How do cells interpret the multiple signals they receive into the complex behaviours of gastrulation? (360G-Wellcome-102490_Z_13_Z)

During early development the embryo generates a complex architecture from multipotent cells. One of the first events is the establishment of bilateral symmetry: during gastrulation, cells rearrange themselves as they acquire different fates, all controlled by signals from different subpopulations of cells. Although we know many of the players, we know surprisingly little aboutwhich particular signal regulates which cell behaviour, or how cells integratesignals to generate regional complexity. Using the chick embryo as a model, wewill first create an atlas of cell behaviours and signalling activity in normal embryos and during experimentally-induced twinning. Subsequently, we will investigate the individual contribution of each of the pathways, and combinations thereof, to these complex cellular decisions, using gain- and loss-of-function experiments in normal embryos and fragments. Finally, we aim to integrate this knowledge by creating an agent model with predictive power, relating signalling to cellular behaviours during normal development and twinning. Together this project will disentangle the roles of different signals in establishing polarity, assigning cell fates and selecting from a vast array of possible cell behaviours during amniote gastrulation, which are also relevant to human twinning.