scholarly journals Enzyme synthesis in myxamoebae of the cellular slime mould Dictyostelium discoideum during growth in axenic culture

1972 ◽  
Vol 126 (3) ◽  
pp. 601-608 ◽  
Author(s):  
J. M. Ashworth ◽  
J. Quance
Keyword(s):  
Dictyostelium Discoideum ◽  
Axenic Culture ◽  
Growth Cycle ◽  
Enzyme Synthesis ◽  
Intracellular Location ◽  
Cellular Slime Mould ◽  
Slime Mould ◽  
Intracellular Fraction ◽  
Cellular Slime ◽  
Specific Activities

1. The specific activities of β-N-acetylglucosaminidase, acid phosphatase, α-mannosidase, β-glucosidase, UDP-glucose pyrophosphorylase and alkaline phosphatase have been determined in myxamoebae of the cellular slime mould Dictyostelium discoideum Ax-2 grown on different media and in different phases of the growth cycle. 2. Variations in enzymic composition occur with changes in growth medium and phase of the growth cycle. 3. The intracellular location of the enzymes studied has been determined. 4. Two enzymes, β-N-acetylglucosaminidase and α-mannosidase, are not only synthesized preferentially as the myxamoebae enter the stationary phase of growth but they are also excreted. The excretion process appears to be specific, because other enzymes that occur in the same intracellular fraction are not excreted.

scholarly journals Growth of myxamoebae of the cellular slime mould Dictyostelium discoideum in axenic culture

1970 ◽  
Vol 119 (2) ◽  
pp. 171-174 ◽  
Author(s):  
D. J. Watts ◽  
J. M. Ashworth
Keyword(s):  
Cell Differentiation ◽  
Dictyostelium Discoideum ◽  
Axenic Culture ◽  
Axenic Medium ◽  
Cellular Slime Mould ◽  
Slime Mould ◽  
Solid Media ◽  
Cellular Slime

1. A simple axenic medium suitable for the growth of the myxamoebae of a strain of the cellular slime mould Dictyostelium discoideum is described. 2. Procedures suitable for the growth of this strain in liquid and on solid media are described. 3. Conditions suitable for initiating the cell differentiation of myxamoebae grown axenically are described.

scholarly journals Enzyme synthesis in the cellular slime mould Dictyostelium discoideum during the differentiation of myxamoebae grown axenically

1972 ◽  
Vol 126 (3) ◽  
pp. 609-615 ◽  
Author(s):  
J. Quance ◽  
J. M. Ashworth
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Cell Differentiation ◽  
Dictyostelium Discoideum ◽  
Specific Activity ◽  
Enzyme Synthesis ◽  
Cellular Slime Mould ◽  
Slime Mould ◽  
Cellular Slime ◽  
Developmental Programme

1. Myxamoebae of the cellular slime mould Dictyostelium discoideum Ax-2 were grown on different media, and were harvested either in the stationary or exponential phases of the growth cycle to yield samples of myxamoebae differing in enzymic composition. 2. Morphogenesis and cell differentiation phenomena in D. discoideum appear to be similar in myxamoebae grown and harvested under different conditions. 3. The specific activity of the enzymes β-N-acetylglucosaminidase, acid phosphatase, α-mannosidase, β-glucosidase and alkaline phosphatase have been determined during cell differentiation of myxamoebae grown and harvested under different conditions. 4. The pattern of synthesis of these enzymes, all of which have been claimed to be part of the ‘developmental programme’, either remains unaffected despite the origin of the myxamoebae (alkaline phosphatase) or is qualitatively similar but quantitatively affected (acid phosphatase, β-glucosidase) or is both qualitatively and quantitatively affected by changes in the myxamoebae (α-mannosidase, β-N-acetylglucosaminidase). 5. The implications of these results for the concept of a ‘developmental programme‘ are discussed.

scholarly journals The isolation and characterization of lysosomal particles from myxamoebae of the cellular slime mould Dictyostelium discoideum

1970 ◽  
Vol 118 (3) ◽  
pp. 505-512 ◽  
Author(s):  
Edith Wiener ◽  
J. M. Ashworth
Keyword(s):  
Cell Differentiation ◽  
Dictyostelium Discoideum ◽  
Lysosomal Enzyme ◽  
Lysosomal Enzymes ◽  
Cellular Slime Mould ◽  
Slime Mould ◽  
Isolation And Characterization ◽  
Cellular Slime ◽  
Specific Activities

1. The myxamoebae of the cellular slime mould Dictyostelium discoideum possess several typically lysosomal enzyme activities. 2. These enzymes are present in the cell in association and in a lysosome-like particle. 3. The lysosomes of myxamoebae grown axenically have a different enzymic composition and a different density from those grown on bacteria. 4. During cell differentiation the specific activities of the lysosomal enzymes change. 5. It is suggested that both during growth and differentiation the amounts of lysosomal enzymes present in the cell are regulated.

Control of cellular differentiation by temperature in the cellular slime mould Dictyostelium discoideum

1984 ◽  
Vol 69 (1) ◽  
pp. 159-165
Author(s):  
M. Maeda
Keyword(s):  
Low Temperature ◽  
Dictyostelium Discoideum ◽  
Cellular Differentiation ◽  
Cellular Slime Mould ◽  
Slime Mould ◽  
Cellular Slime

The effects of low temperature on morphogenesis and cellular differentiation of Dictyostelium discoideum were examined. During incubation at 5 degrees C, the vegetative and preaggregation cells never developed, but cell masses at the aggregation or slug stage developed to form hemispherical, or dumbbell-shaped multicellular structures. By staining with FITC-antispore IgG, the structures formed after 10 days of incubation of tipped aggregates at 5 degrees C were found to be composed of 90% spores, 5% prespore cells and 5% non-stained cells. Since only 20% of the total cells constituting the tipped aggregate had been prespore cells at the beginning of incubation, this showed that spore differentiation proceeded even at low temperature, while stalk differentiation was completely inhibited. Similar results were obtained when the cells were incubated at 3 degrees C. However, at 0 degree C, morphogenesis and cellular differentiation did not occur, although most of the prespore cells at the late culmination stage differentiated incompletely into spores. Possible reasons for the high proportion of spores being induced by low temperature are discussed.

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