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

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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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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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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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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Epigenetic activation of meiotic recombination in Arabidopsis centromeres via loss of H3K9me2 and non-CG DNA methylation

10.1101/160929 ◽

2017 ◽

Cited By ~ 2

Author(s):

Charles J. Underwood ◽

Kyuha Choi ◽

Christophe Lambing ◽

Xiaohui Zhao ◽

Heïdi Serra ◽

...

Keyword(s):

Dna Methylation ◽

Meiotic Recombination ◽

Double Strand Breaks ◽

Pericentromeric Heterochromatin ◽

Repair Pathway ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Histone 3 ◽

Differential Control

AbstractEukaryotic centromeres contain the kinetochore, which connects chromosomes to the spindle allowing segregation. During meiosis centromeres are suppressed for crossovers, as recombination in these regions can cause chromosome mis-segregation. Plant centromeres are surrounded by repetitive, transposon-dense heterochromatin that is epigenetically silenced by histone 3 lysine 9 dimethylation (H3K9me2), and DNA methylation in CG and non-CG sequence contexts. Here we show that disruption of Arabidopsis H3K9me2 and non-CG DNA methylation pathways increases meiotic DNA double strand breaks (DSBs) within centromeres, whereas crossovers increase within pericentromeric heterochromatin. Increased pericentromeric crossovers in H3K9me2/non-CG mutants occurs in both inbred and hybrid backgrounds, and involves the interfering crossover repair pathway. Epigenetic activation of recombination may also account for the curious tendency of maize transposon Ds to disrupt CHROMOMETHYLASE3 when launched from proximal loci. Thus H3K9me2 and non-CG DNA methylation exert differential control of meiotic DSB and crossover formation in centromeric and pericentromeric heterochromatin.

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TOPOVIBL-REC114 interaction regulates meiotic DNA double-strand breaks

10.1101/2021.11.30.470517 ◽

2021 ◽

Author(s):

Alexandre Nore ◽

Ariadna B Juarez-Martinez ◽

Julie AJ Clement ◽

Christine Brun ◽

Bouboub Diagouraga ◽

...

Keyword(s):

Dna Cleavage ◽

Point Mutations ◽

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Catalytic Complex ◽

Strand Breaks ◽

Genome Wide ◽

Dna Cleavage Activity ◽

Meiotic Dsbs

Meiosis requires the formation of programmed DNA double strand breaks (DSBs), essential for fertility and for generating genetic diversity. In male and female meiotic cells, DSBs are induced by the catalytic activity of the TOPOVIL complex formed by SPO11 and TOPOVIBL. To ensure genomic integrity, DNA cleavage activity is tightly regulated, and several accessory factors (REC114, MEI4, IHO1, and MEI1) are needed for DSB formation in mice. How and when these proteins act is not understood. Here, we show that REC114 is a direct partner of TOPOVIBL, and identified their conserved interacting domains by structural analysis. We then analysed the role of this interaction by monitoring meiotic DSBs in female and male mice carrying point mutations in TOPOVIBL that decrease or disrupt its binding to REC114. In these mutants, DSB activity was strongly reduced genome-wide in oocytes, but only in sub-telomeric regions in spermatocytes. In addition, in mutant spermatocytes, DSB activity was delayed in autosomes. These results provide evidence that REC114 is a key member of the TOPOVIL catalytic complex, and that the REC114/TOPOVIBL interaction ensures the efficiency and timing of DSB activity by integrating specific chromosomal features.

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A global view of meiotic double-strand break end resection

Science ◽

10.1126/science.aak9704 ◽

2017 ◽

Vol 355 (6320) ◽

pp. 40-45 ◽

Cited By ~ 79

Author(s):

Eleni P. Mimitou ◽

Shintaro Yamada ◽

Scott Keeney

Keyword(s):

Meiotic Recombination ◽

Strand Break ◽

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Naked Dna ◽

Global View ◽

Genome Wide ◽

End Resection

DNA double-strand breaks that initiate meiotic recombination are exonucleolytically processed. This 5′→3′ resection is a central, conserved feature of recombination but remains poorly understood. To address this lack, we mapped resection endpoints genome-wide at high resolution inSaccharomyces cerevisiae. Full-length resection requires Exo1 exonuclease and the DSB-responsive kinase Tel1, but not Sgs1 helicase. Tel1 also promotes efficient and timely resection initiation. Resection endpoints display pronounced heterogeneity between genomic loci that reflects a tendency for nucleosomes to block Exo1, yet Exo1 also appears to digest chromatin with high processivity and at rates similar to naked DNA in vitro. This paradox points to nucleosome destabilization or eviction as a defining feature of the meiotic resection landscape.

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Modulation of Prdm9-controlled meiotic chromosome asynapsis overrides hybrid sterility in mice

eLife ◽

10.7554/elife.34282 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 27

Author(s):

Sona Gregorova ◽

Vaclav Gergelits ◽

Irena Chvatalova ◽

Tanmoy Bhattacharyya ◽

Barbora Valiskova ◽

...

Keyword(s):

Meiotic Chromosome ◽

Hybrid Sterility ◽

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Recombination Hotspots ◽

Chromosome Synapsis ◽

Reproductive Isolation Mechanisms ◽

Meiotic Recombination Hotspots ◽

Isolation Mechanisms

Hybrid sterility is one of the reproductive isolation mechanisms leading to speciation. Prdm9, the only known vertebrate hybrid-sterility gene, causes failure of meiotic chromosome synapsis and infertility in male hybrids that are the offspring of two mouse subspecies. Within species, Prdm9 determines the sites of programmed DNA double-strand breaks (DSBs) and meiotic recombination hotspots. To investigate the relation between Prdm9-controlled meiotic arrest and asynapsis, we inserted random stretches of consubspecific homology on several autosomal pairs in sterile hybrids, and analyzed their ability to form synaptonemal complexes and to rescue male fertility. Twenty-seven or more megabases of consubspecific (belonging to the same subspecies) homology fully restored synapsis in a given autosomal pair, and we predicted that two or more DSBs within symmetric hotspots per chromosome are necessary for successful meiosis. We hypothesize that impaired recombination between evolutionarily diverged chromosomes could function as one of the mechanisms of hybrid sterility occurring in various sexually reproducing species.

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Lessons from the meiotic recombination landscape of the ZMM deficient budding yeast Lachancea waltii

10.1101/2021.12.13.472358 ◽

2021 ◽

Author(s):

Fabien Dutreux ◽

Abhishek Dutta ◽

Emilien Peltier ◽

Sabrina Bibi-Triki ◽

Anne Friedrich ◽

...

Keyword(s):

Meiotic Recombination ◽

Budding Yeast ◽

Double Strand Breaks ◽

Dna Double Strand Breaks ◽

Yeast Saccharomyces Cerevisiae ◽

Strand Breaks ◽

Crossover Interference ◽

Recombination Hotspots ◽

Elevated Frequency ◽

Underlying Mechanisms

Meiotic recombination has been deeply characterized in a few model species only, notably in the budding yeast Saccharomyces cerevisiae. Interestingly, most members of the ZMM pathway that implements meiotic crossover interference in S. cerevisiae have been lost in Lachancea yeast species after the divergence of Lachancea kluyveri from the rest of the clade. This suggests major differences in the control of crossover distribution. After investigating meiosis in L. kluyveri, we determined the meiotic recombination landscape of Lachancea waltii and identified several characteristics that should help understand better the underlying mechanisms. Such characteristics include systematic regions of loss of heterozygosity (LOH) in L. waltii hybrids, compatible with dysregulated Spo11-mediated DNA double strand breaks (DSB) independently of meiosis. They include a higher recombination rate in L. waltii than in L. kluyveri despite the lack of multiple ZMM pro-crossover factors. L. waltii exhibits an elevated frequency of zero-crossover bivalents as L. kluyveri but opposite to S. cerevisiae. L. waltii gene conversion tracts lengths are comparable to those observed in S. cerevisiae and shorter than in L. kluyveri despite the lack of Mlh2, a factor limiting conversion tracts size in S. cerevisiae. L. waltii recombination hotspots are not shared with either S. cerevisiae or L. kluyveri, showing that meiotic recombination hotspots can evolve at a rather limited evolutionary scale within budding yeasts. Finally, in line with the loss of several ZMM genes, we found only residual crossover interference in L. waltii likely coming from the modest interference existing between recombination precursors.

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ATR is required to complete meiotic recombination in mice

10.1101/133744 ◽

2017 ◽

Cited By ~ 3

Author(s):

Sarai Pacheco ◽

Andros Maldonado-Linares ◽

Marina Marcet-Ortega ◽

Cristina Rojas ◽

Ana Martínez-Marchal ◽

...

Keyword(s):

Meiotic Recombination ◽

Meiotic Prophase ◽

Protein A ◽

Homology Search ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Molecular Features ◽

Chromosome Synapsis ◽

Meiotic Dsbs

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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Caenorhabditis elegans RMI2 functional homolog-2 (RMIF-2) and RMI1 (RMH-1) have both overlapping and distinct meiotic functions within the BTR complex

PLoS Genetics ◽

10.1371/journal.pgen.1009663 ◽

2021 ◽

Vol 17 (7) ◽

pp. e1009663

Author(s):

Maria Velkova ◽

Nicola Silva ◽

Maria Rosaria Dello Stritto ◽

Alexander Schleiffer ◽

Pierre Barraud ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Sister Chromatid ◽

Meiotic Recombination ◽

Sister Chromatid Exchange ◽

Double Strand Breaks ◽

Scaffolding Protein ◽

Scaffolding Proteins ◽

Dna Double Strand Breaks ◽

Strand Breaks ◽

Functional Homolog

Homologous recombination is a high-fidelity repair pathway for DNA double-strand breaks employed during both mitotic and meiotic cell divisions. Such repair can lead to genetic exchange, originating from crossover (CO) generation. In mitosis, COs are suppressed to prevent sister chromatid exchange. Here, the BTR complex, consisting of the Bloom helicase (HIM-6 in worms), topoisomerase 3 (TOP-3), and the RMI1 (RMH-1 and RMH-2) and RMI2 scaffolding proteins, is essential for dismantling joint DNA molecules to form non-crossovers (NCOs) via decatenation. In contrast, in meiosis COs are essential for accurate chromosome segregation and the BTR complex plays distinct roles in CO and NCO generation at different steps in meiotic recombination. RMI2 stabilizes the RMI1 scaffolding protein, and lack of RMI2 in mitosis leads to elevated sister chromatid exchange, as observed upon RMI1 knockdown. However, much less is known about the involvement of RMI2 in meiotic recombination. So far, RMI2 homologs have been found in vertebrates and plants, but not in lower organisms such as Drosophila, yeast, or worms. We report the identification of the Caenorhabditis elegans functional homolog of RMI2, which we named RMIF-2. The protein shows a dynamic localization pattern to recombination foci during meiotic prophase I and concentration into recombination foci is mutually dependent on other BTR complex proteins. Comparative analysis of the rmif-2 and rmh-1 phenotypes revealed numerous commonalities, including in regulating CO formation and directing COs toward chromosome arms. Surprisingly, the prevalence of heterologous recombination was several fold lower in the rmif-2 mutant, suggesting that RMIF-2 may be dispensable or less strictly required for some BTR complex-mediated activities during meiosis.

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