RT Journal Article SR Electronic(1) A1 Bacon, C. W. A1 Sussman, A. S.YR 1973 T1 Effects of the Self-Inhibitor of Dictyostelium discoideum on Spore Metabolism JF Microbiology, VO 76 IS 2 SP 331 OP 344 DO https://doi.org/10.1099/00221287-76-2-331 PB Microbiology Society, SN 1465-2080, AB Summary: The effects of the self-inhibitor, N,N-dimethylguanosine, on the metabolism of spores of Dictyostelium discoideum were investigated. It is concluded that since both self-inhibited and activated spores had similar initial Q O2 values, the site of action of the self-inhibitor was not on respiratory metabolism. Incorporation of [U14C]glucose revealed that organic acids and amino acids accumulated in self-inhibited spores and that protein synthesis was inhibited. Succinic acid accumulated only when the activated self-inhibited spores became anaerobic so its accumulation was not directly related to self-inhibition. Phenylalanine, methionine and tryptophan were absent in dormant spores but appeared after heat-activation and accumulated in self-inhibited spores. The accumulation of amino acids was related to the inability of self-inhibited spores to synthesize protein. In vivo analysis showed that protein synthesis began early in spore germination and that the self-inhibitor immediately arrested this process when added to activated spores and slowed it when added to germinating spores. No effect of self-inhibitor on RNA synthesis during germination was detected. Thus, we conclude that the self-inhibitor, a methylated base of guanine, regulated spore germination by preventing the synthesis of protein necessary for subsequent development., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-76-2-331