File:Preplacodal development model.jpg

Model for Sequential Phases of Preplacodal Development

During late blastula stage, Bmp acts as a morphogen that specifies neural crest (NC) within a narrow but low range of signaling, whereas higher levels of Bmp signaling establish the nonneural ectoderm as a broad zone of uncommitted cells with potential to form epidermal or preplacodal ectoderm (PPE). Within the nonneural ectoderm, changing levels of Bmp do not distinguish preplacodal from epidermal potential, and preplacodal competence factors are uniformly induced throughout this domain. However, expression of tfap2a/c overlaps with the lateral edges of the neural plate where, perhaps in combination with neural markers, they cell-autonomously specify NC fate. During late gastrula stage (9–10 hpf), PPE fate is specified in competent cells near the neural-nonneural border by dorsally expressed Bmp antagonists, Fgf and Pdgf. Complete attenuation of Bmp is required for PPE specification. Relevant markers for each ectodermal domain are shown.

Original file name: Figure 8. Journal.pgen.1001133.g008.jpg

Reference

<pubmed>20885782</pubmed>| PLoS Genet.

© 2010 Kwon et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.