Nucleosomal organization of replication origins and meiotic recombination hotspots in fission yeast
Ontology highlight
ABSTRACT:
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE28879 | GEO | 2011/12/31
SECONDARY ACCESSION(S): PRJNA140631
REPOSITORIES: GEO
Similar Datasets
Project description:DNA double-strand breaks (DSBs) are introduced in meiosis to initiate recombination and to generate crossovers, the reciprocal exchanges of genetic material between parental chromosomes. Here we present the first high-resolution map of meiotic DSBs in individual human genomes. Comparing DSB maps between individuals shows that along with DNA binding by PRDM9, additional factors dictate the efficiency of DSB formation. Furthermore, we find that in human males, the frequency of DSB formation is the primary determinant of crossover rate. Patterns of sequence polymorphisms around meiotic DSB hotspots provide evidence for both GC-biased gene conversion and for a mutagenic role of DSB repair and/or recombination. Finally, we provide compelling evidence that the aberrant repair of meiotic DSBs is a driver of human genomic disorders. Detection of meiotic double strand breaks in testis of several human male individuals.
2014-11-17 | E-GEOD-59836 | biostudies-arrayexpress
Project description:In eukaryotes, chromosomal DNA is equally distributed to daughter cells during mitosis, whereas the number of chromosomes is halved during meiosis. Despite considerable progress in understanding the molecular mechanisms that regulate mitosis, there is currently a lack of complete understanding of the molecular mechanisms regulating meiosis. Here, we took advantage of the fission yeast Schizosaccharomyces pombe, for which highly synchronous meiosis can be induced, and performed quantitative proteomics and phosphoproteomics analyses to track changes in protein expression and phosphorylation during meiotic cell divisions. We compared the proteomes and phosphoproteomes of mitotic cells with cells harvested around meiosis I, or meiosis II in strains bearing either the temperature-sensitive pat1-114 allele or conditional ATP analog-sensitive pat1-as2 allele of the Pat1 kinase. Comparing pat1-114 with pat1-as2 also allowed us to investigate the impact of elevated temperature (25°C versus 34°C) on meiosis, an issue that sexually reproducing organisms face due to climate change. Using TMTpro 18plex labeling and phosphopeptide enrichment strategies, we performed quantification of a total of 4673 proteins and 7172 phosphosites in S. pombe. We found that the protein level of 2680 proteins and the rate of phosphorylation of 4005 phosphosites significantly changed during progression of S. pombe cells through meiosis. The proteins exhibiting changes in expression and phosphorylation during meiotic cell divisions were represented mainly by those involved in the meiotic cell cycle, meiotic recombination, meiotic nuclear division, meiosis I, centromere clustering, microtubule cytoskeleton organization, ascospore formation, organonitrogen compound biosynthetic process, carboxylic acid metabolic process, gene expression, and ncRNA processing, among others. In summary, our findings provide global overview of changes in the levels and phosphorylation of proteins during progression of S. pombe cells through meiosis at normal and elevated temperatures, laying the groundwork for further elucidation of the functions and importance of specific proteins and their phosphorylation in regulating meiotic cell divisions in this yeast.
2024-10-09 | PXD053920 | Pride
Project description:Precise double-strand break (DSB) signaling and repair is paramount for maintaining genome stability. Homologous recombination (HR) is the chosen DSB repair pathway when cyclin-dependent kinase (CDK) activity is high, as it correlates well with the availability of an intact sister chromatid to be used as a template. However, the late stages of mitosis, anaphase and telophase, are paradoxical scenarios since high CDK levels favor HR repair despite sister chromatids being no longer aligned. To identify factors that specifically are involved in DSB repair in late mitosis, we have now undertaken a comparative proteomic analysis in Saccharomyces cerevisiae and found that Msc1, a poorly characterized protein previously identified as important in meiotic HR, is significantly enriched upon both random and guided DSBs. We further show that the knockout mutant for MSC1 is more sensitive to DSBs in late mitosis, and that msc1Δ has a delayed repair of DBSs as indicated by increased Rad53 hyperphosphorylation, fewer Rad52 repair factories and slower HR completion. We have found that Msc1 is an NE protein that faces the NE lumen and tends to form patches in nuclear halves that contain Rad52 factories. Either depletion or overexpression of Msc1 leads to DSB-independent abnormal nuclear morphologies in late mitosis, including blebbing, compartmentalization and premature signs of karyokinesis. In this regard, one of the two Msc1 orthologs in Schizosaccharomyces pombe, Les1, has been shown to regulate karyokinesis. We discuss how Msc1 may protect the late NE from abnormal events during DSB repair, providing a previously unreported link between NE homeostasis and DSB repair in late mitosis.
