Induction of Cellular Morphogenesis in Myxococcus Xanthus. II. Macromolecular Synthesis and Mechanism of Inducer Action

Sadler, William (University of Minnesota, Minneapolis), and Martin Dworkin. Induction of cellular morphogenesis in Myxococcus xanthus. II. Macromolecular synthesis and mechanism of inducer action. J. Bacteriol. 91:1520-1525. 1966.-Net changes in ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and protein syntheses in cells of Myxococcus xanthus during induced, synchronous conversion to microcysts are described. The net synthesis of all three macromolecules was temporarily halted for a brief period during the initiation of shape change. Synthesis then resumed and leveled off when refractile microcysts began to appear. The conversion was completely sensitive, throughout the process, to low concentrations of chloramphenicol and actinomycin D. The uptake of amino acids and uracil was linear throughout the conversion, suggesting that the plateaus in rates of net synthesis of protein and RNA represented a period of rapid turnover. The most effective inducers of microcyst formation were fully saturated aliphatic compounds containing 2 to 4 carbon atoms and at least one primary or secondary alcohol group. Studies with labeled inducer indicated that the inducer need not be taken up by the cells to be effective, and probably interacts with some peripheral structure of the cell. The possibility that induction involves an alteration of a membrane-DNA complex is discussed.