​Epithelial-to-mesenchymal transition is the process during which non-motile epithelial cells acquire mesenchymal phenotypes. This process is essential for development and in disease. This transition is marked by changes in key cellular processes and signaling. This transition needs extensive remodeling of the cytoskeleton. We want to study how the cytoskeleton is regulated during this transition during mammalian development. EMT during early human development has been studied using human pluripotent stem cell models, but these studies are limited to 2D models. While the 2D models help study early human development at a cellular level, they fail to give a holistic view of the cues a developing human embryo receives in vivo. We have generated gastruloids, an emerging model for recapitulating gastrulation, the first instance of EMT during development. We will use the 2D and 3D models to study how the cytoskeleton is regulated in developmental EMT.