title: DNA methylation changes during cleft palate formation induced by retinoic acid in mice.
abstract: OBJECTIVE
  The aim of this study was to analyze epigenetic (specifically, DNA methylation) participation in the mechanisms of cleft palate only induced by maternal exposure to all-trans retinoic acid in mice.
  
  
  METHODS
  Cleft palate only was induced in fetuses by maternal exposure to all-trans retinoic acid. Their secondary palates were excised for analysis. Cytosine extension assay and restriction landmark genomic scanning were performed to analyze DNA methylation status. The expression levels of the DNA methyltransferases were examined by real-time reverse transcriptase-polymerase chain reaction.
  
  
  RESULTS
  Using cytosine extension assay, on gestation day 14.5, the status of DNA methylation within CpG islands and in global DNA was decreased significantly in all-trans retinoic acid-treated groups compared with the controls (p < .01 and p < .05). In the controls, the status within CpG islands on gestation day 14.5 was significantly increased compared with gestation days 13.5 and 18.5 (p < .01). Using real-time reverse transcriptase-polymerase chain reaction, there was no significant change in the expression of DNA methyltransferases, except on gestation day 18.5. Using restriction landmark genomic scanning on gestation day 18.5, five spots (0.49%) in the controls and one spot (0.1%) in all-trans retinoic acid-treated groups were specifically detected.
  
  
  CONCLUSIONS
  These results indicate that changes in DNA methylation may play an important role in the manifestation of cleft palate only caused by environmental factors such as maternal exposure to all-trans retinoic acid.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Graduate School of Medicine, Chiba University, Japan. motone-k@kza.biglobe.ne.jp
authors.forename: Motone
authors.initials: M
authors.lastname: Kuriyama
authors.forename: Akikazu
authors.initials: A
authors.lastname: Udagawa
authors.forename: Shinya
authors.initials: S
authors.lastname: Yoshimoto
authors.forename: Masaharu
authors.initials: M
authors.lastname: Ichinose
authors.forename: Koji
authors.initials: K
authors.lastname: Sato
authors.forename: Koji
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Matsuno
authors.forename: Kunio
authors.initials: K
authors.lastname: Shiota
authors.forename: Chisato
authors.initials: C
authors.lastname: Mori
mesh_terms: D000818:Animals; D002972:Cleft Palate / Q000139:chemically induced* / Q000196:embryology; D018899:CpG Islands / Q000187:drug effects; D003596:Cytosine / Q000032:analysis; D004247:DNA / Q000032:analysis / Q000187:drug effects; D019175:DNA Methylation / Q000187:drug effects*; D015254:DNA Modification Methylases / Q000032:analysis / Q000187:drug effects; D044127:Epigenesis, Genetic / Q000187:drug effects; D005260:Female; D005865:Gestational Age; D018811:Maternal Exposure / Q000009:adverse effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010159:Palate / Q000187:drug effects / Q000196:embryology; D015183:Restriction Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014212:Tretinoin / Q000009:adverse effects*
chemical_list: D014212:Tretinoin; D003596:Cytosine; D004247:DNA; D015254:DNA Modification Methylases