Mutagenic and cytotoxic properties of oxidation products of 5-methylcytosine revealed by next-generation sequencing.

ABSTRACT: 5-methylcytosine (5-mC) can be sequentially oxidized to 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and finally to 5-carboxylcytosine (5-caC), which is thought to function in active DNA cytosine demethylation in mammals. Although the roles of 5-mC in epigenetic regulation of gene expression are well established, the effects of 5-hmC, 5-foC and 5-caC on DNA replication remain unclear. Here we report a systematic study on how these cytosine derivatives (5-hmC, 5-foC and 5-caC) perturb the efficiency and accuracy of DNA replication using shuttle vector technology in conjugation with next-g sequencing. Our results demonstrated that, in Escherichia coli cells, all the cytosine derivatives could induce CT transition mutation at frequencies of 0.17%-1.12%, though no effect on replication efficiency was observed. These findings provide an important new insight on the potential mutagenic properties of cytosine derivatives occurring as the intermediates of DNA demethylation.

SUBMITTER: Xing XW 

PROVIDER: S-EPMC3774748 | biostudies-other | 2013

REPOSITORIES: biostudies-other