EMBO J (2012) 31 18, 3678–3690 doi:; DOI: 10.1038/emboj.2012.214; published online July 31 2012
EMBO J (2012) 31 18, 3667–3677; doi:; DOI: 10.1038/emboj.2012.180; published online July 31 2012
Eukaryotic cells duplicate their genome in a pre-determined order that appears to reflect a fundamental property of chromatin. Each chromosomal region replicates at a consistent, developmental- and tissue-specific time during the S phase of the cell cycle, and regions that replicate at the same time form distinct patterns in three-dimensional nuclear space. Although orderly progression of DNA replication is important for insuring stable genetic and epigenetic inheritance, the mechanisms underlying replication patterns have yet to be elucidated. Two reports in The EMBO Journal now identify a protein, Rif1, as a novel global determinant of the mammalian DNA replication program, and provide a link between higher order chromatin assembly and proper cell-cycle progression.