Patterns of cell movement within the Dictyostelium slug revealed by cell type-specific, surface labeling of living cells

Abe, Tomoaki; Early, Anne; Siegert, Florian; Weijer, Cornelis J.; Williams, Jeffrey

doi:10.1016/0092-8674(94)90053-1

Cited by 79 publications

(51 citation statements)

References 39 publications

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“…Although they were initially identified using the bi-partite promoter of the ecmA gene, many other genes are expressed only in one or other region (Maeda et al, 2003). This indicates that the two subtypes are of wide developmental significance and the fact that they differ in their movement patterns within the slug and at culmination supports this notion (Jermyn and Williams, 1991;Abe et al, 1994).…”

Section: Introductionmentioning

confidence: 65%

TheDictyosteliumbZIP transcription factor DimB regulates prestalk-specific gene expression

et al. 2006

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The ecmA gene is specifically expressed in prestalk cells and its transcription is induced by the chlorinated hexaphenone DIF-1. We have purified a novel bZIP transcription factor, DimB, by affinity chromatography on two spatially separated ecmA promoter fragments. Mutagenesis of the cap-site proximal DimB-binding site (the -510 site) greatly decreases ecmA expression in the pstO cells, which comprise the rear half of the prestalk zone, and also in the Anterior-Like Cells, which lie scattered throughout the prespore region. However, DimB is not essential for normal expression of the ecmA gene, instead it spatially limits its expression; ecmA is relatively highly expressed in the subset of prestalk cells that coats the prestalk zone, but in slugs of a DimB-null strain, ecmA is highly expressed throughout the prestalk zone. Because the -510 site is required for correct ecmA expression, we posit a separate activator protein that competes with DimB for binding to the -510 site. DimB rapidly accumulates in the nucleus when cells are exposed to DIF-1, and ChIP analysis shows that, in the presence of extracellular cAMP, DIF-1 causes DimB to associate with the ecmA promoter in vivo. Thus, DIF-1 regulates DimB activity to generate a gradient of ecmA expression in the prestalk zone of the slug.

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Section: Introductionmentioning

confidence: 65%

TheDictyosteliumbZIP transcription factor DimB regulates prestalk-specific gene expression

et al. 2006

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“…Normally, cells within the prestalk region of migrating slugs undergo a movement and differentiation cycle that presages events at culmination (Abe et al, 1994). A subset of the pstA cells, located very near the slug tip, activate expression of ecmB and are then termed pstAB cells.…”

Section: A a A A A A A A T T T T A T T T A A A T T T A A T C A A A Amentioning

confidence: 99%

GSK3 is a multifunctional regulator ofDictyosteliumdevelopment

et al. 2004

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phosphorylates GskA and this activates it (Kim et al., 1999;Kim et al., 2002). The activity of ZAK1 is developmentally regulated, with kinetics that are approximately coincident with the activation profile of GskA. Furthermore, there is no peak of GskA kinase activity in a zakA-null strain (Kim et al., 1999).Glycogen synthase kinase 3 (GSK3) is a central regulator of metazoan development and the Dictyostelium GSK3 homologue, GskA, also controls cellular differentiation. The originally derived gskA-null mutant exhibits a severe pattern formation defect. It forms very large numbers of pre-basal disc cells at the expense of the prespore population. This defect arises early during multicellular development, making it impossible to examine later functions of GskA. We report the analysis of a gskA-null mutant, generated in a different parental strain, that proceeds through development to form mature fruiting bodies. In this strain, Ax2/gskA-, early development is accelerated and slug migration greatly curtailed. In a monolayer assay of stalk cell formation, the Ax2/gskAstrain is hypersensitive to the stalk cell-inducing action of DIF-1 but largely refractory to the repressive effect exerted by extracellular cAMP. During normal development, apically situated prestalk cells express the ecmB gene just as they commit themselves to stalk cell differentiation. In the Ax2/gskA-mutant, ecmB is expressed throughout the prestalk region of the slug, suggesting that GskA forms part of the repressive signalling pathway that prevents premature commitment to stalk cell differentiation. GskA may also play an inductive developmental role, because microarray analysis identifies a large gene family, the 2C family, that require gskA for optimal expression. These observations show that GskA functions throughout Dictyostelium development, to regulate several key aspects of cellular patterning.

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“…3) Analyses of ALCs have revealed that normal proportioning is controlled by inter-conversion of prestalk and prespore cells with ALCs as intermediate. 4) Under appropriate conditions, the slug transforms into its final morphology, a fruiting body, which consists of a spore mass above vacuolated and dead stalk cells.…”

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confidence: 99%