2024-08-10 | PXD043515 | Pride
Project description:Meiotic recombination is initiated by the Spo11-dependent programmed DNA double-strand breaks (DSBs) that are preferentially concentrated within genomic regions known as hotspots, but the factor(s) which specify the positions for meiotic DSB hotspots remain unclear. Here, we show that the frequency and distribution of R-loops, a type of functional chromatin structure comprising single-stranded DNA and a DNA:RNA hybrid, change dramatically throughout meiosis. We detected the formation of multiple de novo R-loops in the pachytene stage, and found they co-localize with meiotic DSB hotspots. We further show that transcription-replication head-on collisions could promote R-loop formation during meiosis, and apparently direct the initiation of meiotic DSB formation. Furthermore, the hotspots can be eliminated by reverse the direction of either transcription or replication, and reconstituted by reverse both of their direction. Our study reveals that R-loops may play dual roles in meiotic recombination. In addition to participation in meiotic DSB processing, some meiotic DSB hotspots may be originated from the transcription-replication head-on collisions during meiotic DNA replication.
2023-05-14 | GSE167915 | GEO
Project description:During the repair of DNA double-strand breaks (DSBs), de novo synthesized DNA strand can displace the parental strand to generate single-strand DNA (ssDNA) flaps. Many programmed DSBs and thus many ssDNA flaps occur during meiosis. However, how these flaps are removed remains enigmatic. Here, we show that meiosis-specific depletion of Dna2 (dna2-md) in Saccharomyces cerevisiae causes an abundant accumulation of RPA-ssDNA flaps and an expansion of RPA from DSBs to broader regions. As a result, DSB repair is defective and spores are inviable, although the levels of crossovers/non-crossovers seem to be unaffected. Furthermore, inducing Dna2 expression at pachytene is highly effective in removing accumulated RPA and restoring spore viability. Moreover, the depletion of Pif1, an activator of polymerase δ required for meiotic recombination-associated DNA synthesis, and Pif1 inhibitor Mlh2 decreased and increased RPA accumulation in dna2-md, respectively. Together, our findings show that meiotic DSB repair requires Dna2 to remove RPA-ssDNA flaps generated from meiotic recombination-associated DNA synthesis. Additionally, we showed that Dna2 also regulates DSB-independent RPA distribution.
2023-08-30 | GSE217628 | GEO
Project description:DNA double-strand breaks (DSBs) are introduced in meiosis to initiate recombination and to generate crossovers, the reciprocal exchanges of genetic material between parental chromosomes. Here we present the first high-resolution map of meiotic DSBs in individual human genomes. Comparing DSB maps between individuals shows that along with DNA binding by PRDM9, additional factors dictate the efficiency of DSB formation. Furthermore, we find that in human males, the frequency of DSB formation is the primary determinant of crossover rate. Patterns of sequence polymorphisms around meiotic DSB hotspots provide evidence for both GC-biased gene conversion and for a mutagenic role of DSB repair and/or recombination. Finally, we provide compelling evidence that the aberrant repair of meiotic DSBs is a driver of human genomic disorders.
2014-11-17 | GSE59836 | GEO
Project description:DNA double strand breaks (DSBs) in repetitive sequences are a potent source of genomic instability, due to the possibility of non-allelic homologous recombination (NAHR). Repetitive sequences are especially at risk during meiosis, when numerous programmed DSBs are introduced into the genome to initiate meiotic recombination 1. Within the budding yeast repetitive ribosomal (r)DNA array, meiotic DSB formation is prevented in part through Sir2-dependent heterochromatin 2,3. Here, we demonstrate that the edges of the rDNA array are exceptionally susceptible to meiotic DSBs, revealing an inherent heterogeneity within the rDNA array. We find that this localised DSB susceptibility necessitates a border-specific protection system consisting of the meiotic ATPase Pch2 and the origin recognition complex subunit Orc1. Upon disruption of these factors, DSB formation and recombination specifically increased in the outermost rDNA repeats, leading to NAHR and rDNA instability. Strikingly, the Sir2-dependent heterochromatin of the rDNA itself was responsible for the induction of DSBs at the rDNA borders in pch2? cells. Thus, while Sir2 activity globally prevents meiotic DSBs within the rDNA, it creates a highly permissive environment for DSB formation at the heterochromatin/euchromatin junctions. Heterochromatinised repetitive DNA arrays are abundantly present in most eukaryotic genomes. Our data define the borders of such chromatin domains as distinct high-risk regions for meiotic NAHR, whose protection may be a universal requirement to prevent meiotic genome rearrangements associated with genomic diseases and birth defects. This SuperSeries is composed of the following subset Series: GSE30071: ssDNA mapping in dmc1 strains GSE30072: ChIP-chip of DSB factors in wild type and pch2 strains Two types of study were undertaken to understand the regulation of meiotic DSB formation close to repetitive DNA elements in yeast. First, DSBs were mapped using ssDNA enrichment in strains isogenic for a dmc1 mutation, and also including pch2 delete, orc1-161, rdna delete and a reciprocal translocation between chromosomes 2 and 12 (trans2to12). Second, the association of the DSB factors Hop1, Rec114, Mer2, and Mre1, as well as total histone H3 and H3K4-trimethylation were measured by ChIP-chip analysis in wild-type and pch2 delete strains.
2011-08-14 | E-GEOD-30073 | biostudies-arrayexpress
Project description:DNA double strand breaks (DSBs) in repetitive sequences are a potent source of genomic instability, due to the possibility of non-allelic homologous recombination (NAHR). Repetitive sequences are especially at risk during meiosis, when numerous programmed DSBs are introduced into the genome to initiate meiotic recombination 1. Within the budding yeast repetitive ribosomal (r)DNA array, meiotic DSB formation is prevented in part through Sir2-dependent heterochromatin 2,3. Here, we demonstrate that the edges of the rDNA array are exceptionally susceptible to meiotic DSBs, revealing an inherent heterogeneity within the rDNA array. We find that this localised DSB susceptibility necessitates a border-specific protection system consisting of the meiotic ATPase Pch2 and the origin recognition complex subunit Orc1. Upon disruption of these factors, DSB formation and recombination specifically increased in the outermost rDNA repeats, leading to NAHR and rDNA instability. Strikingly, the Sir2-dependent heterochromatin of the rDNA itself was responsible for the induction of DSBs at the rDNA borders in pch2? cells. Thus, while Sir2 activity globally prevents meiotic DSBs within the rDNA, it creates a highly permissive environment for DSB formation at the heterochromatin/euchromatin junctions. Heterochromatinised repetitive DNA arrays are abundantly present in most eukaryotic genomes. Our data define the borders of such chromatin domains as distinct high-risk regions for meiotic NAHR, whose protection may be a universal requirement to prevent meiotic genome rearrangements associated with genomic diseases and birth defects. This SuperSeries is composed of the SubSeries listed below.
2011-08-15 | GSE30073 | GEO
Project description:Spo11-mediated DNA double strand breaks (DSBs) that initiate meiotic recombination are temporally and spatially controlled. The meiotic cohesin Rec8 has been implicated in regulating DSB formation, but little is known about the features of their interplay. To shed light on this point, we investigated the genome-wide localization of Spo11 in budding yeast during early meiosis by chromatin immunoprecipitation using high-density tiling arrays. We found that Spo11 is dynamically localized to meiotic chromosomes. Spo11 initially accumulated around centromeres and thereafter localized to arm regions as premeiotic S-phase proceeded. During this stage, a substantial proportion of Spo11 bound to Rec8 binding sites. Eventually, some of Spo11 further bound to both DSB and Rec8 sites. We also showed that such a change in a distribution of Spo11 is affected by hydroxyurea (HU) treatment. Interestingly, deletion of REC8 influences the localization of Spo11 to centromeres and in some of the intervals of the chromosomal arms. Thereby we observed a lack of DSB formation in a region-specific manner. These observations suggest that Rec8 would prearrange the distribution of Spo11 along chromosomes and will provide clues to understanding temporal and spatial regulation of DSB formation. Keywords: ChIP-chip â?¢ The goal of the experiment Genome-wide localization of Spo11, Mre11, Rec8, and DSB sites on meiotic chromosomes in Saccharomyces cerevisiae â?¢ Keywords Meiosis, Meiotic homologous recombination, Premeiotic DNA replication, cohesin, Saccharomyces cerevisiae, Genome tilling array (chromosome III, IV, V, VI), Spo11, Mre11, Rec8, DSB (Double strand break) â?¢ Experimental factor Distribution of Spo11, Mre11, and Rec8 in wild type in early meiosis (1.5 hrs, 2 hrs, 3 hrs, 4 hrs, and 5 hrs in sporulation medium) Distribution of Spo11 in rec8delta cells in early meiosis (1.5 hrs, 2 hrs, 3 hrs, 4 hrs, and 5 hrs in sporulation medium) Distribution of Spo11 in wild type in the presence of HU (2hrs and 4 hrs in sporulation medium containing HU) Distribution of DSB sites in rad50S mutant cells at 7 hrs in sporulation medium Distribution of DSB sites in rec8delta rad50S mutant cells at 7 hrs in sporulation medium â?¢ Experimental design ChIP analyses: SK1 background cells expressing FLAG tagged protein were used for the ChIP using anti-FLAG M2 antibody. ChIP-chip analyses: In all cases, hybridization data for ChIP fraction was compared with WCE (whole cell extract) fraction. Saccharomyces cerevisiae affymetrix genome tiling array (SC3456a520015F for chromosome III, IV, V, VI and rikDACF for chromosome VI) were used. Mapping of DSB sites: DSB rich fraction was concentrated by ChIP of Spo11-FLAG in rad50S mutant without crosslinking. In the mutant, DSBs ramain unrepaired with covalently attached Spo11.Meiotic cells (at 7 hours in sporulation medium) were used for the analyses. â?¢ Quality control steps taken Confirmation of several loci by quantitative real time PCR. Southern blotting of several DSB sites.
2010-05-18 | E-GEOD-8422 | biostudies-arrayexpress
Project description:Homologous recombination initiated by double-strand breaks (DSBs) is crucial for chromosome pairing and segregation during meiosis. Here we unveil mouse ANKRD31 as a lynchpin controlling DSB formation. Spermatocytes lacking ANKRD31 have altered DSB locations and fail to target DSBs to X and Y pseudoautosomal regions (PAR). They also have delayed and fewer recombination sites but, paradoxically, more total DSBs, indicating DSB dysregulation. Unrepaired DSBs and pairing failures—stochastic on autosomes, nearly absolute on X and Y—cause meiotic arrest and male sterility, while Ankrd31-deficient females have reduced oocyte reserves. A crystal structure defines direct ANKRD31–REC114 molecular contacts and reveals a surprising pleckstrin homology domain in REC114. In vivo, ANKRD31 recruits REC114 to the PAR and elsewhere. Our findings inform a model that ANKRD31 is a scaffold anchoring REC114 and other factors to specific genomic locations, promoting efficient and timely DSB formation but also suppressing formation of clustered DSBs.
2019-12-25 | GSE118913 | GEO