3D Simulations of Morphogen Transport in an Early Fish Embryo

During the early stages of embryonic development, various means of cell communication orchestrate tissue development within the highly dynamic environment. Signalling gradients of morphogens determine cell fates, tissue generation, and in the long run organs of the final organism. In our research we focus on the distribution and effects of Wnt8a, a morphogen involved in the development and differentiation of the brain. In a previous work we were able to show experimentally that this protein is distributed by a novel short-range propagation mechanism by means of specialized filopodia[1]. Here we present our results on extending these simulations of a simple flat tissue towards a more accurate description of the embryo in a 3D environment.The simulation models the tissue expansion on a 3D spherical surface and morphogen distribution via filopodia formation. It integrates length and angle distributions as well as growth frequencies of the filopodia, cell migration, and a slight ligand decay consistently with experimental measurements. Additionally it extends our previous model by explicitly considering the movement of the Wnt8a source.[1] Filopodia-based Wnt transport during vertebrate tissue patterning. Stanganello, E., Hagemann, A. I. H., Mattes, B., Sinner, C., Meyen, D., Weber, S., Schug, A., Raz, E. and Scholpp, S., Nature Communications 6, 2015