...-posterior axis patterning. Wnt signaling Axin Sea urchin Anterior-posterior axis Animal-vegetal axis Endomesoderm During embryonic development in most bilaterally symmetrical animals (Bilateria), the establishment of the anterior-posterior (AP) and dorsal-ventral (DV) axes are two early...

...Brenna S. McCauley; Eda Akyar; H. Rosa Saad; Veronica F. Hinman In many invertebrates, the nuclearization of β-catenin at one pole of the embryo initiates endomesoderm specification. An intriguing possibility is that a gradient of nuclear β-catenin (nβ-catenin), similar to that operating...

...Jenifer Croce; Ryan Range; Shu-Yu Wu; Esther Miranda; Guy Lhomond; Jeff Chieh-fu Peng; Thierry Lepage; David R. McClay In the sea urchin, entry of β-catenin into the nuclei of the vegetal cells at 4th and 5th cleavages is necessary for activation of the endomesoderm gene regulatory network. Beyond...

... and sufficient to specify endomesoderm. We show that endomesoderm specification is crucial for anteroposterior axis establishment in the ectoderm. The endomesoderm secretes as yet unidentified signals that posteriorize the ectoderm, which would otherwise adopt an anterior fate. Our results point to a conserved...

... range in the endomesoderm and that its effects on the blastocoelar cell precursors are likely to be direct. The activity of Nodal and BMP2/4 are antagonistic, and although bmp2/4 is transcribed in the ventral ectoderm downstream of Nodal, the BMP2/4 ligand is translocated to the dorsal side, where...

...Jenifer C. Croce; David R. McClay Endomesoderm is the common progenitor of endoderm and mesoderm early in the development of many animals. In the sea urchin embryo, the Delta/Notch pathway is necessary for the diversification of this tissue, as are two early transcription factors, Gcm and FoxA...

... for correspondence (e-mail: miarnone@szn.it ) * These authors contributed equally to this study 9 12 2008 © 2009. 2009 Strongylocentrotus purpuratus QPCR Endomesoderm Sea urchin larval development Hindgut specification GRN Triple in situ hybridization The sea urchin embryo...

... mesoderm lineage, the trunk lateral cells, develop from a single pair of endomesoderm cells, the A6.3 blastomeres, which form part of the anterior endoderm, hematopoietic mesoderm and muscle derivatives. MAPK signaling is active in the endoderm descendants of A6.3, but is absent from the mesoderm lineage...

...Paola Oliveri; Katherine D. Walton; Eric H. Davidson; David R. McClay The foxa gene is an integral component of the endoderm specification subcircuit of the endomesoderm gene regulatory network in the Strongylocentrotus purpuratus embryo. Its transcripts become confined to veg2, then veg1...

... of endomesoderm specification. For example, there is excellent evidence for interactions required for skeletogenic patterning that occur between the skeletogenic mesenchyme and the ectodermal wall, and for other interactions between the skeletogenic mesenchyme and secondary mesenchyme cells at the gastrula stage...