title: CpG site-specific alteration of hydroxymethylcytosine to methylcytosine beyond DNA replication.
abstract: Hydroxymethylcytosines (hmC), one of several reported cytosine modifications, was recently found to be enriched in embryonic stem cells and neuronal cells, and thought to play an important role in regulating gene expression and cell specification. However, unlike methylcytosines (mC), the fate of hmC beyond DNA replication is not well understood. Here, to monitor the status of hmC during DNA replication, we prepared a stable episomal vector-based monitoring system called MoCEV in 293T cells. The MoCEV system containing fully hydroxymethylated-cytosine fragments revealed a significant modification towards mC after several rounds of DNA replication. Strikingly this modification was specifically observed at the CpG sites (71.9% of cytosines), whereas only 1.1% of modified cytosines were detected at the non-CpG sites. Since the unmodified MoCEV did not undergo any DNA methylation during cell division, the results strongly suggest that somatic cells undergo hmC to mC specifically at the CpG sites during cell division.
authors.affiliation: RIKEN Omics Science Center, 1-7-22 Suehiro-cho, Yokohama, Kanagawa 230-0045, Japan. kubosaki@gsc.riken.jp
authors.forename: Atsutaka
authors.initials: A
authors.lastname: Kubosaki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tomaru
authors.forename: Erina
authors.initials: E
authors.lastname: Furuhata
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Jay W
authors.initials: JW
authors.lastname: Shin
authors.forename: Christophe
authors.initials: C
authors.lastname: Simon
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Ando
authors.forename: Ryota
authors.initials: R
authors.lastname: Hasegawa
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Hayashizaki
authors.forename: Harukazu
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D044503:5-Methylcytosine / Q000032:analysis / Q000378:metabolism* / Q000031:analogs & derivatives; D001483:Base Sequence; D018899:CpG Islands; D003596:Cytosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D019175:DNA Methylation; D004261:DNA Replication; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: C011865:5-hydroxymethylcytosine; D044503:5-Methylcytosine; D003596:Cytosine