Patterns of alkaline phosphatase activity during alternative developmental pathways in the cellular slime mold, Polysphondylium pallidum

1973 ◽  
Vol 51 (2) ◽  
pp. 301-310 ◽  
Author(s):  
Danton H. O'Day ◽  
David W. Francis
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Fruiting Body ◽  
Slime Mold ◽  
Cellular Slime Mold ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Polysphondylium Pallidum ◽  
Cellular Slime

The enzyme alkaline phosphatase (EC 3.1.3.1) was studied during axenic growth, microcyst differentiation and fruiting body formation in the cellular slime mold Polysphondylium pallidum. The enzyme activity decreases during growth and microcyst differentiation but increases during fruiting body formation where it is localized in prestalk cells. Two major isozymes exist for the enzyme and these change qualitatively and quantitatively during multicellular development. Beryllium was found to be a potent inhibitor of the slime mold phosphatase. When beryllium was added to growing cells or cells undergoing fruiting body formation markedly reduced alkaline phosphatase activity was detectable in the cells but growth and development were unaffected. The results are discussed in relation to other work on the cellular slime molds.

Cell differentiation during fruiting body formation in polysphondylium pallidum

1979 ◽  
Vol 35 (1) ◽  
pp. 203-215
Author(s):  
D.H. O'Day
Keyword(s):  
Cell Differentiation ◽  
Fruiting Body ◽  
Neutral Red ◽  
Immunofluorescent Staining ◽  
Stalk Cell ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Polysphondylium Pallidum ◽  
Slime Moulds ◽  
Cellular Slime

The spatial pattern of cellular differentiation was studied during fruiting body formation in Polysphondylium pallidum using 3 different staining methods: Calcofluor fluorescence (cellulose accumulation), neutral red (prestalk cells) and immunofluorescence (prespore cells). Neutral-red staining revealed the existence of a clear prestalk region which becomes evident during aggregation and continues throughout culmination. Immunofluorescent staining demonstrated that cells in the prestalk region gradually lose their presporeness (fluorescence) as they are transformed into differentiated stalk cells. Calcofluor staining revealed that stalk cell differentiation begins during the mid-aggregation phase and that the mode of formation of the main stalk and the side branches differs slightly in morphology. Calcofluor staining also demonstrated the development, during aggregation, of a thick cellulosic girdle with lateral tubular extensions which surround the aggregation streams. The above results are discussed in terms of our present knowledge about differentiation and morphogenesis in cellular slime moulds.

Effects of continuous competition in two species of cellular slime mold: Dictyostelium discoideum and Polysphondylium pallidum

1971 ◽  
Vol 49 (10) ◽  
pp. 1305-1315 ◽  
Author(s):  
Donald J. McQueen
Keyword(s):  
Dictyostelium Discoideum ◽  
Resource Use ◽  
Slime Mold ◽  
Mixed Cultures ◽  
Cellular Slime Mold ◽  
Resource Exploitation ◽  
Fruiting Body Formation ◽  
Polysphondylium Pallidum ◽  
Cellular Slime

Competitively induced population changes were studied in the laboratory. The experimental organisms chosen for the work were two cellular slime mold species: Dictyostelium discoideum and Polysphondylium pallidum. Culturing these organisms on a temperature gradient of 15 °C to 30 °C induces long-term continuous competition for food and space. The organisms respond by changing their rates of resource exploitation and their susceptibility to interference.Before competition, D. discoideum interfered with P. pallidum fruiting, body formation. This effect was not observed after competition. Specifically, when grown alone before competition, P. pallidum fruited from 18° to 37 °C and D. discoideum from 9° to 27 °C. In mixed cultures, before competition. P. pallidum fruited from about 24° to 37 °C and D. discoideum from about 9° to 27 °C. In mixed cultures, after continued competition, P. pallidum fruited from about 20° to 37 °C and D. discoideum from about 9° to 24 °C. There is evidence to suggest that the change is genetic and related to parasexuality in P. pallidum.Rates of resource exploitation (which depend upon spore germination times and amoeba colony expansion rates) also changed. Germination times were unaltered but amoeba colony expansion rates increased.Apparently continued competition resulted in convergence and divergence with respect to resource use. Because P. pallidum gained the ability to fruit in the presence of D. discoideum it converged with respect to resource use. At the same time the two species diverged by increasing rates of resource use over different segments of the temperature range.

