Models of Dictyostelium discoideum Aggregation

Abstract

Since its discovery in the 1940’s, the life cycle of the cellular slime mould Dictyostelium discoideum has attracted the interest of developmental biologists. It involves a relatively simple transition from unicellular to multicellular organization. Briefly, amoebae feed on bacteria in the soil and divide. Exhaustion of the food supply triggers a developmental sequence which leads, via cell aggregation, to the formation of a migrating slug-like “organism”. The slug eventually culminates into a fruiting body, aiding the dispersal of spores from which, under favourable conditions, new amoebae develop. To date a variety of species in different taxonomic groups are known whose life cycles follow a similar pattern (Margulis & Schwartz 1988). Over the past fifty years, many of the molecular and cellular mechanisms which are involved in cell aggregation, collective movement and differentiation have been identified, and much work is devoted to the understanding of the interaction of these mechanisms in shaping Dictyostelium development. Mathematical modelling has proved a useful tool with which to study these interactions on a quantitative basis.