Date : 06/06/2011

Internship proposal for : Master 1 or Master 2

Laboratory
Laboratoire Joliot-Curie - USR3010
ENS Lyon & CNRS
46, Allee d'Italie
69007 Lyon
Website : http://www.ens-lyon.fr/Joliot-Curie/spip.php?rubrique53
Main discipline : Biophysics
Lab director : Françoise Argoul

Mentor
Prof. Arezki Boudaoud
email : This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
phone : 04 72 72 88 75

Subjects
1.: Morphogenesis
2.: Development
3.: Mechanics

Tools and methodologies
1.: Continuum mechanics
2.: Cell-based models
3.: Gene regulatory networks

Summary of lab's interests

Our team combines biological, physical and computational approaches to Development. We address the emergence of shape, how shape serves as a template for differentiation and how shape feeds back on cell identity. Our model system is the shoot apex of Arabidopsis, which is a major determinant of plant architecture. In addition to standard molecular tools, we are developing cutting-edge methods for live imaging and mechanical characterization. We use physical and computational approaches to understand the links between the cell and tissue levels.

Summary of project

The emergence of shape in an organism involves changes in its structural elements -- adding new materials and remodeling old materials. In this context, morphogenesis appears as a physical process guided by the activity of cells. Therefore the investigation of morphogenesis must also address the dynamics of the structural elements of the organism during its development. Plants are perfectly suited for such an investigation, as their shape is mostly imposed by the stiff cell walls that surround cells and by the osmotic pressure that inflates cells. The main goal of the project is to build predictive mechanical models of morphogenesis. Theses models will be based on a representation of walls and cells as visco-elastic elements (springs or ellipsoids), viscosity being an effective representation of growth. The team has a strong background in this approach for two-dimensional tissues, and the project will address extensions to three-dimensional tissues. A first question will be that of the maintenance of a stable, dynamic, axisymmetric dome at the tip of the stem. What is the minimal set of rules to obtain such a stationary shape ? Do these rules allow us to reproduce the variability of shapes observed in Nature ? More generally, this work will help building a new framework for morphogenesis.