A components study of competition in two cellular slime mold species: Dictyostelium discoideum and Polysphondylium pallidum

1971 ◽  
Vol 49 (8) ◽  
pp. 1163-1177 ◽  
Author(s):  
Donald J. McQueen
Keyword(s):  
Dictyostelium Discoideum ◽  
Computer Model ◽  
Fruiting Body ◽  
Slime Mold ◽  
Mixed Cultures ◽  
Cellular Slime Mold ◽  
Fruiting Bodies ◽  
Polysphondylium Pallidum ◽  
Cellular Slime ◽  
Time Required

The mechanics of a short-term interspecific competitive situation for two species of cellular slime mold, Dictyostelium discoideum and Polysphondylium pallidum, were assessed experimentally, modelled mathematically, and linked together to form a computer model, the predictions of which were tested. Five major components in the model were exploitation, toxic interference, effect of physical factors or external forces, availability of resources, and number of potential competitors engaged in exploitation and interference. The exploitation component depended upon time required for spore germination, rate and form of amoeba colony expansion, time required for fruiting body production, and rate and form of fruiting body colony expansion.Both species interfered with the other's ability to form fruiting bodies. In mixed cultures, D. discoideum amoebae divided and consumed food between 9° and 27 °C but did not produce fruiting bodies above 24 °C. In mixed cultures, P. pallidum amoebae divided and consumed food between 18° and 37 °C but did not produce fruiting bodies below 24 °C. Temperature altered the parameter values of all subcomponents contributing to exploitation and interference. Numbers altered interference ability. A computer model for predicting area occupied by fruiting bodies of both species was used to run 324 simulations and was accurate in 90.1% of the cases.

Induction of encystment of Polysphondylium pallidum amoeba

1977 ◽  
Vol 23 (5) ◽  
pp. 518-521 ◽  
Author(s):  
Joseph Lonski ◽  
Nicholas Pesut
Keyword(s):  
Slime Mold ◽  
Cellular Slime Mold ◽  
Polysphondylium Pallidum ◽  
Cellular Slime

The induction of microcyst formation could be triggered in washed amoebae of the cellular slime mold Polysphondylium pallidum (strain-2) by the addition of 2 mM ethionine. Methionine at a ratio of 2:1 with ethionine would inhibit microcyst induction by ethionine. The involvement of polyamines in morphogenesis was also shown. Putrescine (0.02 to 0.1 M) induced the formation of microcysts, whereas spermidine (2 to 4 mM) was capable of causing a fourfold reduction in 0.05 M putrescine-induced microcysts but incapable of inhibiting microcyst induction by 0.08 M putrescine. Glycerol (0.5 M or 0.4 M) was also found to be an effective inducer of microcysts.

scholarly journals Spatial patterns in the fruiting bodies of the cellular slime mold Polysphondylium pallidum

1988 ◽  
Vol 38 (2) ◽  
pp. 73-81 ◽  
Author(s):  
Edward C. Cox ◽  
Fred W. Spiegel ◽  
Gerard Byrne ◽  
James W. McNally ◽  
Leslie Eisenbud
Keyword(s):  
Spatial Patterns ◽  
Slime Mold ◽  
Cellular Slime Mold ◽  
Fruiting Bodies ◽  
Polysphondylium Pallidum ◽  
Cellular Slime

Participation of the cell surfaces in determining the developmental courses in the cellular slime mould Dictyostelium purpureum

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 153-160
Author(s):  
M. Saito ◽  
K. Yanagisawa
Keyword(s):  
Fruiting Body ◽  
Developmental Courses ◽  
Fruiting Bodies ◽  
Cell Surfaces ◽  
Fruiting Body Formation ◽  
Con A ◽  
Body Formation ◽  
Dictyostelium Purpureum ◽  
Cellular Slime ◽  
Type Strains

Dictyostelium purpureum S5 and S6, mating type strains, form fruiting-bodies in a monoclonal culture, but produce macrocysts in a mix culture. The effects of Concanavalin A (Con A) on both fruiting-body formation and macrocyst formation, and changes of Con Amediated cell agglutinability during development were studied. It was found that Con A inhibits macrocyst formation but not fruiting-body formation, and that macrocyst-forming cells are much more susceptible to Con A agglutination than are fruiting-body-forming cells during the aggregation stages. When fruiting-body-forming cells are treated with either trypsin or α-chymotrypsin, their Con A agglutinability is enhanced to the same extent as that of macrocyst-forming cells. It was also found that when S6 cells are treated with proteases they sometimes produce normal macrocysts even in a monoclonal culture. The results obtained in these experiments showed that the surface properties of fruitingbody- forming cells and macrocyst-forming cells are different, and that the cell surface might play an important role in determining the two developmental courses.

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