1
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Kursel LE, Goktepe K, Rog O. Skp1 is a conserved structural component of the meiotic synaptonemal complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.24.600447. [PMID: 38979327 PMCID: PMC11230192 DOI: 10.1101/2024.06.24.600447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The synaptonemal complex (SC) is a meiotic interface that assembles between parental chromosomes and is essential for the formation of gametes. While the dimensions and ultrastructure of the SC are conserved across eukaryotes, its protein components are highly divergent. Recently, an unexpected component of the SC has been described in the nematode C. elegans: the Skp1-related proteins SKR-1/2, which are components of the Skp1, Cullin, F-box (SCF) ubiquitin ligase. Here, we find that the role of SKR-1 in the SC is conserved in nematodes. The P. pacificus Skp1 ortholog, Ppa-SKR-1, colocalizes with other SC proteins throughout meiotic prophase, where it occupies the middle of the SC. Like in C. elegans, the dimerization interface of Ppa-SKR-1 is required for its SC function. A dimerization mutant, Ppa-skr-1 F105E , fails to assemble SC and is almost completely sterile. Interestingly, the evolutionary trajectory of SKR-1 contrasts with other SC proteins. Unlike most SC proteins, SKR-1 is highly conserved in nematodes. Our results suggest that the structural role of SKR-1 in the SC has been conserved since the common ancestor of C. elegans and P. pacificus, and that rapidly evolving SC proteins have maintained the ability to interact with SKR-1 for at least 100 million years.
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Affiliation(s)
- Lisa E Kursel
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, United States
| | - Kaan Goktepe
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, United States
| | - Ofer Rog
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, United States
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2
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Morgan C, Howard M, Henderson IR. HEI10 coarsening, chromatin and sequence polymorphism shape the plant meiotic recombination landscape. CURRENT OPINION IN PLANT BIOLOGY 2024; 81:102570. [PMID: 38838583 DOI: 10.1016/j.pbi.2024.102570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/03/2024] [Accepted: 05/16/2024] [Indexed: 06/07/2024]
Abstract
Meiosis is a conserved eukaryotic cell division that produces spores required for sexual reproduction. During meiosis, chromosomes pair and undergo programmed DNA double-strand breaks, followed by homologous repair that can result in reciprocal crossovers. Crossover formation is highly regulated with typically few events per homolog pair. Crossovers additionally show wider spacing than expected from uniformly random placement - defining the phenomenon of interference. In plants, the conserved HEI10 E3 ligase is initially loaded along meiotic chromosomes, before maturing into a small number of foci, corresponding to crossover locations. We review the coarsening model that explains these dynamics as a diffusion and aggregation process, resulting in approximately evenly spaced HEI10 foci. We review how underlying chromatin states, and the presence of interhomolog polymorphisms, shape the meiotic recombination landscape, in light of the coarsening model. Finally, we consider future directions to understand the control of meiotic recombination in plant genomes.
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Affiliation(s)
- Chris Morgan
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Martin Howard
- Department of Computational and Systems Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
| | - Ian R Henderson
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, United Kingdom.
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3
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Arter M, Keeney S. Divergence and conservation of the meiotic recombination machinery. Nat Rev Genet 2024; 25:309-325. [PMID: 38036793 DOI: 10.1038/s41576-023-00669-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2023] [Indexed: 12/02/2023]
Abstract
Sexually reproducing eukaryotes use recombination between homologous chromosomes to promote chromosome segregation during meiosis. Meiotic recombination is almost universally conserved in its broad strokes, but specific molecular details often differ considerably between taxa, and the proteins that constitute the recombination machinery show substantial sequence variability. The extent of this variation is becoming increasingly clear because of recent increases in genomic resources and advances in protein structure prediction. We discuss the tension between functional conservation and rapid evolutionary change with a focus on the proteins that are required for the formation and repair of meiotic DNA double-strand breaks. We highlight phylogenetic relationships on different time scales and propose that this remarkable evolutionary plasticity is a fundamental property of meiotic recombination that shapes our understanding of molecular mechanisms in reproductive biology.
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Affiliation(s)
- Meret Arter
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
- Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
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4
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Castellani M, Zhang M, Thangavel G, Mata-Sucre Y, Lux T, Campoy JA, Marek M, Huettel B, Sun H, Mayer KFX, Schneeberger K, Marques A. Meiotic recombination dynamics in plants with repeat-based holocentromeres shed light on the primary drivers of crossover patterning. NATURE PLANTS 2024; 10:423-438. [PMID: 38337039 PMCID: PMC10954556 DOI: 10.1038/s41477-024-01625-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 01/15/2024] [Indexed: 02/12/2024]
Abstract
Centromeres strongly affect (epi)genomic architecture and meiotic recombination dynamics, influencing the overall distribution and frequency of crossovers. Here we show how recombination is regulated and distributed in the holocentric plant Rhynchospora breviuscula, a species with diffused centromeres. Combining immunocytochemistry, chromatin analysis and high-throughput single-pollen sequencing, we discovered that crossover frequency is distally biased, in sharp contrast to the diffused distribution of hundreds of centromeric units and (epi)genomic features. Remarkably, we found that crossovers were abolished inside centromeric units but not in their proximity, indicating the absence of a canonical centromere effect. We further propose that telomere-led synapsis of homologues is the feature that best explains the observed recombination landscape. Our results hint at the primary influence of mechanistic features of meiotic pairing and synapsis rather than (epi)genomic features and centromere organization in determining the distally biased crossover distribution in R. breviuscula, whereas centromeres and (epi)genetic properties only affect crossover positioning locally.
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Affiliation(s)
- Marco Castellani
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Meng Zhang
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Gokilavani Thangavel
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Yennifer Mata-Sucre
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Centre of Biosciences, Federal University of Pernambuco, Recife, Brazil
| | - Thomas Lux
- Plant Genome and Systems Biology, German Research Centre for Environmental Health, Helmholtz Zentrum München, Neuherberg, Germany
| | - José A Campoy
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Department of Pomology, Estación Experimental de Aula Dei (EEAD), Consejo Superior de Investigaciones Científicas, Zaragoza, Spain
| | - Magdalena Marek
- Max Planck Genome-Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Bruno Huettel
- Max Planck Genome-Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Hequan Sun
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- School of Automation Science and Engineering, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Klaus F X Mayer
- Plant Genome and Systems Biology, German Research Centre for Environmental Health, Helmholtz Zentrum München, Neuherberg, Germany
- School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Korbinian Schneeberger
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
- Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine University, Düsseldorf, Germany
| | - André Marques
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany.
- Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine University, Düsseldorf, Germany.
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5
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Blundon JM, Cesar BI, Bae JW, Čavka I, Haversat J, Ries J, Köhler S, Kim Y. Skp1 proteins are structural components of the synaptonemal complex in C. elegans. SCIENCE ADVANCES 2024; 10:eadl4876. [PMID: 38354250 PMCID: PMC10866564 DOI: 10.1126/sciadv.adl4876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/12/2024] [Indexed: 02/16/2024]
Abstract
The synaptonemal complex (SC) is a zipper-like protein assembly that links homologous chromosomes to regulate recombination and segregation during meiosis. The SC has been notoriously refractory to in vitro reconstitution, thus leaving its molecular organization largely unknown. Here, we report a moonlighting function of two paralogous S-phase kinase-associated protein 1 (Skp1)-related proteins (SKR-1 and SKR-2), well-known adaptors of the Skp1-Cul1-F-box (SCF) ubiquitin ligase, as the key missing components of the SC in Caenorhabditis elegans. SKR proteins repurpose their SCF-forming interfaces to dimerize and interact with meiosis-specific SC proteins, thereby driving synapsis independent of SCF activity. SKR-1 enables the formation of the long-sought-after soluble complex with previously identified SC proteins in vitro, which we propose it to represent a complete SC building block. Our findings demonstrate how a conserved cell cycle regulator has been co-opted to interact with rapidly evolving meiotic proteins to construct the SC and provide a foundation for understanding its structure and assembly mechanisms.
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Affiliation(s)
- Joshua M. Blundon
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Brenda I. Cesar
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jung Woo Bae
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Ivana Čavka
- The European Molecular Biology Laboratory, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Jocelyn Haversat
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jonas Ries
- The European Molecular Biology Laboratory, Heidelberg, Germany
| | - Simone Köhler
- The European Molecular Biology Laboratory, Heidelberg, Germany
| | - Yumi Kim
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
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6
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Wang R, Li J, Tian Y, Sun Y, Zhang Y, Liu M, Zhang R, Zhao L, Li Q, Meng X, Zhou J, Gao J. The dynamic recruitment of LAB proteins senses meiotic chromosome axis differentiation in C. elegans. J Cell Biol 2024; 223:e202212035. [PMID: 38010234 PMCID: PMC10666650 DOI: 10.1083/jcb.202212035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 09/19/2023] [Accepted: 11/09/2023] [Indexed: 11/29/2023] Open
Abstract
During meiosis, cohesin and meiosis-specific proteins organize chromatin into an axis-loop architecture, coordinating homologous synapsis, recombination, and ordered chromosome segregation. However, how the meiotic chromosome axis is assembled and differentiated with meiotic progression remains elusive. Here, we explore the dynamic recruitment of two long arms of the bivalent proteins, LAB-1 and LAB-2, in Caenorhabditis elegans. LAB proteins directly interact with the axis core HORMA complexes and weak interactions contribute to their recruitment. LAB proteins phase separate in vitro, and this capacity is promoted by HORMA complexes. During early prophase, synapsis oppositely regulates the axis enrichment of LAB proteins. After the pachytene exit, LAB proteins switch from a reciprocal localization pattern to a colocalization pattern, and the normal dynamic pattern of LAB proteins is altered in meiotic mutants. We propose that LAB recruitment senses axis differentiation, and phase separation of meiotic structures helps subdomain establishment and accurate segregation of the chromosomes.
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Affiliation(s)
- Ruoxi Wang
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Jiaxiang Li
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Yuqi Tian
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Yating Sun
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Yu Zhang
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Mengfei Liu
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Ruirui Zhang
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Li Zhao
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Qian Li
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaoqian Meng
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
| | - Jun Zhou
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Jinmin Gao
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
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7
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Vrielynck N, Peuch M, Durand S, Lian Q, Chambon A, Hurel A, Guérin J, Guérois R, Mercier R, Grelon M, Mézard C. SCEP1 and SCEP2 are two new components of the synaptonemal complex central element. NATURE PLANTS 2023; 9:2016-2030. [PMID: 37973938 DOI: 10.1038/s41477-023-01558-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/28/2023] [Indexed: 11/19/2023]
Abstract
The synaptonemal complex (SC) is a proteinaceous structure that forms between homologous chromosomes during meiosis prophase. The SC is widely conserved across species, but its structure and roles during meiotic recombination are still debated. While the SC central region is made up of transverse filaments and central element proteins in mammals and fungi, few central element proteins have been identified in other species. Here we report the identification of two coiled-coil proteins, SCEP1 and SCEP2, that form a complex and localize at the centre of the Arabidopsis thaliana SC. In scep1 and scep2 mutants, chromosomes are aligned but not synapsed (the ZYP1 transverse filament protein is not loaded), crossovers are increased compared with the wild type, interference is lost and heterochiasmy is strongly reduced. We thus report the identification of two plant SC central elements, and homologues of these are found in all major angiosperm clades.
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Affiliation(s)
- Nathalie Vrielynck
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin, Versailles, France
| | - Marion Peuch
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin, Versailles, France
| | - Stéphanie Durand
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Qichao Lian
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Aurélie Chambon
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin, Versailles, France
| | - Aurélie Hurel
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin, Versailles, France
| | - Julie Guérin
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin, Versailles, France
| | - Raphaël Guérois
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, Gif-sur-Yvette, France
| | - Raphaël Mercier
- Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Mathilde Grelon
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin, Versailles, France.
| | - Christine Mézard
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin, Versailles, France.
- Université Paris-Saclay, INRAE, AgroParisTech, CNRS, Institut Jean-Pierre Bourgin, Versailles, France.
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8
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Abstract
The raison d'être of meiosis is shuffling of genetic information via Mendelian segregation and, within individual chromosomes, by DNA crossing-over. These outcomes are enabled by a complex cellular program in which interactions between homologous chromosomes play a central role. We first provide a background regarding the basic principles of this program. We then summarize the current understanding of the DNA events of recombination and of three processes that involve whole chromosomes: homolog pairing, crossover interference, and chiasma maturation. All of these processes are implemented by direct physical interaction of recombination complexes with underlying chromosome structures. Finally, we present convergent lines of evidence that the meiotic program may have evolved by coupling of this interaction to late-stage mitotic chromosome morphogenesis.
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Affiliation(s)
- Denise Zickler
- Institute for Integrative Biology of the Cell (I2BC), Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA;
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9
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Myles KM, Vo AA, Ragle JM, Ward JD. A spontaneous TIR1 loss-of-function allele in C. elegans. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000994. [PMID: 37908494 PMCID: PMC10613879 DOI: 10.17912/micropub.biology.000994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/12/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023]
Abstract
The auxin-inducible degron (AID) system is a widely-used system for conditional protein depletion. During the course of an experiment, we depleted the nuclear hormone receptor transcription factor NHR-23 to study molting, and we recovered a spontaneous suppressor allele that bypassed the L1 larval arrest caused by NHR-23 depletion. These mutants also failed to deplete a BFP::AID reporter in the strain background, suggesting a broader defect in the AID system. These animals carried an in-frame 18 base pair insertion that produced a 6 amino acid repeat in TIR1. The larval arrest in these animals could be restored by expressing a wild-type TIR1 transgene from an extrachromosomal array. Sister siblings that lost this array developed normally on auxin. Together, these experiments indicate that the TIR1 mutation was causing the loss of developmental arrest in the nhr-23::AID strain. This result highlights the importance of setting up a robust secondary screen to detect such mutants if performing forward genetic screens in conjunction with the AID system.
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Affiliation(s)
- Krista M. Myles
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States
| | - An A. Vo
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States
| | - James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States
| | - Jordan D. Ward
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States
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10
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Liu C, Rex R, Lung Z, Wang JS, Wu F, Kim HJ, Zhang L, Sohn LL, Dernburg AF. A cooperative network at the nuclear envelope counteracts LINC-mediated forces during oogenesis in C. elegans. SCIENCE ADVANCES 2023; 9:eabn5709. [PMID: 37436986 PMCID: PMC10337908 DOI: 10.1126/sciadv.abn5709] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 06/08/2023] [Indexed: 07/14/2023]
Abstract
Oogenesis involves transduction of mechanical forces from the cytoskeleton to the nuclear envelope (NE). In Caenorhabditis elegans, oocyte nuclei lacking the single lamin protein LMN-1 are vulnerable to collapse under forces mediated through LINC (linker of nucleoskeleton and cytoskeleton) complexes. Here, we use cytological analysis and in vivo imaging to investigate the balance of forces that drive this collapse and protect oocyte nuclei. We also use a mechano-node-pore sensing device to directly measure the effect of genetic mutations on oocyte nuclear stiffness. We find that nuclear collapse is not a consequence of apoptosis. It is promoted by dynein, which induces polarization of a LINC complex composed of Sad1 and UNC-84 homology 1 (SUN-1) and ZYGote defective 12 (ZYG-12). Lamins contribute to oocyte nuclear stiffness and cooperate with other inner nuclear membrane proteins to distribute LINC complexes and protect nuclei from collapse. We speculate that a similar network may protect oocyte integrity during extended oocyte arrest in mammals.
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Affiliation(s)
- Chenshu Liu
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Rachel Rex
- Department of Mechanical Engineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - Zoe Lung
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - John S. Wang
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Fan Wu
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Hyung Jun Kim
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Liangyu Zhang
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Lydia L. Sohn
- Department of Mechanical Engineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - Abby F. Dernburg
- California Institute for Quantitative Biosciences (QB3) and Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biological Sciences and Engineering, Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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11
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Gershoni M, Braun T, Hauser R, Barda S, Lehavi O, Malcov M, Frumkin T, Kalma Y, Pietrokovski S, Arama E, Kleiman SE. A pathogenic variant in the uncharacterized RNF212B gene results in severe aneuploidy male infertility and repeated IVF failure. HGG ADVANCES 2023; 4:100189. [PMID: 37124137 PMCID: PMC10133878 DOI: 10.1016/j.xhgg.2023.100189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/28/2023] [Indexed: 05/02/2023] Open
Abstract
Quantitative and qualitative spermatogenic impairments are major causes of men's infertility. Although in vitro fertilization (IVF) is effective, some couples persistently fail to conceive. To identify causal variants in patients with severe male infertility factor and repeated IVF failures, we sequenced the exome of two consanguineous family members who underwent several failed IVF cycles and were diagnosed with low sperm count and motility. We identified a rare homozygous nonsense mutation in a previously uncharacterized gene, RNF212B, as the causative variant. Recurrence was identified in another unrelated, infertile patient who also faced repeated failed IVF treatments. scRNA-seq demonstrated meiosis-specific expression of RNF212B. Sequence analysis located a protein domain known to be associated with aneuploidy, which can explain multiple IVF failures. Accordingly, FISH analysis revealed a high aneuploidy rate in the patients' sperm cells and their IVF embryos. Finally, inactivation of the Drosophila orthologs significantly reduced male fertility. Given that members of the evolutionary conserved RNF212 gene family are involved in meiotic recombination and crossover maturation, our findings indicate a critical role of RNF212B in meiosis, genome stability, and in human fertility. Since recombination is completely absent in Drosophila males, our findings may indicate an additional unrelated role for the RNF212-like paralogs in spermatogenesis.
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Affiliation(s)
- Moran Gershoni
- ARO-The Volcani Center Institute of Animal Science, Bet Dagan, Israel
- Corresponding author
| | - Tslil Braun
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Ron Hauser
- Racine IVF Unit and Male Fertility Clinic and Sperm Bank, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shimi Barda
- Racine IVF Unit and Male Fertility Clinic and Sperm Bank, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ofer Lehavi
- Racine IVF Unit and Male Fertility Clinic and Sperm Bank, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mira Malcov
- Racine IVF Unit and Male Fertility Clinic and Sperm Bank, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tsvia Frumkin
- Racine IVF Unit and Male Fertility Clinic and Sperm Bank, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yael Kalma
- Racine IVF Unit and Male Fertility Clinic and Sperm Bank, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shmuel Pietrokovski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- Corresponding author
| | - Eli Arama
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
- Corresponding author
| | - Sandra E. Kleiman
- Racine IVF Unit and Male Fertility Clinic and Sperm Bank, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Corresponding author
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12
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Liu K, Grasso EM, Pu S, Zou M, Liu S, Eliezer D, Keeney S. Structure and DNA-bridging activity of the essential Rec114-Mei4 trimer interface. Genes Dev 2023; 37:518-534. [PMID: 37442580 PMCID: PMC10393192 DOI: 10.1101/gad.350461.123] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023]
Abstract
The DNA double-strand breaks (DSBs) that initiate meiotic recombination are formed by an evolutionarily conserved suite of factors that includes Rec114 and Mei4 (RM), which regulate DSB formation both spatially and temporally. In vivo, these proteins form large immunostaining foci that are integrated with higher-order chromosome structures. In vitro, they form a 2:1 heterotrimeric complex that binds cooperatively to DNA to form large, dynamic condensates. However, understanding of the atomic structures and dynamic DNA binding properties of RM complexes is lacking. Here, we report a structural model of a heterotrimeric complex of the C terminus of Rec114 with the N terminus of Mei4, supported by nuclear magnetic resonance experiments. This minimal complex, which lacks the predicted intrinsically disordered region of Rec114, is sufficient to bind DNA and form condensates. Single-molecule experiments reveal that the minimal complex can bridge two or more DNA duplexes and can generate force to condense DNA through long-range interactions. AlphaFold2 predicts similar structural models for RM orthologs across diverse taxa despite their low degree of sequence similarity. These findings provide insight into the conserved networks of protein-protein and protein-DNA interactions that enable condensate formation and promote formation of meiotic DSBs.
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Affiliation(s)
- Kaixian Liu
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Emily M Grasso
- Department of Biochemistry, Weill Cornell Medicine, New York, New York 10065, USA
| | - Stephen Pu
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Mengyang Zou
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
- Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York 10065, USA
| | - Shixin Liu
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, New York 10065, USA
| | - David Eliezer
- Department of Biochemistry, Weill Cornell Medicine, New York, New York 10065, USA
- Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York 10065, USA
- Program in Structural Biology, Weill Cornell Medicine, New York, New York 10065, USA
| | - Scott Keeney
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA;
- Weill Cornell Graduate School of Medical Sciences, Cornell University, New York, New York 10065, USA
- Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
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13
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Rafiei N, Ronceret A. Crossover interference mechanism: New lessons from plants. Front Cell Dev Biol 2023; 11:1156766. [PMID: 37274744 PMCID: PMC10236007 DOI: 10.3389/fcell.2023.1156766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/17/2023] [Indexed: 06/06/2023] Open
Abstract
Plants are the source of our understanding of several fundamental biological principles. It is well known that Gregor Mendel discovered the laws of Genetics in peas and that maize was used for the discovery of transposons by Barbara McClintock. Plant models are still useful for the understanding of general key biological concepts. In this article, we will focus on discussing the recent plant studies that have shed new light on the mysterious mechanisms of meiotic crossover (CO) interference, heterochiasmy, obligatory CO, and CO homeostasis. Obligatory CO is necessary for the equilibrated segregation of homologous chromosomes during meiosis. The tight control of the different male and female CO rates (heterochiasmy) enables both the maximization and minimization of genome shuffling. An integrative model can now predict these observed aspects of CO patterning in plants. The mechanism proposed considers the Synaptonemal Complex as a canalizing structure that allows the diffusion of a class I CO limiting factor linearly on synapsed bivalents. The coarsening of this limiting factor along the SC explains the interfering spacing between COs. The model explains the observed coordinated processes between synapsis, CO interference, CO insurance, and CO homeostasis. It also easily explains heterochiasmy just considering the different male and female SC lengths. This mechanism is expected to be conserved in other species.
