Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA345347 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The four mammalian Argonaute family members are thought to share redundant functions in the microRNA pathway, yet only AGO2 possesses the catalytic "slicer" function required for RNA interference. Whether AGO1, AGO3, or AGO4 possess specialized functions remains unclear. Here, we Series_summary = show that AGO4 localizes to spermatocyte nuclei during meiotic prophase I, specifically at sites of asynapsis and in the transcriptionally silenced XY sub-domain, the sex body. We generated Ago4 knockout mice and show that Ago4-/- spermatogonia initiate meiosis early, resulting from premature induction of retinoic acid-response genes. During prophase I, the sex body assembles incorrectly in Ago4-/- mice, leading to disrupted meiotic sex chromosome inactivation (MSCI). This is associated with a dramatic loss of microRNAs, >20% of which arise from the X chromosome. Loss of AGO4 results in increased AGO3 in spermatocytes, indicating some degree of redundancy. Thus, AGO4 regulates meiotic entry and MSCI in mammalian germ cells, implicating small RNA pathways in these processes. mRNA transcripts were isolated and prepared using pachytene spermatocytes, pre-meiotic testes and other tissues from Ago4+/+ and Ago4-/- littermates and sequenced using Illumina HiSeq2000. small RNA transcripts were isolated and prepared using pachytene spermatocytes from adult Ago4+/+ and Ago4-/- littermates and sequenced using Illumina GAII.
2012-08-01 | E-GEOD-39652 | biostudies-arrayexpress
Project description:Meiotic sex chromosome inactivation (MSCI) is an essential event in meiotic progression in mammalian spermatogenesis. We found that La Ribonucleoprotein 7 (LARP7) is involved in MSCI. LARP7 plays a role in fetal germ cells to promote their proliferation, but is once abolished in postnatal gonocytes and re-expresses in spermatocytes at the onset of meiosis. In spermatocytes, LARP7 localizes to the XY body, a compartmentalized chromatin domain on sex chromosomes. This study aimed to elucidate a possible function of LARP7 in the XY body by using germline-specific Larp7-deficient mice.
2024-10-01 | GSE261526 | GEO
Project description:The four mammalian Argonaute family members are thought to share redundant functions in the microRNA pathway, yet only AGO2 possesses the catalytic "slicer" function required for RNA interference. Whether AGO1, AGO3, or AGO4 possess specialized functions remains unclear. Here, we Series_summary = show that AGO4 localizes to spermatocyte nuclei during meiotic prophase I, specifically at sites of asynapsis and in the transcriptionally silenced XY sub-domain, the sex body. We generated Ago4 knockout mice and show that Ago4-/- spermatogonia initiate meiosis early, resulting from premature induction of retinoic acid-response genes. During prophase I, the sex body assembles incorrectly in Ago4-/- mice, leading to disrupted meiotic sex chromosome inactivation (MSCI). This is associated with a dramatic loss of microRNAs, >20% of which arise from the X chromosome. Loss of AGO4 results in increased AGO3 in spermatocytes, indicating some degree of redundancy. Thus, AGO4 regulates meiotic entry and MSCI in mammalian germ cells, implicating small RNA pathways in these processes.
2012-08-01 | GSE39652 | GEO
Project description:Spermatogenesis in the Drosophila male germline proceeds through a unique transcriptional program controlled both by germline-specific transcription factors and by testis-specific versions of core transcriptional machinery. This program includes the activation of genes on the heterochromatic Y chromosome, and reduced transcription from the X chromosome, but how expression from these sex chromosomes is regulated has not been defined. To resolve this, we profiled active chromatin features in the testes from wildtype and meiotic arrest mutants and integrate this with single-cell gene expression data from the Fly Cell Atlas. These data assign the timing of promoter activation for genes with germline-enriched expression throughout spermatogenesis, and general alterations of promoter regulation in germline cells. By profiling both active RNA polymerase II and histone modifications in isolated spermatocytes, we detail widespread patterns associated with regulation of the sex chromosomes. Our results demonstrate that the X chromosome is not enriched for silencing histone modifications, implying that sex chromosome inactivation does not occur in Drosophila. Instead, a lack of dosage compensation in spermatocytes accounts for the reduced expression from this chromosome. Finally, profiling uncovers dramatic ubiquitinylation of histone H2A and lysine-16 acetylation of histone H4 across the Y chromosome in spermatocytes that may contribute to the activation of this heterochromatic chromosome.
2023-10-04 | GSE225300 | GEO
Project description:In mammals and several other taxa, the ability of males to cope with the limited synapsis of the X and Y chromosomes during prophase I of meiosis relies on the process of meiotic sex chromosome inactivation (MSCI). Components of the somatic DNA damage response machinery, including ATR, TOPBP1, MDC1 and BRCA1 play key roles in MSCI, although how they establish XY silencing remains incompletely understood. In particular, it remains unclear how DDR factors coordinate XY silencing with DNA repair, chromosome synapsis and the formation of the sex body, a distinct phase-separated sub-nuclear structure formed during prophase I to house the unsynapsed XY bivalent. Here we report a mutant mouse (Topbp1B5/B5), harboring mutations in the BRCT5 domain of Topbp1, that shows impaired XY silencing but grossly normal sex body formation. While Topbp1B5/B5 mice are viable, without detectable somatic defects, males are completely infertile. Distinct from mice lacking ATR or TOPBP1 specifically during meiosis, Topbp1B5/B5 males exhibit normal chromosome synapsis and canonical markers of DNA repair in early prophase I. ATR signaling is mostly intact in Topbp1B5/B5 spermatocytes, although specific ATR-dependent events are disrupted, including localization of the RNA:DNA helicase Senataxin to chromatin loops of the XY. Strikingly, while Topbp1B5/B5 spermatocytes are able to initiate MSCI the completion of gene silencing is defective, with a subset of X chromosome genes displaying distinct patterns of transcriptional deregulation. These findings suggest a non-canonical role for the ATR-TOPBP1 signaling axis in XY silencing dynamics at advanced stages in pachynema. This is the first DDR mutant that separates XY silencing from sex body formation, as well as TOPBP1’s role in spermatogenesis from its roles in organismal viability.
