title: 5-hydroxymethyl-cytosine enrichment of non-committed cells is not a universal feature of vertebrate development.
abstract: 5-hydroxymethyl-cytosine (5-hmC) is a cytosine modification that is relatively abundant in mammalian pre-implantation embryos and embryonic stem cells (ESC) derived from mammalian blastocysts. Recent observations imply that both 5-hmC and Tet1/2/3 proteins, catalyzing the conversion of 5-methyl-cytosine to 5-hmC, may play an important role in self renewal and differentiation of ESCs. Here we assessed the distribution of 5-hmC in zebrafish and chick embryos and found that, unlike in mammals, 5-hmC is immunochemically undetectable in these systems before the onset of organogenesis. In addition, Tet1/2/3 transcripts are either low or undetectable at corresponding stages of zebrafish development. However, 5-hmC is enriched in later zebrafish and chick embryos and exhibits tissue-specific distribution in adult zebrafish. Our findings show that 5-hmC enrichment of non-committed cells is not a universal feature of vertebrate development and give insights both into evolution of embryonic pluripotency and the potential role of 5-hmC in its regulation.
authors.affiliation: Wolfson Centre for Stem Cells, Tissue Engineering and Modelling (STEM), School of Clinical Sciences, University of Nottingham, Nottingham, UK.
authors.forename: Rimple D
authors.initials: RD
authors.lastname: Almeida
authors.forename: Matthew
authors.initials: M
authors.lastname: Loose
authors.forename: Virginie
authors.initials: V
authors.lastname: Sottile
authors.forename: Elena
authors.initials: E
authors.lastname: Matsa
authors.forename: Chris
authors.initials: C
authors.lastname: Denning
authors.forename: Lorraine
authors.initials: L
authors.lastname: Young
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Johnson
authors.forename: Martin
authors.initials: M
authors.lastname: Gering
authors.forename: Alexey
authors.initials: A
authors.lastname: Ruzov
mesh_terms: D044503:5-Methylcytosine / Q000378:metabolism / Q000031:analogs & derivatives; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation; D002642:Chick Embryo; D017077:Culture Media, Conditioned; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D047108:Embryonic Development; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D038081:Organogenesis; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014714:Vertebrates / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C540839:TET1 protein, mouse; C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine