title: Ultrastructural localization of 5-methylcytosine on DNA and RNA.
abstract: DNA methylation is the major epigenetic modification and it is involved in the negative regulation of gene expression. Its alteration can lead to neoplastic transformation. Several biomolecular approaches are nowadays used to study this modification on DNA, but also on RNA molecules, which are known to play a role in different biological processes. RNA methylation is one of the most common RNA modifications and 5-methylcytosine presence has recently been suggested in mRNA. However, an analysis of nucleic acid methylation at electron microscope is still lacking. Therefore, we visualized DNA methylation status and RNA methylation sites in the interphase nucleus of HeLa cells and rat hepatocytes by ultrastructural immunocytochemistry and cytochemical staining. This approach represents an efficient alternative to study nucleic acid methylation. In particular, this ultrastructural method makes the visualization of this epigenetic modification on a single RNA molecule possible, thus overcoming the technical limitations for a (pre-)mRNA methylation analysis.
authors.affiliation: Laboratory of Cell Biology and Neurobiology, Department of Biology and Biotechnology, University of Pavia, Via Ferrata 9, 27100, Pavia, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Masiello
authors.affiliation: Laboratory of Cell Biology and Neurobiology, Department of Biology and Biotechnology, University of Pavia, Via Ferrata 9, 27100, Pavia, Italy. marco.biggiogera@unipv.it.
authors.forename: Marco
authors.identifier: 0000-0003-3834-6712
authors.initials: M
authors.lastname: Biggiogera
mesh_terms: D044503:5-Methylcytosine / Q000032:analysis*; D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry / Q000648:ultrastructure; D002478:Cells, Cultured; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D006367:HeLa Cells; D022781:Hepatocytes / Q000737:chemistry / Q000166:cytology / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D007399:Interphase; D051379:Mice; D008854:Microscopy, Electron; D009685:Nuclear Envelope / Q000737:chemistry / Q000648:ultrastructure; D012313:RNA / Q000737:chemistry* / Q000648:ultrastructure; D051381:Rats
chemical_list: D012313:RNA; D044503:5-Methylcytosine; D004247:DNA
keywords: 5mC; EM immunolabelling; Electron microscopy; Epigenetics; Methylation gradient; mRNA methylation