Fig. 8. Aberrant chemotaxis in DEP-1-expressing NIH3T3 cells. Cells were placed in Dunn chambers and a gradient of PGDF introduced. Cell motility was recorded by time-lapse videomicroscopy. (A) Parallel cultures of control 1A2 and DEP-1-expressing 2D3 cells imaged at 10-minute intervals for the first 60 minutes of a 6-hour chemotaxis assay. 1A2 cells migrate up the PDGF gradient, while 2D3 cells do not. (B) Horizon plots of 1A2 and 2D3 cell populations analysed for directional migration over the full 6-hour period of the assay. Significant unimodal clustering of cell directions is seen in the 1A2 population (arrow plus 95% confidence limit). As the mean direction of cell movement is upward, we conclude that 1A2 cells show positive chemotaxis to a source of PDGF (n=25 cells, taken from three separate experiments in each case).