An anisotropic attraction model for the diversity and robustness of cell arrangement in nematodes

In early embryogenesis stages in animals, cells are arranged into a species-specific pattern in a robust manner. The cell arrangement patterns are diverse, even among close relatives. We evaluated how the diversity and robustness are achieved in developing embryos. We succeeded in reproducing different patterns of cell arrangements observed in various nematode species using Caenorhabditis elegans embryos by changing the eggshell shapes. This implies that the diversity of cell arrangements can be explained by differences in a shape parameter. Additionally, we found that the cell arrangement was robust against eggshell deformation. Computational modeling revealed that, in addition to repulsion forces, attraction forces are sufficient for this robustness. Genetic perturbation experiments demonstrated that attraction forces derived from cell adhesion are necessary for the robustness. The proposed model accounts for both diversity and robustness of cell arrangements and contributes to our understanding of how diversity and robustness are achieved in developing embryos.