Cell sorting out during the differentiation of mixtures of metabolically distinct populations of Dictyostelium discoideum

Development ◽  
1973 ◽  
Vol 29 (3) ◽  
pp. 647-661
Author(s):  
C. K. Leach ◽  
J. M. Ashworth ◽  
D. R. Garrod
Keyword(s):  
Life Cycle ◽  
Dictyostelium Discoideum ◽  
Cell Sorting ◽  
Relative Number ◽  
Exponential Phase ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Axenic Medium ◽  
Spore Population ◽  
The Relationship

The behaviour, during the multicellular phase of the life-cycle, of amoebae of Dictyostelium discoideum grown in different media is described. Amoebal populations were marked by growth-temperature-sensitive genetic lesions which do not interfere with developmental phenomena. The fate of cell populations was determined by measuring the relative number of mutant and wild-type cells at various stages in the life-cycle. Cells sort out during development in such a way that they may be ordered in a sequence in which those given early in the following list preferentially appear in the spore population when mixed with those given later in the list: cells grown in axenic medium + 86 mm glucose and harvested when in the exponential phase of growth; cells grown in axenic medium and harvested when in the exponential phase of growth; cells grown on bacteria and harvested when in the exponential phase of growth; cells grown in axenic medium + 86 mM glucose and harvested when in the stationary phase of growth. Chemotactic aggregation and grex migration are not essential for sorting-out to occur but, in the normal life-cycle, the cells of a grex formed from amoebae grown in different media have sorted out anteroposteriorly. The relationship between this sorting out behaviour and the mechanism of pattern formation in fruiting-body morphogenesis is discussed. Differences in density of the amoebae cannot account for the sorting out predispositions we observe.

scholarly journals Adenosine 3′:5′-cyclic monophosphate concentrations and phosphodiesterase activities during axenic growth and differentiation of cells of the cellular slime mould Dictyostelium discoideum

1973 ◽  
Vol 134 (1) ◽  
pp. 311-319 ◽  
Author(s):  
A. M. Malkinson ◽  
J. M. Ashworth
Keyword(s):  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Exponential Phase ◽  
Axenic Medium ◽  
Fruiting Body Formation ◽  
Solid Media ◽  
Cellular Slime ◽  
Second Peak ◽  
Axenic Growth ◽  
Approximate Doubling

During growth of myxamoebae of Dictyostelium discoideum (strain Ax-2) in axenic medium, the myxamoebae secrete cyclic AMP. As the cells leave the exponential phase of growth and enter the stationary phase, there is an approximate doubling of the intracellular cyclic AMP content, but the amount of extracellular cyclic AMP remains proportional, at all times, to the number of myxamoebae present. During development of axenically grown myxamoebae, there is first a rise in the intracellular concentration of cyclic AMP, followed by a rise in the amount of extracellular cyclic AMP, which reaches a peak at the time of aggregation and then declines. There is a second peak in the amount of extracellular cyclic AMP found at the time of fruiting-body formation, but this second peak is not associated with a rise in the intracellular cyclic AMP concentration. Controls thus exist over the synthesis and secretion of cyclic AMP. Evidence is presented for the belief that the activity of the adenylate cyclase enzyme controls the amount of cyclic AMP synthesized rather than the activity or amount of cyclic AMP phosphodiesterase present. Similar changes occur in extracellular cyclic AMP and phosphodiesterase concentrations during incubation of myxamoebae in buffered suspensions to those occuring during the first few hours of development of such cells on solid media, but the timing of these changes is different.

scholarly journals Overproduction of discoidin I by a temperature-sensitive motility mutant of Dictyostelium discoideum.

1984 ◽  
Vol 4 (6) ◽  
pp. 1035-1041 ◽  
Author(s):  
S Biswas ◽  
S C Kayman ◽  
M Clarke
Keyword(s):  
Dictyostelium Discoideum ◽  
Gel Electrophoresis ◽  
Peptide Mapping ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Axenic Medium ◽  
Two Dimensional Gel Electrophoresis ◽  
Motility Mutant ◽  
And Migration ◽  
Mutant Cells

Dictyostelium discoideum MC2 is a temperature-sensitive motility mutant of AX3. Mutant cells are incapable of growth, phagocytosis, and migration under restrictive conditions (Kayman et al., J. Cell Biol. 92:705-711, 1982). We show here that at the restrictive temperature MC2 cells grown axenically or on bacteria synthesized excessive quantities of the lectin discoidin I. By two-dimensional gel electrophoresis and peptide mapping, the proteins overproduced by MC2 cells were indistinguishable from discoidin I synthesized at lower levels in AX3 cells. At least two of the three species of discoidin I were overproduced. This protein family constituted 9% of the total protein in cells that were incubated overnight at 27 degrees C in axenic medium. Although MC2 cells are defective in nutrient uptake under restrictive conditions, the overproduction of discoidin I did not appear to be part of a pleiotropic response to starvation. We propose that transcription of the coordinately regulated discoidin I genes is altered in mutant cells. This alteration may be related to the motility defects manifested by MC2.

