A Model of Convergent Extension in Animal Morphogenesis

In this paper we argue that the pattern of cell movements in the morphogenetic process known as convergent extension can be understood as a energy minimization process, provided the cell-cell adhesive energy has a certain kind of anisotropy. This single simple property is sufficient cause for the type of cell elongation, alignment, and intercalation of a cellular array that is the characteristic of convergent extension. We describe the type of anisotropy required. We show that the final aspect ratio of the array of cells is independent of the initial configuration and of the degree of cell elongation. We find how it depends on the anisotropy.