Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 87 (10), 845-61

Dual Chemotaxis Signalling Regulates Dictyostelium Development: Intercellular Cyclic AMP Pulses and Intracellular F-actin Disassembly Waves Induce Each Other

Affiliations

Dual Chemotaxis Signalling Regulates Dictyostelium Development: Intercellular Cyclic AMP Pulses and Intracellular F-actin Disassembly Waves Induce Each Other

Michael G Vicker et al. Eur J Cell Biol.

Abstract

Aggregating Dictyostelium discoideum amoebae periodically emit and relay cAMP, which regulates their chemotaxis and morphogenesis into a multicellular, differentiated organism. Cyclic AMP also stimulates F-actin assembly and chemotactic pseudopodium extension. We used actin-GFP expression to visualise for the first time intracellular F-actin assembly as a spatio-temporal indicator of cell reactions to cAMP, and thus the kinematics of cell communication, in aggregating streams. Every natural cAMP signal pulse induces an autowave of F-actin disassembly, which propagates from each cell's leading end to its trailing end at a linear rate, much slower than the calculated and measured velocities of cAMP diffusion in aggregating Dictyostelium. A sequence of transient reactions follows behind the wave, including anterior F-actin assembly, chemotactic pseudopodium extension and cell advance at the cell front and, at the back, F-actin assembly, extension of a small retrograde pseudopodium (forcing a brief cell retreat) and chemotactic stimulation of the following cell, yielding a 20s cAMP relay delay. These dynamics indicate that stream cell behaviour is mediated by a dual signalling system: a short-range cAMP pulse directed from one cell tail to an immediately following cell front and a slower, long-range wave of intracellular F-actin disassembly, each inducing the other.

Similar articles

See all similar articles

Cited by 7 articles

See all "Cited by" articles

LinkOut - more resources

Feedback