In vitro stalk cell differentiation in wild-type and ‘slugger’ mutants of Dictyostelium discoideum

Development ◽  
1993 ◽  
Vol 118 (2) ◽  
pp. 523-526 ◽  
Author(s):  
K. Inouye ◽  
J. Gross
Keyword(s):  
Dictyostelium Discoideum ◽  
Fruiting Body ◽  
Cell Maturation ◽  
Stalk Cell ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Close Relationship ◽  
Long Time

In ‘slugger’ mutants of Dictyostelium discoideum, aggregates of cells remain for an abnormally long time in the migratory phase under conditions where wild-type aggregates form fruiting bodies. In the present work, we have examined the relationship between the defect in fruiting body formation in these mutants and their ability to form mature stalk cells. We dissociated anterior cells from slugs of the mutants and their parents and tested their ability to form stalk cells when incubated at low density in the presence of (1) the stalk cell morphogen Differentiation Inducing Factor-1 (DIF-1) together with cyclic AMP, or (2) 8-Br-cAMP, which is believed to penetrate cell membrane and activate cAMP- dependent protein kinase (PKA). Most of the mutants were markedly defective in forming stalk cells in response to DIF-1 plus cAMP, confirming a close relationship between fruiting body formation and stalk cell maturation. On the other hand, many of these same mutants formed stalk cells efficiently in response to 8-Br-cAMP. This supports evidence for an essential role of PKA in stalk cell maturation and fruiting body formation. It also indicates that many of the mutants owe their slugger phenotype to defects in functions required for optimal adenylyl cyclase activity.

Culmination in the slime mould Dictyostelium discoideum studied with a scanning electron microscope

Development ◽  
1976 ◽  
Vol 35 (2) ◽  
pp. 323-333
Author(s):  
D. J. Watts ◽  
T. E. Treffry
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dictyostelium Discoideum ◽  
Fruiting Body ◽  
Maximum Height ◽  
Slow Process ◽  
Fruiting Body Formation ◽  
Basal Disc ◽  
Body Formation ◽  
Scanning Electron

Myxamoebae of Dictyostelium discoideum were allowed to develop on cellulose acetate filters, and specimens taken at various stages of fruiting body formation were prepared for study by scanning electron microscopy. In the immature fruiting body where the mass of pre-spore cells has just been lifted off the substratum by the developing stalk, the pre-spore cells are irregular in shape and are similar in appearance to cells in aggregates at earlier stages of development. As the stalk lengthens, the pre-spore cells gradually separate from one another and become rounded and elongate, but mature spores are not visible until the fruiting body reaches its maximum height. It is concluded that, contrary to previous reports, spore maturation is a slow process and is not completed until the sorus becomes pigmented. The mature stalk is surrounded by a smooth cellulose sheath but this does not envelop the cells of the basal disc, which remain discrete. The fruiting body is enclosed in a slime sheath and this may be important in holding together the mass of spores.

scholarly journals fbfB, a Gene Encoding a Putative Galactose Oxidase, Is Involved in Stigmatella aurantiacaFruiting Body Formation

1998 ◽  
Vol 180 (5) ◽  
pp. 1241-1247 ◽  
Author(s):  
Barbara Silakowski ◽  
Heidi Ehret ◽  
Hans Ulrich Schairer
Keyword(s):  
Fruiting Body ◽  
Rhodobacter Capsulatus ◽  
Fusion Gene ◽  
Three Dimensional ◽  
Galactose Oxidase ◽  
Fruiting Bodies ◽  
Wild Type ◽  
Primary Alcohols ◽  
Fruiting Body Formation ◽  
Body Formation

ABSTRACT Stigmatella aurantiaca is a gram-negative bacterium which forms, under conditions of starvation in a multicellular process, characteristic three-dimensional structures: the fruiting bodies. For studying this complex process, mutants impaired in fruiting body formation have been induced by transposon insertion with a Tn5-derived transposon. The gene affected (fbfB) in one of the mutants (AP182) was studied further. Inactivation of fbfB results in mutants which form only clumps during starvation instead of wild-type fruiting bodies. This mutant phenotype can be partially rescued, if cells of mutants impaired in fbfB function are mixed with those of some independent mutants defective in fruiting before starvation. The fbfBgene is expressed about 14 h after induction of fruiting body formation as determined by measuring β-galactosidase activity in a merodiploid strain harboring the wild-type gene and anfbfB-Δtrp-lacZ fusion gene or by Northern (RNA) analysis with the Rhodobacter capsulatus pufBA fragment fused tofbfB as an indicator. The predicted polypeptide FbfB has a molecular mass of 57.8 kDa and shows a significant homology to the galactose oxidase (GaoA) of the fungus Dactylium dendroides. Galactose oxidase catalyzes the oxidation of galactose and primary alcohols to the corresponding aldehydes.

scholarly journals Developmental Aggregation of Myxococcus xanthus Requires frgA, anfrz-Related Gene

