Understanding how biological tissues are shaped during development is one of the most fascinating open questions in biology. Epithelial tissues form robust mechanical and chemical barriers. This property is essential for the physiology of adult organs and the protection against pathogens. Epithelia also show tremendous plasticity during embryonic development and organ regeneration, namely the capacity to adapt to intrinsic or extrinsic signals or perturbations. Two kinds of plasticity are manifested. First, tissues are remodelled by cell movements or cell shape changes during morphogenesis. Second, as tissues grow, epithelial cells need to accommodate new space for dividing cells so that local cell growth and cell division impact on the global tissue growth. Cells may also extrude live or by apoptosis. Together, cell movements, cell division and extrusion endow epithelial tissues with fluid properties (reviewed in Guillot and Lecuit, 2013a). Tissue robustness and plasticity relies on unique properties of cell contacts, in particular adhesive mechanisms and actomyosin tensile forces that are generated and transmitted at the cell cortex. Disruption of tissue cohesion and plasticity leads to loss of tissue homeostasis and profound tissue disorders such as perturbation of the polarized organization and of growth control as manifested in solid cancers.
Research in my group integrates developmental, cellular and biophysical understanding of how tissue cohesion and plasticity are controlled in animals using Drosophila as a model organism.
Our ongoing and future research aims at understanding the molecular mechanisms of tissue morphogenesis and tissue growth in epithelia. A major ambition is to integrate genetic control and mechanical constraints in the regulation of tissue morphogenesis and homeostasis.
The projects we work on in the context of the Labex INFORM are the following:
- Polarization and organisation of E-cadherin in clusters: (Veronika Aksenova, coll. with A Le Bivic and PF Lenne). We study how polarity proteins control E-cadherin apico-basal distribution and its organisation in epithelial cells.
- Force transmission by adhesion complexes: (Girish Kale, coll. with PF Lenne). We study how Vinculin senses and mediates force transmission by E-cadherin at cell cell contacts and use this to map subcellular force distribution during tissue morphogenesis.
- Biomechanics of tissue invagination: (Anaïs Bailles, coll. with PF Lenne). We study invagination of the embryonic endoderm and how tissue curvature and cellular flows emerge from patterns of contractility mediated by actomyosin networks.
- Morphogenesis of dendritic neurons: (Amrutha Palavalli). We are interested in how morphogenesis of dendritic neurons, which form 2D arborisation at the base of the epithelial layer is controlled, are explore the role of mechanical tension in this process
- More information here