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Updated: Jan 16, 2026
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A Method for Labeling Vasculature in Embryonic Mice
Published on: October 7, 2011
16.2K
Vascular Patterning affects Intramembranous Ossification through HIF1α-Vegf Signaling
Soma Dash1,2, Jonathan R Rettig1, Madelaine Gogol3
1Department of Biological Sciences, University at Albany, SUNY Albany.
Biorxiv : the Preprint Server for Biology
|September 26, 2025
Summary
The Mediator complex subunit Med23 is crucial for vascular development and craniofacial bone formation. Its absence causes vascular defects and impairs neural crest cell differentiation, leading to severe developmental issues.
Area of Science:
- Developmental Biology
- Molecular Biology
- Genetics
Background:
- Vasculature development is critical for organogenesis, involving endothelial cells that provide structure and signaling.
- The Mediator complex, a transcriptional regulator, is essential for proper vascular development.
- The specific role of Mediator tail subunit Med23 in endothelial cells remained largely uninvestigated.
Purpose of the Study:
- To investigate the function of the Mediator tail subunit Med23 in endothelial cells during embryonic development.
- To elucidate the role of Med23 in vascular patterning and craniofacial development.
- To understand the molecular mechanisms linking Med23, vascularization, and osteogenesis.
Main Methods:
- Endothelial-specific knockout of Med23 in mouse embryos using Tek-Cre.
- Phenotypic analysis of vascular and craniofacial abnormalities.
- Spatial transcriptomics to identify gene expression changes.
- Pharmacological manipulation of hypoxia-inducible factor 1-alpha (HIF1α) and vascular endothelial growth factor A (VEGFA).
Main Results:
- Endothelial Med23 knockout led to vascular anomalies (edema, hemorrhage) and craniofacial defects (micrognathia, cleft palate).
- Neural crest cell migration was unaffected, but osteogenic differentiation was severely impaired.
- Downregulated expression of key vascular (Vegfr1) and osteogenic (Col1a1) genes, elevated HIF1α, and reduced VEGF signaling were observed.
- Pharmacological rescue of craniofacial ossification and improved embryonic viability were achieved by inhibiting HIF1α and supplementing VEGFA.
Conclusions:
- Med23 plays a critical role in coordinating vascular patterning and intramembranous ossification.
- Distinct hypoxic and angiogenic requirements exist for craniofacial bone versus axial/appendicular bone development.
- Endothelial cells and cranial vasculature instruct neural crest cell differentiation during craniofacial development.
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