ATR is required to complete meiotic recombination in mice

ABSTRACTPrecise execution of recombination during meiosis is essential for forming chromosomally balanced gametes. Meiotic recombination initiates with the formation and resection of DNA double-strand breaks (DSBs). Binding of replication protein A (RPA) at resected DSBs fosters association of RAD51 and DMC1, the primary effectors of homology search. It is well appreciated that cellular responses to meiotic DSBs are critical for efficient repair and quality control, but molecular features of these responses remain poorly understood, particularly in mammals. Here we provide evidence that the DNA damage response protein kinase ATR is crucial for meiotic recombination and completion of meiotic prophase in mice. Using a hypomorphic Atr mutation and pharmacological inhibition of ATR in vivo and in cultured spermatocytes, we show that ATR, through its effector kinase CHK1, promotes efficient RAD51 and DMC1 assembly at RPA-coated DSB sites and establishment of interhomolog connections during meiosis. Furthermore, our findings suggest that ATR promotes local accumulation of recombination markers on unsynapsed axes during meiotic prophase to favor homologous chromosome synapsis. These data reveal that ATR plays multiple roles in mammalian meiotic recombination.

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Tex19.1 Regulates Meiotic DNA Double Strand Break Frequency in Mouse Spermatocytes

10.1101/099119 ◽

2017 ◽

Cited By ~ 4

Author(s):

James H. Crichton ◽

Christopher J. Playfoot ◽

Marie MacLennan ◽

David Read ◽

Howard J. Cooke ◽

...

Keyword(s):

Ubiquitin Ligase ◽

Meiotic Recombination ◽

Homologous Chromosome ◽

E3 Ubiquitin Ligase ◽

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Genetic Pathway ◽

Strand Breaks ◽

Chromosome Synapsis ◽

Meiotic Dsbs

AbstractMeiosis relies on the SPO11 endonuclease to generate the recombinogenic DNA double strand breaks (DSBs) required for homologous chromosome synapsis and segregation. The number of meiotic DSBs needs to be sufficient to allow chromosomes to search for and find their homologs, but not excessive to the point of causing genome instability. Here we report that meiotic DSB frequency in mouse spermatocytes is regulated by the mammal-specific gene Tex19.1. We show that the chromosome asynapsis previously reported in Tex19.1-/- spermatocytes is preceded by reduced numbers of recombination foci in leptotene and zygotene. Tex19.1 is required for the generation of normal levels of Spo11-dependent DNA damage during leptotene, but not for upstream events such as MEI4 foci formation or accumulation of H3K4me3 at recombination hotspots. Furthermore, we show that mice carrying mutations in the E3 ubiquitin ligase UBR2, a TEX19.1-interacting partner, phenocopy the Tex19.1-/- recombination defects. These data show that Tex19.1 and Ubr2 are required for mouse spermatocytes to generate sufficient meiotic DSBs to ensure that homology search is consistently successful, and reveal a hitherto unknown genetic pathway regulating meiotic DSB frequency in mammals.Author SummaryMeiosis is a specialised type of cell division that occurs during sperm and egg development to reduce chromosome number prior to fertilisation. Recombination is a key step in meiosis as it facilitates the pairing of homologous chromosomes prior to their reductional division, and generates new combinations of genetic alleles for transmission in the next generation. Regulating the amount of recombination is key for successful meiosis: too much will likely cause mutations, chromosomal re-arrangements and genetic instability, whereas too little causes defects in homologous chromosome pairing prior to the meiotic divisions. This study identifies a genetic pathway requiredto generate robust meiotic recombination in mouse spermatocytes. We show that male mice with mutations in Tex19.1 or Ubr2, which encodes an E3 ubiquitin ligase that interacts with TEX19.1, have defects in generating normal levels of meiotic recombination. We show that the defects in these mutants impact on the recombination process at the stage when programmed DNA double strand breaks are being made. This defect likely contributes to the chromosome synapsis and meiotic progression phenotypes previously described in these mutant mice. This study has implications for our understanding of how this fundamental aspect of genetics and inheritance is controlled.

