... that although the early-gastrula organizer contains cells that give rise to the axial mesoderm, the bulk of the progenitors of the head process and the notochord are localized outside the early gastrula organizer. In the mid-gastrula organizer, early gastrula organizer derived cells that are fated...

... that underlie this organizing ability. Hensen’s node induction neural tissue axial mesoderm somite Definitive (gut) endoderm was identified in sections as a ring of cells, one layer thick, encircling a large central lumen. The regions grafted are shown in Fig. 1B . The medial sector...

... expression reflects the function of different regions of the primitive streak and their derivatives. These studies have confirmed that mesoderm derived from the proximal primitive streak is specified appropriately. Despite the absence of a morphologically distinct node, sparse axial mesoderm cells in eed...

... induction. Subsequently, Pintallavis is expressed in axial midline cells of all three germ layers. In axial mesoderm expression is graded with highest levels posteriorly. Midline neural plate cells that give rise to the floor plate transiently express Pin tallavis , apparently in response to induction...

...A. Ruiz i Altaba ABSTRACT The cellular mechanisms responsible for the formation of the Xenopus nervous system have been examined in total exogastrula embryos in which the axial mesoderm appears to remain segregated from prospective neural ectoderm and in recombinates of ectoderm and mesoderm...