Time lapse movies of the cell movement in dorsal marginal open-faced explants. Green-fluorescein-labeled cells were chased by time-lapse imaging microscopy. The images showed the cell movement for 9 hours. After 4 hours of observation, unidirectional movements were observed in the control MO-injected explants (movie 1; ControlMOmovie). The cells migrated along a bilateral polarity, and the cell shape became long and narrow at 9 hours after dissection. In contrast, the xGLUT1MO-injected explants (movie 2; GLUTMOmovie) exhibited randomly moving cells lacking polarity. And in this explants, the cell shape remained spherical. These results are suggesting that xGLUT1 would be required for the formation of cell polarity in gastrulation movement.