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Super-resolution mapping of cellular double-strand break resection complexes during homologous recombination

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2021963118 ◽

2021 ◽

Vol 118 (11) ◽

pp. e2021963118

Author(s):

Donna R. Whelan ◽

Eli Rothenberg

Keyword(s):

Homologous Recombination ◽

Single Molecule ◽

Protein A ◽

Super Resolution ◽

Initial Step ◽

Double Strand Breaks ◽

Homology Search ◽

Major Pathway ◽

Strand Breaks

Homologous recombination (HR) is a major pathway for repair of DNA double-strand breaks (DSBs). The initial step that drives the HR process is resection of DNA at the DSB, during which a multitude of nucleases, mediators, and signaling proteins accumulates at the damage foci in a manner that remains elusive. Using single-molecule localization super-resolution (SR) imaging assays, we specifically visualize the spatiotemporal behavior of key mediator and nuclease proteins as they resect DNA at single-ended double-strand breaks (seDSBs) formed at collapsed replication forks. By characterizing these associations, we reveal the in vivo dynamics of resection complexes involved in generating the long single-stranded DNA (ssDNA) overhang prior to homology search. We show that 53BP1, a protein known to antagonize HR, is recruited to seDSB foci during early resection but is spatially separated from repair activities. Contemporaneously, CtBP-interacting protein (CtIP) and MRN (MRE11-RAD51-NBS1) associate with seDSBs, interacting with each other and BRCA1. The HR nucleases EXO1 and DNA2 are also recruited and colocalize with each other and with the repair helicase Bloom syndrome protein (BLM), demonstrating multiple simultaneous resection events. Quantification of replication protein A (RPA) accumulation and ssDNA generation shows that resection is completed 2 to 4 h after break induction. However, both BRCA1 and BLM persist later into HR, demonstrating potential roles in homology search and repair resolution. Furthermore, we show that initial recruitment of BRCA1 and removal of Ku are largely independent of MRE11 exonuclease activity but dependent on MRE11 endonuclease activity. Combined, our observations provide a detailed description of resection during HR repair.

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Massive crossover elevation via combination of HEI10 and recq4a recq4b during Arabidopsis meiosis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1713071115 ◽

2018 ◽

Vol 115 (10) ◽

pp. 2437-2442 ◽

Cited By ~ 38

Author(s):

Heïdi Serra ◽

Christophe Lambing ◽

Catherine H. Griffin ◽

Stephanie D. Topp ◽

Divyashree C. Nageswaran ◽

...

Keyword(s):

Meiotic Recombination ◽

Homologous Chromosome ◽

Crop Improvement ◽

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Dsb Repair ◽

Strand Breaks ◽

Homologous Chromosomes ◽

Meiotic Dsbs ◽

Competing Pathways

During meiosis, homologous chromosomes undergo reciprocal crossovers, which generate genetic diversity and underpin classical crop improvement. Meiotic recombination initiates from DNA double-strand breaks (DSBs), which are processed into single-stranded DNA that can invade a homologous chromosome. The resulting joint molecules can ultimately be resolved as crossovers. In Arabidopsis, competing pathways balance the repair of ∼100–200 meiotic DSBs into ∼10 crossovers per meiosis, with the excess DSBs repaired as noncrossovers. To bias DSB repair toward crossovers, we simultaneously increased dosage of the procrossover E3 ligase gene HEI10 and introduced mutations in the anticrossovers helicase genes RECQ4A and RECQ4B. As HEI10 and recq4a recq4b increase interfering and noninterfering crossover pathways, respectively, they combine additively to yield a massive meiotic recombination increase. Interestingly, we also show that increased HEI10 dosage increases crossover coincidence, which indicates an effect on interference. We also show that patterns of interhomolog polymorphism and heterochromatin drive recombination increases distally towards the subtelomeres in both HEI10 and recq4a recq4b backgrounds, while the centromeres remain crossover suppressed. These results provide a genetic framework for engineering meiotic recombination landscapes in plant genomes.

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γ-H2AX is present at mouse meiotic kinetochores

10.1101/2020.03.10.986273 ◽

2020 ◽

Author(s):

Andrea Guajardo ◽

Alberto Viera ◽

María Teresa Parra ◽

Manuel M. Valdivia ◽

Julio S. Rufas ◽

...

