Nekrasov, MaximAmrichova, JaneParker, Brian JSoboleva, TatianaJack, CameronWilliams, RohanHuttley, Gavin AustinTremethick, David2015-12-101545-9993http://hdl.handle.net/1885/69232Although it has been clearly established that well-positioned histone H2A.Z-containing nucleosomes flank the nucleosome-depleted region (NDR) at the transcriptional start site (TSS) of active mammalian genes, how this chromatin-based information is transmitted through the cell cycle is unknown. We show here that in mouse trophoblast stem cells, the amount of histone H2A.Z at promoters decreased during S phase, coinciding with homotypic (H2A.Z-H2A.Z) nucleosomes flanking the TSS becoming heterotypic (H2A.Z-H2A). To our surprise these nucleosomes remained heterotypic at M phase. At the TSS, we identified an unstable heterotypic histone H2A.Z-containing nucleosome in G1 phase that was lost after DNA replication. These dynamic changes at the TSS mirror a global expansion of the NDR at S and M phases, which, unexpectedly, is unrelated to transcriptional activity. Coincident with the loss of histone H2A.Z at promoters, histone H2A.Z is targeted to the centromere when mitosis begins.Keywords: histone H2AZ; animal cell; article; cell cycle; cell cycle G1 phase; cell cycle M phase; cell cycle S phase; centromere; DNA replication; dynamics; inheritance; mitosis; mouse; nonhuman; nucleosome; nucleotide sequence; priority journal; stem cell; tropho201210.1038/nsmb.24242016-02-24