Axial and lateral traction stresses during the establishment (and loss) of a TA. (A and B) Average stress maps during the establishment (A) and loss (B) of a TA (n = 8 cells). Top and bottom rows display the color contours of the magnitude of the axial and lateral traction stresses, respectively. Columns 1–7 show the average stress maps in a time interval of 12 s before and after the TA establishment or loss, and RA denotes the mean ratio of peak axial to lateral stress. (C and D) Average peak front axial (blue), back axial (black), and lateral stresses (red) during the establishment of a front TA (C) and the loss of a back TA (D). Average values refer to the cells shown in A and B. u.a., unit area.