Program
| MSD3b | |
|---|---|
| Athanasius F. M. (Stan) Marée | |
| University of Utrecht | |
| Title | Cell polarity in plants and animals: a conservation of principles |
| Abstract | Animal cells display a fascinating ability to undergo cell shape changes and move. In contrast, plant cells are encased in a relatively rigid cellulose cell wall, which impedes cell motility. Even though plants and animals split up 1.6 billion years ago, molecular and genetic studies reveal that plant and animal cells still share the a similar core machinery required for cell shape changes. A fascinating similarity between animal and plant cells in the organisation of cytoskeletal elements in the regions of active protrusive growth and cell wall extension (the `leading edges'), is parallelled by a striking conserved molecular mechanism responsible for the creation and organisation of these `leading edges'. The key players underlying cell polarity in animals, the small G-proteins, are very similar to polarity determinants in plants, the Rho of Plants, ROPs. Both are switched between active, membrane-bound forms and inactive forms that can enter the cytosol. To unravel and understand the interplay and feedbacks which brings about animate cell motility, we have developed a multiscale model of a motile cell, describing small G-protein dynamics, PIPs, actin filament turnover, and cell deformation. By explicitly modelling the fish epidermal keratocyte, we study how the emergence of a single, stable front and directed motion. We then contrast this to the cell shape changes that occur in the pavement cells (PCs) in the leaves of plants. PCs develop complex forms that resemble pieces from a jigsaw puzzle. The cells grow multiple lobes, which fit perfectly into the indentations of the neighbouring cells, generating interdigitating patterns. We will show that similar modular principles as found in the keratocyte play a role. Here, however, it generates an interdigitating pattern between cells, generating multiple stable `leading edges'. Thus, we are able to unravel both mathematically and computationally a 1.6-billion-year-old principle of cell polarity. |
| Location | Woodward 3 |