Fig. 7. Cell migration under the pressure of overlaid thin agar sheet. Wild-type (a) and MHC-null (b) cells were compressed between a thin agar sheet and a glass coverslip. Arrows represent the direction of the anterior extension. 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. However, the MHC-null cell was not able to migrate. Asterisks represent the position of the nucleus of this cell. The MHC-null cell did not show the posterior retraction, although it showed anterior extensions. Bar, 10 µm. Movies 2 and 3 showing cell migration are available at jcs.biologists.org/supplemental.