title: Paradoxical methylation of the tyrosine hydroxylase gene in mouse preimplantation embryos.
abstract: The mouse tyrosine hydroxylase (Th) gene is located in an evolutionarily conserved imprinted gene cluster on distal chromosome 7. It is associated with a CpG island that spans the promoter of the gene. Using a bisulfite sequencing method we show that the Th promoter is fully methylated in both male and female mouse germ cells and in human spermatozoa, suggesting that it belongs to the newly identified category of CpG islands, the similarly methylated regions (SMRs). Contrary to other tissue-specific gene sequences, the mouse Th promoter escapes the initial wave of genome demethylation during the first few cell cycles, but becomes demethylated between the morula and the blastocyst stages. This unusual methylation ontogeny may be a characteristic of the SMRs and/or related to the localization of the Th gene in an imprinted gene cluster.
authors.affiliation: Laboratoire de Génétique de la Neurotransmission et des Processus Néurodégénératifs, CNRS UMR7091, Hôpital Pitié-Salpêtrière, 75013, Paris, France.
authors.forename: Tamás
authors.initials: T
authors.lastname: Arányi
authors.forename: Antoine
authors.initials: A
authors.lastname: Kerjean
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Tóth
authors.forename: Jacques
authors.initials: J
authors.lastname: Mallet
authors.forename: Rolando
authors.initials: R
authors.lastname: Meloni
authors.forename: András
authors.initials: A
authors.lastname: Páldi
mesh_terms: D000818:Animals; D018899:CpG Islands / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D004622:Embryo, Mammalian / Q000378:metabolism*; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009865:Oocytes / Q000378:metabolism; D011247:Pregnancy; D011401:Promoter Regions, Genetic / Q000235:genetics; D017422:Sequence Analysis, DNA; D013094:Spermatozoa / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*
chemical_list: D004247:DNA; D014446:Tyrosine 3-Monooxygenase