scholarly journals Mitochondrial processing peptidase activity is controlled by the processing of α-MPP during development in Dictyostelium discoideum

Microbiology ◽  
2010 ◽  
Vol 156 (4) ◽  
pp. 978-989 ◽  
Author(s):  
Koki Nagayama ◽  
Tetsuo Ohmachi
Keyword(s):  
Life Cycle ◽  
Dictyostelium Discoideum ◽  
Early Development ◽  
Normal Development ◽  
Peptidase Activity ◽  
Fruiting Bodies ◽  
Wild Type ◽  
Formation Stage ◽  
Mitochondrial Processing Peptidase ◽  
Processing Peptidase

We investigated the expression of the α subunit of the Dictyostelium mitochondrial processing peptidase (Ddα-MPP) during development. Ddα-MPP mRNA is expressed at the highest levels in vegetatively growing cells and during early development, and is markedly downregulated after 10 h of development. The Ddα-MPP protein is expressed as two forms, designated α-MPPH and α-MPPL, throughout the Dictyostelium life cycle. The larger form, α-MPPH, is cleaved to produce the functional α-MPPL form. We were not able to isolate mutants in which the α-mpp gene had been disrupted. Instead, an antisense transformant, αA2, expressing α-MPP at a lower level than the wild-type AX-3 was isolated to examine the function of the α-MPP protein. Development of the αA2 strain was normal until the slug formation stage, but the slug stage was prolonged to ∼24 h. In this prolonged slug stage, only α-MPPH was present, and α-MPPL protein and MPP activity were not detected. After 28 h, α-MPPL and MPP activity reappeared, and normal fruiting bodies were formed after a delay of approximately 8 h compared with normal development. These results indicate that MPP activity is controlled by the processing of α-MPPH to α-MPPL during development in Dictyostelium.

Relationship of the cGMP-binding activity to the cGMP-specific phosphodiesterase in Dictyostelium discoideum

1986 ◽  
Vol 64 (6) ◽  
pp. 528-534 ◽  
Author(s):  
A. M. Parissenti ◽  
M. B. Coukell
Keyword(s):  
Dictyostelium Discoideum ◽  
Kinase Activity ◽  
Deae Cellulose ◽  
Binding Activity ◽  
Wild Type ◽  
Dependent Protein ◽  
Low Levels ◽  
Relationship Of ◽  
The Relationship ◽  
Type Strains

Optimal conditions for assaying and stabilizing the soluble cGMP-binding activity in Dictyostelium discoideum were established. Using these procedures, we investigated the relationship between the cGMP-binding activity and the cGMP-specific phosphodiesterase in this organism. In wild-type strains, the binding and phosphodiesterase activities were found to be regulated differently during development. Also, stmF mutants, which possess very low levels of cGMP-specific phosphodiesterase activity, exhibited normal levels of cGMP-binding activity. Fractionation studies revealed that the binding and phosphodiesterase activities could be resolved by DEAE-cellulose chromatography. Finally, the effect of pH on cGMP binding was different from that reported for cGMP-mediated activation of the phosphodiesterase. Taken together, these results indicate that the cGMP-binding protein and the cGMP-specific phosphodiesterase are probably unrelated. In addition, the cGMP-binding activity is not associated with cGMP-stimulated kinase activity and it does not elute from DEAE-cellulose like the highly conserved cGMP-dependent protein kinases found in other systems.

scholarly journals CHARACTERIZATION OF DOMINANT RESISTANCE TO COBALT CHLORIDE IN DICTYOSTELIUM DISCOIDEUM AND ITS USE IN PARASEXUAL GENETIC ANALYSIS

Genetics ◽  
1978 ◽  
Vol 90 (1) ◽  
pp. 37-47
Author(s):  
Keith L Williams
Keyword(s):  
Dictyostelium Discoideum ◽  
Cobalt Chloride ◽  
Resistance Mutation ◽  
Differential Sensitivity ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Cobaltous Chloride ◽  
Chloride Resistance ◽  
Resistant Strains

ABSTRACT Strains of Dictyostelium discoideum resistant to cobaltous chloride have been isolated at a frequency of approximately 10-6. The resistant strains have one of three phenotypes, recessive to wild type, dominant to wild type and dominant to wild type but requiring the presence of cobaltous chloride to maintain resistance. Strains carrying a dominant cobaltous chloride resistance mutation and a recessive growth temperature-sensitive mutation can be mixed with wild-type haploid lines and then subjected to selection so that only diploid lines survive. Differential sensitivity to cycloheximide has also been observed. Hypersensitivity to cycloheximide in combination with dominant cobaltous chloride resistance provides a means of selecting diploids without the use of temperature-sensitive mutations.

