title: A three-dimensional model of myxobacterial aggregation by contact-mediated interactions.
abstract: Myxobacteria provide one of the simplest models of cell-cell interaction and organized cell movement leading to cellular differentiation. When starved, tens of thousands of cells change their movement pattern from outward spreading to inward concentration; they form aggregates that become fruiting bodies. Cells inside fruiting bodies differentiate into round, nonmotile, environmentally resistant spores. Traditionally, cell aggregation has been considered to imply chemotaxis; a long-range cell interaction. However, myxobacterial aggregation is the consequence of direct cell-contact interactions, not chemotaxis. We present here a 3D stochastic lattice-gas cellular automata model of cell aggregation based on local cell-cell contact, and no chemotaxis. We demonstrate that a 3D discrete stochastic model can simulate two stages of cell aggregation. First, a "traffic jam" forms embedded in a field of motile cells. The jam then becomes an aggregation center that accumulates more cells. We show that, at high cell density, cells stream around the traffic jam, generating a 3D hemispherical mound. Later, when the nuclear traffic jam dissolves, the aggregation center becomes a 3D ring of streaming cells.
authors.affiliation: Department of Mathematics and Center for the Study of Biocomplexity, University of Notre Dame, Notre Dame, IN 46556-5670, USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Sozinova
authors.forename: Yi
authors.initials: Y
authors.lastname: Jiang
authors.forename: Dale
authors.initials: D
authors.lastname: Kaiser
authors.forename: Mark
authors.initials: M
authors.lastname: Alber
mesh_terms: D008954:Models, Biological; D009068:Movement / Q000502:physiology*; D016941:Myxococcus xanthus / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D013171:Spores, Bacterial / Q000502:physiology