The body's control over tissue cell migration appears to fail during malignant invasion. Since in these cases only the invading cells are escaping the control, it seems likely that their own control systems of cell migration are malfunctioning. This proposal aims at the role of the centrosphere in the control of tissue cell migration in vitro. Using a new method that allows for the first time to visualize reproducibly the centrosphere in living, migrating cells the proposal intends to relate movements of the centrosphere with movements of the entire normal and virus-transformed cells. In particular the timing of movements of the centrosphere with respect to other time marks during reflattening after mitosis, symmetrical migration of sister cells, cell-cell collision, contact guidance, group migration and substrate-probing of the cells will be examined, in order to determine the controlling events. Traumatization of the centrosphere by microirradiation and drugs will be related to subsequent changes of motile behavior of the cells. Changes in microtubules radiating from the immunofluorescence. Similar methods will be aplied to determine the role of microfilaments and intermediate filaments in the movement of the centrosphere. The ability of multiple centriole pairs to cooperate within the same cell will be tested by a careful examination of the migration and the centrosphere in syncitia of normal and transformed cultured cells. (L)