Overproduction of discoidin I by a temperature-sensitive motility mutant of Dictyostelium discoideum

1984 ◽  
Vol 4 (6) ◽  
pp. 1035-1041
Author(s):  
S Biswas ◽  
S C Kayman ◽  
M Clarke
Keyword(s):  
Dictyostelium Discoideum ◽  
Gel Electrophoresis ◽  
Peptide Mapping ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Axenic Medium ◽  
Two Dimensional Gel Electrophoresis ◽  
Motility Mutant ◽  
And Migration ◽  
Mutant Cells

Dictyostelium discoideum MC2 is a temperature-sensitive motility mutant of AX3. Mutant cells are incapable of growth, phagocytosis, and migration under restrictive conditions (Kayman et al., J. Cell Biol. 92:705-711, 1982). We show here that at the restrictive temperature MC2 cells grown axenically or on bacteria synthesized excessive quantities of the lectin discoidin I. By two-dimensional gel electrophoresis and peptide mapping, the proteins overproduced by MC2 cells were indistinguishable from discoidin I synthesized at lower levels in AX3 cells. At least two of the three species of discoidin I were overproduced. This protein family constituted 9% of the total protein in cells that were incubated overnight at 27 degrees C in axenic medium. Although MC2 cells are defective in nutrient uptake under restrictive conditions, the overproduction of discoidin I did not appear to be part of a pleiotropic response to starvation. We propose that transcription of the coordinately regulated discoidin I genes is altered in mutant cells. This alteration may be related to the motility defects manifested by MC2.

scholarly journals Inheritance of extrachromosomal ribosomal DNA during the asexual life cycle of Dictyostelium discoideum: examination by use of DNA polymorphisms.

1985 ◽  
Vol 5 (2) ◽  
pp. 273-280 ◽  
Author(s):  
D L Welker ◽  
K P Hirth ◽  
K L Williams
Keyword(s):  
Life Cycle ◽  
Dictyostelium Discoideum ◽  
Ribosomal Dna ◽  
Dna Polymorphisms ◽  
Haploid Cell ◽  
Wild Type ◽  
Parasexual Cycle ◽  
Restriction Fragments ◽  
Type Isolate ◽  
Ca 50

Wild-type isolates of Dictyostelium discoideum exhibited differences in the size of restriction fragments of the extrachromosomal 88-kilobase ribosomal DNA (rDNA) palindrome. Polymorphisms in rDNA also were found among strains derived solely from the NC4 wild-type isolate. These variations involved EcoRI fragments II, III, and V; they included loss of the EcoRI site separating fragments II and V and deletion and insertion of DNA. More than one rDNA form can coexist in the same diploid or haploid cell. However, one or another parental rDNA tended to predominate in diploids constructed, using the parasexual cycle, between haploid NC4-derived strains and haploid wild-type isolates. In some cases, most if not all of the rDNA of such diploids were of one form after ca. 50 generations of growth. Segregant haploids, derived from diploids that possessed predominantly a single rDNA allele, possessed the same allele as the diploid and did not recover the other form. This evidence implies that replication does not proceed from a single chromosomal or extrachromosomal copy of the rDNA during the asexual life cycle of D. discoideum.

Temperature-sensitive mutants of bacteriophage SH-133 specific for the hydrogen bacterium Pseudomonas facilis: isolation, complementation, and partial characterization

1979 ◽  
Vol 25 (1) ◽  
pp. 86-93
Author(s):  
Christine M. Battreall ◽  
William E. Friedrichs ◽  
Jeffrey P. Reed ◽  
Gary M. Aron
Keyword(s):  
Uv Light ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Wild Type ◽  
Temperature Sensitive Mutants ◽  
Specific Phage ◽  
Autotrophic Metabolism ◽  
Complementation Groups ◽  
Type Phage ◽  
The Relationship

