Figure 2

Typical trajectories of the center of mass of a chemotactic cell with a non-absorbing object of unit radius placed in its path. (a) The equation describing these paths is given by Eq. (6). Initially the cells are placed at z = -3 with d = 0.25, 0.5, 0.75,1,1.25,1.5. Note that here d corresponds to the x position of the cell at z = -3. In this diagram we do not consider any mechanical interaction between the cell and the sphere. (b) Same as (a) but now the cell radius is fixed at 0.1 and we allow interactions (i.e. attachment upon contact) between the cell and the sphere. Note that cells with d ≲ 0.5 do NOT make it past the obstacle. This is because the capture radius, as given by Eq.(7), for a cell with radius 0.1 and an obstacle of unit radius is equal to 0.55.