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Updated: Jun 14, 2026
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Quantitative PCR-based Assay to Measure Sonic Hedgehog Signaling in Cellular Model of Ciliogenesis
Published on: January 31, 2025
The primary cilium as a Hedgehog signal transduction machine
Sarah C Goetz1, Polloneal J R Ocbina, Kathryn V Anderson
1Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, New York 10065, USA.
Methods in Cell Biology
|April 6, 2010
Summary
The Hedgehog (Hh) signaling pathway in vertebrates relies on intraflagellar transport (IFT) proteins and primary cilia for its function. These cellular structures actively regulate Hh pathway components, including Smoothened, impacting development and cancer.
Area of Science:
- Cell Biology
- Developmental Biology
- Molecular Biology
Background:
- The Hedgehog (Hh) signal transduction pathway is crucial for embryonic development and implicated in human cancers.
- Mammalian Hh signaling has been linked to intraflagellar transport (IFT) and the primary cilium, a cellular projection found in most vertebrate cells.
Purpose of the Study:
- To review the integral roles of IFT proteins and cilia in regulating vertebrate Hh signal transduction.
- To discuss mechanisms controlling Hh pathway protein localization to cilia, particularly Smoothened (Smo).
Main Methods:
- Review of genetic and cell biological studies.
- Analysis of phenotypes resulting from loss of cilia-associated proteins.
- Comparative analysis of Hh signaling in vertebrates and Drosophila.
Main Results:
- Evidence strongly supports the dependence of mammalian Hh signaling on primary cilia.
- IFT proteins and cilia play active roles in Hh signal mediation, not just passive concentration.
- Smoothened (Smo) localization to the cilium is regulated by Hh ligand.
Conclusions:
- Cilia and IFT are essential for vertebrate Hh pathway regulation.
- Understanding these roles provides insights into developmental patterning and cancer.
- Evolutionary comparisons suggest ancient links between cilia and Hh pathway components.
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