The morphogenesis of dictyostelium discoideum — Pattern formation in a biological excitable system

Siegert, Florian; Vasiev, Bakhtier; Weijer, Cornelis J.

doi:10.1007/bfb0104961

Cited by 1 publication

(8 citation statements)

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“…Multiple tip phenotype induced by caffeine was observed in all the slime molds species we investigated suggesting a conserved mechanism regulating secondary tip formation in slime molds. The formation of secondary tips is controlled by relayed cAMP signal strength and suppression of tip dominance [ 17 ]. In this study, we examined the mechanism that regulates multiple tip formation in the presence of caffeine.…”

Section: Discussionmentioning

confidence: 99%

“…The single slug tip, like an organiser of the metazoan embryo regulates multicellular development [ 15 ]. The tip of the slug acts as a pacemaker [ 16 ] and secretes cAMP signals periodically with a propagation speed of 200 μm/min [ 17 ]. The cell movement within the slug is directed and move with an average period of 3 minutes [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

“…The tip of the slug acts as a pacemaker [ 16 ] and secretes cAMP signals periodically with a propagation speed of 200 μm/min [ 17 ]. The cell movement within the slug is directed and move with an average period of 3 minutes [ 17 ]. The cAMP waves are initiated at the slug tip and propagate towards the back of the slug [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

“…Because of the primary tip dominance, additional tip formation is repressed [ 14 ], a phenomenon called tip inhibition and adenosine plays a crucial role in this process by inhibiting new tip formation [ 14 ]. The mechanism of multiple tip formation is not well understood but it is believed that cAMP relay might regulate this process [ 17 ]. Caffeine is known to inhibit the oscillatory cAMP relay [ 17 , 18 ] and removes tip inhibition by reducing the amplitude and oscillation frequency of cAMP signals [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

“…The mechanism of multiple tip formation is not well understood but it is believed that cAMP relay might regulate this process [ 17 ]. Caffeine is known to inhibit the oscillatory cAMP relay [ 17 , 18 ] and removes tip inhibition by reducing the amplitude and oscillation frequency of cAMP signals [ 17 ]. Caffeine, the antagonist of adenosine favours tip activation inducing multiple tip formation [ 17 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

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Regulation of multiple tip formation by caffeine in cellular slime molds

et al. 2012

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BackgroundThe multicellular slug in Dictyostelium has a single tip that acts as an organising centre patterning the rest of the slug. High adenosine levels at the tip are believed to be responsible for this tip dominance and the adenosine antagonist, caffeine overrides this dominance promoting multiple tip formation.ResultsCaffeine induced multiple tip effect is conserved in all the Dictyostelids tested. Two key components of cAMP relay namely, cAMP phosphodiesterase (Pde4) and adenyl cyclase-A (AcaA) levels get reduced during secondary tip formation in Dictyostelium discoideum. Pharmacological inhibition of cAMP phosphodiesterase also resulted in multiple tips. Caffeine reduces cAMP levels by 16.4, 2.34, 4.71 and 6.30 folds, respectively in D. discoideum, D. aureostipes, D. minutum and Polysphondylium pallidum. We propose that altered cAMP levels, perturbed cAMP gradient and impaired signalling may be the critical factors for the origin of multiple tips in other Dictyostelids as well. In the presence of caffeine, slug cell movement gets impaired and restricted. The cell type specific markers, ecmA (prestalk) and pspA (prespore) cells are not equally contributing during additional tip formation. During additional tip emergence, prespore cells transdifferentiate to compensate the loss of prestalk cells.ConclusionCaffeine decreases adenyl cyclase–A (AcaA) levels and as a consequence low cAMP is synthesised altering the gradient. Further if cAMP phosphodiesterase (Pde4) levels go down in the presence of caffeine, the cAMP gradient breaks down. When there is no cAMP gradient, directional movement is inhibited and might favour re-differentiation of prespore to prestalk cells.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%