Fig. 10. Effect of exogenous 4.1B expression on the chemotaxis of T15 sarcoma cells. The motility of cells in the Dunn chemotaxis chamber was recorded 5 hours after microinjection and evaluated in a way similar to experiments presented in Fig. 2A. (A,B) Cell tracks with starting points shifted to a common origin are for uninjected cells (A) and in cells expressing a mixture of 4.1B and GFP (B). Bar, 100 µm. The speed of cell migration of the expressing cells was significantly reduced 2.3 times (ANOVA P<0.02; numbers of time-lapse recordings and cells were 14 and 41, respectively, for uninjected cells, and 9 and 29, respectively, for cells expressing 4.1B and GFP). (C,D) Circular histograms of cells that migrated 10 µm for uninjected cells (C) and for cells expressing 4.1B and GFP (D). Arrow (mean direction) and a grey wedge (its 95% confidence interval) indicate unimodal significant clustering of the directions (Rayleigh test P<0.001). The chemotactic response, measured by the displacement in the gradient direction, is significantly different (ANOVA P<0.05; numbers of cells that migrated 10 µm were 41 for uninjected cells and 27 for cells expressing 4.1B and GFP).