2000 ◽  
Vol 182 (23) ◽  
pp. 6614-6621 ◽  
Author(s):  
Kyungyun Cho ◽  
Anke Treuner-Lange ◽  
Kathleen A. O'Connor ◽  
David R. Zusman
Keyword(s):  
Fruiting Body ◽  
Myxococcus Xanthus ◽  
Complex Life Cycle ◽  
Fruiting Bodies ◽  
Related Gene ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Extracellular Signals ◽  
Directed Motility

ABSTRACT Myxococcus xanthus is a gram-negative bacterium which has a complex life cycle that includes multicellular fruiting body formation. Frizzy mutants are characterized by the formation of tangled filaments instead of hemispherical fruiting bodies on fruiting agar. Mutations in the frz genes have been shown to cause defects in directed motility, which is essential for both vegetative swarming and fruiting body formation. In this paper, we report the discovery of a new gene, called frgA (forfrz-related gene), which confers a subset of the frizzy phenotype when mutated. The frgA null mutant showed reduced swarming and the formation of frizzy aggregates on fruiting agar. However, this mutant still displayed directed motility in a spatial chemotaxis assay, whereas the majority offrz mutants fail to show directed movements in this assay. Furthermore, the frizzy phenotype of the frgA mutant could be complemented extracellularly by wild-type cells or strains carrying non-frz mutations. The phenotype of the frgAmutant is similar to that of the abcA mutant and suggests that both of these mutants could be defective in the production or export of extracellular signals required for fruiting body formation rather than in the sensing of such extracellular signals. ThefrgA gene encodes a large protein of 883 amino acids which lacks homologues in the databases. The frgA gene is part of an operon which includes two additional genes, frgBand frgC. The frgB gene encodes a putative histidine protein kinase, and the frgC gene encodes a putative response regulator. The frgB and frgCnull mutants, however, formed wild-type fruiting bodies.

scholarly journals Imaging Promoter Assay of Adenylyl Cyclase A Gene in Dictyostelium discoideum during Fruiting Body Formation by Dual-Color Bioluminescence Microscopy

2021 ◽  
Author(s):  
Taro Hayashi ◽  
Katsunori Ogoh ◽  
Hirobumi Suzuki
Keyword(s):  
Adenylyl Cyclase ◽  
Dictyostelium Discoideum ◽  
Fruiting Body ◽  
Cell Aggregation ◽  
Adenosine Monophosphate ◽  
Fruiting Body Formation ◽  
Promoter Assay ◽  
Body Formation ◽  
Secondary Messenger ◽  
Dual Color

Cyclic adenosine monophosphate (cAMP), which is derived from adenosine triphosphate through adenylyl cyclase A (acaA), acts as an intracellular secondary messenger and an extracellular chemotactic substance in important biological processes. In the social amoebae Dictyostelium discoideum, cAMP mediates cell aggregation, development, and differentiation to spore and stalk cells during fruiting body formation. The acaA gene is transcribed under the control of three different alternative promoters. This study aimed to develop a promoter assay for acaA in D. discoideum using bioluminescence microscopy. Here, we inserted green- and red-emitting luciferase genes into downstream of promoter regions 1 and 3, respectively. Promoter activities were visualized by bioluminescence microscopy. We confirmed the differential expression of acaA under the control of promoters 1 and 3 at the different stages of D. discoideum development. We also demonstrated the application of dual-color bioluminescence imaging in the development of an imaging promoter assay.

Induction by acid load of the maturation of prestalk cells in Dictyostelium discoideum

Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 669-681
Author(s):  
K. Inouye
Keyword(s):  
Cell Differentiation ◽  
Dictyostelium Discoideum ◽  
Cell Maturation ◽  
Stalk Cell ◽  
Body Construction ◽  
Acid Load ◽  
Cellular Slime ◽  
Plasma Membrane Proton Pump

During the process of fruiting body construction in the cellular slime mould Dictyostelium discoideum, prestalk cells become mature stalk cells in a well-controlled manner. To identify the natural inducer of stalk cell maturation, substances known to induce stalk cell differentiation under in vitro conditions, and some other related compounds, were examined for their effects in vivo on migrating slugs, the precursor structures of the fruiting bodies. Among these substances, addition of weak acids such as CO2, and addition followed by removal of weak bases such as NH3, strikingly induced the maturation of prestalk cells in situ in slugs. On the other hand, inhibitors of the plasma membrane proton pump did not efficiently induce the maturation of prestalk cells in intact slugs. Differentiation inducing factor (DIF), an endogenous inducer of prestalk differentiation, seemed to be an even poorer inducer of stalk cell maturation when applied to intact slugs. The activities of these substances in inducing stalk cell maturation showed a good correlation with their effects on the cytoplasmic pH (pHi) of prestalk cells; the larger the pHi drop, the stronger the induction of stalk cell maturation, suggesting a requirement for a pHi decrease for the maturation of prestalk cells. Based on these results, it was proposed that stalk cell differentiation, which is induced by DIF, is blocked halfway during normal development by (an) agent(s) that prevent(s) the decrease in pHi.

