Role of LARP7 in meiotic sex chromosome silencing
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE261526 | GEO | 2024/10/01
REPOSITORIES: GEO
Similar Datasets
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: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: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:In mammals, the X and Y chromosomes are subject to meiotic sex chromosome inactivation (MSCI) during prophase I in the male germline, but their status thereafter is currently unclear. An abundance of X-linked spermatogenesis genes has spawned the view that the X must be active [1-8]. On the other hand, the idea that the imprinted paternal X of the early embryo may be pre-inactivated by MSCI suggests that silencing may persist longer [9-12]. To clarify this issue, we establish a comprehensive X-expression profile during mouse spermatogenesis. Here, we discover that the X and Y occupy a novel compartment in the post-meiotic spermatid and adopt a non-Rabl configuration. We demonstrate that this post-meiotic sex chromatin (PMSC) persists throughout spermiogenesis into mature sperm and exhibits epigenetic similarity to the XY body. In the spermatid, 87% of X-linked genes remain suppressed post-meiotically, while autosomes are largely active. We conclude that chromosome-wide X-silencing continues from meiosis to the end of spermiogenesis and discuss implications for proposed mechanisms of imprinted X-inactivation. Independent germ cell preps were used for array analysis. Duplicates were provided for each sample.
2007-12-07 | E-GEOD-4193 | biostudies-arrayexpress
Project description:In mammals, the X and Y chromosomes are subject to meiotic sex chromosome inactivation (MSCI) during prophase I in the male germline, but their status thereafter is currently unclear. An abundance of X-linked spermatogenesis genes has spawned the view that the X must be active [1-8]. On the other hand, the idea that the imprinted paternal X of the early embryo may be pre-inactivated by MSCI suggests that silencing may persist longer [9-12]. To clarify this issue, we establish a comprehensive X-expression profile during mouse spermatogenesis. Here, we discover that the X and Y occupy a novel compartment in the post-meiotic spermatid and adopt a non-Rabl configuration. We demonstrate that this post-meiotic sex chromatin (PMSC) persists throughout spermiogenesis into mature sperm and exhibits epigenetic similarity to the XY body. In the spermatid, 87% of X-linked genes remain suppressed post-meiotically, while autosomes are largely active. We conclude that chromosome-wide X-silencing continues from meiosis to the end of spermiogenesis and discuss implications for proposed mechanisms of imprinted X-inactivation. Keywords: Specific germ cells from murine testis
2006-02-09 | GSE4193 | GEO
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:Analysis the difference in the transcriptomes (expression and alternative splicing) of either spermatocytes or round spermatids between Larp7 conditional knock-out and control mice
2019-11-07 | GSE128832 | GEO
Project description:Zfy genes are required for efficient meiotic sex chromosome inactivation (MSCI) in spermatocytes
| PRJNA345347 | 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:Background: The ubiquitin-conjugating enzyme HR6B is required for spermatogenesis in mouse. Loss of HR6B results in aberrant histone modification patterns on the trancriptionally silenced X and Y chromosomes (XY body) and on centromeric chromatin in meiotic prophase. We studied the relationship between these chromatin modifications and their effects on global gene expression patterns, in spermatocytes and spermatids. Results: HR6B is enriched on the XY body and on centromeric regions in pachytene spermatocytes. Global gene expression analyses revealed that spermatid-specific single- and multicopy X-linked genes are prematurely expressed in Hr6b knockout spermatocytes. Very few other differences in gene expression were observed in these cells, except for upregulation of major satellite repeat transcription. In contrast, in Hr6b knockout spermatids, 7298 genes were differentially expressed; 65% of these genes was downregulated, but we observed a global upregulation of gene transcription from the X chromosome. In wildtype spermatids, approximately 20% of the single-copy X-linked genes reach an average expression level that is similar to the average expression from autosomes. Conclusions: Spermatids maintain an enrichment of repressive chromatin marks on the X chromosome, originating from meiotic prophase, but this does not interfere with transcription of the single-copy X-linked genes that are reactivated or specifically activated in spermatids. HR6B represses major satellite repeat transcription in spermatocytes, and functions in the maintenance of X chromosome silencing in spermatocytes and spermatids. It is discussed that these functions involve modification of chromatin structure, possibly including H2B ubiquitylation. 8 Affymetrix microarrays were generated: 4 from wildtype and HR6B knockout spermatocytes (2 replicates each), and 4 from wildtype and HR6B knockout spermatids (2 replicates each).
2010-05-27 | E-GEOD-21749 | biostudies-arrayexpress