Project description:This SuperSeries is composed of the following subset Series: GSE39908: Bromodomain-dependent stage-specific male genome programming by Brdt [ChIP-Seq] GSE39909: Bromodomain-dependent stage-specific male genome programming by Brdt [Illumina BeadArray] Refer to individual Series
Project description:Male germ cell differentiation is a highly regulated multistep process initiated by the commitment of progenitor cells into meiosis and characterized by major chromatin reorganizations in haploid spermatids. We report here that a single member of the double bromodomain BET factors, Brdt, is a master regulator of both meiotic divisions and post-meiotic genome repackaging. Upon its activation at the onset of meiosis, Brdt drives and determines the developmental timing of a testis-specific gene expression program. In meiotic cells, Brdt initiates a genuine histone acetylation-guided programming of the genome by activating essential meiotic genes and repressing a “progenitor cells” gene expression program, while “priming” a post-meiotic gene group for further activation. At post-meiotic stages, a global chromatin hyperacetylation gives the signal for Brdt’s first bromodomain to direct the genome-wide replacement of histones by transition proteins. Brdt is therefore a unique and essential regulator of male germ cell differentiation, which, by using various domains in a developmentally controlled manner, first drives a specific spermatogenic gene expression program, and later controls the tight packaging of the male genome. Total RNA obtained from testes from prepuberal mice at 17dpp and at 20dpp were compared between Brdt-/- and Brdt+/- (17dpp), between Brdt-/- and Brdt +/+ (20dpp) and between BrdtBD1del and Brdt wt mice (20dpp). In each experiments, 6 replicates of each genotype and condition were used.
Project description:Male germ cell differentiation is a highly regulated multistep process initiated by the commitment of progenitor cells into meiosis and characterized by major chromatin reorganizations in haploid spermatids. We report here that a single member of the double bromodomain BET factors, Brdt, is a master regulator of both meiotic divisions and post-meiotic genome repackaging. Upon its activation at the onset of meiosis, Brdt drives and determines the developmental timing of a testis-specific gene expression program. In meiotic cells, Brdt initiates a genuine histone acetylation-guided programming of the genome by activating essential meiotic genes and repressing a M-bM-^@M-^\progenitor cellsM-bM-^@M-^] gene expression program, while M-bM-^@M-^\primingM-bM-^@M-^] a post-meiotic gene group for further activation. At post-meiotic stages, a global chromatin hyperacetylation gives the signal for BrdtM-bM-^@M-^Ys first bromodomain to direct the genome-wide replacement of histones by transition proteins. Brdt is therefore a unique and essential regulator of male germ cell differentiation, which, by using various domains in a developmentally controlled manner, first drives a specific spermatogenic gene expression program, and later controls the tight packaging of the male genome. Examination of Brdt binding on chromatin in meiotic (spermatocytes) and post-meiotic (round spermatids) male germ cells from adult wild type mice
Project description:Male germ cell differentiation is a highly regulated multistep process initiated by the commitment of progenitor cells into meiosis and characterized by major chromatin reorganizations in haploid spermatids. We report here that a single member of the double bromodomain BET factors, Brdt, is a master regulator of both meiotic divisions and post-meiotic genome repackaging. Upon its activation at the onset of meiosis, Brdt drives and determines the developmental timing of a testis-specific gene expression program. In meiotic cells, Brdt initiates a genuine histone acetylation-guided programming of the genome by activating essential meiotic genes and repressing a “progenitor cells” gene expression program, while “priming” a post-meiotic gene group for further activation. At post-meiotic stages, a global chromatin hyperacetylation gives the signal for Brdt’s first bromodomain to direct the genome-wide replacement of histones by transition proteins. Brdt is therefore a unique and essential regulator of male germ cell differentiation, which, by using various domains in a developmentally controlled manner, first drives a specific spermatogenic gene expression program, and later controls the tight packaging of the male genome.
Project description:Male germ cell differentiation is a highly regulated multistep process initiated by the commitment of progenitor cells into meiosis and characterized by major chromatin reorganizations in haploid spermatids. We report here that a single member of the double bromodomain BET factors, Brdt, is a master regulator of both meiotic divisions and post-meiotic genome repackaging. Upon its activation at the onset of meiosis, Brdt drives and determines the developmental timing of a testis-specific gene expression program. In meiotic cells, Brdt initiates a genuine histone acetylation-guided programming of the genome by activating essential meiotic genes and repressing a “progenitor cells” gene expression program, while “priming” a post-meiotic gene group for further activation. At post-meiotic stages, a global chromatin hyperacetylation gives the signal for Brdt’s first bromodomain to direct the genome-wide replacement of histones by transition proteins. Brdt is therefore a unique and essential regulator of male germ cell differentiation, which, by using various domains in a developmentally controlled manner, first drives a specific spermatogenic gene expression program, and later controls the tight packaging of the male genome.
Project description:NUT, nuclear protein in testis is the universal fusion partner of BRD4 in the highly aggressive NUT Midline Carcinoma (NMC), but its physiological function was unknown. Here we show that Nut is exclusively expressed in post-meiotic spermatogenic cells, at the time of genome-wide histone hyperacetylation. Inactivation of Nut induces a spermatogenesis arrest at the histone-to-protamine replacement stage, leading to male infertility. Subsequent molecular investigations show that Nut sustains global histone H4 hyperacetylation in post-meiotic cells. Additionally, Nut mediates a p300/CBP-dependent gene expression program and, by enhancing acetylation of H4 at both K5 and K8 sites, provides binding sites for the first bromodomain of Brdt, which drives histone removal. Nut’s major function is therefore to use the ubiquitous HATs p300/CBP to direct a cell-type specific histone hyperacetylation. Its ectopic activity in NMC recreates a forced p300-induced histone hyperacetylation / bromodomain binding loop that normally operates in post-meiotic spermatogenic cells.
Project description:Brdt is a testis specific member of a family of chromatin interacting proteins. All of the family members have been shown to regulate transcription. Brdt is highly expressed in round spermatids, and may play a role in transcriptional regulation in these cells. We investigated transcriptional changes in mutant round spermatids that were homozygous for a mutation in which the first bromodomain of Brdt was removed. Round spermatids were purified from seven adult animals of each genotype for each Affymetrix microarray. Purity of round spermatids was assessed by propidium iodide staining.
Project description:Newly discovered histone lysine acylations increase the functional diversity of nucleosomes well beyond acetylation. Here, we focus on histone butyrylation in the context of sperm cell differentiation. Specifically, we investigate the butyrylation of histone H4 lysine 5 and 8 at gene promoters, where acetylation guides the binding of Brdt, a bromodomain-and-extra-terminal protein, thereby mediating stage-specific gene expression programs. Genome-wide mapping data show that highly active Brdt-bound gene promoters systematically harbour competing histone acetylation and butyrylation marks at H4 K5 and K8. Histone butyrylation, despite acting as a direct stimulator of transcription, competes with acetylation, especially at H4 K5, to prevent Brdt binding. The observed in vivo H4 K5K8 acetylation butyrylation state at active promoters is reproduced in vitro where p300 indistinctly acetylates and butyrylates H4 K5 and K8. Altogether, highly active gene promoter regions are characterized by alternating H4 acetylation and butyrylation sustaining direct gene activation and a dynamic bromodomain binding.