Fig. 3. Although pten^– cells undergo positive chemotaxis up spatial gradients of cAMP, they exhibit the same fundamental behavioral defects manifested in the absence of attractant. (A,B) Perimeter and centroid tracks of representative parental AX2 (A) and pten^– (B) cells pulsed for 6 hour with cAMP to achieve aggregation competence and then analyzed in a spatial gradient of attractant. (C,D) Perimeter and centroid tracks of representative parental AX2 (C) and pten^– (D) cells developed on pads to achieve aggregation competence and then analyzed in a spatial gradient of attractant. (E,F) Pad-developed parental (E) and pten^– (F) cells undergoing chemotaxis that were reconstructed with 3D-DIAS software over 150-second or 125-second periods, respectively. The thin arrows in A-D indicate the net direction of migration for each cell. The thick arrow in A-F indicates direction of increasing cAMP concentration. Plus (+) and minus (–) in A-D indicate a positive or negative chemotactic index, respectively, for each cell computed over the period of analysis. Color-coding of reconstructions in E and F are the same as in Fig. 1.