Patterning of development in Dictyostelium discoideum: factors regulating growth, differentiation, spore dormancy, and germination.
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.
Cotter
D A
DA
Department of Biology, University of Windsor, Ont., Canada.
Sands
T W
TW
Virdy
K J
KJ
North
M J
MJ
Klein
G
G
Satre
M
M
D000225:Adenine / Q000031:analogs & derivatives / Q000502:physiology; D000595:Amino Acid Sequence; D000641:Ammonia / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D000242:Cyclic AMP / Q000502:physiology; D004023:Dictyostelium / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D005656:Fungal Proteins / Q000378:metabolism; D006133:Growth Substances / Q000378:metabolism; D006588:Hexanones / Q000378:metabolism; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000502:physiology; D013172:Spores, Fungal / Q000502:physiology
D005656:Fungal Proteins; D006133:Growth Substances; D006588:Hexanones; C053433:1-((3,5-dichloro)-2,6-dihydroxy-4-methoxyphenyl)-1-hexanone; C017263:discadenine; D000641:Ammonia; D000242:Cyclic AMP; D000225:Adenine