Three-dimensional scroll waves of cAMP could direct cell movement and gene expression in Dictyostelium slugs.
Complex three-dimensional waves of excitation can explain the observed cell movement pattern in Dictyostelium slugs. Here we show that these three-dimensional waves can be produced by a realistic model for the cAMP relay system [Martiel, J. L. & Goldbeter, A. (1987) Biophys J. 52, 807-828]. The conversion of scroll waves in the prestalk zone of the slug into planar wave fronts in the prespore zone can result from a smaller fraction of relaying cells in the prespore zone. Further, we show that the cAMP concentrations to which cells in a slug are exposed over time display a simple pattern, despite the complex spatial geometry of the waves. This cAMP distribution agrees well with observed patterns of cAMP-regulated cell type-specific gene expression. The core of the spiral, which is a region of low cAMP concentration, might direct expression of stalk-specific genes during culmination.
Bretschneider
T
T
Zoologisches Institut, Ludwig-Maximilians-Universität München, Germany.
Siegert
F
F
Weijer
C J
CJ
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D002465:Cell Movement; D000242:Cyclic AMP / Q000502:physiology*; D004023:Dictyostelium / Q000235:genetics / Q000502:physiology*; D015870:Gene Expression; D008954:Models, Biological; D013997:Time Factors
D000255:Adenosine Triphosphate; D000242:Cyclic AMP