title: The Molecular Circuit Regulating Tooth Development in Crocodilians.
abstract: Alligators have robust regenerative potential for tooth renewal. In contrast, extant mammals can either renew their teeth once (diphyodont dentition, as found in humans) or not at all (monophyodont dentition, present in mice). Previously, the authors used multiple mitotic labeling to map putative stem cells in alligator dental laminae, which contain quiescent odontogenic progenitors. The authors demonstrated that alligator tooth cycle initiation is related to β-catenin/Wnt pathway activity in the dental lamina bulge. However, the molecular circuitry underlying the developmental progression of polyphyodont teeth remains elusive. Here, the authors used transcriptomic analyses to examine the additional molecular pathways related to the process of alligator tooth development. The authors collected juvenile alligator dental laminae at different developmental stages and performed RNA-seq. This data shows that Wnt, bone morphogenetic protein (BMP), and fibroblast growth factor (FGF) pathways are activated at the transition from pre-initiation stage (bud) to initiation stage (cap). Intriguingly, the activation of Wnt ligands, receptors and co-activators accompanies the inactivation of Wnt antagonists. In addition, the authors identified the molecular circuitry at different stages of tooth development. The authors conclude that multiple pathways are associated with specific stages of tooth development in the alligator. This data shows that Wnt pathway activation may play the most important role in the initiation of tooth development. This result may offer insight into ways to modulate the genetic controls involved in mammalian tooth renewal.
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.|Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA.|Graduate School of Clinical Dentistry, National Taiwan University, Taipei, Taiwan.|Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: S
authors.initials: S
authors.lastname: Tsai
authors.affiliation: Qassim College of Dentistry, Qassim University, Saudi Arabia.
authors.forename: A
authors.initials: A
authors.lastname: Abdelhamid
authors.affiliation: Qassim College of Dentistry, Qassim University, Saudi Arabia.
authors.forename: M K
authors.initials: MK
authors.lastname: Khan
authors.affiliation: Qassim College of Dentistry, Qassim University, Saudi Arabia.
authors.forename: A
authors.initials: A
authors.lastname: Elkarargy
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Widelitz
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.|Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan.|Integrative Stem Cell Center, China Medical University Hospital, China Medical University, Taichung, Taiwan.
authors.forename: C M
authors.initials: CM
authors.lastname: Chuong
authors.affiliation: Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA pingwu@usc.edu.
authors.forename: P
authors.initials: P
authors.lastname: Wu
mesh_terms: D000489:Alligators and Crocodiles; D000818:Animals; D009805:Odontogenesis / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D051153:Wnt Proteins / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: D051153:Wnt Proteins; D051176:beta Catenin
keywords: RNA-seq; molecular pathway; niche; polyphyodont; stem cell; tooth cycle