Time-lapse differential interference contrast images of a migrating Dictyostelium cell on the silicone substrate. Movement of beads was observed around the cell. Note that the direction of bead movement reversed repeatedly. Images were acquired at 3.2 second intervals.

Locomotory behavior of a wild-type cell under the pressure of an overlaid thin agar sheet. The wild-type cell was able to migrate under the pressure of the agar sheet. This cell showed both the posterior retraction and the anterior extension. Images were acquired at 8 second intervals.

Locomotory behavior of a myosin II heavy chains (MHC)-null cell under the pressure of an overlaid thin agar sheet. The MHC-null cell was not able to migrate. This cell did not show the posterior retraction, although it showed the anterior extensions. Images were acquired at 8 second intervals.