title: Restricted expression of chromatin remodeling associated factor Chd3 during tooth root development.
abstract: OBJECTIVE
  The tooth root is one of the critical parts to maintain tooth function; however, the molecular mechanisms of root development remain unknown. We aimed to identify specific factors for root morphogenesis using a newly developed experimental system.
  
  
  METHODS
  Tentative cementoblasts and periodontal ligament cells from mouse mandibular molars were isolated using laser capture microdissection. More than 500 cementoblasts and periodontal ligament cells were separately captured. After RNA extraction and amplification, mRNA expression in isolated cementoblasts was compared with that of periodontal ligament cells by cDNA microarray analysis. Then, putative cementoblast-specific genes were subjected to in situ hybridization analysis to confirm the results in mouse mandible.
  
  
  RESULTS
  Approximately 2000 genes were differentially expressed between these tissues. Among those genes, zinc finger helicase (ZFH), also termed chromodomain-helicase-DNA-binding protein 3 (Chd3), was one of the highly expressed transcripts in tentative cementoblasts. In situ hybridization revealed that ZFH/Chd3 was strongly expressed in Hertwig's epithelial root sheath rather than in cementum. Moreover, its expression disappeared when root formation was advanced in the first molar. In contrast, Chd3 was continuously expressed in dental epithelial cells of the cervical loop, in which root extension is never terminated.
  
  
  CONCLUSIONS
  These results suggest that ZFH/Chd3 might play an important role in tooth root development and subsequent cementogenesis.
authors.affiliation: Section of Oral Implantology and Regenerative Dental Medicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Date
authors.forename: Y
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: H
authors.initials: H
authors.lastname: Kondo
authors.forename: S
authors.initials: S
authors.lastname: Kuroda
authors.forename: K
authors.initials: K
authors.lastname: Ohya
authors.forename: M S
authors.initials: MS
authors.lastname: Ota
authors.forename: S
authors.initials: S
authors.lastname: Iseki
authors.forename: S
authors.initials: S
authors.lastname: Kasugai
mesh_terms: D000565:Ameloblasts / Q000502:physiology; D000818:Animals; D018929:Cell Culture Techniques; D042002:Chromatin Assembly and Disassembly / Q000235:genetics; D004265:DNA Helicases / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D003739:Dental Cementum / Q000502:physiology; D004658:Enamel Organ / Q000254:growth & development; D004847:Epithelial Cells / Q000502:physiology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D007180:Incisor / Q000254:growth & development; D061346:Laser Capture Microdissection; D008297:Male; D008334:Mandible / Q000166:cytology; D051379:Mice; D008813:Mice, Inbred ICR; D008963:Molar / Q000254:growth & development; D009024:Morphogenesis / Q000235:genetics; D009693:Nucleic Acid Hybridization; D009805:Odontogenesis / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D010513:Periodontal Ligament / Q000166:cytology; D014083:Tooth Germ / Q000254:growth & development; D014092:Tooth Root / Q000254:growth & development*
chemical_list: C507367:Chd7 protein, mouse; D004268:DNA-Binding Proteins; D004265:DNA Helicases