Project description:This SuperSeries is composed of the following subset Series: GSE23033: Polycomb function during oogenesis is required for mouse early embryonic development (germinal vesicle oocytes) GSE28710: Polycomb function during oogenesis is required for mouse early embryonic development (2-cell embryos) Refer to individual Series
Project description:In mammals, totipotent pre-implantation embryos are formed by fusion of highly differentiated oocytes and spermatozoa. Acquisition of totipotency concurs with remodeling of chromatin states of parental genomes (âepigenetic reprogrammingâ), changes in maternally contributed transcriptome and proteome, and zygotic genome activation. Genomes of mature germ cells are more proficient in supporting embryonic development than those of somatic cells. It is currently unknown whether transgenerational inheritance of chromatin states present in mature gametes underlies the efficacy of early embryonic development after natural conception. Here, we show that Ring1 and Rnf2, two core components of the Polycomb Repressive Complex 1 (PRC1), serve redundant gene regulatory functions during oogenesis that are required to support embryonic development beyond the two-cell stage. Numerous developmental regulatory genes that are established Polycomb targets in various somatic cell types are de-repressed in Ring1/Rnf2 double mutant (dm) fully grown germinal vesicle (GV) oocytes. Translation of tested aberrant maternal transcripts is, however, delayed until after fertilization. Exchange of maternal pro-nuclei between control and Ring1/Rnf2 maternally dm early zygotes demonstrates an essential role for Ring1 and Rnf2 during oogenesis in defining cytoplasmic and nuclear maternal contributions that are both essential for proper initiation of embryonic development. A large number of genes up-regulated in Ring1/Rnf2 dm GV oocytes harbor PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) in spermatozoa and in embryonic stem cells (ESCs), and are repressed during normal oogenesis and early embryogenesis. These data strongly support the model that Polycomb acts in the female and male germline to silence differentiation inducing genes and to program chromatin states, thereby sustaining developmental potential across generations. Expression profiling of late 2-cell embryos was performed with the following genotypes: maternal Ring1-Rnf+ (control), maternal Ring1-Rnf2- (maternal Ring1/Rnf2 double mutant). These embryos were obtained by crossing Ring1-/-Rnf2F/F control females or Ring1-/-Rnf2F/F Zp3-cre expreimental females, respectively, to Ring1+/+Rnf2F/F control males. To distinguish between maternal transcripts present in the 2-cell embryo and newly (embryonicaly) transcribed transcripts, embryos from both genotypes were either not treated (expression profiling therefore shows all maternal and embryonic transcripts) or alpha-amanitin treated (alpha-amanitin inhibits de novo transcription, therefore expression profiling of treated embryos will only show maternal transcripts). 11 samples were analyzed: 3 biological replicates (except alpha-amanitin treated maternal Ring1/Rnf2 double mutant, where only 2 replicates were analyzed) of each genotype and treatment group were analyzed. Each sample contains 40 late 2-cell embryos.
