Patterning of development in Dictyostelium discoideum: factors regulating growth, differentiation, spore dormancy, and germination

Abstract

Cellular communication dictates all stages of growth and development in the cellular slime molds. Dictyostelium discoideum utilizes a number of signal molecules for cell-to-cell communication, including growth and density factors, cAMP, ammonia, differentiation-inducing factor, discadenine, and spore autoactivator. A source and sink model is presented in which the assimilation of ammonia plays a major role in determining cell fate and pattern formation. This model emphasizes a recycling of ammonia by prespore cells, the accumulation of free hydrophilic and neutral amino acids, and their incorporation into proteins associated with sporulation and (or) germination. If spore cAMP signalling is regulated by the relative concentrations of discadenine and autoactivator, and its disruption triggers the initiation of the spore germination cascade, then the accumulation of intracellular cAMP may be necessary for both sporulation and dormancy maintenance.

Combining biochemical network motifs within an ARN-agent control system

“…These experiments are used to compare the behaviors and aggregation time with the values for real Dd in the literature. In experiments AG8-9 and AFG8 mound formation completes within the range reported for the actual organism of 9-13 hours [14,16]. These results are comparable with other work.…”

Applications and design of cooperative multi-agent ARN-based systems

“…In experiments AG8-9 and AFG8 mound formation completes within the range reported for the actual organism of 9-13 hours (Cotter et al 1992;Becker et al 2010). …”

Transcriptional Transitions during Dictyostelium Spore Germination

“…The changes include both an increase and a decrease in mRNA abundance, suggesting that both mRNA degradation and gene expression events must take place. These results were somewhat unexpected because the major morphological changes occur later, during spore swelling and during amoeba emergence; therefore, the initiation of spore swelling had been considered a less complex event (9,11). Moreover, our results suggest that germination is accompanied by two other large transitions, one immediately after induction and the other during emergence.…”

“…Group III contains many signal transduction genes that are induced during early germination, an interesting finding in the context of the regulation of germination. Previous studies showed that spore germination is regulated by two mechanisms (11). The germination inhibitor discadenine, a modified adenine nucleotide, is a potent inhibitor of spore germination (1).…”