2024-02-09 | PXD042199 | Pride
Project description:During spermatogenesis, germ cells that fail to synapse their chromosomes or fail to undergo meiotic sex chromosome inactivation (MSCI) are eliminated via apoptosis during mid-pachytene. Previous work showed that Y-linked genes Zfy1 and Zfy2 act as “executioners” for this checkpoint, and that wrongful expression of either gene during pachytene triggers germ cell death. Here, we show that in mice, Zfy genes are also necessary for efficient MSCI and the sex chromosomes are not correctly silenced in Zfy-deficient spermatocytes. In addition to this microarray data set, qPCR and RNA FISH data were used to confirm that MSCI is leaky in males lacking Zfy genes. The array data demonstrates that transgenic restoration of Zfy2 corrects the MSCI leakage phenotype. The associated RNA FISH data demonstrates that Zfy1 and Zfy2 are both able to correct the leakage phenotype.
2016-10-05 | GSE87598 | GEO
Project description:Chromosomal rearrangement interferes with meiotic X-chromosome inactivation
| PRJNA98079 | ENA
Project description:H3K9 tri-methylation (H3K9me3) plays emerging roles in gene regulation, beyond its accumulation on pericentric constitutive heterochromatin. It remains a mystery why and how H3K9me3 undergoes dynamic regulation in male meiosis. Here, we identify a novel, critical regulator of H3K9 methylation and spermatogenic heterochromatin organization: the germline-specific protein ATF7IP2 (MCAF2). We show that, in male meiosis, ATF7IP2 amasses on autosomal and X pericentric heterochromatin, spreads through the entirety of the sex chromosomes, and accumulates on thousands of autosomal promoters and retrotransposon loci. On the sex chromosomes, which undergo meiotic sex chromosome inactivation (MSCI), the DNA damage response pathway recruits ATF7IP2 to X pericentric heterochromatin, where it facilitates the recruitment of SETDB1, a histone methyltransferase that catalyzes H3K9me3. In the absence of ATF7IP2, male germ cells are arrested in meiotic prophase. Analyses of ATF7IP2-deficient meiosis reveal the protein’s essential roles in the maintenance of MSCI, suppression of retrotransposons, and global activation of autosomal genes. We propose that ATF7IP2 is a downstream effector of the DDR pathway in meiosis that coordinates the organization of heterochromatin and gene regulation through the spatial regulation of SETDB1-mediated H3K9me3 deposition. CUT&RUN of H3K9me3 in Atf7ip2+/+ and Atf7ip2-/- pachytene spermatocytes and CUT&Tag of ATF7IP2 in C57/B6 WT pachytene spermatocytes.
2024-02-14 | GSE244083 | GEO
Project description:Meiotic synapsis and recombination ensure correct homologous segregation and genetic diversity. Asynapsed homologues are transcriptionally inactivated by meiotic silencing, which serves a surveillance function and in males drives meiotic sex chromosome inactivation. Silencing depends on the DNA damage response (DDR) network, but how DDR proteins engage repressive chromatin marks is unknown. We identify the histone H3-lysine-9 methyltransferase SETDB1 as the bridge linking the DDR to silencing in male mice. At the onset of silencing, X-chromosome H3K9 trimethylation (H3K9me3) enrichment is downstream of DDR factors. Without Setdb1, the X chromosome accrues DDR proteins but not H3K9me3. Consequently, sex chromosome remodelling and silencing fails, causing germ cell apoptosis. Our data implicate TRIM28 in linking the DDR to SETDB1, and uncover additional factors with putative meiotic XY-silencing functions. Furthermore, we show that SETDB1 imposes timely expression of meiotic and post-meiotic genes. Setdb1 thus unites the DDR network, asynapsis and meiotic chromosome silencing.
2018-11-01 | GSE107671 | GEO
Project description:As a serine/threonine phosphatase, protein phosphatase 2A (PP2A) is essential in numerous physiological processes. Our previously study confirmed PP2A dysfunction can cause azoospermia by generating catalytic subunit of PP2A (Ppp2ca) conditional knockout (CKO) in C57BL/6J mice. Here, we further explored the possible mechanisms by focusing on meiosis initiation and spermatogenesis. The deficiency of Ppp2ca in germ cells conspicuously disturbed spermatogonial differentiation and lead to pachytene arrest, accompanied by defects in programmed double-strand break (DSB) repair and meiotic sex chromosome inactivation (MSCI). Furthermore, Ppp2ca-deficient spermatocytes exhibited abnormal agglutination and cohesion complex degradation of chromosome, probably contributing to pachytene arrest. Our study demonstrates the irreplaceable role of PP2A in spermatogenesis and provide more evidences on azoospermia etiology.
2021-12-01 | GSE181132 | GEO