Genetic analysis of the developmental processes during germination and outgrowth of Bacillus subtilis spores with temperature-sensitive mutants.

HE developmental processes in bacteriophage T4 have been studied extenTsively with temperature-sensitive mutants and amber mutants (EDGAR, DENHARDT and EPSTEIN 1964; EDGAR and LIELAUSIS 1964). In Bacillus subtilis, the sporulation process has been studied with asporogenous mutants ( RYTER, SCHAEFFER and IONESCO 1966; TAKAHASHI 1965). We examined the developmental processes involved in the transition from bacterial spores to vegetative cells with temperature-sensitive ( t s ) mutants of B. subtilis. When incubated at a high temperature (48"C), the mutant spores discontinued their development at various stages of outgrowth. The mutant loci were mapped on the chromosome by transformation and transduction techniques. The results will be discussed from the aspect of sequential expression of genetic information during the course of germination and outgrowth of spores.