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14
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Koury SA. Predicting recombination suppression outside chromosomal inversions in Drosophila melanogaster using crossover interference theory. Heredity (Edinb) 2023; 130:196-208. [PMID: 36721031 PMCID: PMC10076299 DOI: 10.1038/s41437-023-00593-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 01/20/2023] [Accepted: 01/20/2023] [Indexed: 02/02/2023] Open
Abstract
Recombination suppression in chromosomal inversion heterozygotes is a well-known but poorly understood phenomenon. Surprisingly, recombination suppression extends far outside of inverted regions where there are no intrinsic barriers to normal chromosome pairing, synapsis, double-strand break formation, or recovery of crossover products. The interference hypothesis of recombination suppression proposes heterozygous inversion breakpoints possess chiasma-like properties such that recombination suppression extends from these breakpoints in a process analogous to crossover interference. This hypothesis is qualitatively consistent with chromosome-wide patterns of recombination suppression extending to both inverted and uninverted regions of the chromosome. The present study generated quantitative predictions for this hypothesis using a probabilistic model of crossover interference with gamma-distributed inter-event distances. These predictions were then tested with experimental genetic data (>40,000 meioses) on crossing-over in intervals that are external and adjacent to four common inversions of Drosophila melanogaster. The crossover interference model accurately predicted the partially suppressed recombination rates in euchromatic intervals outside inverted regions. Furthermore, assuming interference does not extend across centromeres dramatically improved model fit and partially accounted for excess recombination observed in pericentromeric intervals. Finally, inversions with breakpoints closest to the centromere had the greatest excess of recombination in pericentromeric intervals, an observation that is consistent with negative crossover interference previously documented near Drosophila melanogaster centromeres. In conclusion, the experimental data support the interference hypothesis of recombination suppression, validate a mathematical framework for integrating distance-dependent effects of structural heterozygosity on crossover distribution, and highlight the need for improved modeling of crossover interference in pericentromeric regions.
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Affiliation(s)
- Spencer A Koury
- Department of Ecology and Evolution, Stony Brook University, 650 Life Sciences Building, Stony Brook, NY, 11794, USA.
- 2613 Ashwood Ave, Nashville, TN, 37212, USA.
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15
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Yu Z, Kim HJ, Dernburg AF. ATM signaling modulates cohesin behavior in meiotic prophase and proliferating cells. Nat Struct Mol Biol 2023; 30:436-450. [PMID: 36879153 PMCID: PMC10113158 DOI: 10.1038/s41594-023-00929-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 01/25/2023] [Indexed: 03/08/2023]
Abstract
Cohesins are ancient and ubiquitous regulators of chromosome architecture and function, but their diverse roles and regulation remain poorly understood. During meiosis, chromosomes are reorganized as linear arrays of chromatin loops around a cohesin axis. This unique organization underlies homolog pairing, synapsis, double-stranded break induction, and recombination. We report that axis assembly in Caenorhabditis elegans is promoted by DNA-damage response (DDR) kinases that are activated at meiotic entry, even in the absence of DNA breaks. Downregulation of the cohesin-destabilizing factor WAPL-1 by ATM-1 promotes axis association of cohesins containing the meiotic kleisins COH-3 and COH-4. ECO-1 and PDS-5 also contribute to stabilizing axis-associated meiotic cohesins. Further, our data suggest that cohesin-enriched domains that promote DNA repair in mammalian cells also depend on WAPL inhibition by ATM. Thus, DDR and Wapl seem to play conserved roles in cohesin regulation in meiotic prophase and proliferating cells.
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Affiliation(s)
- Zhouliang Yu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA.,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,California Institute for Quantitative Biosciences, Berkeley, CA, USA
| | - Hyung Jun Kim
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Abby F Dernburg
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA. .,Howard Hughes Medical Institute, Chevy Chase, MD, USA. .,Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. .,California Institute for Quantitative Biosciences, Berkeley, CA, USA.
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16
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Abstract
KEY MESSAGE Chromatin state, and dynamic loading of pro-crossover protein HEI10 at recombination intermediates shape meiotic chromosome patterning in plants. Meiosis is the basis of sexual reproduction, and its basic progression is conserved across eukaryote kingdoms. A key feature of meiosis is the formation of crossovers which result in the reciprocal exchange of segments of maternal and paternal chromosomes. This exchange generates chromosomes with new combinations of alleles, increasing the efficiency of both natural and artificial selection. Crossovers also form a physical link between homologous chromosomes at metaphase I which is critical for accurate chromosome segregation and fertility. The patterning of crossovers along the length of chromosomes is a highly regulated process, and our current understanding of its regulation forms the focus of this review. At the global scale, crossover patterning in plants is largely governed by the classically observed phenomena of crossover interference, crossover homeostasis and the obligatory crossover which regulate the total number of crossovers and their relative spacing. The molecular actors behind these phenomena have long remained obscure, but recent studies in plants implicate HEI10 and ZYP1 as key players in their coordination. In addition to these broad forces, a wealth of recent studies has highlighted how genomic and epigenomic features shape crossover formation at both chromosomal and local scales, revealing that crossovers are primarily located in open chromatin associated with gene promoters and terminators with low nucleosome occupancy.
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Affiliation(s)
- Andrew Lloyd
- Institute of Biological, Environmental & Rural Sciences (IBERS), Aberystwyth University, Penglais, Aberystwyth, SY23 3DA, Ceredigion, UK.
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17
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Fozard JA, Morgan C, Howard M. Coarsening dynamics can explain meiotic crossover patterning in both the presence and absence of the synaptonemal complex. eLife 2023; 12:e79408. [PMID: 36847348 PMCID: PMC10036115 DOI: 10.7554/elife.79408] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 02/24/2023] [Indexed: 03/01/2023] Open
Abstract
The shuffling of genetic material facilitated by meiotic crossovers is a critical driver of genetic variation. Therefore, the number and positions of crossover events must be carefully controlled. In Arabidopsis, an obligate crossover and repression of nearby crossovers on each chromosome pair are abolished in mutants that lack the synaptonemal complex (SC), a conserved protein scaffold. We use mathematical modelling and quantitative super-resolution microscopy to explore and mechanistically explain meiotic crossover pattering in Arabidopsis lines with full, incomplete, or abolished synapsis. For zyp1 mutants, which lack an SC, we develop a coarsening model in which crossover precursors globally compete for a limited pool of the pro-crossover factor HEI10, with dynamic HEI10 exchange mediated through the nucleoplasm. We demonstrate that this model is capable of quantitatively reproducing and predicting zyp1 experimental crossover patterning and HEI10 foci intensity data. Additionally, we find that a model combining both SC- and nucleoplasm-mediated coarsening can explain crossover patterning in wild-type Arabidopsis and in pch2 mutants, which display partial synapsis. Together, our results reveal that regulation of crossover patterning in wild-type Arabidopsis and SC-defective mutants likely acts through the same underlying coarsening mechanism, differing only in the spatial compartments through which the pro-crossover factor diffuses.
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Affiliation(s)
- John A Fozard
- Computational and Systems Biology, John Innes Centre, Norwich Research ParkNorwichUnited Kingdom
| | - Chris Morgan
- Cell and Developmental Biology, John Innes Centre, Norwich Research ParkNorwichUnited Kingdom
| | - Martin Howard
- Computational and Systems Biology, John Innes Centre, Norwich Research ParkNorwichUnited Kingdom
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18
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Zhang L, Stauffer WT, Wang JS, Wu F, Yu Z, Liu C, Kim HJ, Dernburg AF. Recruitment of Polo-like kinase couples synapsis to meiotic progression via inactivation of CHK-2. eLife 2023; 12:84492. [PMID: 36700544 PMCID: PMC9998088 DOI: 10.7554/elife.84492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/25/2023] [Indexed: 01/27/2023] Open
Abstract
Meiotic chromosome segregation relies on synapsis and crossover (CO) recombination between homologous chromosomes. These processes require multiple steps that are coordinated by the meiotic cell cycle and monitored by surveillance mechanisms. In diverse species, failures in chromosome synapsis can trigger a cell cycle delay and/or lead to apoptosis. How this key step in 'homolog engagement' is sensed and transduced by meiotic cells is unknown. Here we report that in C. elegans, recruitment of the Polo-like kinase PLK-2 to the synaptonemal complex triggers phosphorylation and inactivation of CHK-2, an early meiotic kinase required for pairing, synapsis, and double-strand break (DSB) induction. Inactivation of CHK-2 terminates DSB formation and enables CO designation and cell cycle progression. These findings illuminate how meiotic cells ensure CO formation and accurate chromosome segregation.
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Affiliation(s)
- Liangyu Zhang
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
| | - Weston T Stauffer
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Department of Integrative Biology, University of California, BerkeleyBerkeleyUnited States
| | - John S Wang
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Fan Wu
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Zhouliang Yu
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
| | - Chenshu Liu
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Hyung Jun Kim
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Abby F Dernburg
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
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19
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Liu K, Grasso EM, Pu S, Liu S, Eliezer D, Keeney S. Structure and DNA bridging activity of the essential Rec114â€"Mei4 trimer interface. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.18.524603. [PMID: 36711595 PMCID: PMC9882322 DOI: 10.1101/2023.01.18.524603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The DNA double-strand breaks (DSBs) that initiate meiotic recombination are formed by an evolutionarily conserved suite of factors that includes Rec114 and Mei4 (RM), which regulate DSB formation both spatially and temporally. In vivo , these proteins form large immunostaining foci that are integrated with higher order chromosome structures. In vitro , they form a 2:1 heterotrimeric complex that binds cooperatively to DNA to form large, dynamic condensates. However, understanding of the atomic structures and dynamic DNA binding properties of RM complexes is lacking. Here, we report a structural model of a heterotrimeric complex of the C-terminus of Rec114 with the N-terminus of Mei4, supported by nuclear magnetic resonance experiments. This minimal complex, which lacks the predicted intrinsically disordered region of Rec114, is sufficient to bind DNA and form condensates. Single-molecule experiments reveal that the minimal complex can bridge two or more DNA duplexes and can generate force to condense DNA through long-range interactions. AlphaFold2 predicts similar structural models for RM orthologs across diverse taxa despite their low degree of sequence similarity. These findings provide insight into the conserved networks of protein-protein and protein-DNA interactions that enable condensate formation and promote formation of meiotic DSBs.
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20
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Ito M, Shinohara A. Chromosome architecture and homologous recombination in meiosis. Front Cell Dev Biol 2023; 10:1097446. [PMID: 36684419 PMCID: PMC9853400 DOI: 10.3389/fcell.2022.1097446] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 12/22/2022] [Indexed: 01/09/2023] Open
Abstract
Meiocytes organize higher-order chromosome structures comprising arrays of chromatin loops organized at their bases by linear axes. As meiotic prophase progresses, the axes of homologous chromosomes align and synapse along their lengths to form ladder-like structures called synaptonemal complexes (SCs). The entire process of meiotic recombination, from initiation via programmed DNA double-strand breaks (DSBs) to completion of DSB repair with crossover or non-crossover outcomes, occurs in the context of chromosome axes and SCs. These meiosis-specific chromosome structures provide specialized environments for the regulation of DSB formation and crossing over. In this review, we summarize insights into the importance of chromosome architecture in the regulation of meiotic recombination, focusing on cohesin-mediated axis formation, DSB regulation via tethered loop-axis complexes, inter-homolog template bias facilitated by axial proteins, and crossover regulation in the context of the SCs. We also discuss emerging evidence that the SUMO and the ubiquitin-proteasome system function in the organization of chromosome structure and regulation of meiotic recombination.
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Affiliation(s)
- Masaru Ito
- *Correspondence: Masaru Ito, ; Akira Shinohara,
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21
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Continuous double-strand break induction and their differential processing sustain chiasma formation during Caenorhabditis elegans meiosis. Cell Rep 2022; 40:111403. [PMID: 36170820 DOI: 10.1016/j.celrep.2022.111403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/01/2022] [Accepted: 09/01/2022] [Indexed: 11/22/2022] Open
Abstract
Faithful chromosome segregation into gametes depends on Spo11-induced DNA double-strand breaks (DSBs). These yield single-stranded 3' tails upon resection to promote crossovers (COs). While early Mre11-dependent end resection is the predominant pathway in most organisms, Exo1 or Dna2/BLM can also contribute to the efficient processing of meiotic DSBs. Although its enzymatic activity has been thoroughly dissected, the temporal dynamics underlying Spo11 activity have remained mostly elusive. We show that, in Caenorhabditis elegans, SPO-11-mediated DSB induction takes place throughout early meiotic prophase I until mid-late pachynema. We find that late DSBs are essential for CO formation and are preferentially processed by EXO-1 and DNA-2 in a redundant fashion. Further, EXO-1-DNA-2-mediated resection ensures completion of conservative DSB repair and discourages activation of KU-dependent end joining. Taken together, our data unveil important temporal aspects of DSB induction and identify previously unknown functional implications for EXO-1-DNA-2-mediated resection activity in C. elegans.
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22
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Chuang YC, Smith GR. Meiotic crossover interference: Methods of analysis and mechanisms of action. Curr Top Dev Biol 2022; 151:217-244. [PMID: 36681471 PMCID: PMC10063388 DOI: 10.1016/bs.ctdb.2022.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Segregation of chromosomes during meiosis, to form haploid gametes from diploid precursor cells, requires in most species formation of crossovers physically connecting homologous chromosomes. Along with sister chromatid cohesion, crossovers allow tension to be generated when chromosomes begin to segregate; tension signals that chromosome movement is proceeding properly. But crossovers too close to each other might result in less sister chromatid cohesion and tension and thus failed meiosis. Interference describes the non-random distribution of crossovers, which occur farther apart than expected from independence. We discuss both genetic and cytological methods of assaying crossover interference and models for interference, whose molecular mechanism remains to be elucidated. We note marked differences among species.
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Affiliation(s)
| | - Gerald R Smith
- Fred Hutchinson Cancer Center, Seattle, WA, United States.
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23
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Vernizzi L, Lehner CF. Dispersive forces and resisting spot welds by alternative homolog conjunction govern chromosome shape in Drosophila spermatocytes during prophase I. PLoS Genet 2022; 18:e1010327. [PMID: 35895750 PMCID: PMC9359577 DOI: 10.1371/journal.pgen.1010327] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/08/2022] [Accepted: 07/05/2022] [Indexed: 11/19/2022] Open
Abstract
The bivalent chromosomes that are generated during prophase of meiosis I comprise a pair of homologous chromosomes. Homolog pairing during prophase I must include mechanisms that avoid or eliminate entanglements between non-homologous chromosomes. In Drosophila spermatocytes, non-homologous associations are disrupted by chromosome territory formation, while linkages between homologous chromosomes are maintained by special conjunction proteins. These proteins function as alternative for crossovers that link homologs during canonical meiosis but are absent during the achiasmate Drosophila male meiosis. How and where within bivalents the alternative homolog conjunction proteins function is still poorly understood. To clarify the rules that govern territory formation and alternative homolog conjunction, we have analyzed spermatocytes with chromosomal aberrations. We examined territory formation after acute chromosome cleavage by Cas9, targeted to the dodeca satellite adjacent to the centromere of chromosome 3 specifically in spermatocytes. Moreover, we studied territory organization, as well as the eventual orientation of chromosomes during meiosis I, in spermatocytes with stable structural aberrations, including heterozygous reciprocal autosomal translocations. Our observations indicate that alternative homolog conjunction is applied in a spatially confined manner. Comparable to crossovers, only a single conjunction spot per chromosome arm appears to be applied usually. These conjunction spots resist separation by the dispersing forces that drive apart homologous pericentromeric heterochromatin and embedded centromeres within territories, as well as the distinct chromosomal entities into peripheral, maximally separated territories within the spermatocyte nucleus. Already the primordial eukaryote appears to have used meiosis for sexual reproduction, because this sophisticated process follows a canonical program in lineages ranging from unicellular organisms to plants and animals. The maternal and paternal copies of a particular chromosome, i.e., the homologs, are first physically linked into a bivalent before the first meiotic division. Linkage is essential for error-free chromosome segregation. In canonical meiosis, linkage is achieved by crossovers. These are regulated so that each chromosome pair is linked, but only by very few crossovers. Surprisingly, crossovers are absent during meiosis in males of the fruit fly Drosophila melanogaster. Instead, an alternative homolog conjunction system is used. It is not yet clear how this functions. Here, we demonstrate that the alternative chromosome glue appears to be applied in a locally restricted manner rather than all along the paired homologs. Just two spots of glue appear to conjoin the two homologous chromosomes usually, with one spot linking the left and another the right chromosome arm. Thus, number and location of linkages appear to be similar as crossovers, raising the possibility of mechanistic similarities in the establishment of the two distinct types of homolog linkage.
