Ammonia depletion and DIF trigger stalk cell intact Dictyostelium discoideum slugs

Development ◽  
1989 ◽  
Vol 105 (3) ◽  
pp. 569-574 ◽  
Author(s):  
M. Wang ◽  
P. Schaap
Keyword(s):  
Cell Differentiation ◽  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Stalk Cell

The differentiation-inducing factor, DIF, was induce stalk cell differentiation in Dictyostelium incubated as submerged monolayers. We investigated the regulates the differentiation of stalk cells in the was found that in migrating or submerged slugs DIF cell differentiation, which is most likely due to the antagonist. Cyclic AMP and ammonia were earlier antagonists in vitro. We show here that ammonia, but an antagonist for DIF-induced stalk cell can induce stalk cell differentiation when ammonia are enzymically depleted. However, depletion of cAMP increase the efficacy of DIF. We propose that the cell differentiation during early culmination may be drop in ammonia levels inside the organism.

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 Secreted Cyclic Di-GMP Induces Stalk Cell Differentiation in the Eukaryote Dictyostelium discoideum

2015 ◽  
Vol 198 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Zhi-hui Chen ◽  
Pauline Schaap
Keyword(s):  
Cell Death ◽  
Cell Differentiation ◽  
Dictyostelium Discoideum ◽  
Autophagic Cell Death ◽  
Stalk Cell ◽  
Signal Molecule ◽  
Major Life ◽  
Content Type

Cyclic di-GMP (c-di-GMP) is currently recognized as the most widely used intracellular signal molecule in prokaryotes, but roles in eukaryotes were only recently discovered. In the social amoebaDictyostelium discoideum, c-di-GMP, produced by a prokaryote-type diguanylate cyclase, induces the differentiation of stalk cells, thereby enabling the formation of spore-bearing fruiting bodies. In this review, we summarize the currently known mechanisms that control the major life cycle transitions ofDictyosteliumand focus particularly on the role of c-di-GMP in stalk formation. Stalk cell differentiation has characteristics of autophagic cell death, a process that also occurs in higher eukaryotes. We discuss the respective roles of c-di-GMP and of another signal molecule, differentiation-inducing factor 1, in autophagic cell deathin vitroand in stalk formationin vivo.

Stalk cell differentiation by cells from migrating slugs of Dictyostelium discoideum: special properties of tip cells

Development ◽  
1977 ◽  
Vol 42 (1) ◽  
pp. 105-113
Author(s):  
C. D. Town ◽  
E. Stanford
Keyword(s):  
Cell Differentiation ◽  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Active Substance ◽  
High Efficiency ◽  
Stalk Cell ◽  
Cell Populations ◽  
Distinct Cell ◽  
Tip Cells

When fragments of migrating slugs of D. discoideum are disaggregated and spread on agar containing 1 MM cyclic AMP, cells from all parts of the slug form stalk cells with high efficiency. When cyclic AMP is not added to the agar, normal fruiting of dissociated slug cells can be prevented by overlaying them with cellophane. Under these conditions only cells from the anterior 10% of the slug (the ‘tip’) give rise to appreciable numbers of stalk cells, all other cells remaining amoeboid. By separating distinct cell populations with cellophane we have shown that tip cells can induce cells from other parts of the slug to differentiate into stalk cells. The ability of tips to induce stalk cells is independent of tip age, but the proportion of cells induced depends both on the age of the slug and the part of the slug from which they are derived. The proportion induced is greater in older slugs than in newly formed ones, and in the older slugs is greater in the cells from fronts than from backs. The active substance released by the tip cells may be cyclic AMP.

Evidence that the Dictyostelium Dd-STATa protein is a repressor that regulates commitment to stalk cell differentiation and is also required for efficient chemotaxis

Development ◽  
1999 ◽  
Vol 126 (15) ◽  
pp. 3391-3405 ◽  
Author(s):  
S. Mohanty ◽  
K.A. Jermyn ◽  
A. Early ◽  
T. Kawata ◽  
L. Aubry ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Cyclic Amp ◽  
Ectopic Expression ◽  
Negative Control ◽  
Stalk Cell ◽  
Undifferentiated Cells ◽  
Small Spore ◽  
Null Strain

Dd-STATa is a structural and functional homologue of the metazoan STAT (Signal Transducer and Activator of Transcription) proteins. We show that Dd-STATa null cells exhibit several distinct developmental phenotypes. The aggregation of Dd-STATa null cells is delayed and they chemotax slowly to a cyclic AMP source, suggesting a role for Dd-STATa in these early processes. In Dd-STATa null strains, slug-like structures are formed but they have an aberrant pattern of gene expression. In such slugs, ecmB/lacZ, a marker that is normally specific for cells on the stalk cell differentiation pathway, is expressed throughout the prestalk region. Stalk cell differentiation in Dictyostelium has been proposed to be under negative control, mediated by repressor elements present in the promoters of stalk cell-specific genes. Dd-STATa binds these repressor elements in vitro and the ectopic expression of ecmB/lacZ in the null strain provides in vivo evidence that Dd-STATa is the repressor protein that regulates commitment to stalk cell differentiation. Dd-STATa null cells display aberrant behavior in a monolayer assay wherein stalk cell differentiation is induced using the stalk cell morphogen DIF. The ecmB gene, a general marker for stalk cell differentiation, is greatly overinduced by DIF in Dd-STATa null cells. Also, Dd-STATa null cells are hypersensitive to DIF for expression of ST/lacZ, a marker for the earliest stages in the differentiation of one of the stalk cell sub-types. We suggest that both these manifestations of DIF hypersensitivity in the null strain result from the balance between activation and repression of the promoter elements being tipped in favor of activation when the repressor is absent. Paradoxically, although Dd-STATa null cells are hypersensitive to the inducing effects of DIF and readily form stalk cells in monolayer assay, the Dd-STATa null cells show little or no terminal stalk cell differentiation within the slug. Dd-STATa null slugs remain developmentally arrested for several days before forming very small spore masses supported by a column of apparently undifferentiated cells. Thus, complete stalk cell differentiation appears to require at least two events: a commitment step, whereby the repression exerted by Dd-STATa is lifted, and a second step that is blocked in a Dd-STATa null organism. This latter step may involve extracellular cAMP, a known repressor of stalk cell differentiation, because Dd-STATa null cells are abnormally sensitive to the inhibitory effects of extracellular cyclic AMP.

Differanisole A, an inducer of the differentiation of Friend leukemic cells, induces stalk cell differentiation in Dictyostelium discoideum

FEBS Letters ◽  
1993 ◽  
Vol 322 (1) ◽  
pp. 73-75 ◽  
Author(s):  
Yuzuru Kubohara ◽  
Koji Okamoto ◽  
Yoshimasa Tanaka ◽  
Ken-ichi Asahi ◽  
Akira Sakurai ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Dictyostelium Discoideum ◽  
Leukemic Cells ◽  
Stalk Cell
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