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The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions
07:34

The Power of Simplicity: Sea Urchin Embryos as in Vivo Developmental Models for Studying Complex Cell-to-cell Signaling Network Interactions

Published on: February 16, 2017

Multiple signaling pathways coordinate to induce a threshold response in a chordate embryo

Naoyuki Ohta1, Yutaka Satou

  • 1Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, Japan.

Plos Genetics
|October 8, 2013
PubMed

Insights

Secreted signaling molecules control cell fate by triggering threshold responses in gene transcription. In Ciona intestinalis, EphrinA and Smad pathways refine neural gene boundaries by antagonizing FGF signaling, ensuring precise cell differentiation.

Area of Science:

  • Developmental biology
  • Cell signaling
  • Molecular genetics

Background:

  • Secreted signaling molecules induce threshold responses for cell fate specification in animal development.
  • Fibroblast Growth Factor (FGF) signaling initiates neural gene expression (Otx, Nodal) in early Ciona intestinalis embryos.

Purpose of the Study:

  • To investigate the role of additional signaling molecules in sharpening neural gene expression boundaries.
  • To elucidate the mechanisms by which EphrinA and Smad pathways refine FGF-induced neural gene expression.

Main Methods:

  • Analysis of gene expression patterns in Ciona intestinalis embryos.
  • Investigating the interplay between FGF, EphrinA, and Smad signaling pathways.
  • Examining the regulation of ERK phosphorylation and transcription factor activity.

Main Results:

  • EphrinA signaling antagonizes FGF signaling by differentially inhibiting ERK phosphorylation in neural versus epidermal cells.
  • Smad transcription factors, activated by Admp and Gdf1/3-like signaling, repress occasional neural gene activation by residual ERK activity.
  • These coordinated signaling events establish a sharp expression boundary for neural genes.

Conclusions:

  • A network of signaling pathways, including FGF, EphrinA, and Smad, precisely controls cell fate determination.
  • The interplay between these pathways generates a robust threshold response, delineating sharp boundaries for neural gene expression.
  • This mechanism ensures accurate cell fate specification during embryonic development.

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