Project description:In mammals, totipotent pre-implantation embryos are formed by fusion of highly differentiated oocytes and spermatozoa. Acquisition of totipotency concurs with remodeling of chromatin states of parental genomes (M-bM-^@M-^\epigenetic reprogrammingM-bM-^@M-^]), changes in maternally contributed transcriptome and proteome, and zygotic genome activation. Genomes of mature germ cells are more proficient in supporting embryonic development than those of somatic cells. It is currently unknown whether transgenerational inheritance of chromatin states present in mature gametes underlies the efficacy of early embryonic development after natural conception. Here, we show that Ring1 and Rnf2, two core components of the Polycomb Repressive Complex 1 (PRC1), serve redundant gene regulatory functions during oogenesis that are required to support embryonic development beyond the two-cell stage. Numerous developmental regulatory genes that are established Polycomb targets in various somatic cell types are de-repressed in Ring1/Rnf2 double mutant (dm) fully grown germinal vesicle (GV) oocytes. Translation of tested aberrant maternal transcripts is, however, delayed until after fertilization. Exchange of maternal pro-nuclei between control and Ring1/Rnf2 maternally dm early zygotes demonstrates an essential role for Ring1 and Rnf2 during oogenesis in defining cytoplasmic and nuclear maternal contributions that are both essential for proper initiation of embryonic development. A large number of genes up-regulated in Ring1/Rnf2 dm GV oocytes harbor PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) in spermatozoa and in embryonic stem cells (ESCs), and are repressed during normal oogenesis and early embryogenesis. These data strongly support the model that Polycomb acts in the female and male germline to silence differentiation inducing genes and to program chromatin states, thereby sustaining developmental potential across generations. Expression profiling of fully grown mouse GV oocytes was performed with the following genotypes: Ring1+/+Rnf2F/F (control), Ring1-/-Rnf2F/F (Ring1 mutant), Ring1+/+Rnf2F/FZp3-cre (Rnf2 mutant) and Ring1-/-Rnf2F/FZp3-cre (Ring1/Rnf2 double mutant). 12 samples were analyzed: 3 biological replicates of each of the 4 genotypes (Ring1+/+Rnf2F/F (control), Ring1-/-Rnf2F/F (Ring1 mutant), Ring1+/+Rnf2F/FZp3-cre (Rnf2 mutant) and Ring1-/-Rnf2F/FZp3-cre (Ring1/Rnf2 double mutant)). Each sample contains 50 GV oocytes.
Project description:In mammals, totipotent pre-implantation embryos are formed by fusion of highly differentiated oocytes and spermatozoa. Acquisition of totipotency concurs with remodeling of chromatin states of parental genomes (“epigenetic reprogramming”), changes in maternally contributed transcriptome and proteome, and zygotic genome activation. Genomes of mature germ cells are more proficient in supporting embryonic development than those of somatic cells. It is currently unknown whether transgenerational inheritance of chromatin states present in mature gametes underlies the efficacy of early embryonic development after natural conception. Here, we show that Ring1 and Rnf2, two core components of the Polycomb Repressive Complex 1 (PRC1), serve redundant gene regulatory functions during oogenesis that are required to support embryonic development beyond the two-cell stage. Numerous developmental regulatory genes that are established Polycomb targets in various somatic cell types are de-repressed in Ring1/Rnf2 double mutant (dm) fully grown germinal vesicle (GV) oocytes. Translation of tested aberrant maternal transcripts is, however, delayed until after fertilization. Exchange of maternal pro-nuclei between control and Ring1/Rnf2 maternally dm early zygotes demonstrates an essential role for Ring1 and Rnf2 during oogenesis in defining cytoplasmic and nuclear maternal contributions that are both essential for proper initiation of embryonic development. A large number of genes up-regulated in Ring1/Rnf2 dm GV oocytes harbor PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) in spermatozoa and in embryonic stem cells (ESCs), and are repressed during normal oogenesis and early embryogenesis. These data strongly support the model that Polycomb acts in the female and male germline to silence differentiation inducing genes and to program chromatin states, thereby sustaining developmental potential across generations. Expression profiling of fully grown mouse GV oocytes was performed with the following genotypes: Ring1+/+Rnf2F/F (control), Ring1-/-Rnf2F/F (Ring1 mutant), Ring1+/+Rnf2F/FZp3-cre (Rnf2 mutant) and Ring1-/-Rnf2F/FZp3-cre (Ring1/Rnf2 double mutant).