scholarly journals A WD40 Repeat Protein Regulates Fungal Cell Differentiation and Can Be Replaced Functionally by the Mammalian Homologue Striatin

2004 ◽  
Vol 3 (1) ◽  
pp. 232-240 ◽  
Author(s):  
Stefanie Pöggeler ◽  
Ulrich Kück
Keyword(s):  
Cell Differentiation ◽  
Fruiting Body ◽  
Differentiation Process ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Wd40 Repeat ◽  
Body Formation ◽  
Repeat Protein ◽  
Type Protein ◽  
Wild Type Protein

ABSTRACT Fruiting body development in fungi is a complex cellular differentiation process that is controlled by more than 100 developmental genes. Mutants of the filamentous fungus Sordaria macrospora showing defects in fruiting body formation are pertinent sources for the identification of components of this multicellular differentiation process. Here we show that the sterile mutant pro11 carries a defect in the pro11 gene encoding a multimodular WD40 repeat protein. Complementation analysis indicates that the wild-type gene or C-terminally truncated versions of the wild-type protein are able to restore the fertile phenotype in mutant pro11. PRO11 shows significant homology to several vertebrate WD40 proteins, such as striatin and zinedin, which seem to be involved in Ca2+-dependent signaling in cells of the central nervous system and are supposed to function as scaffolding proteins linking signaling and eukaryotic endocytosis. Cloning of a mouse cDNA encoding striatin allowed functional substitution of the wild-type protein with restoration of fertility in mutant pro11. Our data strongly suggest that an evolutionarily conserved cellular process controlling eukaryotic cell differentiation may regulate fruiting body formation.

scholarly journals Loss of the Polyketide Synthase StlB Results in Stalk Cell Overproduction in Polysphondylium violaceum

2020 ◽  
Vol 12 (5) ◽  
pp. 674-683
Author(s):  
Takaaki B Narita ◽  
Yoshinori Kawabe ◽  
Koryu Kin ◽  
Richard A Gibbs ◽  
Adam Kuspa ◽  
...  
Keyword(s):  
Fruiting Body ◽  
Polyketide Synthase ◽  
Stalk Cell ◽  
Marker Genes ◽  
Cell Type ◽  
Fruiting Body Formation ◽  
Knock Out ◽  
Body Formation ◽  
Group 4 ◽  
Basal Disk

Abstract Major phenotypic innovations in social amoeba evolution occurred at the transition between the Polysphondylia and group 4 Dictyostelia, which comprise the model organism Dictyostelium discoideum, such as the formation of a new structure, the basal disk. Basal disk differentiation and robust stalk formation require the morphogen DIF-1, synthesized by the polyketide synthase StlB, the des-methyl-DIF-1 methyltransferase DmtA, and the chlorinase ChlA, which are conserved throughout Dictyostelia. To understand how the basal disk and other innovations evolved in group 4, we sequenced and annotated the Polysphondylium violaceum (Pvio) genome, performed cell type-specific transcriptomics to identify cell-type marker genes, and developed transformation and gene knock-out procedures for Pvio. We used the novel methods to delete the Pvio stlB gene. The Pvio stlB− mutants formed misshapen curly sorogens with thick and irregular stalks. As fruiting body formation continued, the upper stalks became more regular, but structures contained 40% less spores. The stlB− sorogens overexpressed a stalk gene and underexpressed a (pre)spore gene. Normal fruiting body formation and sporulation were restored in Pvio stlB− by including DIF-1 in the supporting agar. These data indicate that, although conserved, stlB and its product(s) acquired both a novel role in the group 4 Dictyostelia and a role opposite to that in its sister group.

scholarly journals Bypass of A- and B-Signaling Requirements for Myxococcus xanthus Development by Mutations in spdR

2002 ◽  
Vol 184 (5) ◽  
pp. 1455-1457 ◽  
Author(s):  
Hubert Tse ◽  
Ronald E. Gill
Keyword(s):  
Fruiting Body ◽  
Double Mutant ◽  
Myxococcus Xanthus ◽  
Wild Type ◽  
Fruiting Body Formation ◽  
Body Formation ◽  
Factor Production

ABSTRACT Mutations in spdR, previously reported to bypass the developmental requirement for B-signaling in Myxococcus xanthus, also bypass the requirement for A-signaling but not C-, D-, or E-signaling. Mutations in spdR restored nearly wild-type levels of sporulation to representative A-signal-deficient mutants carrying asgA476, asgB480, and asgC767 and improved the quality of fruiting body formation in the asgB480 mutant. The defect in A-factor production by the asgB480 mutant was not restored in the spdR2134 asgB480 double mutant.

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