Apparent dependence of sporulation on synthesis of highly phosphorylated nucleotides in Bacillus subtilis.

Bacillus subtilis contains an enzyme that synthesizes the highly phosphorylated nucleotide adenosine 5',3'(2')-bis(triphosphate), abbreviated p(3)Ap(3). This enzyme can be demonstrated to be present in the cytoplasmic membrane of B. subtilis at all stages of growth and development.

Studies on the control of development: isolation of Bacillus subtilis mutants blocked early in sporulation and defective in synthesis of highly phosphorylated nucleotides.

To test our model on the mechanism of initiation of differentiation in Bacillus subtilis, we tested early blocked (stage 0) sporulation mutants for their ability to synthesize highly phosphorylated nucleotides. We also isolated early blocked asporogenous mutants with the aid of the intercalating drug tilorone. Among all mutants tested we found that the spo0F-bearing strain was unable to synthesize adenosine 3'(2')-triphosphate 5'-triphosphate, pppAppp.

Control of development: role of regulatory nucleotides synthesized by membranes of Bacillus subtilis in initiation of sporulation.

A model explaining the mechanism of initiation of differentiation is presented. It is based on the finding that sporulation in B. subtilis can be induced by the same nutrient deficiencies that also induce the synthesis of highly phosphorylated nucleotides.