Sonic Hedgehog in feather morphogenesis: induction of mesenchymal condensation and association with cell death.
Sonic hedgehog is involved in vertebrate tissue interactions during development. During early feather development, Sonic hedgehog appears very early in epithelial placodes. During late feather development, Sonic hedgehog expression precedes the development of the marginal plates and is specifically localized in the marginal plate epithelium, which will later undergo cell death. By using retroviral vectors, exogenous Sonic hedgehog overexpression in developing feathers induced enlarged feather buds that have either lost their anterior-posterior polarity or exhibited reverse orientation. The enlarged dermal condensations may be mediated through broader TGF-beta 2 expression and reduced protein kinase C (PKC) expression. Reciprocal mesenchymal interaction is required for the induction and maintenance of Sonic hedgehog in the epithelial placodes. In scaleless mutant, Sonic hedgehog is absent in the apteric region and aberrantly expressed in the mesenchyme of the abnormal feather ridge. These findings suggest that Sonic hedgehog mediates key interactions between the epithelium and mesenchyme during feather morphogenesis.
Department of Pathology, University of Southern California, Los Angeles 90033, USA.
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Ting-Berreth
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CM
Chuong
D000818:Animals; D016923:Cell Death; D002642:Chick Embryo; D004848:Epithelium; D005241:Feathers / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D053823:Hedgehog Proteins; D008648:Mesoderm; D009024:Morphogenesis; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D019063:Tenascin / Q000378:metabolism; D015534:Trans-Activators; D016212:Transforming Growth Factor beta / Q000378:metabolism
D053823:Hedgehog Proteins; D019006:Neural Cell Adhesion Molecules; D011506:Proteins; D011993:Recombinant Fusion Proteins; D019063:Tenascin; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D011493:Protein Kinase C