Supplementary Movie 2

H2B-cherry quail embryo filmed from the ventral view with a 20x objective. In the first part of the movie all nuclei are shown in white, in the second part of the movie Z stacks have been color coded to see tissue differential movement along the dorsoventral axis. Note that cells from the endoderm (located ventrally, colored coded in red) move toward the posterior direction faster than cells in the PSM (located dorsally compared to the endoderm and color coded in green). Anterior region is on the left.