SUMMARY: The P4 variant of Dictyostelium discoideum is characterized by the production of fruiting structures in which the overall proportion of stalk to spore material is increased, relative to the wild type. The altered morphology of the mutant is due to increased sensitivity to cyclic AMP which promotes stalk cell differentiation. In the presence of 10−4m-cyclic AMP the entire population of P4 amoebae forms clumps of stalk cells on the surface of the dialysis membrane support.
Measurement of changes in activity of a range of developmentally-regulated enzymes during the development of P4 in the presence and absence of cyclic AMP has allowed us to identify three classes of enzyme: (i) Those, such as β-glucosidase II, trehalose-6-phosphate synthetase and uridine diphosphogalactose-4-epimerase, which are required for the production of spores, (ii) Enzymes, primarily but perhaps not exclusively, required during stalk cell formation. Typical of these are N-acetylglucosaminidase and alkaline phosphatase. (iii) General enzymes, such as threonine dehydrase, α-mannosidase and uridine diphosphoglucose pyrophosphorylase, which are present in both pre-stalk and pre-spore cells and appear to be necessary for the development of both cell types.
BonnerJ. T.1947; Evidence for the formation of cell aggregates by chemotaxis in the development of the slime mold Dictyostelium discoideum. Journal of Experimental Zoology 106:1–26
BonnerJ. T.1949; The demonstration of acrasin in the later stages of the development of the slime mold Dictyostelium discoideum. Journal of Experimental Zoology 106:259–271
CeccariniC.,
FilosaM. F.1965; Carbohydrate content during development of the slime mold,Dictyostelium discoideum. Journal of Cellular and Comparative Physiology 66:135–140
ChiaW. K.1975; Induction of stalk cell differentiation by cyclic AMP in a susceptible variant of Dictyostelium discoideum. Developmental Biology 44:239–252
DimondR. L.,
BrennerM.,
LoomisW. F.Jun.1973; Mutations affecting N-acetylglucosaminidase in Dictyostelium discoideum. Proceedings of the National Academy of Sciences of the United States of America703356–3360
KonijnT. M.,
BarkleyD. S.,
ChangY. Y.,
BonnerJ. T.1968; Cyclic AMP; a naturally occurring acrasin in the cellular slime molds. American Naturalist 162:225–233
LowryO. H.,
RosebroughN. J.,
FarrA. J.,
RandallR. J.1951; Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry 193:265–275
MaedaY.,
MaedaM.1974; Heterogeneity of the cell population of the cellular slime mold Dictyostelium discoideum before aggregation, and its relation to the subsequent locations of the cells. Experimental Cell Research 84:88–94
NestleM.,
SussmanM.1972; The effect of cyclic-AMP on morphogenesis and enzyme accumulation in Dictyostelium discoideum. Developmental Biology 38:545–554
NewellP. C.1971; The development of the cellular slime mold Dictyostelium discoideum, a model system for the study of cellular differentiation. In Essays in Biochemistry7 pp. 87–126 Edited by
CampbellP. N.,
DickinsF.
London and New York: Academic Press;
NewellP. C.,
EllingsonJ. S.,
SussmanM.1969; Synchrony of enzyme accumulation in a population of differentiating slime mold cells. Biochimica et biophysica acta 177:610–614
NewellP. C.,
FrankeJ.,
SussmanM.1972; Regulation of four functionally related enzymes during shifts in the developmental program of Dictyostelium discoideum. Journal of Molecular Biology 28:136–142
NewellP. C.,
SussmanM.1970; Regulation of enzyme synthesis by slime mold cell assemblies embarked upon alternative developmental programs. Journal of Molecular Biology 49:627–637
O’DayD. H.,
FrancisD. W.1973; Patterns of alkaline phosphatase activity during alternative developmental pathways in the cellular slime mold, Polysphondylium pallidum. Canadian Journal of Zoology 51:301–310
PanP. C.,
BonnerJ. T.,
WednerH. J.,
ParkerC. W.1974; Immunofluorescence evidence for the distribution of cyclic-AMP in cells and cell masses of the cellular slime molds. Proceedings of the National Academy of Sciences of the United States of America711623–1625
SussmanM.,
SussmanR.1969; Patterns of RNA synthesis and of enzyme accumulation and dis-appearance during cellular slime mold cytodifferentiation. Symposia of the Society for General Microbiology 19:403–435
WhiteG. J.,
SussmanM.1963; Polysaccharides involved in slime mold development. II. Water soluble acid mucopolysaccharides. Biochimica et biophysica acta 74:179–187