scholarly journals SUMO Localizes to the Central Element of the Synaptonemal Complex and is Essential for Meiotic Chromosome Synapsis in Saccharomyces cerevisiae

2013 ◽  
Author(s):  
Louis Fong Taylor
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Synaptonemal Complex ◽  
Meiotic Chromosome ◽  
Central Element ◽  
Chromosome Synapsis

scholarly journals Structural analysis of the human SYCE2–TEX12 complex provides molecular insights into synaptonemal complex assembly

Open Biology ◽  
2012 ◽  
Vol 2 (7) ◽  
pp. 120099 ◽  
Author(s):  
Owen R. Davies ◽  
Joseph D. Maman ◽  
Luca Pellegrini
Keyword(s):  
Structural Analysis ◽  
Synaptonemal Complex ◽  
Recurrent Miscarriage ◽  
Central Element ◽  
Biological Data ◽  
Structural Basis ◽  
Structural Framework ◽  
Chromosome Synapsis ◽  
Heterotypic Interactions ◽  
Physical Features

The successful completion of meiosis is essential for all sexually reproducing organisms. The synaptonemal complex (SC) is a large proteinaceous structure that holds together homologous chromosomes during meiosis, providing the structural framework for meiotic recombination and crossover formation. Errors in SC formation are associated with infertility, recurrent miscarriage and aneuploidy. The current lack of molecular information about the dynamic process of SC assembly severely restricts our understanding of its function in meiosis. Here, we provide the first biochemical and structural analysis of an SC protein component and propose a structural basis for its function in SC assembly. We show that human SC proteins SYCE2 and TEX12 form a highly stable, constitutive complex, and define the regions responsible for their homotypic and heterotypic interactions. Biophysical analysis reveals that the SYCE2–TEX12 complex is an equimolar hetero-octamer, formed from the association of an SYCE2 tetramer and two TEX12 dimers. Electron microscopy shows that biochemically reconstituted SYCE2–TEX12 complexes assemble spontaneously into filamentous structures that resemble the known physical features of the SC central element (CE). Our findings can be combined with existing biological data in a model of chromosome synapsis driven by growth of SYCE2–TEX12 higher-order structures within the CE of the SC.

scholarly journals Quantitative basis of meiotic chromosome synapsis analyzed by electron tomography

2019 ◽  
Author(s):  
Marie-Christin Spindler ◽  
Sebastian Filbeck ◽  
Christian Stigloher ◽  
Ricardo Benavente
Keyword(s):  
Central Region ◽  
3D Model ◽  
Electron Tomography ◽  
Meiotic Chromosome ◽  
Topological Analysis ◽  
Central Element ◽  
Morphological Data ◽  
Homologous Chromosomes ◽  
Chromosome Synapsis ◽  
Quantitative Basis

AbstractThe synaptonemal complex is a multiprotein complex, which mediates the synapsis and recombination between homologous chromosomes during meiosis. The complex is comprised of two lateral elements and a central element connected by perpendicular transverse filaments (TFs). A 3D model based on actual morphological data of the SC is missing. Here, we applied electron tomography (ET) and manual feature extraction to generate a quantitative 3D model of the murine SC. We quantified the length (90 nm) and width (2 nm) of the TFs. Interestingly, the 80 TFs/μm are distributed asymmetrically in the central region of the SC challenging available models of SC organization. Furthermore, our detailed 3D topological analysis does not support a bilayered organization of the central region as proposed earlier. Overall, our quantitative analysis is relevant to understand the functions and dynamics of the SC and provides the basis for analyzing multiprotein complexes in their morphological context using ET.

scholarly journals Meiotic chromosome synapsis depends on multivalent SYCE1-SIX6OS1 interactions that are disrupted in cases of human infertility

2020 ◽  
Vol 6 (36) ◽  
pp. eabb1660
Author(s):  
Fernando Sánchez-Sáez ◽  
Laura Gómez-H ◽  
Orla M. Dunne ◽  
Cristina Gallego-Páramo ◽  
Natalia Felipe-Medina ◽  
...  
Keyword(s):  
Meiotic Chromosome ◽  
Central Element ◽  
Mouse Genetics ◽  
Structural Components ◽  
Targeted Deletion ◽  
Homologous Chromosomes ◽  
Chromosome Synapsis ◽  
N Terminus ◽  
Binding Interfaces ◽  
Reductional Division

Meiotic reductional division depends on the synaptonemal complex (SC), a supramolecular protein assembly that mediates homologous chromosomes synapsis and promotes crossover formation. The mammalian SC has eight structural components, including SYCE1, the only central element protein with known causative mutations in human infertility. We combine mouse genetics, cellular, and biochemical studies to reveal that SYCE1 undergoes multivalent interactions with SC component SIX6OS1. The N terminus of SIX6OS1 binds and disrupts SYCE1’s core dimeric structure to form a 1:1 complex, while their downstream sequences provide a distinct second interface. These interfaces are separately disrupted by SYCE1 mutations associated with nonobstructive azoospermia and premature ovarian failure (POF), respectively. Mice harboring SYCE1’s POF mutation and a targeted deletion within SIX6OS1’s N terminus are infertile with failure of chromosome synapsis. We conclude that both SYCE1-SIX6OS1 binding interfaces are essential for SC assembly, thus explaining how SYCE1’s reported clinical mutations give rise to human infertility.

scholarly journals Topoisomerases Modulate the Timing of Meiotic DNA Breakage and Chromosome Morphogenesis in Saccharomyces cerevisiae

Genetics ◽  
2020 ◽  
Vol 215 (1) ◽  
pp. 59-73 ◽  
Author(s):  
Jonna Heldrich ◽  
Xiaoji Sun ◽  
Luis A. Vale-Silva ◽  
Tovah E. Markowitz ◽  
Andreas Hochwagen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Prophase ◽  
Meiotic Chromosome ◽  
Strand Break ◽  
Temperature Sensitive ◽  
Chromosomal Dna ◽  
Link Type ◽  
Chromosome Synapsis ◽  
Intergenic Regions

During meiotic prophase, concurrent transcription, recombination, and chromosome synapsis place substantial topological strain on chromosomal DNA, but the role of topoisomerases in this context remains poorly defined. Here, we analyzed the roles of topoisomerases I and II (Top1 and Top2) during meiotic prophase in Saccharomyces cerevisiae. We show that both topoisomerases accumulate primarily in promoter-containing intergenic regions of actively transcribing genes, including many meiotic double-strand break (DSB) hotspots. Despite the comparable binding patterns, top1 and top2 mutations have different effects on meiotic recombination. TOP1 disruption delays DSB induction and shortens the window of DSB accumulation by an unknown mechanism. By contrast, temperature-sensitive top2-1 mutants exhibit a marked delay in meiotic chromosome remodeling and elevated DSB signals on synapsed chromosomes. The problems in chromosome remodeling were linked to altered Top2 binding patterns rather than a loss of Top2 catalytic activity, and stemmed from a defect in recruiting the chromosome remodeler Pch2/TRIP13 to synapsed chromosomes. No chromosomal defects were observed in the absence of TOP1. Our results imply independent roles for Top1 and Top2 in modulating meiotic chromosome structure and recombination.

ZIP1 is a synaptonemal complex protein required for meiotic chromosome synapsis

Cell ◽  
1993 ◽  
Vol 72 (3) ◽  
pp. 365-378 ◽  
Author(s):  
Mary Sym ◽  
JoAnne Engebrecht ◽  
G.Shirleen Roeder
Keyword(s):  
Synaptonemal Complex ◽  
Meiotic Chromosome ◽  
Chromosome Synapsis ◽  
Complex Protein ◽  
Synaptonemal Complex Protein

scholarly journals Meiotic chromosome synapsis depends on multivalent SYCE1-SIX6OS1 interactions that are disrupted in cases of human infertility

2020 ◽  
Author(s):  
Fernando Sánchez-Sáez ◽  
Laura Gómez-H ◽  
Orla M. Dunne ◽  
Cristina Gallego-Páramo ◽  
Natalia Felipe-Medina ◽  
...  
Keyword(s):  
Meiotic Chromosome ◽  
Central Element ◽  
Mouse Genetics ◽  
Obstructive Azoospermia ◽  
Targeted Deletion ◽  
Homologous Chromosomes ◽  
Chromosome Synapsis ◽  
N Terminus ◽  
Binding Interfaces ◽  
Reductional Division

AbstractMeiotic reductional division is dependent on the synaptonemal complex (SC), a supramolecular protein assembly that mediates homologous chromosomes synapsis and promotes crossover formation. The mammalian SC is formed of eight structural components, including SYCE1, the only central element protein with known causative mutations in human infertility. We combine mouse genetics, cellular and biochemical studies to reveal that SYCE1 undergoes multivalent interactions with SC component SIX6OS1. The N-terminus of SIX6OS1 binds and disrupts SYCE1’s core dimeric structure to form a 1:1 complex, whilst their downstream sequences provide a distinct second interface. These interfaces are separately disrupted by SYCE1 mutations associated with non-obstructive azoospermia and premature ovarian failure, respectively. Mice harbouring SYCE1’s POF mutation and a targeted deletion within SIX6OS1’s N-terminus are infertile with failure of chromosome synapsis. We conclude that both SYCE1-SIX6OS1 binding interfaces are essential for SC assembly, thus explaining how SYCE1’s reported clinical mutations give rise to human infertility.

scholarly journals Topoisomerases modulate the timing of meiotic DNA breakage and chromosome morphogenesis in Saccharomyces cerevisiae

2019 ◽  
Author(s):  
Jonna Heldrich ◽  
Xiaoji Sun ◽  
Luis A. Vale-Silva ◽  
Tovah E. Markowitz ◽  
Andreas Hochwagen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Meiotic Prophase ◽  
Meiotic Chromosome ◽  
Strand Break ◽  
Temperature Sensitive ◽  
Chromosomal Dna ◽  
Meiotic Chromosomes ◽  
Chromosome Synapsis ◽  
Intergenic Regions

AbstractDuring meiotic prophase, concurrent transcription, recombination, and chromosome synapsis, place substantial topological strain on chromosomal DNA, but the role of topoisomerases in this context remains poorly defined. Here, we analyzed the roles topoisomerases I and II (Top1 and Top2) during meiotic prophase in Saccharomyces cerevisiae. We show that both topoisomerases accumulate primarily in promoter-containing intergenic regions of actively transcribing genes. Enrichment partially overlaps meiotic double-strand break (DSB) hotspots, but disruption of either topoisomerase has different effects during meiotic recombination. TOP1 disruption delays DSB induction and shortens the window of DSB accumulation by an unknown mechanism. By contrast, temperature-sensitive top2-1 mutants accumulate DSBs on synapsed chromosomes and exhibit a marked delay in meiotic chromosome remodeling. This defect results from a delay in recruiting the meiotic chromosome remodeler Pch2/TRIP13 but, unexpectedly, is not due to a loss of Top2 catalytic activity. Instead, mutant Top2-1 protein has reduced contact with chromatin but remains associated with meiotic chromosomes, and we provide evidence that this altered binding is responsible for the delay in chromosome remodeling. Our results imply independent roles for topoisomerases I and II in modulating meiotic recombination.

scholarly journals The rec102 mutant of yeast is defective in meiotic recombination and chromosome synapsis.

Genetics ◽  
1992 ◽  
Vol 130 (1) ◽  
pp. 59-69
Author(s):  
J Bhargava ◽  
J Engebrecht ◽  
G S Roeder
Keyword(s):  
Synaptonemal Complex ◽  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
Meiotic Chromosome ◽  
Crossing Over ◽  
Homologous Chromosomes ◽  
Chromosome Synapsis ◽  
Recombination Pathway ◽  
Yeast Mutants ◽  
Meiosis I

Abstract A mutation at the REC102 locus was identified in a screen for yeast mutants that produce inviable spores. rec102 spore lethality is rescued by a spo13 mutation, which causes cells to bypass the meiosis I division. The rec102 mutation completely eliminates meiotically induced gene conversion and crossing over but has no effect on mitotic recombination frequencies. Cytological studies indicate that the rec102 mutant makes axial elements (precursors to the synaptonemal complex), but homologous chromosomes fail to synapse. In addition, meiotic chromosome segregation is significantly delayed in rec102 strains. Studies of double and triple mutants indicate that the REC102 protein acts before the RAD52 gene product in the meiotic recombination pathway. The REC102 gene was cloned based on complementation of the mutant defect and the gene was mapped to chromosome XII between CDC25 and STE11.

Genetic control of chromosome synapsis in yeast meiosis

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Craig N. Giroux ◽  
Michael E. Dresser ◽  
Howard F. Tiano
Keyword(s):  
Cell Cycle ◽  
Synaptonemal Complex ◽  
Meiotic Recombination ◽  
Meiotic Chromosome ◽  
Experimental System ◽  
Mitotic Cell ◽  
Specific Gene ◽  
Chromosome Behavior ◽  
Chromosome Synapsis ◽  
Yeast Meiosis

Both meiosis-specific and general recombination functions, recruited from the mitotic cell cycle, are required for elevated levels of recombination and for chromosome synapsis (assembly of the synaptonemal complex) during yeast meiosis. The meiosis-specific SPO11 gene (previously shown to be required for meiotic recombination) has been isolated and shown to be essential for synaptonemal complex formation but not for DNA metabolism during the vegetative cell cycle. In contrast, the RAD52 gene is required for mitotic and meiotic recombination but not for synaptonemal complex assembly. These data suggest that the synaptonemal complex may be necessary but is clearly not sufficient for meiotic recombination. Cytological analysis of spread meiotic nuclei demonstrates that chromosome behavior in yeast is comparable with that observed in larger eukaryotes. These spread preparations support the immunocytological localization of specific proteins in meiotic nuclei. This combination of genetic, molecular cloning, and cytological approaches in a single experimental system provides a means of addressing the role of specific gene products and nuclear structures in meiotic chromosome behavior.Key words: synaptonemal complex, chromosome behavior, meiosis.

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