Dose-dependent Nodal/Smad signals pattern the early mouse embryo.
Nodal signals in the early post-implantation stage embryo are essential to establish initial proximal-distal (P-D) polarity and generate the final anterior-posterior (A-P) body axis. Nodal signaling in the epiblast results in the phosphorylation of Smad2 in the overlying visceral endoderm necessary to induce the AVE, in part via Smad2-dependent activation of the T-box gene Eomesodermin. Slightly later following mesoderm induction a continuum of dose-dependent Nodal signaling during the process of gastrulation underlies specification of mesodermal and definitive endoderm progenitors. Dynamic Nodal expression during the critical 72 h time window immediately following implantation, accomplished by a series of feed-back and feed-forward mechanisms serves to provide key positional cues required for establishment of the body plan and controls cell fate decisions in the early mammalian embryo.
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK. Electronic address: elizabeth.robertson@path.ox.ac.uk.
Elizabeth J
EJ
Robertson
D000818:Animals; D019521:Body Patterning / Q000235:genetics; D004622:Embryo, Mammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D005855:Germ Layers / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D051379:Mice; D008957:Models, Genetic; D055457:Nodal Protein / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D051899:Smad2 Protein / Q000235:genetics* / Q000378:metabolism
D055457:Nodal Protein; C526008:Nodal protein, mouse; D051899:Smad2 Protein; C497783:Smad2 protein, mouse
Epiblast; Gastrulation; Nodal; Smad2/3; TGFβ