Epithelial Dlx-2 homeogene expression and cementogenesis.
The Dlx-2 (distal-less gene) homeoprotein transcription factor controls early tooth development but has not been studied during the late stages of biomineralization. Transgenic mice containing a Dlx-2/LacZ reporter construct were used to map the Dlx-2 expression pattern in cementoblasts, the dental cells most closely related to bone cells and therefore suggested to be uniquely positioned osteoblasts. During initial root formation, marked expression of Dlx-2 was evident in molar and incisor root epithelium, whereas dental papilla and follicle were negative. Dlx-2 was expressed in this epithelium from the apical loop to the area of its disruption. During acellular cementum formation in both incisors and molars, Dlx-2 expression was observed in the majority of differentiated cementoblasts from the apical region to the erupting zones. During cellular cementum formation, the presence of which characterizes growth-limited molars, Dlx-2 expression was restricted to the innermost cementoblasts and entrapped cementocytes. These data further support the hypothesis of a complex origin and fate of cementum-forming cells, as previously suggested by the expression patterns of a set of mesenchymal and epithelial markers, notably ameloblastin as shown here. Dlx-2 expression might constitute a landmark of cementoblast subpopulations of epithelial origin. (J Histochem Cytochem 48:277-283, 2000)
Lézot
F
F
Laboratoire de Biologie-Odontologie, EA 2380, Institut Biomédical des Cordeliers, Université Paris VII, Paris, France.
Davideau
J L
JL
Thomas
B
B
Sharpe
P
P
Forest
N
N
Berdal
A
A
D000375:Aging; D000818:Animals; D025021:Cementogenesis; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D003739:Dental Cementum / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism*; D018398:Homeodomain Proteins; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D016601:RNA-Binding Proteins; D014157:Transcription Factors
D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C088334:Distal-less homeobox proteins; D018398:Homeodomain Proteins; D016601:RNA-Binding Proteins; C093661:Tes protein, mouse; D014157:Transcription Factors