Invité par Nicolas Minc, Matteo Rauzi (Université Côte d’Azur, CNRS, Inserm, iBV, Nice, France) donnera un séminaire IJM le 7 avril sur le thème :
Composite morphogenesis: how can a tissue fold and extend at the same time
During embryo development, epithelia can undergo different shape transformations. While these changes can be sequential, and thus driven by specific sequential cellular mechanisms, this is not always the case. A single tissue can undergo multiple simultaneous shape transformations resulting in a composite process. For instance, in vertebrates, during neurulation, the dorsal tissue folds forming the neural tube while elongating along the anterior-posterior axis separating the future head from the anus (Keller, 2002). This raises an important question: how can a tissue undergo multiple simultaneous shape transformations if each transformation is per se driven by different and functionally specific cellular mechanisms? In addition, which signaling pathways are controlling composite morphogenetic processes? We use the protostome Drosophila and the deuterostome sea urchin P. lividus embryo as model systems and focus on the process of simultaneous tissue folding and extension resulting in the formation of an epithelial tube at the onset of gastrulation. By using advanced multi-view light sheet microscopy coupled to infrared femtosecond laser manipulation, optogenetics and quantitative big data analysis, we aim to shed new light on evolutionary conserved signaling pathways, mechanisms and mechanics controlling and driving composite morphogenesis.