title: Methylation analyses on promoters of mPer1, mPer2, and mCry1 during perinatal development.
abstract: Recent studies revealed dramatic changes in circadian clock genes' expression during the perinatal period. In this study, we characterized DNA methylation for three clock genes mPer1, mPer2, and mCry1 at their selected promoter regions during development. Results for the suprachiasmatic nucleus (SCN) and liver (at embryonic day 19, postnatal day 1 and postnatal day 7) were compared to those of sperm. Few methylations were detected for the mPer2 and mCry1 promoters. The 3rd E-box region of the mPer1 promoter exhibited methylation only in sperm. Significant demethylation was observed in the 4th E-box region of the mPer1 promoter between E19 and P1 in the SCN but not in liver tissue. This demethylation state was maintained at P7 for the SCN. Luciferase reporter assays using in vitro methylated promoters revealed an inhibitory effect of promoter methylation on mPer1 expression. The results suggested that epigenetic mechanisms such as DNA methylation might contribute to the developmental expression of clock genes.
authors.affiliation: College of Life Sciences, Wuhan University, Hubei Province 430072, PR China.
authors.forename: Yaoting
authors.initials: Y
authors.lastname: Ji
authors.forename: Yue
authors.initials: Y
authors.lastname: Qin
authors.forename: Hongbing
authors.initials: H
authors.lastname: Shu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000235:genetics*; D056931:Cryptochromes / Q000235:genetics*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D008099:Liver / Q000254:growth & development / Q000378:metabolism; D008156:Luciferases / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D056950:Period Circadian Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D013493:Suprachiasmatic Nucleus / Q000254:growth & development / Q000378:metabolism; D014162:Transfection
chemical_list: C538964:Cry1 protein, mouse; D056931:Cryptochromes; C539023:Per1 protein, mouse; C513312:Per2 protein, mouse; D056950:Period Circadian Proteins; D008156:Luciferases