title: Making waves: pattern formation by a cell-surface-associated signal.
abstract: Starving Myxococcus xanthus cells organize into two strikingly different spatio-temporal patterns, either rippling or aggregation of cells into fruiting bodies. Formation of both patterns depends on a cell-surface-associated, non-diffusible signal, the C-signal. A key motility parameter modulated by the C-signal during pattern formation is the frequency at which cells reverse their gliding direction, with low and high levels of C-signalling causing an increase and a decrease in the reversal frequency, respectively. Recently, a simple yet elegant mathematical model was proposed to explain the mechanism underlying the non-linear dependence of the reversal frequency on C-signalling levels. The mathematical solution hinges on the introduction of a negative feedback loop into the biochemical circuit that regulates the reversal frequency. This system displays an oscillatory behaviour in which the oscillation frequency depends in a non-monotonic manner on the level of C-signalling. Thus, the biochemical oscillator recapitulates the effect of the C-signal on the reversal frequency. The challenge for biologists now is to test the mathematical model experimentally.
authors.affiliation: Max Planck Institute for Mathematics in the Sciences, Inselstr. 22-26, 04103 Leipzig, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Stevens
authors.forename: Lotte
authors.initials: L
authors.lastname: Søgaard-Andersen
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D008954:Models, Biological; D009068:Movement; D016941:Myxococcus xanthus / Q000166:cytology / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins