TOPBP1 Shapes XY Silencing Dynamics during Meiosis to Ensure Male Fertility
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE232588 | GEO | 2024/02/09
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:Vertebrate recombination concentrates in meiotic chromatin regions (hotspots) that are opened in some species by the DNA-sequence-specific-binding histone H3 trimethyltransferase PRDM9, while other species recombine in regions with already opened chromatin and other function. Inactivation of the mouse Prdm9 gene induces the shift of hotspots to functional regions, gross fertility reduction in males, and sterility in females. In contrast, the other vertebrate species lacking PRDM9 remain fertile. To resolve this discrepancy, we generated Prdm9 deletions in the Rattus norvegicus genome and generated the first rat genome-wide maps of recombination-initiating double-strand break hotspots. Rat strains carrying the same wild-type Prdm9 allele shared 88% hotspots but strains with different Prdm9 alleles only 3%. After Prdm9 deletion, rat hotspots relocated to functional regions, 40% to positions corresponding to Prdm9-independent mouse hotspots. Despite of hotspot relocation and of decreased fertility, Prdm9-deficient rats of the SHR/OlaIpcv strain produced apparently normal offspring. Rat PRDM9 thus makes recombination landscape unique, but it is unnecessary for recombination. This peculiarity is likely similar for human PRDM9 and may resolve the paradox between the apparently species-specific functions. PRDM9 is known to play a role in speciation, as it causes mouse hybrid sterility via meiotic asynapsis. Besides the expected mild meiotic arrest, we also detected apoptosis of postmeiotic spermatids, suggesting that PRDM9 has an additional role during spermatogenesis and perhaps also in speciation.
2021-03-25 | GSE163474 | GEO
Project description:Abdominal aortic aneurysms (AAAs) are a prevalent and deadly human pathology with strong sexual dimorphism. Research demonstrates that sex hormones influence, but do not fully explain, male versus female AAA pathology. In addition to sex hormones, the X and Y sex chromosomes, and their unique complements of genes, may contribute to sexually dimorphic AAA pathology. Here, for the first time, we defined the effect of female (XX) versus male (XY) chromosome complement on AAA formation and rupture in phenotypically female mice using an established murine model. Abdominal aortas from female mice bearing the XY chromosome selectively expressed Y chromosome genes, while genes known to escape X-inactivation were higher in XX females. The majority of gene differences in XY females fell within inflammatory pathways. When XY females were infused with AngII, AAA incidences doubled and aneurysms ruptured. AAAs from XY females exhibited significant inflammation. Moreover, infusion of AngII to XY females augmented aortic activity of matrix metalloproteinases. Finally, testosterone exposure applied chronically, or as a single bolus at postnatal day 1, markedly worsened AAA outcomes in XY compared to XX females. These results demonstrate that an XY sex chromosome complement profoundly influences aortic gene expression profiles and promotes AAA severity.
2016-11-07 | GSE81580 | GEO
Project description: Not available
| S-EPMC6596448 | biostudies-literature
Project description: Not available
| S-EPMC8082845 | biostudies-literature
Project description:This gene set contains skin fibroblasts from either labia majora of 46,XY sex reversed females having complete androgen insensitivity syndrome due to inactivation mutations of the androgen receptor gene and from the scrotum of normal males. Both, labia majora and scrotum origin from the same embryological anlagen, the labioscrotal swellings. The phenotypic difference is due to androgen dependent virilization in males. This is not possible in 46,XY patients with complete androgen insensitivity syndrome because the androgen receptor pathway is knocked out. A cell type comparison design experiment design type compares cells of different type for example different cell lines. Cell Line: genital skin fibroblasts from different locations mutant line: normal 46,XY male and 46,XY sex reversed female due to inactivating mutations of the androgen receptor gene Keywords: cell_type_comparison_design
2007-10-20 | GSE6797 | GEO
Project description:Male germ cells establish a unique heterochromatin domain, the XY-body, early in meiosis. How this domain is maintained through the end of meiosis and into post-meiotic germ cell differentiation is poorly understood. ADAD2 is a late meiotic male germ cell specific RNA binding protein, loss of which leads to post-meiotic germ cell defects. Analysis of ribosome association in Adad2 mutants revealed defective translation of Mdc1, a key regulator of XY-body formation, late in meiosis. As a result, Adad2 mutants show normal establishment but failed maintenance of the XY-body. Observed XY-body defects are concurrent with abnormal autosomal heterochromatin and ultimately lead to severely perturbed post-meiotic germ cell heterochromatin and cell death. These findings highlight the requirement of ADAD2 for Mdc1 translation, the role of MDC1 in maintaining meiotic male germ cell heterochromatin, and the importance of late meiotic heterochromatin for normal post-meiotic germ cell differentiation.
2021-12-11 | GSE190525 | GEO
Project description:This gene set contains skin fibroblasts from either labia majora of 46,XY sex reversed females having complete androgen insensitivity syndrome due to inactivation mutations of the androgen receptor gene and from the scrotum of normal males. Both, labia majora and scrotum origin from the same embryological anlagen, the labioscrotal swellings. The phenotypic difference is due to androgen dependent virilization in males. This is not possible in 46,XY patients with complete androgen insensitivity syndrome because the androgen receptor pathway is knocked out. A cell type comparison design experiment design type compares cells of different type for example different cell lines. Cell Line: genital skin fibroblasts from different locations mutant line: normal 46,XY male and 46,XY sex reversed female due to inactivating mutations of the androgen receptor gene Computed
2010-06-25 | E-GEOD-6797 | biostudies-arrayexpress