Berlin 2008 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 1: Cell Migration and Tissue Dynamics
BP 1.10: Vortrag
Montag, 25. Februar 2008, 12:30–12:45, C 243
Dynamics of Anisotropic Tissue Growth — •Thomas Bittig1, Ortrud Wartlick2, Anna Kicheva2, Marcos González-Gaitán2, and Frank Jülicher1 — 1Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany — 2Department of Biochemistry and Department of Molecular Biology, Geneva University, Sciences II, Quai Ernest-Ansermet 30, 1211 Geneva 4, Switzerland
During the development of multicellular organisms, organs grow to well-defined shapes and sizes. The proper size and patterning of tissues are ensured by signaling molecules as e.g. morphogens. Secreted from localized sources, they form graded concentration profiles in the target tissue which provide positional information to the cells.
We describe the growing tissue as a viscous fluid medium in which cell division induces active stresses that drive cell rearrangements. We focus on the case where cell division is anisotropic and a preferred orientation of cell division exists. We determine cellular flow fields using both analytical and numerical methods. If cell division and cell death balance, there is no net growth, but for anisotropic cell division the tissue undergoes spontaneous shear deformations. This is an example of convergence-extension movements which are often observed in developing tissues. Our theory of tissue growth provides a basis for the study of the transport of signaling molecules in growing tissues. Using our theory, we discuss the diffusion and degradation of morphogens in the growing Drosophila wing disk, a precusor of the fly wing.