BioProject

Genome-wide DNA demethylation, including the erasure of genome imprints, in primordial germ cells (PGCs), is critical as a first step for creating the totipotent epigenome in the germ line. More...

Genome-wide DNA demethylation, including the erasure of genome imprints, in primordial germ cells (PGCs), is critical as a first step for creating the totipotent epigenome in the germ line. Here, we provide evidence that contrary to the prevailing model involving active DNA demethylation, imprint erasure in mouse PGCs occurs in a manner consistent with replication-coupled passive DNA demethylation: PGCs erase imprints during their rapid proliferation with little de novo as well as maintenance DNA methylation potential and no major chromatin alterations. Our findings necessitate the re-evaluation of and provide novel insights into the mechanism of genome-wide DNA demethylation in PGCs. Overall design: We performed expression analysis of primordial germ cells (PGCs) at embryonic days 10.5-13.5. Because the number of PGCs available at these stages were low, cDNAs were amplified by the method that we previously published (Kurimoto et al. 2006, NAR 34: e42 (PMID 16547197)). To include analysis of PGC gene expression at E9.5, we re-normalized the data from our E9.5 PGC samples (GSM744103, GSM744104) from our previous publication (Hayashi et al., 2011, Cell 146: 519-32 (PMD 21820164)) together with the data from this submission. Less...