Berlin 2015 – scientific programme

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BP: Fachverband Biologische Physik

BP 26: Posters: Statistical Physics of Biological Systems

BP 26.15: Poster

Tuesday, March 17, 2015, 14:00–16:00, Poster A

Stochastic Terminal Dynamics in Epithelial Cell Intercalation — •Matthias Häring¹, Stephan Eule¹, Jakob Metzger¹, Lars Reichl¹, Deqing Kong², Yujun Zhang², Jörg Großhans², and Fred Wolf¹ — ¹Max Planck Institute for Dynamics and Self-Organization, Am Faßberg, 37077 Göttingen, Germany — ²Institute for Developmental Biochemistry, Medical School, University of*Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany

We found that the constriction of epithelial cell contacts during intercalation in germ band extension in Drosophila embryos follows intriguingly simple quantitative laws. The mean contact length ⟨ L ⟩ follows ⟨ L ⟩(t)∼ (T−t)^α , where T is the finite collapse time; the time dependent variance of contact length is proportional to the square of the mean; finally the time dependent probability density of the contact lengths remains close to Gaussian during the entire process. These observations suggest that the dynamics of contact collapse can be captured by a single stochastic differential equation in a small noise regime. Here, we present such a model, providing an effective description of the non-equilibrium statistical mechanics of contact collapse. All model parameters are fixed by measurements of time dependent mean and variance of contact lengths. Our model predicts the existence of a quasi-stationary distribution of contact lengths. We investigate this quasi-stationary distribution numerically and present an analytical solution for model parameters that are close to the measured values.