Umeda, T. and Inouye, K. (2004) Cell sorting by differential cell motility: a model for pattern formation in Dictyostelium. J. theor. Biol. 226, 215-224.
Movies in QuickTime (mac, unix) and avi (wondows) formats
An example of numerical calculation starting from a circular aggregate
of 499 cells and a pacemaker cell positioned near the centre of the aggregate.
The aggregate comprises five cell types with the parameters shown in the
Table 1. Parameters used in the simulation
||3.0 x 10-3
||2.6 x 10-3
||2.2 x 10-3
||0.5 x 10-3
||0.6 x 10-3
Diameter of cell aggregate at t = 0 : 0.3 mm.
Speed : 25 s/frame (5 min/s).
Colour codes :
|Black||: pstAB cells|
|green||: pstA cells|
|orange||: pstO cells|
|yellow||: pstB cells|
|blue||: prespore cells|
- The motive force of prestalk cells and prespore cells is estimated
from the experimental data by Inouye and Takeuchi (1980) and the
average volume per cell.
- The intrinsic resistant rate of prestalk cells and prespore cells is
obtained from the ratio between f and the velocity of a slug
in which the resistance of slime sheath can be neglected
(sufficiently large L in Eq. A of Inouye and Takeuchi 1979).
- Based on Hayashi and Takeuchi (1976); Sternfeld and David (1982);
Gaskell et al. (1992) and author's unpublished data.
Starting from random distribution of all cell types, sorting of
the majority of prestalk cells from prespore cells, shift of the
prestalk region to one end of the aggregate, migration of the aggregate,
and its elongation take place successively.
Shown below are selected frames from the movie overlaid on a single frame
(size reduced to 70%).