Project description:In mammals, totipotent pre-implantation embryos are formed by fusion of highly differentiated oocytes and spermatozoa. Acquisition of totipotency concurs with remodeling of chromatin states of parental genomes (“epigenetic reprogramming”), changes in maternally contributed transcriptome and proteome, and zygotic genome activation. Genomes of mature germ cells are more proficient in supporting embryonic development than those of somatic cells. It is currently unknown whether transgenerational inheritance of chromatin states present in mature gametes underlies the efficacy of early embryonic development after natural conception. Here, we show that Ring1 and Rnf2, two core components of the Polycomb Repressive Complex 1 (PRC1), serve redundant gene regulatory functions during oogenesis that are required to support embryonic development beyond the two-cell stage. Numerous developmental regulatory genes that are established Polycomb targets in various somatic cell types are de-repressed in Ring1/Rnf2 double mutant (dm) fully grown germinal vesicle (GV) oocytes. Translation of tested aberrant maternal transcripts is, however, delayed until after fertilization. Exchange of maternal pro-nuclei between control and Ring1/Rnf2 maternally dm early zygotes demonstrates an essential role for Ring1 and Rnf2 during oogenesis in defining cytoplasmic and nuclear maternal contributions that are both essential for proper initiation of embryonic development. A large number of genes up-regulated in Ring1/Rnf2 dm GV oocytes harbor PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) in spermatozoa and in embryonic stem cells (ESCs), and are repressed during normal oogenesis and early embryogenesis. These data strongly support the model that Polycomb acts in the female and male germline to silence differentiation inducing genes and to program chromatin states, thereby sustaining developmental potential across generations. Expression profiling of late 2-cell embryos was performed with the following genotypes: maternal Ring1-Rnf+ (control), maternal Ring1-Rnf2- (maternal Ring1/Rnf2 double mutant). These embryos were obtained by crossing Ring1-/-Rnf2F/F control females or Ring1-/-Rnf2F/F Zp3-cre expreimental females, respectively, to Ring1+/+Rnf2F/F control males. To distinguish between maternal transcripts present in the 2-cell embryo and newly (embryonicaly) transcribed transcripts, embryos from both genotypes were either not treated (expression profiling therefore shows all maternal and embryonic transcripts) or alpha-amanitin treated (alpha-amanitin inhibits de novo transcription, therefore expression profiling of treated embryos will only show maternal transcripts).
Project description:Polycomb group (PcG) proteins are transcriptional repressors important to maintain cell identity during embryonic development. Ezh2, the catalytic subunit of the Polycomb Repressive Complex 2, is responsible for placing the epigenetic repressive mark histone H3 lysine 27 trimethylation (H3K27me3). In contrast to results in mouse models, zebrafish embryos mutant for both maternal and zygotic ezh2 (MZezh2) can form a normal body plan at 1 day post fertilization (dpf) but die at 2 dpf, exhibiting pleiotropic phenotypes. To elucidate the specificity of PcG-mediated repression during early zebrafish development, we conducted in depth analysis of the transcriptome, epigenome, and proteome of the MZezh2 mutant embryos at 1 dpf. We found that, despite modifications in the epigenetic landscape, transcriptome and proteome analysis revealed only minor changes in gene and protein expression levels.
Project description:Polycomb group proteins are essential for oogenesis, yet mechanisms underlying the non-canonical Polycomb landscapes in oocytes remain unclear. Here we report BAP1, a core component of the Polycomb Repressive-Deubiquitinase (PR-DUB) complex, as a key negative regulator of Polycomb activity during oogenesis. BAP1 restricts pervasive H2AK119ub1 accumulation in oocytes and protects oocyte-specific broad H3K27ac, particularly within gene-poor regions, from ectopic H3K27me3 deposition. While PR-DUB has been linked to gene repression, in oocytes BAP1 primarily promotes transcription and contributes minimally to Polycomb-mediated silencing. BAP1-deficient oocytes cannot support preimplantation development due to impaired maternal-to-zygotic transition and defective embryonic enhancer activation. Notably, aberrant H3K27me3 landscape established in BAP1-null oocytes persists into early embryos. Together, these findings reveal a critical role for PR-DUB in safeguarding the oocyte epigenome by protecting euchromatin from ectopic Polycomb activity, rather than enforcing transcriptional repression.