THE RENEWAL OF THE EPIDERMIS - A TOPOLOGICAL MECHANISM

Using a topological approach, we study the dynamics of the basement me mbrane of the mammalian epidermis when basal cells detach or divide. A theoretical characterization of the steady state of the tissue, in ve ry good agreement with experimental data, includes for the first time the division and the disappearance of cells in a two-dimensional rando m cellular structure. We predict a strong correlation between the size of the attachment of basal cells to the basement membrane and their b iological behavior (division or detachment). This suggests that the ma in factor determining the fate of basal cells, and thus controlling th e renewal of the epidermis, is the cells' surface tension and adhesion .