Seventeen temperature-sensitive mutants of bacteriophage SH-133 have been isolated following mutagenesis with UV-light, nitrosoguanidine, and ethyl methanesulfonate. The mutants were classified into 15 complementation groups according to their ability to complement each other at 32 °C, the nonpermissive temperature. Each mutant was studied with regard to the relationship between its ability to multiply in heterotrophically (H-) and autotrophically (A-) grown Pseudomonas facilis cells. At 27 °C, the permissive temperature, the plaque-forming ability of the 17 mutants and wild-type phage was reduced 10-fold in A-grown cells. At 32 °C, mutants belonging to 10 groups exhibited identical levels of multiplicity-dependent leak under both modes of growth. However, the infection of A-grown cells by mutants belonging to the remaining five groups resulted in as much as 500-fold inhibition of multiplicity-dependent leak when contrasted with the infection of cells grown heterotrophically. These observations indicate that the expression of five SH-133 phage cistrons is defective when multiplication proceeds under autotrophic metabolism. Seven mutants were found to differ from the wild-type phage with regard to thermal stability at 56 °C which suggests that they possess altered structural proteins. Four of the seven thermosensitive mutants exhibited reduced levels of multiplicity-dependent leak in A-grown cells. The data suggest that the reduction in plaque-forming ability of SH-133 in A-grown cells is caused by a defect in the expression of specific phage structural components.

scholarly journals Adenovirus Protein VI Mediates Membrane Disruption following Capsid Disassembly

2005 ◽  
Vol 79 (4) ◽  
pp. 1992-2000 ◽  
Author(s):  
Christopher M. Wiethoff ◽  
Harald Wodrich ◽  
Larry Gerace ◽  
Glen R. Nemerow
Keyword(s):  
Conformational Changes ◽  
Lytic Activity ◽  
Temperature Sensitive ◽  
Membrane Penetration ◽  
Wild Type ◽  
Cytosolic Delivery ◽  
Α Helix ◽  
The Relationship ◽  
Capsid Disassembly ◽  
Protein Vi

ABSTRACT In contrast to enveloped viruses, the mechanisms involved in membrane penetration by nonenveloped viruses are not as well understood. In these studies, we determined the relationship between adenovirus (Ad) capsid disassembly and the development of membrane lytic activity. Exposure to low pH or heating induced conformational changes in wild-type Ad but not in temperature-sensitive Ad (ts1) particles that fail to escape the early endosome. Wild-type Ad but not ts1 particles permeabilized model membranes (liposomes) and facilitated the cytosolic delivery of a ribotoxin. Alterations in wild-type Ad capsids were associated with the exposure of a pH-independent membrane lytic factor. Unexpectedly, this factor was identified as protein VI, a 22-kDa cement protein located beneath the peripentonal hexons in the viral capsid. Recombinant protein VI and preprotein VI, but not a deletion mutant lacking an N-terminal amphipathic α-helix, possessed membrane lytic activity similar to partially disassembled virions. A new model of Ad entry is proposed based on our present observations of capsid disassembly and membrane penetration.

scholarly journals Development of Dictyostelium discoideum is associated with alteration of fucosylated N-glycan structures

2009 ◽  
Vol 423 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Birgit Schiller ◽  
Alba Hykollari ◽  
Josef Voglmeir ◽  
Gerald Pöltl ◽  
Karin Hummel ◽  
...  
Keyword(s):  
Life Cycle ◽  
Simple Model ◽  
Dictyostelium Discoideum ◽  
Cross Reactivity ◽  
Exponential Phase ◽  
Mass Spectrometric ◽  
Social Amoeba ◽  
The Core ◽  
The Social ◽  
Axenic Cultures

The social amoeba Dictyostelium discoideum has become established as a simple model for the examination of cell–cell interactions, and early studies suggested that shifts in glycosylation profiles take place during its life cycle. In the present study, we have applied HPLC and mass spectrometric methods to show that the major N-glycans in axenic cultures of the AX3 strain are oligomannosidic forms, most of which carry core fucose and/or intersecting and bisecting N-acetylglucosamine residues, including the major structure with the composition Man8GlcNAc4Fuc1. The postulated α1,3-linkage of the core fucose correlates with the cross-reactivity of Dictyostelium glycoproteins with a horseradish peroxidase antiserum; a corresponding core α1,3-fucosyltransferase activity capable of modifying oligomannosidic N-glycans was detected in axenic Dictyostelium extracts. The presence of fucose on the N-glycans and the reactivity to the antiserum, but not the fucosyltransferase activity, are abolished in the fucose-deficient HL250 strain. In later stages of development, N-glycans at the mound and culmination stages show a reduction in both the size and the degree of modification by intersecting/bisecting residues compared with mid-exponential phase cultures, consistent with the hypothesis that glycosidase and glycosyltransferase expression levels are altered during the slime mould life cycle.

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