperature. Neither the wild type cells of Balb/C-3T3 nor the temperature-sensitive derivative of tsA83 grown at the permissive temperature could be 'mutated' under similar conditions. One such 'mutant' (RI8) was 'inducible' from a G1+ phenotype at 33 degrees C to G1- state at 38 degrees C within one cell generation time. The 'inducible' property of RI8 from G1+ to G1- lends support to the theory that the duration of the G1+ phenotype is determined by the level of precursors for DNA synthesis. Since the G1- variants were isolated from revertants, the frequency of 'mutagenesis' appeared to be artifically high.
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002460:Cell Line; D003584:Cytological Techniques; D004247:DNA / Q000378:metabolism*; D014644:Genetic Variation; D006358:Hot Temperature; D007399:Interphase; D007668:Kidney; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D014466:Ultraviolet Rays
chemical_list: D004247:DNA