Séminaire IUSTI – 16 oct. 2020 – 11h salle 250

Mechanics of cell contacts during tissue morphogenesis

Raphaël Clément – IBDM, AMU, Marseille

Tissue shape changes during embryonic development can be achieved by the local generation of contractile forces at cell contacts. Understanding how such forces are converted into cell shape changes is essential to our understanding of tissue morphogenesis. To that end we analyzed in vivo the deformation dynamics of cell contacts resulting from both endogenous forces (Myosin-II contractile activity) and external forces (optical tweezers). It is consistent with a simple viscoelastic framework, with internal dissipation occurring on the minute timescale. Interestingly this timescale is commensurate with that of endogenous force generation, allowing efficient remodelling of cell contacts. We also show that the turnover of cytoskeletal filaments, by renewing the mechanical structure of the cell, participates in dissipation and therefore affects the reversibility of deformations. I’ll also discuss recent results on the mechanism of spontaneous symmetry breaking that underlie the asymmetric division of the oocyte during mammalian meiosis.