title: Tooth, hair and claw: comparing epithelial stem cell niches of ectodermal appendages.
abstract: The vertebrate ectoderm gives rise to organs that produce mineralized or keratinized substances, including teeth, hair, and claws. Most of these ectodermal derivatives grow continuously throughout the animal׳s life and have active pools of adult stem cells that generate all the necessary cell types. These organs provide powerful systems for understanding the mechanisms that enable stem cells to regenerate or renew ectodermally derived tissues, and remarkable progress in our understanding of these systems has been made in recent years using mouse models. We briefly compare what is known about stem cells and their niches in incisors, hair follicles, and claws, and we examine expression of Gli1 as a potential example of a shared stem cell marker. We summarize some of the features, structures, and functions of the stem cell niches in these ectodermal derivatives; definition of the basic elements of the stem cell niches in these organs will provide guiding principles for identification and characterization of the niche in similar systems.
authors: Program in Craniofacial and Mesenchymal Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA; Université Paris Descartes, Sorbonne Paris Cite, UMR S872, Paris, France; Centre de Recherche des Cordeliers, Université Pierre et Marie Curie, UMR S872, Paris, France; INSERM U872, Paris, France.
authors: Adrien
authors: A
authors: Naveau
authors: Program in Craniofacial and Mesenchymal Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA.
authors: Kerstin
authors: K
authors: Seidel
authors: Program in Craniofacial and Mesenchymal Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA; Department of Pediatrics and Institute for Human Genetics, University of California, San Francisco, San Francisco, CA, USA. Electronic address: ophir.klein@ucsf.edu.
authors: Ophir D
authors: OD
authors: Klein
mesh_terms: D000818:Animals; D004475:Ectoderm / Q000166:cytology* / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D006197:Hair / Q000166:cytology* / Q000378:metabolism; D006724:Hoof and Claw / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D055153:Stem Cell Niche; D014070:Tooth / Q000166:cytology* / Q000378:metabolism
keywords: Claw; Ectodermal derivatives; Gli1; Hair; Nail; Niche; Stem cells; Tooth