title: 5-Carboxylcytosine is localized to euchromatic regions in the nuclei of follicular cells in axolotl ovary.
abstract: 5-Methylcytosine (5-mC) is an epigenetic modification associated with gene repression. Recent studies demonstrated that 5-mC can be enzymatically oxidised into 5-hydroxymethylcytosine and further into 5-formylcytosine (5-fC) and 5-carboxylcytsine (5-caC). 5-caC has been found in embryonic stem cells and in mouse pre-implantation embryos but no detectable levels of this modification have been reported for somatic tissues to date. Whereas it has been suggested that 5-caC can serve as an intermediate in the process of active demethylation, the function of this form of modified cytosine remains obscure. Here we show that 5-caC is immunochemically detectable in somatic cells of axolotl ovary. We demonstrate that both 5-hmC and 5-caC are localized to the euchromatin in the nuclei of axolotl follicular cells with similar patterns of spatial distribution. Our results suggest that 5-carboxylcytosine may play a distinct functional role in certain biological contexts.
authors.affiliation: School of Biology, University of Nottingham, Nottingham, UK.
authors.forename: Anthony
authors.initials: A
authors.lastname: Alioui
authors.forename: Lee M
authors.initials: LM
authors.lastname: Wheldon
authors.forename: Abdulkadir
authors.initials: A
authors.lastname: Abakir
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Ferjentsik
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Johnson
authors.forename: Alexey
authors.initials: A
authors.lastname: Ruzov
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives; D000558:Ambystoma mexicanum; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D019175:DNA Methylation; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D022041:Euchromatin / Q000378:metabolism*; D005260:Female; D051379:Mice; D018613:Microscopy, Confocal; D010053:Ovary / Q000378:metabolism* / Q000473:pathology
chemical_list: D022041:Euchromatin; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine