scholarly journals De novo deletion mutations at recombination hotspots in mouse germlines

2020 ◽  
Author(s):  
Agnieszka Lukaszewicz ◽  
Julian Lange ◽  
Scott Keeney ◽  
Maria Jasin
Keyword(s):  
De Novo ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Atm Kinase ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Recombination Hotspots ◽  
Genome Wide ◽  
Meiotic Dsbs ◽  
Meiotic Recombination Hotspots

AbstractNumerous DNA double-strand breaks (DSBs) arise genome-wide during meiosis to ensure recombination between homologous chromosomes, which is required for gamete formation1,2. The ATM kinase plays a central role in controlling both the number and position of DSBs3-5, but the consequences of deregulated DSB formation have not been explored. Here we discovered that an unanticipated type of DNA deletion arises at meiotic recombination hotspots in the absence of ATM. Deletions form via joining of ends from two closely-spaced DSBs at adjacent hotspots or within a single hotspot. Deletions are also detected in normal cells, albeit at much lower frequency, revealing that the meiotic genome has a hidden potential for deletion events. Remarkably, a subset of deletions contain insertions that likely originated from DNA fragments released from hotspots on other chromosomes. Moreover, although deletions form primarily within one chromosome, joining between homologous chromosomes is also observed. This predicts in turn gross chromosome rearrangements, with evidence of damage to multiple chromatids and aborted gap repair. Thus, multiple nearby meiotic DSBs are normally suppressed by ATM to protect genomic integrity. We expect the de novo germline mutations we observe to affect human health and genome evolution.

scholarly journals TOPOVIBL-REC114 interaction regulates meiotic DNA double-strand breaks

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.

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

eLife ◽  
2018 ◽  
Vol 7 ◽  
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.

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

2018 ◽  
Vol 115 (10) ◽  
pp. 2437-2442 ◽  
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.

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

2017 ◽  
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.

scholarly journals ZCWPW1 is recruited to recombination hotspots by PRDM9, and is essential for meiotic double strand break repair

2019 ◽  
Author(s):  
Daniel Wells ◽  
Emmanuelle Bitoun ◽  
Daniela Moralli ◽  
Gang Zhang ◽  
Anjali Gupta Hinch ◽  
...  
Keyword(s):  
Binding Sites ◽  
Protein S ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Histone Marks ◽  
Cpg Dinucleotides ◽  
Recombination Hotspots ◽  
Genome Wide

AbstractDuring meiosis, homologous chromosomes pair (synapse) and recombine, enabling balanced segregation and generating genetic diversity. In many vertebrates, recombination initiates with double-strand breaks (DSBs) within hotspots where PRDM9 binds, and deposits H3K4me3 and H3K36me3. However, no protein(s) recognising this unique combination of histone marks have yet been identified.We identified Zcwpw1, which possesses H3K4me3 and H3K36me3 recognition domains, as highly co-expressed with Prdm9. Here, we show that ZCWPW1 has co-evolved with PRDM9 and, in human cells, is strongly and specifically recruited to PRDM9 binding sites, with higher affinity than sites possessing H3K4me3 alone. Surprisingly, ZCWPW1 also recognizes CpG dinucleotides, including within many Alu transposons.Male Zcwpw1 homozygous knockout mice show completely normal DSB positioning, but persistent DMC1 foci at many hotspots, particularly those more strongly bound by PRDM9, severe DSB repair and synapsis defects, and downstream sterility. Our findings suggest a model where ZCWPW1 recognition of PRDM9-bound sites on either the homologous, or broken, chromosome is critical for synapsis, and hence fertility.Graphical Abstract LegendIn humans and other species, recombination is initiated by double strand breaks at sites bound by PRDM9. Upon binding, PRDM9 deposits the histone marks H3K4me3 and H3K36me, but the functional importance of these marks has remained unknown. Here, we show that PRDM9 recruits ZCWPW1, a reader of both these marks, to its binding sites genome-wide. ZCWPW1 does not help position the breaks themselves, but is essential for their downstream repair and chromosome pairing, and ultimately meiotic success and fertility in mice.

scholarly journals Extensive sex differences at the initiation of genetic recombination

2017 ◽  
Author(s):  
Kevin Brick ◽  
Sarah Thibault-Sennett ◽  
Fatima Smagulova ◽  
Kwan-Wood G. Lam ◽  
Yongmei Pu ◽  
...  
Keyword(s):  
Sex Differences ◽  
Chromosomal Abnormalities ◽  
Genetic Recombination ◽  
Double Strand Breaks ◽  
Local Context ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Genome Wide ◽  
Meiotic Dsbs ◽  
Initiation Stage

AbstractHomologous recombination in meiosis is initiated by programmed DNA double strand breaks (DSBs) and DSB repair as a crossover is essential to prevent chromosomal abnormalities in gametes. Sex differences in recombination have been previously observed by analyses of recombination end-products. To understand when and how sex differences are established, we built genome-wide maps of meiotic DSBs in both male and female mice. We found that most recombination initiates at sex-biased DSB hotspots. Local context, the choice of DSB targeting pathway and sex-specific patterns of DNA methylation give rise to these differences. Sex differences are not limited to the initiation stage, as the rate at which DSBs are repaired as crossovers appears to differ between the sexes in distal regions. This uneven repair patterning may be linked to the higher aneuploidy rate in females. Together, these data demonstrate that sex differences occur early in meiotic recombination.

scholarly journals Genome-wide mapping of DNA double-strand breaks from eukaryotic cell cultures using Break-seq

2021 ◽  
Vol 2 (2) ◽  
pp. 100554
Author(s):  
Ishita Joshi ◽  
Jenna DeRycke ◽  
Megan Palmowski ◽  
Robert LeSuer ◽  
Wenyi Feng
Keyword(s):  
Cell Cultures ◽  
Eukaryotic Cell ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Genome Wide

scholarly journals Four-pronged negative feedback of DSB machinery in meiotic DNA-break control in mice

2021 ◽  
Author(s):  
Ihsan Dereli ◽  
Marcello Stanzione ◽  
Fabrizio Olmeda ◽  
Frantzeskos Papanikos ◽  
Marek Baumann ◽  
...  
Keyword(s):  
Negative Feedback ◽  
Protein Complexes ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Damage Response ◽  
Auxiliary Protein ◽  
Genomic Locations ◽  
Spatiotemporal Control

Abstract In most taxa, halving of chromosome numbers during meiosis requires that homologous chromosomes (homologues) pair and form crossovers. Crossovers emerge from the recombination-mediated repair of programmed DNA double-strand breaks (DSBs). DSBs are generated by SPO11, whose activity requires auxiliary protein complexes, called pre-DSB recombinosomes. To elucidate the spatiotemporal control of the DSB machinery, we focused on an essential SPO11 auxiliary protein, IHO1, which serves as the main anchor for pre-DSB recombinosomes on chromosome cores, called axes. We discovered that DSBs restrict the DSB machinery by at least four distinct pathways in mice. Firstly, by activating the DNA damage response (DDR) kinase ATM, DSBs restrict pre-DSB recombinosome numbers without affecting IHO1. Secondly, in their vicinity, DSBs trigger IHO1 depletion mainly by another DDR kinase, ATR. Thirdly, DSBs enable homologue synapsis, which promotes the depletion of IHO1 and pre-DSB recombinosomes from synapsed axes. Finally, DSBs and three DDR kinases, ATM, ATR and PRKDC, enable stage-specific depletion of IHO1 from all axes. We hypothesize that these four negative feedback pathways protect genome integrity by ensuring that DSBs form without excess, are well-distributed, and are restricted to genomic locations and prophase stages where DSBs are functional for promoting homologue pairing and crossover formation.

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