Mid-Term Report Summary - LIMBCELLDYNAMICS (Imaging and Regulation of the Cellular Dynamics Driving the Vertebrate Limb Formation)
We have made tremendous progress in establishing the quail animal as a true genetic animal model. We are now able to generate transgenic quail lines in extremely fast and efficient manners and we are getting closer to generate custom genetically engineered quails. Quails display several advantages that make them excellent models to study embryonic processes: 1) quails belong to the Amniote clade therefore, their embryonic development is very close to mammal development including humans; 2) the generation time of quails is 10 weeks which is much faster than any other common birds and equivalent to mouse; 3) quail embryos are highly amenable live imaging methodologies, enabling to grasp the dynamic dimension of embryonic processes, a very difficult task using other Amniote models. By successfully generating numerous transgenic quail lines which report dynamic cell behavior and signaling pathways integration we have started to shed new light on the consecutive steps involved in limb formation in vertebrates (i.e.limb progenitor cells specification and emergence). For instance, we found that cell division acts as a major epithelial remodeling driver that is necessary for the establishement of proper gastrulation, the process during which limb progenitors, along with other mesodermal progenitors, are being generated. This work has been recently published "Developmental Cell". Thanks to these novel genetic tools, we are pursuing the investigation of the molecular and celluar events by which limbs acquire their position along with the ones underlying limb initiation and patterning. This work is currently ongoing.