Mutants of Dictyostelium discoideum defective in spore germination

After activation, wild-type Dictyostelium discoideum spores germinate rapidly and synchronously in phosphate buffer as well as in complex medium. Mutants defective in spore germination were isolated and characterized. These mutants (called grm) did not germinate normally in buffer but did germinate in complex medium in the presence of bacteria. One mutant (grm B) swelled normally, but amoebae were not formed. Another mutant (grm F) swelled and germinated poorly in buffer. The members of the third group of mutants (A, C, D, and E) did not swell or give rise to amoebae in buffer.