Meiotic double-strand break end resection mapping by S1Seq
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ABSTRACT:
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE85253 | GEO | 2016/08/06
SECONDARY ACCESSION(S): PRJNA337955
REPOSITORIES: GEO
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Project description:The DNA double-strand breaks that initiate homologous recombination during meiosis are subject to extensive 5ʹâ??3â?² exonucleolytic processing. This resection is a central and conserved feature of recombination, yet its mechanism is poorly understood. Using a purpose-made deep-sequencing method, namely S1Seq, we mapped meiotic resection endpoints genome-wide at high spatial resolution in Saccharomyces cerevisiae. Generating full-length resection tracts requires Exo1 exonuclease activity and the DNA-damage responsive kinase Tel1, but not the helicase Sgs1. Tel1 is also required for efficient and timely initiation of resection. We find that distributions of resection endpoints at individual genomic loci display pronounced heterogeneity that reflects a tendency for nucleosomes to block Exo1 in vivo, yet modeling experiments indicate that Exo1 digests chromatin with high apparent processivity and at rates approaching those for naked DNA in vitro. This paradox points to nucleosome destabilization or eviction as a determining feature of the meiotic resection landscape. 36 samples total: two biological replicate S1Seq maps of S.cerevisiae for each genetic background and time point in meiosis
2016-08-06 | E-GEOD-85253 | biostudies-arrayexpress
Project description:Exonucleolytic resection is a critical step in repair of DNA double-strand breaks (DSBs) via homologous recombination, but resection mechanisms are not well understood, particularly in mammalian meiosis. Here, we use a genome-wide, nucleotide-resolution analysis to define the molecular structure of resected DSBs in mouse spermatocytes. Resection tracts averaged 1100 nucleotides on each side of a DSB, but with a broad distribution and substantial fine-scale heterogeneity at individual hotspots. Surprisingly, eliminating the nuclease activity of EXO1 only modestly decreased resection lengths, thus EXO1 is not the major 5′→3′ exonuclease in mouse meiosis. In contrast, the DSB-responsive kinase ATM proved to be a key regulator of both the initiation and extension of resection. In wild type, apparent intermolecular recombination intermediates clustered near to but offset from DSB positions, consistent with joint molecules with incompletely invaded 3′ ends. Finally, we provide evidence for PRDM9-dependent chromatin remodeling leading to increased accessibility at recombination sites. Our findings give insight into the mechanisms of DSB processing and repair in meiotic chromatin.
2020-07-10 | GSE141850 | GEO
Project description:Resection, nucleolytic processing of DSB ends is necessary to generate 3' single-stranded DNA tails (ssDNA) for homologous recombination (HR). Meiotic recombination initiated by Spo11 induced double-strand breaks (DSBs) is essential for the accurate segregation of homologous chromosomes. After cleavage, Spo11 stays covalently linked to the DSB ends, which requires MRX/Sae2 incision on broken molecules to allow following Exo1-mediated resection. Exonuclease I activity is inhibited by nucleosome bound DNA in vitro. To ensure resection proceeds, resection machineries must overcome chromatin barrier. Here we show that in the absence of Fun30, an SNF2-like ATPase, resection tract lengths shortened, albeit less severe than exo1-nd (with more longer resection tracts than that in exo1nd), across all DSB hotspots, suggesting that Fun30 is required for meiotic resection. Additive resection defect in fun30Δ exo1-nd (nuclease dead) compared to exo1-nd mutant indicates that Fun30 regulates MRX/Sae2 nicking positions. We also observed extremely short resection tracts in the double mutants are mostly confined to NDR, suggesting initial nicking step is blocked by nucleosomes.
2023-05-01 | GSE221377 | GEO
Project description:Resection, nucleolytic processing of DSB ends is necessary to generate 3' single-stranded DNA tails (ssDNA) for homologous recombination (HR). Meiotic recombination initiated by Spo11 induced double-strand breaks (DSBs) is essential for the accurate segregation of homologous chromosomes. After cleavage, Spo11 stays covalently linked to the DSB ends, which requires MRX/Sae2 incision on broken molecules to allow following Exo1-mediated resection. Exonuclease I activity is inhibited by nucleosome bound DNA in vitro. To ensure resection proceeds, resection machineries must overcome chromatin barrier. Here we show that DSB dependent enrichment of Fun30 proteins at hotspots and meiotic axes.
2023-05-01 | GSE221033 | GEO
Project description:Chromosomal double-strand breaks (DSBs) are resected by 5’-nucleases to form 3’ single-strand DNA (ssDNA) substrates for binding by homologous recombination and DNA damage checkpoint proteins. Two redundant pathways of extensive resection were described both in cells and in vitro, one relying on Exo1 exonuclease and the other on Sgs1 helicase and Dna2 nuclease. However, it remains unknown how resection proceeds within the context of chromatin where histones and histone-bound proteins represent barriers for resection enzymes. Here, we have identified the yeast nucleosome remodeling enzyme Fun30 as novel factor promoting DSB end resection. Fun30 is the major nucleosome remodeler promoting extensive Exo1- and Sgs1-dependent resection of DSBs while the RSC and INO80 chromatin remodeling complexes play redundant roles with Fun30 in resection adjacent to DSB ends. ATPase and helicase domains of Fun30, which are needed for nucleosome remodeling, are also required for resection. Fun30 is robustly recruited to DNA breaks and spreads around the DSB coincident with resection. Fun30 becomes less important for resection in the absence of the histone-bound Rad9 checkpoint adaptor protein known to block 5’ strand processing and in the absence of either histone H3 K79 methylation or γ-H2A, which mediate recruitment of the Rad9 . Together these data suggest that Fun30 helps to overcome the inhibitory effect of Rad9 on DNA resection.
2012-10-04 | GSE38601 | GEO
Project description:Chromosomal double-strand breaks (DSBs) are resected by 5M-bM-^@M-^Y-nucleases to form 3M-bM-^@M-^Y single-strand DNA (ssDNA) substrates for binding by homologous recombination and DNA damage checkpoint proteins. Two redundant pathways of extensive resection were described both in cells and in vitro, one relying on Exo1 exonuclease and the other on Sgs1 helicase and Dna2 nuclease. However, it remains unknown how resection proceeds within the context of chromatin where histones and histone-bound proteins represent barriers for resection enzymes. Here, we have identified the yeast nucleosome remodeling enzyme Fun30 as novel factor promoting DSB end resection. Fun30 is the major nucleosome remodeler promoting extensive Exo1- and Sgs1-dependent resection of DSBs while the RSC and INO80 chromatin remodeling complexes play redundant roles with Fun30 in resection adjacent to DSB ends. ATPase and helicase domains of Fun30, which are needed for nucleosome remodeling, are also required for resection. Fun30 is robustly recruited to DNA breaks and spreads around the DSB coincident with resection. Fun30 becomes less important for resection in the absence of the histone-bound Rad9 checkpoint adaptor protein known to block 5M-bM-^@M-^Y strand processing and in the absence of either histone H3 K79 methylation or M-NM-3-H2A, which mediate recruitment of the Rad9 . Together these data suggest that Fun30 helps to overcome the inhibitory effect of Rad9 on DNA resection. Genome-wide expression profiling of Yeast gene expression in two cell type including the wild type and a FUN30 knockout cell, each cell type is tested in two duplicates. Test relative gene integration efficiency in yeast genome-wide homozygous diploid deletion mutants.
2012-10-04 | E-GEOD-38601 | biostudies-arrayexpress
Project description:Programed DNA double-strand breaks (DSBs) catalyzed by the topoisomerase II-like enzymes, SPO11 and TOPVIBL, initiate meiotic recombination. Following DSB formation, the MRE11-RAD50-NBS1/Xrs2 (MRN/X) complex, along with EXO1 and DNA2, cleave the SPO11-DNA to generate 3′ single-stranded DNA (ssDNA) ends, which are prerequisite for meiotic DSB repair. In both yeast and mammals, MRE11 exhibits endonucleolytic cleavage of the 5′ terminated DNA strand in the vicinity of the DSBs and exonucleolytic resection from 3′ to 5′ towards the DSB ends. RAD50 is a structure maintenance of chromosome (SMC) related protein that contains one ATPase domain at its N- and C- terminal ends, respectively, Zn hook, and anti-parallel coiled coils. RAD50 plays a crucial role in facilitating the MRE11 nuclease activity on DSBs by ATP binding and hydrolysis. However, the in vivo function of Rad50 in mammalian germ cells, particularly its in vivo role in the resection of meiotic DSB ends at the molecular level remains elusive. Here, we performed END-seq with synchronized zygotene spermatocytes from control and germ cell specific Rad50 mutant (Rad50-sKO) mice. We find that the number of formed DSB in the mutant spermatocytes was reduced compared to control spermatocytes (6 636 DSBs in Rad50-sKO spermatocytes vs 8 168 in control spermatocytes) and abnormal DSB end resection occurred in mutant spermatocytes (DSB end resection length: 1 279 nts in Rad50-sKO spermatocytes vs 1 923 nts in control spermatocytes). Thus, RAD50 is essential for DSB formation and end resection during mammalian meiosis.
