Fig. 6. Motility analysis of Ad2–TR in HeLa cells treated with PKA or p38 inhibitors and in MK2^+/+ and MK2^–/– mouse embryo fibroblasts. Ad2–TR was imaged in time-lapse mode and ES analyzed for each particle (n) in control or inhibitor-treated HeLa cells at 20–60 min p.i., and in mouse embryo fibroblasts at 30–45 min p.i. Population velocities, population motilities and the average fractions of the vectorial ES components (mot c and mot p) were determined as described in Materials and methods. v_c and v_p (mean/SEM) are the average vectorial velocity components to and from the center for each particle, respectively. v_l depicts the mean lateral vectorial velocity and 2 v_l/(v_c + v_p) is the relative fraction of the average lateral speeds. Light gray (HeLa cells) and dark gray shaded values (mouse MK2 cells) indicate significant differences (p <0.05) to the control HeLa cells (no drug) and MK2^+/+ cells, respectively. Note that the sum of mot c plus mot p approximates but is not identical to the population motility. Supplementary animation is available at The EMBO Journal Online.