Isolation and properties of Dictyostelium discoideum mutants temperature-sensitive for spore germination

Roche Institute of Molecular Biology, Nutley, New Jersey 07110, U.S.A. ABSTRACT SUMMARY: A new class of temperature-sensitive mutants defective in spore germination (termed spg ) was isolated and characterized. The mutants germinate normally at 19°C but are defective at 27°C. Analysis of the germination of these mutants at the non-permissive temperature after periods of incubation at 19°C shows that the temperature-sensitive step in germination occurs somewhere between 60 and 120 min at 19°C. Activated mutant spores can be deactivated by incubation at 27°C prior to shift to the permissive temperature. The mutants are not temperature-sensitive for growth or development.