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Updated: Jun 23, 2026
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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
Published on: February 16, 2017
Hedgehog signaling patterns mesoderm in the sea urchin
Katherine D Walton1, Jacob Warner, Philip H Hertzler
1Department of Biology, Duke University, Box 90338, Durham, NC 27708, USA.
Developmental Biology
|April 28, 2009
Summary
The Hedgehog (Hh) signaling pathway is crucial for sea urchin mesoderm development. Disrupting Hh signaling leads to skeletal defects and abnormal patterning of various mesodermal cell types.
Area of Science:
- Developmental Biology
- Evolutionary Developmental Biology
- Molecular Biology
Background:
- The Hedgehog (Hh) signaling pathway is vital for vertebrate development, patterning diverse structures.
- In sea urchins, Hh signaling is implicated in mesoderm organization during gastrulation.
- Key components like Hh ligand, Patched (Ptc), and Smoothened (Smo) are expressed in specific embryonic tissues.
Purpose of the Study:
- To investigate the role of the Hedgehog (Hh) signaling pathway in sea urchin mesoderm patterning.
- To determine the necessity of Hh signaling for the proper development of different mesoderm subtypes.
Main Methods:
- Perturbation experiments involving Hh, Ptc, and Smo in sea urchin embryos.
- Observation and analysis of embryonic development, focusing on mesoderm patterning and skeletogenesis.
- Assessment of cell type specification, asymmetry, and muscle formation.
Main Results:
- Disruptions in Hh, Ptc, or Smo signaling resulted in skeletal defects.
- Perturbations led to abnormal patterning of non-skeletogenic mesoderm, affecting cell numbers and asymmetry.
- Late developmental defects included disorganized circumesophageal muscle and impaired swallowing ability.
Conclusions:
- Hedgehog (Hh) signaling is essential for the patterning of all mesoderm subtypes in the sea urchin embryo.
- The pathway plays a critical role in late-stage mesoderm development, including skeletogenesis and cell differentiation.
- These findings highlight the conserved importance of Hh signaling in deuterostome development.
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