Bases for modeling directed cell migration as a self-organized process emergent from local stochastic interactions. Deterministics and stochastics components compose the dynamics of the directed cell migration.

HESSE RIZZI E; RAPACIOLI M; FLORES V

Congreso; VI International Meeting, Latin American Society for Developmental Biology; 2012

Directed cell migration (DCM) is involved in the elaboration of the supracellular complexity. It participates in the elaboration of the spatial patterning. In the absence of directive influences migrating cells display a white noise stochastic behavior without correlations or random walk (standard Brownian motion: sBm).This work aims at defining basic rules to model DCM as a self-organized process emerging from random local interactions. The model is based exclusively on probabilistic rules about local interactions between migrating cells, between chemoatractants and between chemoatractans and migrating cells. It is also established that a transient change in the probability density function of the direction of the cell displacement takes place when a chemotractant contact the surface of a migrating cell. Chemoatractants are generated at random intervals and positions within a small source or origin, they collide whit each other and diffuse at random from their sites of origin generating a chemotactic gradient that operates onto migrating cells. Mathematical analyses of time series representing positional changes of cell migrating in the absence of the chemotactic gradient gives a scaling index β2.00 indicating a dynamics corresponding to a sBm. The same analysis performed on series obtained from cells submitted to the chemotactic gradient subsumes directive influences revealed by a value of β1.63 indicating a dynamics corresponding to fractional Brownian motion. This migratory dynamics subsume a non-stationary trend that installs correlations and memory between successive positions of each migrating cell. The series representing the DCM subsume two different components: a) a deterministic one representing the non-stationary trend and (b) a stochastic one that does not differs from a random motion in the absence of a chemotactic gradient. Removal of the deterministic component of series corresponding to DCM transforms its dynamic into sBm or random walk; reciprocally, the addition of the deterministic component obtained from series representing DCM into series corresponding to cell with sBm, transform the random walk into a directed displacement. This result shows that the dynamics of a DCM subsumes stochastic and deterministics components that cooperatively contribute to this organizing cell behavior.Work supported by grants from CONICET (Argentina)Este trabajo fue seleccionado por los organizadores para su presentación oral. Fue publicado por Melina Rapacioli.