Spontaneous architectural organization of mammalian epidermis from random cell packing.

The cells of the stratum corneum in the epidermis of some mammalian species are precisely stacked in columns in a honeycomb fashion. The epidermis constantly loses surface cells, which are replaced by basal cells that have differentiated during migration to the surface. The path of this migration is seen as precisely defined columns of cells that are in compressed Kelvin's tetrakaidecahedral form. We present a computer simulation of this architectural organization based on the assumption that the cells that migrate upward occupy less crowded regions. The simulation not only explained the mechanism by which the architecture is maintained during the process of cell replacement, but also showed that the architecture was spontaneously organized from initial cells supplied at random. Living organisms consist of self-organizing systems at various levels; however, self-organizing systems have been investigated mostly at the molecular level. The present computer simulation clarified the self-organizing system at the cellular level.