dictyNews
Electronic Edition
Volume 31, number 10
September 26, 2008

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Abstracts
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A 3-D model used to explore how cell adhesion and stiffness affect 
cell sorting and movement in multicellular systems

Eirikur Palsson

Department of Biology, Simon Fraser University, Burnaby, British 
Columbia, Canada V5A 1S6


Journal of Theoretical Biology
Volume 254, Issue 1, 7 September 2008, Pages 1-13

A three-dimensional mathematical model is used to determine the effects 
of adhesion and cell signalling on cell movements during the aggregation 
and slug stages of Dictyostelium discoideum (Dd) and to visualize cell 
sorting. The building blocks of the model are individual deformable 
ellipsoidal cells, where movement depends on internal parameter state 
(cell size and stiffness) and on external cues from the neighboring 
cells, extracellular matrix, and chemical signals. Cell movement and 
deformation are calculated from equations of motion using the total 
force acting on each cell, ensuring that forces are balanced. The 
simulations show that the sorting patterns of prestalk and prespore 
cells, emerging during the slug stage, depend critically on the type 
of cell adhesion and not just on chemotactic differences between 
cells. This occurs because cell size and stiffness can prevent the 
otherwise faster cells from passing the slower cells. The patterns 
are distinctively different when the prestalk cells are more or less 
adhesive than the prespore cells. These simulations suggest that 
sorting is not solely due to differential chemotaxis, and that differences 
in both adhesion strength and type between different cell types play 
a very significant role, both in Dictyostelium and other systems.

Keywords: Dictyostelium; Differential cell adhesion; Pattern formation; 
Ellipsoidal cells; Deformable cells; Prestalk

Submitted by: Eirikur Palsson [epalsson@sfu.ca]
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[End dictyNews, volume 31, number 10]