Regulation of development in Myxococcus xanthus: effect of 3':5'-cyclic AMP, ADP, and nutrition.

An assay was developed to study the regulation of fruiting in Myxococcus xanthus. The nucleotides, adenosine 3':5'-cyclic monophosphate (cyclic AMP) and adenosine diphosphate (ADP), were found to greatly stimulate fruiting under the assay conditions. Very sharp concentration optima were observed. Even under conditions of starvation, these nucleotides greatly increased the number of aggregation sites. Nutrition was found to influence fruiting body morphology. The effect of amino acids on the nucleotide stimulation of fruiting was studied under our assay conditions. L-Methionine and L-isoleucine (1 mM) completely blocked either L-threonine or D,L-diaminopimelic acid synergistically enhanced the amount of fruiting in the presence of these nucleotides. The data presented suggest the existence of differentiation-related regulatory compounds in M. xanthus.