The Prestalk-Prespore Pattern in Cellular Slime Molds

MacWilliams, Harry K.; Bonner, John Tyler

doi:10.1111/j.1432-0436.1979.tb01006.x

Cited by 163 publications

(61 citation statements)

References 69 publications

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“…In intact slugs the anterior-like cells are maintained in the posterior by the presence of the anterior cells which secrete a diffusible inhibitor that prevents anterior-like cell sorting. Although the mechanisms of pattern formation and regeneration have been intensively investigated for many years, little is known about regulation of cell-type proportions (Bonner, 1957;MacWilliams and Bonner, 1979;Williams et al, 1981). The fact that the anteriorlike cells act to restore the normal anterior-posterior pattern in posterior tissue isolates suggests that these cells may be involved in proportion regulation.…”

Section: Introductionmentioning

confidence: 99%

Fate and regulation of anterior-like cells in Dictyostelium slugs

Sternfeld

David

1982

Developmental Biology

180

103

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Section: Introductionmentioning

confidence: 99%

Fate and regulation of anterior-like cells in Dictyostelium slugs

Sternfeld

David

1982

Developmental Biology

180

103

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“…When a slug is transected, the prestalk-prespore pattern can regenerate in the isolated pieces. A number of models for formation of the prestalk-prespore pattern have been proposed (for a review see [2]). However, current information does not permit a choice between models and there is controversy about a central issue, the role of sorting-out.…”

mentioning

confidence: 99%

Cell Sorting daring Pattern Formation in Dictyostelium

1981

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Formation of the prestalk‐prespore pattern in Dictyostelium was investigated in slugs and submerged clumps of cells. Prestalk and prespore cells were identified by staining with vital dyes, which are shown to be stable cell markers. Dissociated slug cells reaggregate and form slugs that contain a prestalk‐prespore pattern indistinguishable from the original pattern. The pattern forms by sorting out of stained prestalk cells from unstained prespore cells. Sorting also occurs in clumps of dissociated slug cells submerged in liquid or agar. A pattern arises in 2 h in which a central core of stained cells is surrounded by a periphery of unstained cells. Sorting appears to be due to differential chemotaxis of stained and unstained cells to cAMP since exogenous cAMP (>10−7 M) reverses the normal direction of sorting‐out such that stained cells sort to the periphery of the clumps. Isolated portions of slugs regenerate a new prestalk‐prespore pattern. Posterior isolates regenerate a pattern within 2 h due to sorting of a population of vitally stained ‘anterior‐like’ cells present in posteriors. Anterior‐like cells do not sort in intact slugs due to the influence of a diffusible inhibitor secreted by the anterior region. During posterior regeneration this signal is absent and anterior‐like cells rapidly acquire the ability to sort. Anterior isolates regenerate a staining pattern more slowly than posterior isolates by a process that requires conversion of stained prestalk cells to unstained prespore cells. The results suggest that pattern formation in Dictyostelium consists of two processes: establishment of appropriate proportions of two cell types and establishment of the pattern itself by a mechanism of sorting‐out.

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“…At this stage of morphogenesis, cells are pre-committed to either the spore or the stalk pathway. Pre-spore cells are located in the posterior and pre-stalk cells the anterior of the slug (MacWilliams & Bonner, 1979). Under favourable conditions the slug undergoes a series of morphological changes resulting in the formation of a fruiting body composed of two main cell types, spore and stalk cells.…”

Section: Introductionmentioning

confidence: 99%

The effect of AMP on the NAD-dependent glutamate dehydrogenase during activation and morphogenesis in the cellular slime moulds

Pamula

Wheldrake²

1992

Journal of General Microbiology

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In extracts from vegetative Dictyostelium discoideum V12 the basal NAD-dependent glutamate dehydrogenase (NAD-GDH) activity was low, but it increased on standing at 4 OC. When 0.1 mM-AMP was included in the assay mix, enzyme activity was stimulated nearly 30-fold. As the extract was allowed to age, the enzyme rapidly lost its ability to be stimulated by AMP. The response of NAD-GDH to AMP was also dependent on the stage of morphogenesis. The ratios of NAD-GDH activity assayed with and without AMP (+AMP/ -AMP ratios) in freshly prepared extracts from cells at 0, 4, 8 and 12 h of development were similar, but declined later in morphogenesis. The + AMP/ -AMP ratio decreased sharply during activation at 4 "C in extracts from cells at 0, 4,16 and 20 h of development. By contrast, extracts from cells starved for 8 and 12 h remained more responsive to AMP throughout activation. Analysis of Western blots showed that vegetative NAD-GDH did not undergo any detectable proteolytic cleavage during 96 h of activation at 4 OC. Also, no change in molecular mass appeared to take place within the cells until culmination (2&24 h), when some breakdown products appeared. Activation of NAD-GDH also occurred in D. discoideum strains NC4 and AX3, and in D. mucoroides. In addition, the enzyme from these four strains was stimulated by AMP and the +AMP/-AMP ratio declined with similar kinetics during activation. The enzyme from Polysphondylium violaceum was not activated on standing, but it was stimulated by AMP. The effect of activation of NAD-GDH is discussed in relation to a postulated catabolic role for this enzyme.

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The Prestalk-Prespore Pattern in Cellular Slime Molds

Cited by 163 publications

References 69 publications

Fate and regulation of anterior-like cells in Dictyostelium slugs

Fate and regulation of anterior-like cells in Dictyostelium slugs

Cell Sorting daring Pattern Formation in Dictyostelium

The effect of AMP on the NAD-dependent glutamate dehydrogenase during activation and morphogenesis in the cellular slime moulds

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