title: beta-Catenin controls hair follicle morphogenesis and stem cell differentiation in the skin.
abstract: beta-Catenin is an essential molecule in Wnt/wingless signaling, which controls decisive steps in embryogenesis. To study the role of beta-catenin in skin development, we introduced a conditional mutation of the gene in the epidermis and hair follicles using Cre/loxP technology. When beta-catenin is mutated during embryogenesis, formation of placodes that generate hair follicles is blocked. We show that beta-catenin is required genetically downstream of tabby/downless and upstream of bmp and shh in placode formation. If beta-catenin is deleted after hair follicles have formed, hair is completely lost after the first hair cycle. Further analysis demonstrates that beta-catenin is essential for fate decisions of skin stem cells: in the absence of beta-catenin, stem cells fail to differentiate into follicular keratinocytes, but instead adopt an epidermal fate.
authors.affiliation: Max-Delbrueck-Center for Molecular Medicine, Robert-Roessle-Strasse 10, 13092, Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Huelsken
authors.forename: R
authors.initials: R
authors.lastname: Vogel
authors.forename: B
authors.initials: B
authors.lastname: Erdmann
authors.forename: G
authors.initials: G
authors.lastname: Cotsarelis
authors.forename: W
authors.initials: W
authors.lastname: Birchmeier
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D015971:Gene Expression Regulation, Enzymologic; D018859:Hair Follicle / Q000166:cytology* / Q000196:embryology*; D019426:Integrases / Q000235:genetics; D053547:Keratin-14; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D007633:Keratins / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D016254:Mutagenesis, Insertional / Q000502:physiology; D010641:Phenotype; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D015534:Trans-Activators; D014764:Viral Proteins; D051176:beta Catenin
chemical_list: C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; D053547:Keratin-14; C507446:Krt14 protein, mouse; D015534:Trans-Activators; D014764:Viral Proteins; D051176:beta Catenin; D007633:Keratins; C045073:Cre recombinase; D019426:Integrases