LIQUID-FILM MODEL OF TETRAKAIDECAHEDRAL PACKING TO ACCOUNT FOR ESTABLISHMENT OF EPIDERMAL-CELL COLUMNS

[摘要] The possibility that the organization of cells into columns in the mammalian epidermis may be a result of the close packing of these cells was investigated in a model system involving the association of randomly produced soap bubbles into a stable froth. Upon floating to the surface of a liquid, soap bubbles were spontaneously assembled into precise columns of interdigitating bubbles. The tetrakaidechahedral shape and the spatial configuration of these bubbles closely resemble those of stacked epidermal cells, although the columns of a frothe were oriented at a 60.degree. angle to their substratum rather than at right angles as occurs in the epidermal cell columns. The organization of the cells in the epidermis into columns is probably due to the assumption of the keratocytes of a minimum surface-close packing array. Such an organizing mechanism would be independent of both positional control of the underlying mitoses and active guidance of the cells as they become superficially displaced within the epidermis. The observation that a high rate of cell turnover is incompatible with the epidermal column structure may be related to the finding that rapidly produced soap bubbles do not, at least initially, assemble into a columnar array.