scholarly journals Dynamic Architecture of DNA Repair Complexes and the Synaptonemal Complex at Sites of Meiotic Recombination

2017 ◽  
Author(s):  
Alexander Woglar ◽  
Anne M. Villeneuve
Keyword(s):  
Synaptonemal Complex ◽  
Meiotic Recombination ◽  
Double Strand Breaks ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Strand Breaks ◽  
Dynamic Architecture ◽  
Blm Helicase ◽  
Differential Timing ◽  
Two Populations

SummaryMeiotic double-strand breaks (DSBs) are generated and repaired in a highly regulated manner to ensure formation of crossovers (COs) while also enabling efficient non-CO repair to restore genome integrity. Here we use Structured-Illumination Microscopy to investigate the dynamic architecture of DSB repair complexes at meiotic recombination sites in relationship to the synaptonemal complex (SC). DSBs resected at both ends are rapidly converted into inter-homolog repair intermediates harboring two populations of BLM helicase and RPA, flanking a single population of MutS γ. These intermediates accumulate until late pachytene, when repair proteins disappear from non-CO sites and CO-designated sites become enveloped by SC-central region proteins, acquire a second MutS γ population, and lose RPA. These and other data suggest that the SC protects CO intermediates from being dismantled inappropriately and promotes step-wise CO maturation by generating a transient CO-specific repair compartment, thereby enabling differential timing and outcome of repair at CO and non-CO sites

scholarly journals Caenorhabditis elegans DSB-3 reveals conservation and divergence among protein complexes promoting meiotic double-strand breaks

2021 ◽  
Vol 118 (33) ◽  
pp. e2109306118
Author(s):  
Albert W. Hinman ◽  
Hsin-Yi Yeh ◽  
Baptiste Roelens ◽  
Kei Yamaya ◽  
Alexander Woglar ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Meiotic Recombination ◽  
Protein Complexes ◽  
Meiotic Chromosome ◽  
Structured Illumination ◽  
Dna Breaks ◽  
Structured Illumination Microscopy ◽  
Strand Breaks ◽  
Double Strand Dna Breaks ◽  
Essential Components

Meiotic recombination plays dual roles in the evolution and stable inheritance of genomes: Recombination promotes genetic diversity by reassorting variants, and it establishes temporary connections between pairs of homologous chromosomes that ensure their future segregation. Meiotic recombination is initiated by generation of double-strand DNA breaks (DSBs) by the conserved topoisomerase-like protein Spo11. Despite strong conservation of Spo11 across eukaryotic kingdoms, auxiliary complexes that interact with Spo11 complexes to promote DSB formation are poorly conserved. Here, we identify DSB-3 as a DSB-promoting protein in the nematode Caenorhabditis elegans. Mutants lacking DSB-3 are proficient for homolog pairing and synapsis but fail to form crossovers. Lack of crossovers in dsb-3 mutants reflects a requirement for DSB-3 in meiotic DSB formation. DSB-3 concentrates in meiotic nuclei with timing similar to DSB-1 and DSB-2 (predicted homologs of yeast/mammalian Rec114/REC114), and DSB-1, DSB-2, and DSB-3 are interdependent for this localization. Bioinformatics analysis and interactions among the DSB proteins support the identity of DSB-3 as a homolog of MEI4 in conserved DSB-promoting complexes. This identification is reinforced by colocalization of pairwise combinations of DSB-1, DSB-2, and DSB-3 foci in structured illumination microscopy images of spread nuclei. However, unlike yeast Rec114, DSB-1 can interact directly with SPO-11, and in contrast to mouse REC114 and MEI4, DSB-1, DSB-2, and DSB-3 are not concentrated predominantly at meiotic chromosome axes. We speculate that variations in the meiotic program that have coevolved with distinct reproductive strategies in diverse organisms may contribute to and/or enable diversification of essential components of the meiotic machinery.

scholarly journals The Yeast Motor Protein, Kar3p, Is Essential for Meiosis I

1997 ◽  
Vol 139 (2) ◽  
pp. 459-467 ◽  
Author(s):  
Carol A. Bascom-Slack ◽  
Dean S. Dawson
Keyword(s):  
Synaptonemal Complex ◽  
Meiotic Recombination ◽  
Molecular Motor ◽  
Motor Protein ◽  
Double Strand Breaks ◽  
Wild Type ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Low Levels ◽  
Meiosis I

The recognition and alignment of homologous chromosomes early in meiosis is essential for their subsequent segregation at anaphase I; however, the mechanism by which this occurs is unknown. We demonstrate here that, in the absence of the molecular motor, Kar3p, meiotic cells are blocked with prophase monopolar microtubule arrays and incomplete synaptonemal complex (SC) formation. kar3 mutants exhibit very low levels of heteroallelic recombination. kar3 mutants do produce double-strand breaks that act as initiation sites for meiotic recombination in yeast, but at levels severalfold reduced from wild-type. These data are consistent with a meiotic role for Kar3p in the events that culminate in synapsis of homologues.

scholarly journals C. elegans DSB-3 Reveals Conservation and Divergence among Protein Complexes Promoting Meiotic Double-Strand Breaks

2021 ◽  
Author(s):  
Albert W Hinman ◽  
Hsin-Yi Yeh ◽  
Baptiste Roelens ◽  
Kei Yamaya ◽  
Alexander Woglar ◽  
...  
Keyword(s):  
Meiotic Recombination ◽  
Protein Complexes ◽  
Meiotic Chromosome ◽  
Structured Illumination ◽  
Dna Breaks ◽  
Structured Illumination Microscopy ◽  
Strand Breaks ◽  
C Elegans ◽  
Double Strand Dna Breaks ◽  
Essential Components

Meiotic recombination plays dual roles in the evolution and stable inheritance of genomes: recombination promotes genetic diversity by reassorting variants, and it establishes temporary connections between pairs of homologous chromosomes that ensure for their future segregation. Meiotic recombination is initiated by generation of double-strand DNA breaks (DSBs) by the conserved topoisomerase-like protein Spo11. Despite strong conservation of Spo11 across eukaryotic kingdoms, auxiliary complexes that interact with Spo11 complexes to promote DSB formation are poorly conserved. Here, we identify DSB-3 as a DSB-promoting protein in the nematode Caenorhabditis elegans. Mutants lacking DSB-3 are proficient for homolog pairing and synapsis but fail to form meiotic crossovers. Lack of crossovers in dsb-3 mutants reflects a requirement for DSB-3 in meiotic DSB formation. DSB-3 concentrates in meiotic nuclei with timing similar to DSB-1 and DSB-2 (predicted homologs of yeast/mammalian Rec114/REC114), and DSB-1, DSB-2, and DSB-3 are interdependent for this localization. Bioinformatics analysis and interactions among the DSB proteins support the identity of DSB-3 as a homolog of MEI4 in conserved DSB-promoting complexes. This identification is reinforced by colocalization of pairwise combinations of DSB-1, DSB-2, and DSB-3 foci in structured illumination microscopy images of spread nuclei. However, unlike yeast Rec114, DSB-1 can interact directly with SPO-11, and in contrast to mouse REC114 and MEI4, DSB-1, DSB-2 and DSB-3 are not concentrated predominantly at meiotic chromosome axes. We speculate that variations in the meiotic program that have co-evolved with distinct reproductive strategies in diverse organisms may contribute to and/or enable diversification of essential components of the meiotic machinery.

scholarly journals Next-generation sequencing reveals two populations of damage-induced small RNAs at endogenous DNA double-strand breaks

2018 ◽  
Vol 46 (22) ◽  
pp. 11869-11882 ◽  
Author(s):  
Franziska Bonath ◽  
Judit Domingo-Prim ◽  
Marcel Tarbier ◽  
Marc R Friedländer ◽  
Neus Visa
Keyword(s):  
Next Generation Sequencing ◽  
Small Rnas ◽  
Double Strand Breaks ◽  
Next Generation ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Two Populations ◽  
Generation Sequencing

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

2017 ◽  
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.

scholarly journals Numerical and Spatial Patterning of Yeast Meiotic DNA Breaks by Tel1

2016 ◽  
Author(s):  
Neeman Mohibullah ◽  
Scott Keeney
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Deep Sequencing ◽  
Meiotic Recombination ◽  
Double Strand Breaks ◽  
Genome Integrity ◽  
Spatial Patterning ◽  
Dna Breaks ◽  
Strand Breaks ◽  
Context Dependent

AbstractThe 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 tell 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.

scholarly journals Poly(ADP-ribose) glycohydrolase promotes formation and homology-directed repair of meiotic DNA double-strand breaks independent of its catalytic activity

2020 ◽  
Author(s):  
Eva Janisiw ◽  
Marilina Raices ◽  
Fabiola Balmir ◽  
Luis Paulin Paz ◽  
Antoine Baudrimont ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Synaptonemal Complex ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Post Translational Modification ◽  
Dna Breaks ◽  
Strand Breaks ◽  
Homology Directed Repair ◽  
Damage Repair ◽  
Somatic Tissues

SummaryPoly(ADP-ribosyl)ation is a reversible post-translational modification synthetized by ADP-ribose transferases and removed by poly(ADP-ribose) glycohydrolase (PARG), which plays important roles in DNA damage repair. While well-studied in somatic tissues, much less is known about poly(ADP-ribosyl)ation in the germline, where DNA double-strand breaks are introduced by a regulated program and repaired by crossover recombination to establish a tether between homologous chromosomes. The interaction between the parental chromosomes is facilitated by meiotic specific adaptation of the chromosome axes and cohesins, and reinforced by the synaptonemal complex. Here, we uncover an unexpected role for PARG in promoting the induction of meiotic DNA breaks and their homologous recombination-mediated repair in Caenorhabditis elegans. PARG-1/PARG interacts with both axial and central elements of the synaptonemal complex, REC-8/Rec8 and the MRN/X complex. PARG-1 shapes the recombination landscape and reinforces the tightly regulated control of crossover numbers without requiring its catalytic activity. We unravel roles in regulating meiosis, beyond its enzymatic activity in poly(ADP-ribose) catabolism.

Double–strand breaks on YACs during yeast meiosis may reflect meiotic recombination in the human genome

1996 ◽  
Vol 13 (4) ◽  
pp. 481-484 ◽  
Author(s):  
Shoshana Klein ◽  
Drora Zenvirth ◽  
Amir Sherman ◽  
Karin Ried ◽  
Gudrun Rappold ◽  
...  
Keyword(s):  
Human Genome ◽  
Meiotic Recombination ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
Yeast Meiosis

scholarly journals Targeted induction of meiotic double-strand breaks reveals chromosomal domain-dependent regulation of Spo11 and interactions among potential sites of meiotic recombination

2007 ◽  
Vol 36 (3) ◽  
pp. 984-997 ◽  
Author(s):  
Tomoyuki Fukuda ◽  
Kazuto Kugou ◽  
Hiroyuki Sasanuma ◽  
Takehiko Shibata ◽  
Kunihiro Ohta
Keyword(s):  
Meiotic Recombination ◽  
Double Strand Breaks ◽  
Strand Breaks
Sign in / Sign up

Export Citation Format

Share Document