Keyword(s):

Meiotic Recombination ◽

Meiotic Prophase ◽

Male Mouse ◽

Sex Chromosome ◽

Double Strand Breaks ◽

Chromosome Inactivation ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Meiotic Sex Chromosome Inactivation ◽

First Time

AbstractThe histone variant H2AX phosphorylated on serine 139, named γ-H2AX, is a canonical DNA double-strand breaks marker. During mammalian meiotic prophase I, γ-H2AX participates in meiotic recombination, meiotic sex chromosome inactivation and meiotic silencing of unsynapsed chromatin. In this study, we have analyzed the distribution of γ-H2AX during male mouse meiosis by immunofluorescence on spread and squashed spermatocytes. We have found that γ-H2AX locates at the inner kinetochore plate of meiotic kinetochores in both meiotic divisions. Therefore our results, for the first time, uncover a novel role for γ-H2AX at mammalian meiotic kinetochores.

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Massive crossover elevation via combination of HEI10 and recq4a recq4b during Arabidopsis meiosis

10.1101/159764 ◽

2017 ◽

Cited By ~ 2

Author(s):

Heïdi Serra ◽

Christophe Lambing ◽

Catherine H. Griffin ◽

Stephanie D. Topp ◽

Mathilde Séguéla-Arnaud ◽

...

Keyword(s):

Meiotic Recombination ◽

Homologous Chromosome ◽

Crop Improvement ◽

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Dsb Repair ◽

Strand Breaks ◽

Homologous Chromosomes ◽

Meiotic Dsbs ◽

Competing Pathways

AbstractDuring meiosis homologous chromosomes undergo reciprocal crossovers, which generate genetic diversity and underpin classical crop improvement. Meiotic recombination initiates from DNA double strand breaks, which are processed into single-stranded DNA that can invade a homologous chromosome. The resulting joint molecules can ultimately be resolved as crossovers. In Arabidopsis, competing pathways balance the repair of ∼100–200 meiotic DSBs into ∼10 crossovers per meiosis, with the excess DSBs repaired as non-crossovers. In order to bias DSB repair towards crossovers, we simultaneously increased dosage of the pro-crossover E3 ligase gene HEI10 and introduced mutations in the anti-crossover helicase genes RECQ4A and RECQ4B. As HEI10 and recq4a recq4b increase interfering and non-interfering crossover pathways respectively, they combine additively to yield a massive meiotic recombination increase. Interestingly, we also show that increased HEI10 dosage increases crossover coincidence, which indicates an effect of HEI10 on interference. We also show that patterns of interhomolog polymorphism and heterochromatin drive recombination increases towards the sub-telomeres in both HEI10 and recq4a recq4b backgrounds, while the centromeres remain crossover-suppressed. These results provide a genetic framework for engineering meiotic recombination landscapes in plant genomes.

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Removal of Spo11 from meiotic DNA breaksin vitrobut notin vivoby Tyrosyl DNA Phosphodiesterase 2

10.1101/527333 ◽

2019 ◽

Cited By ~ 2

Author(s):

Dominic Johnson ◽

Rachal M Allison ◽

Elda Cannavo ◽

Petr Cejka ◽

Matthew J Neale

Keyword(s):

Meiotic Recombination ◽

Dna Cleavage ◽

Protein Complexes ◽

Dna Lesions ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Alternative Processing ◽

Covalently Linked

ABSTRACTMeiotic recombination events are initiated by DNA double-strand breaks (DSBs) created by the topoisomerase-like protein, Spo11. Similar to type-II topoisomerases, Spo11 becomes covalently linked to the 5′ ends generated on each side of the DSB. Whilst Spo11-oligos—the product of nucleolytic removal by Mre11—have been detected in a number of biological systems, the lifetime of the covalent Spo11-DSB precursor has not been systematically determined and may be subject to alternative processing reactions. Here we explore the activity of human Tyrosyl DNA Phosphodiesterase, TDP2, on Spo11-DSBs isolated fromS. cerevisiaecells. We demonstrate that TDP2 can remove Spo11 from natural ssDNA-oligos, and dsDNA ends even when in the presence of excess competitor genomic DNA. Interestingly, TDP2-processed Spo11-DSBs are refractory to resection by Exo1, suggesting that ssDNA generated by Mre11 may be essentialin vivoto facilitate resection-dependent HR at Spo11-DSBs even if TDP2 were active. Moreover, although TDP2 can remove Spo11 peptidesin vitro, TDP2 was unable to remove Spo11in vivo—unlike during the repair of topoisomerase-induced DNA lesions. These results suggest that Spo11-DNA, but not topoisomerase-DNA cleavage complexes, are inaccessible to the TDP2 enzyme, perhaps due to occlusion by higher order protein complexes resident at sites of meiotic recombination.

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MEIOK21: a new component of meiotic recombination bridges required for spermatogenesis

Nucleic Acids Research ◽

10.1093/nar/gkaa406 ◽

2020 ◽

Vol 48 (12) ◽

pp. 6624-6639

Author(s):

Yongliang Shang ◽

Tao Huang ◽

Hongbin Liu ◽

Yanlei Liu ◽

Heng Liang ◽

...

Keyword(s):

Meiotic Recombination ◽

Double Strand Breaks ◽

Strand Exchange ◽

Homology Search ◽

Physical Interaction ◽

Dna Double Strand Breaks ◽

Dsb Repair ◽

Chromosome Localization ◽

Strand Breaks ◽

Homologous Chromosomes

Abstract Repair of DNA double-strand breaks (DSBs) with homologous chromosomes is a hallmark of meiosis that is mediated by recombination ‘bridges’ between homolog axes. This process requires cooperation of DMC1 and RAD51 to promote homology search and strand exchange. The mechanism(s) regulating DMC1/RAD51-ssDNA nucleoprotein filament and the components of ‘bridges’ remain to be investigated. Here we show that MEIOK21 is a newly identified component of meiotic recombination bridges and is required for efficient formation of DMC1/RAD51 foci. MEIOK21 dynamically localizes on chromosomes from on-axis foci to ‘hanging foci’, then to ‘bridges’, and finally to ‘fused foci’ between homolog axes. Its chromosome localization depends on DSBs. Knockout of Meiok21 decreases the numbers of HSF2BP and DMC1/RAD51 foci, disrupting DSB repair, synapsis and crossover recombination and finally causing male infertility. Therefore, MEIOK21 is a novel recombination factor and probably mediates DMC1/RAD51 recruitment to ssDNA or their stability on chromosomes through physical interaction with HSF2BP.

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ATM and PRDM9 Regulate SPO11-bound Recombination Intermediates During Meiosis

10.1101/2019.12.18.881409 ◽

2019 ◽

Cited By ~ 2

Author(s):

Jacob Paiano ◽

Wei Wu ◽

Shintaro Yamada ◽

Nicholas Sciascia ◽

Elsa Callen ◽

...

Keyword(s):

Meiotic Recombination ◽

Homologous Chromosome ◽

Direct Detection ◽

Double Strand Breaks ◽

Sequence Specificity ◽

Dna Sequence Specificity ◽

Strand Breaks ◽

Genome Wide ◽

Meiotic Dsbs

AbstractMeiotic recombination is initiated by genome-wide SPO11-induced double-strand breaks (DSBs) that are processed by MRE11-mediated release of SPO11. The DSB is then resected and loaded with DMC1/RAD51 filaments that invade homologous chromosome templates. In most mammals, DSB locations (“hotspots”) are determined by the DNA sequence specificity of PRDM9. Here, we demonstrate the first direct detection of meiotic DSBs and resection in vertebrates by performing END-seq on mouse spermatocytes using low sample input. We find that DMC1 limits both the minimum and maximum lengths of resected DNA, whereas 53BP1, BRCA1 and EXO1 play surprisingly minimal roles in meiotic resection. Through enzymatic modifications to the END-seq protocol that mimic the in vivo processing of SPO11, we identify a novel meiotic recombination intermediate (“SPO11-RI”) present at all hotspots. The SPO11-bound intermediate is dependent on PRDM9 and caps the 3’ resected end during engagement with the homologous template. We propose that SPO11-RI is generated because chromatin-bound PRDM9 asymmetrically blocks MRE11 from releasing SPO11. In Atm−/− spermatocytes, SPO11-RI is reduced while unresected DNA-bound SPO11 accumulate because of defective MRE11 initiation. Thus in addition to their global roles in governing SPO11 breakage, ATM and PRDM9 are critical local regulators of mammalian SPO11 processing.

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REC8-cohesin, chromatin and transcription orchestrate meiotic recombination in the Arabidopsis genome

10.1101/512400 ◽

2019 ◽

Cited By ~ 1

Author(s):

Christophe Lambing ◽

Andrew J. Tock ◽

Kyuha Choi ◽

Stephanie D. Topp ◽

Pallas C. Kuo ◽

...

Keyword(s):

Meiotic Recombination ◽

Meiotic Chromosome ◽

Double Strand Breaks ◽

Centromeric Heterochromatin ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Chromosome Architecture ◽

Organizational Role ◽

Homolog Pairing ◽

Meiotic Dsbs

AbstractDuring meiosis chromosomes undergo DNA double-strand breaks (DSBs) that can be repaired using a homolog to produce crossovers, which creates genetic diversity. Meiotic recombination occurs coincident with homolog pairing and polymerization of the meiotic axis and synaptonemal complex (SC). REC8-cohesin is required to connect chromosomes to the axis and to organize axis polymerization. However, control of REC8 loading along chromosomes, in relation to chromatin, transcription and recombination, is not yet fully understood. Therefore, we performed REC8 ChIP-seq in Arabidopsis, which revealed strong enrichment in centromeric heterochromatin. REC8 abundance correlates with suppression of meiotic DSBs and crossovers, despite axis loading of SPO11-1 in these regions. Loss of the heterochromatic marks H3K9me2 and non-CG DNA methylation in kyp/suvh4 suvh5 suvh6 mutants causes remodeling of REC8 and gain of meiotic recombination locally in repeated sequences, although centromere cohesion is maintained. In the chromosome arms, REC8 is enriched within gene bodies, exons and GC-rich sequences, and anti-correlates with transcription. Highest REC8 occupancy occurred in facultatively silent, H3K27me3-modified genes. Using immunocytology we show that axis polycomplexes form in rec8 mutants that recruit recombination foci with altered stoichiometry, leading to catastrophic non-homologous recombination. Therefore, REC8 plays a key role organizing meiotic chromosome architecture and promoting high-fidelity interhomolog recombination. Despite this pro-recombination role, local REC8 enrichment associates with DSB repression at the fine scale, which is consistent with the tethered-loop/axis model. Coincident with its organizational role during meiosis, REC8-cohesin occupancy along the chromosomes is shaped by multiple chromatin states and transcription.

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Functional Interactions Between SPO11 and REC102 During Initiation of Meiotic Recombination in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/160.1.111 ◽

2002 ◽

Vol 160 (1) ◽

pp. 111-122

Author(s):

Kehkooi Kee ◽

Scott Keeney

Keyword(s):

Saccharomyces Cerevisiae ◽

Meiotic Recombination ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Whole Cells ◽

Meiotic Gene ◽

Meiotic Chromosomes ◽

Cell Extracts ◽

Cold Sensitive

Abstract In Saccharomyces cerevisiae, formation of the DNA double-strand breaks (DSBs) that initiate meiotic recombination requires the products of at least 10 genes. Spo11p is thought to be the catalytic subunit of the DNA cleaving activity, but the roles of the other proteins, and the interactions among them, are not well understood. This study demonstrates genetic and physical interactions between the products of SPO11 and another early meiotic gene required for DSB formation, REC102. We found that epitope-tagged versions of SPO11 and REC102 that by themselves were capable of supporting normal or nearly normal levels of meiotic recombination conferred a severe synthetic cold-sensitive phenotype when combined in the same cells. DSB formation, meiotic gene conversion, and spore viability were drastically reduced in the doubly tagged strain at a nonpermissive temperature. This conditional defect could be partially rescued by expression of untagged SPO11, but not by expression of untagged REC102, indicating that tagged REC102 is fully dominant for this synthetic phenotype. Both tagged and wild-type Spo11p co-immunoprecipitated with tagged Rec102p from meiotic cell extracts, indicating that these proteins are present in a common complex in vivo. Tagged Rec102p localized to the nucleus in whole cells and to chromatin on spread meiotic chromosomes. Our results are consistent with the idea that a multiprotein complex that includes Spo11p and Rec102p promotes meiotic DSB formation.

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