title: Semi-quantitative immunohistochemical detection of 5-hydroxymethyl-cytosine reveals conservation of its tissue distribution between amphibians and mammals.
abstract: 5-Hydroxymethyl-cytosine (5-hmC) is a form of modified cytosine, which has recently attracted a considerable attention due to its potential role in transcriptional regulation. According to several reports 5-hydroxymethyl-cytosine distribution is tissue-specific in mammals. Thus, 5-hmC is enriched in embryonic cell populations and in adult neuronal tissue. Here, we describe a novel method of semi-quantitative immunohistochemical detection of 5-hmC and utilize it to assess the levels of this modification in amphibian tissues. We show that, similar to mammalian embryos, 5-hmC is enriched in axolotl tadpoles compared with adult tissues. Our data demonstrate that 5-hmC distribution is tissue-specific in amphibians, and that strong 5-hmC enrichment in neuronal cells is conserved between amphibians and mammals. In addition, we identify 5-hmC-enriched cell populations that are distributed in amphibian skin and connective tissue in a mosaic manner. Our results illustrate that immunochemistry can be successfully used not only for spatial identification of cells enriched with 5-hmC, but also for the semi-quantitative assessment of the levels of this epigenetic modification in single cells of different tissues.
authors.affiliation: Wolfson Centre for Stem Cells, Tissue Engineering and Modelling (STEM), School of Clinical Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK.
authors.forename: Rimple D
authors.initials: RD
authors.lastname: Almeida
authors.forename: Virginie
authors.initials: V
authors.lastname: Sottile
authors.forename: Matthew
authors.initials: M
authors.lastname: Loose
authors.forename: Paul A
authors.initials: PA
authors.lastname: De Sousa
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 / Q000378:metabolism; D000663:Amphibians / Q000378:metabolism*; D000818:Animals; D002645:Chickens / Q000378:metabolism; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008322:Mammals / Q000378:metabolism*; D051379:Mice; D010802:Phylogeny; D014018:Tissue Distribution; D014981:Xenopus / Q000378:metabolism; D015027:Zebrafish / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine