20-P019 Study of pallio-subpallial neural tangential migration

tem to observe mesoderm cell migration in chicken embryo using live imaging. In early-stage chicken embryo, mesoderm cells move away from the primitive streak and follow stereotyped migratory route according to their dorsal-ventral fate. Immunohistochemical studies and live cell imaging with fluorescent labeled nucleus and Golgi complex showed a consistent positioning of Golgi complex at the rear end of migrating mesoderm cells, in contrast to what has been reported in cultured cells. Prior to mesoderm cell ingression, Golgi complex in epiblast cells is always located apical to the nucleus. These results suggest that newly formed mesoderm cells, although lost the apical/basal polarity, have inherited this ‘‘basal forward, apical behind’’ organization. We will also provide evidence that the Golgi complex and the microtubule-organizing center (MTOC) positions are related to microtubules organization during mesoderm cell migration. Similar to Golgi complex, abundant microtubules are detected at the apical side. After ingression, microtubules can be seen with GFP-EB1 fusion protein, to project radially and dynamically from MTOC toward the cell periphery. MTOC is also located at the rear end of migrating mesoderm cells as well as Golgi complex.