title: Pitfalls in mitochondrial epigenetics.
abstract: 5-Methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) are fingerprints of epigenetic modifications. These bases have been found in the mitochondrial DNA (mtDNA) and together with the discovery of mitochondrial localization of DNA methyltransferases, this implies that mtDNA is under epigenetic regulation. However, the indirect methods hitherto used to assess mitochondrial 5mC and 5hmC require attention as they readily generate artificial signals that may lead to erroneous conclusions. Here, we demonstrate how three independent, frequently used methods to identify epigenetic modification of DNA readily generate false mtDNA epigenetic signals. The three methods were selective 5mC/5hmC-mediated inhibition of restriction enzymes, bisulfite conversion and 5hmC glucosylation-dependent immunocapture. Adequate controls for all methods are suggested.
authors.affiliation: a Department of Medical Biochemistry , Institute of Clinical Medicine, University of Oslo , Oslo , Norway.
authors.forename: Tina
authors.initials: T
authors.lastname: Pawar
authors.affiliation: a Department of Medical Biochemistry , Institute of Clinical Medicine, University of Oslo , Oslo , Norway.
authors.forename: Lars
authors.initials: L
authors.lastname: Eide
mesh_terms: D044503:5-Methylcytosine / Q000031:analogs & derivatives* / Q000378:metabolism*; D000818:Animals; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D054629:Genome, Mitochondrial; D051379:Mice; D008928:Mitochondria / Q000235:genetics*
chemical_list: C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine
keywords: 5-hydroxymethylcytosine; 5-methylcytosine; Epigenetics; mitochondrial DNA