LAUSR

Imaging and mathematical analyses reveal how Dictyostelium discoideum cells navigate around obstacles in their environment. Slime mold obstacle course The slime mold Dictyostelium discoideum, which lives in the soil, is an experimental model of cell migration. Starving Dictyostelium cells secrete the chemoattractant cAMP, which stimulates the cells to migrate in head-to-tail streams, eventually leading to the formation of fruiting bodies required for cell survival. Eckstein et al. generated substrates containing pillars of different sizes and patterns and performed mathematical analysis of images of cAMP and the migrating cells to determine how the Dictyostelium cells interpreted waves of chemoattractant disrupted by obstacles. This analysis could be applied to understanding how collections of cells interact with spatial barriers in their environment. In its natural habitat in the forest soil, the cellular slime mold Dictyostelium discoideum is exposed to obstacles. Starving Dictyostelium cells secrete cAMP, which is the key extracellular signaling molecule that promotes the aggregation process required for their long-term survival. Here, we investigated the influence of environmental inhomogeneities on the signaling and pattern formation of Dictyostelium cells. We present experimental data and numerical simulations on the pattern formation of signaling Dictyostelium cells in the presence of periodic arrays of millimeter-sized pillars. We observed concentric cAMP waves that initiated almost synchronously at the pillars and propagated outward. In response to these circular waves, the Dictyostelium cells streamed toward the pillars, forming aggregates arranged in patterns that reflected the periodicity of the lattice of pillars. Our results suggest that, in nature, the excitability threshold and synchronization level of the cells are two key parameters that control the nature of the interaction between cells and spatial heterogeneities in their environment.