Dynamical Systems Basis of Metamorphosis: Diversity and Plasticity of Cellular States in Reaction Diffusion Network

Abstract

Dynamics maintaining diversity of cell types in a multi-cellular system are studied in relationship with the plasticity of cellular states. By adopting a simple theoretical framework for intra-cellular chemical reaction dynamics with considering the division and death of cells, developmental process from a single cell is studied. Cell differentiation process is found to occur through instability in transient dynamics and cell-cell interaction. In a long time behavior, extinction of multiple cells is repeated, which leads to itinerancy over successive quasi-stable multi-cellular states consisting of different types of cells. By defining the plasticity of a cellular state, it is shown that the plasticity of cells decreases before the large extinction, from which diversity and plasticity are recovered. After this switching, decrease of plasticity again occurs, leading to the next extinction of multiple cells. This cycle of diversification and extinction is repeated. Relevance of our results to the development and evolution is briefly discussed.