Locomotory behavior of fibroblasts in "sail-sheets".

The locomotory behavior of fibroblasts in two-dimensional cultures (e.g., on culture dishes, cover slips, etc.) was first reported by Abercrombie's group. This paper describes some of the features of movement of fibroblasts in a unique culture system known as sail-sheet cultures (SSCs). Cells in SSCs grow mostly on one another in a three-dimensional form that resembles, to some extent, the in vivo situation. We grew chicken heart fibroblasts (CHFs) as SSCs and studied their locomotory behavior by time-lapse filming extended for periods ranging from 12 h to several days. It was found that CHFs grown as sail-sheets exhibit many features of movement as observed in conventional two-dimensional cultures (CCs). However, we observed that CHFs in SSCs, like those in vivo, lack leading lamella directing their movement. Furthermore, locomotion is significantly slower in SSCs than in CCs. Based on data on the movement of CHFs within the mesh holes of inert grids, we suggest that the mesenchymal cells in SSCs, in addition to their individual movement, move in sheets and that their movement in sheets results in the closure of the mesh holes, a situation that resembles the phenomenon of healing of wounds. Thus SSCs provide a model system for the study of healing of wounds. The presence of collagenlike extracellular matrix (CLECM) between cellular layers in SSCs suggests that CLECM may be involved in guiding the locomotory behavior of CHFs in SSCs.