Actin filaments in normal and migrating corneal epithelial cells.

The distribution of actin filaments in the cytoplasm of normal and migrating rat corneal epithelium was studied by in situ labeling with myosin subfragment-one. In normal epithelium, actin filaments are present as an apical network under microplicae of superficial cell layers. This apical actin network is possibly a cytoskeleton responsible for maintenance of the regular array of microplicae. A dramatic difference in distribution of actin filaments was noted between the normal cells and cells migrating to cover an abrasion. In migrating epithelial cells, actin filaments are concentrated is basal regions of the cells. They are present as bundles of parallel filaments near the basal plasmalemma and in networks of filaments in leading edges and cell processes. These basally located actin filaments may play a role in migration of the cells during wound healing.