Self-organization of dynamic network structure of mesoderm cells

Self-organization of various cellular structures is of fundamental importance in morphogenesis during development of biological organisms. Our colleagues recently found that mesoderm cells organize into dynamic network structure in early chick embryo. During the development of the chick embryo the mesoderm cells that appear through invagination at the primitive streak migrate collectively in the lateral direction between the epiblast and the endoderm. While moving collectively the mesoderm cells organize into a network structure where spaces void of cells filled with extracellular liquid are surrounded by cells that are connected to each other. The network of mesoderm cells undergoes reconnection dynamically. We developed a theoretical model of self-propelling cells of elongated shape to understand the mechanism of the dynamic network structure formation. By introducing a short-range attractive interaction with a repulsive core between elliptically deformed cells the model cells reproduced the network structure for intermediate strengths of the attractive interaction. The results were compared with the experiment quantitatively by using persistent homology.