부산대학교 도서관

An important open question in the modeling of biological tissues is how to identify the right scale for coarse-graining, or equivalently, the right number of degrees of freedom. For confluent biological tissues, both vertex and Voronoi models, which differ only in their representation of the degrees of freedom, have effectively been used to predict behavior, including fluid-solid transitions and cell tissue compartmentalization, which are important for biological function. However, recent work in 2D has hinted that there may be differences between the two models in systems with heterotypic interfaces between two tissue types, and there is a burgeoning interest in 3D tissue models. Therefore, we compare the geometric structure and dynamic sorting behavior in mixtures of two cell types in both 3D vertex and Voronoi models. We find that while the cell shape indices exhibit similar trends in both models, the registration between cell centers and cell orientation at the boundary are significantly different between the two models. We demonstrate that these macroscopic differences are caused by changes to the cusp-like restoring forces introduced by the different representations of the degrees of freedom at the boundary, and that the Voronoi model is more strongly constrained by forces that are an artifact of the way the degrees of freedom are represented. This suggests that vertex models may be more appropriate for 3D simulations of tissues with heterotypic contacts. Author summary: Proper programming of the collective behavior of cells in biological tissues is required for successful embryonic development, and this programming breaks down in diseases such as cancer. Therefore, an important question is how to develop accurate computational models that can predict emergent collective behavior of cells. Two existing computational models, vertex and Voronoi models, have been used successfully to make quantitative predictions for collective cell behavior, and both predict the same fluid-to-solid transition in tissues, which is important for developmental processes such as body axis elongation. In this work, we study whether Voronoi and vertex models predict the same emergent behavior for cell sorting between two different tissue types, which is important for compartmentalization of tissues and organs during development. We find that the two models predict different features for the geometry and motion of cells, and that the more computationally intensive vertex model more accurately represents cell shapes and dynamics near an interface between two tissue types. [ABSTRACT FROM AUTHOR]