Actin aggregation and embryonic epidermal wound healing

Recent experiments on the response of embryonic epidermis to wounding have revealed a cable of filamentous actin at the wound edge, which may be responsible for healing (Martin and Lewis 1991, 1992). We investigate the important question of how the cable forms as a response to wounding. We modify the mechanical model of Murray and Oster (1984) to investigate the post-wounding equilibrium in the epidermal sheet. We analyse the model in both one-dimensional and radially symmetric two-dimensional geometries, to determine the parameter domain in which a solution exists. We show that in both geometries the model solutions reflect the phenomenon of the actin cable for parameter values close to one edge of this domain. We interpret these results in terms of the relative rates of intracellular reorganization of actin and myosin, and thus suggest a possible mechanism for the formation of the actin cable.