The cell-level perspective in social conflicts in Dictyostelium discoideum

Chemotactic cell sorting in Dictyostelium discoideum.

We made mixed mounds of vitally stained prestalk cells and unstained prespore cells, from Dictyostelium discoideum (Dd), and exposed these to external 3',5'-cyclic-AMP (c-AMP) sources. We show that prestalk cells will sort out by moving directionally toward c-AMP sources held at less than 10(-5) M c-AMP. This is evidence for cell sorting via chemotaxis. We present arguments that the natural cel...

Cell-sorting in aggregates of Dictyostelium discoideum.

When Dictyostelium cells are induced to develop between a coverslip and a layer of agarose, they aggregate normally into groups containing up to a thousand cells but are then constrained to form disks only a few cells thick that appear to be equivalent to the three-dimensional mounds formed on top of agarose. Such vertically restricted aggregates frequently develop into elongated motile structu...

Single-gene greenbeard effects in the social amoeba Dictyostelium discoideum.

Selection can favor reproductive altruism if an altruism allele aids copies of itself by helping relatives. The alternative "greenbeard" mechanism, in which an allele directly recognizes and aids copies of itself in others, is generally thought to be too complex for a single gene to carry out. The csA gene in Dictyostelium discoideum acts as a single-gene greenbeard. When wild-type cells are mi...

Sex determination in the social amoeba Dictyostelium discoideum.

The genetics of sex determination remain mysterious in many organisms, including some that are otherwise well studied. Here we report the discovery and analysis of the mating-type locus of the model organism Dictyostelium discoideum. Three forms of a single genetic locus specify this species' three mating types: two versions of the locus are entirely different in sequence, and the third resembl...

influx in Dictyostelium discoideum