2024-04-02 | GSE262706 | GEO
Project description:The Spo11-generated double-strand breaks (DSBs) that initiate meiotic recombination are dangerous lesions that can disrupt genome integrity, so meiotic cells regulate their number, timing, and distribution. Here, we use Spo11-oligonucleotide complexes, a byproduct of DSB formation, to examine the contribution of the DNA damage-responsive kinase Tel1 (ortholog of mammalian ATM) to this regulation in Saccharomyces cerevisiae. A tel1Î mutant had globally increased amounts of Spo11-oligonucleotide complexes and altered Spo11-oligonucleotide lengths, consistent with conserved roles for Tel1 in control of DSB number and processing. A kinase-dead tel1 mutation also increased Spo11-oligonucleotide levels, but mutating known Tel1 phosphotargets on Hop1 and Rec114 did not. Deep sequencing of Spo11 oligonucleotides from tel1Î mutants demonstrated that Tel1 shapes the nonrandom DSB distribution in ways that are distinct but partially overlapping with previously described contributions of the recombination regulator Zip3. Finally, we uncover a context-dependent role for Tel1 in hotspot competition, in which an artificial DSB hotspot inhibits nearby hotspots. Evidence for Tel1-dependent competition involving strong natural hotspots is also provided. Sixteen samples total: The first 12 are two biological replicate Spo11-oligo maps from each of the following: wild type and tel1 each collected at 4, 5, and 6 hours after meiotic induction; the next 4 are one biological replicate Spo11-oligo map from each of the following: wild type and tel1 bearing an artificial hotspot insertion either on Chr III or on Chr IX.
2016-07-22 | E-GEOD-84696 | biostudies-arrayexpress
Project description:The Spo11-generated double-strand breaks (DSBs) that initiate meiotic recombination are dangerous lesions that can disrupt genome integrity, so meiotic cells regulate their number, timing, and distribution. Here, we use Spo11-oligonucleotide complexes, a byproduct of DSB formation, to examine the contribution of the DNA damage-responsive kinase Tel1 (ortholog of mammalian ATM) to this regulation in Saccharomyces cerevisiae. A tel1Δ mutant had globally increased amounts of Spo11-oligonucleotide complexes and altered Spo11-oligonucleotide lengths, consistent with conserved roles for Tel1 in control of DSB number and processing. A kinase-dead tel1 mutation also increased Spo11-oligonucleotide levels, but mutating known Tel1 phosphotargets on Hop1 and Rec114 did not. Deep sequencing of Spo11 oligonucleotides from tel1Δ mutants demonstrated that Tel1 shapes the nonrandom DSB distribution in ways that are distinct but partially overlapping with previously described contributions of the recombination regulator Zip3. Finally, we uncover a context-dependent role for Tel1 in hotspot competition, in which an artificial DSB hotspot inhibits nearby hotspots. Evidence for Tel1-dependent competition involving strong natural hotspots is also provided.
2016-07-22 | GSE84696 | GEO
Project description:Repairing broken chromosomes via joint molecule (JM) intermediates is hazardous and therefore strictly controlled in most organisms. Also in budding yeast meiosis, where production of enough crossovers via JMs is imperative, only a subset of DNA breaks are repaired via JMs, closely regulated by the ZMM pathway. The other breaks are repaired to non-crossovers avoiding JM formation requiring BLM/Sgs1 helicase. "Rogue" JMs that escaped the ZMM pathway and BLM/Sgs1 are eliminated before metaphase by resolvases like Mus81-Mms4 to prevent chromosome nondisjunction. 7 genome-wide meiotic ChIP-seq sets: 2 meiotic time points Smc6-myc DNA interaction (Smc6-ChIP), 2 meiotic time points Smc6-myc DNA interaction in the absence of induced recombination (Smc6-ChIP, spo11delta), 2 meiotic time points Sgs1-myc DNA interaction (Sgs1-ChIP), and 1 meiotic time point untagged as a negative control. (Corresponds to the main Figures 2 and 6, as well as to Figures S4, S7, in the associated publication.)
2013-12-27 | E-GEOD-51977 | biostudies-arrayexpress