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Affiliation(s)
- Luisa Vernizzi
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
| | - Christian F. Lehner
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
- * E-mail:
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24
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Macaraeg J, Reinhard I, Ward M, Carmeci D, Stanaway M, Moore A, Hagmann E, Brown K, Wynne DJ. Genetic analysis of C. elegans Haspin-like genes shows that hasp-1 plays multiple roles in the germline. Biol Open 2022; 11:275645. [PMID: 35678140 PMCID: PMC9277076 DOI: 10.1242/bio.059277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 06/06/2022] [Indexed: 11/20/2022] Open
Abstract
Haspin is a histone kinase that promotes error-free chromosome segregation by recruiting the Chromosomal Passenger Complex (CPC) to mitotic and meiotic chromosomes. Haspin remains less well studied than other M-phase kinases and the models explaining Haspin function have been developed primarily in mitotic cells. Here, we generate strains containing new conditional or nonsense mutations in the C. elegans Haspin homologs hasp-1 and hasp-2 and characterize their phenotypes. We show that hasp-1 is responsible for all predicted functions of Haspin and that loss of function of hasp-1 using classical and conditional alleles produces defects in germline stem cell proliferation, spermatogenesis, and confirms its role in oocyte meiosis. Genetic analysis suggests hasp-1 acts downstream of the Polo-like kinase plk-2 and shows synthetic interactions between hasp-1 and two genes expected to promote recruitment of the CPC by a parallel pathway that depends on the kinase Bub1. This work adds to the growing understanding of Haspin function by characterizing a variety of roles in an intact animal.
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Affiliation(s)
- Jommel Macaraeg
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - Isaac Reinhard
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - Matthew Ward
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - Danielle Carmeci
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - Madison Stanaway
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - Amy Moore
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - Ethan Hagmann
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - Katherine Brown
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
| | - David J Wynne
- University of Portland, 5000 N Willamette Blvd. Portland, OR, 97203, USA
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25
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Zhang R, Liu Y, Gao J. Phase separation in controlling meiotic chromosome dynamics. Curr Top Dev Biol 2022; 151:69-90. [PMID: 36681478 DOI: 10.1016/bs.ctdb.2022.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Sexually reproducing organisms produce haploid gametes through meiotic cell division, during which a single round of DNA replication is followed by two consecutive chromosome segregation. A series of meiosis-specific events take place during the meiotic prophase to ensure successful chromosome segregation. These events include programmed DNA double-strand break formation, chromosome movement driven by cytoplasmic forces, homologous pairing, synaptonemal complex installation, and inter-homolog crossover formation. Phase separation has emerged as a key principle controlling cellular biomolecular material organization and biological processes. Recent studies have revealed the involvements of phase separation in assembling meiotic chromosome-associated structures. Here we review and discuss how phase separation may participate in meiotic chromosome dynamics and propose that it may provide opportunities to understand the mysteries in meiotic regulations.
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Affiliation(s)
- Ruirui Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, China
| | - Yuanyuan Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, China
| | - Jinmin Gao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, China.
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26
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Dello Stritto MR, Vojtassakova N, Velkova M, Hamminger P, Ulm P, Jantsch V. The topoisomerase 3 zinc finger domain cooperates with the RMI1 scaffold to promote stable association of the BTR complex to recombination intermediates in the Caenorhabditis elegans germline. Nucleic Acids Res 2022; 50:5652-5671. [PMID: 35639927 PMCID: PMC9178014 DOI: 10.1093/nar/gkac408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/01/2022] [Accepted: 05/09/2022] [Indexed: 11/14/2022] Open
Abstract
Homologous recombination is the predominant DNA repair pathway used in the gonad. Of the excess DNA double-strand breaks formed in meiosis, only a subset matures into crossovers, with the remainder repaired as non-crossovers. The conserved BTR complex (comprising Bloom helicase, topoisomerase 3 and RMI1/2 scaffold proteins) acts at multiple steps during recombination to dismantle joint DNA molecules, thereby mediating the non-crossover outcome and chromosome integrity. Furthermore, the complex displays a role at the crossover site that is less well understood. Besides catalytic and TOPRIM domains, topoisomerase 3 enzymes contain a variable number of carboxy terminal zinc finger (ZnF) domains. Here, we studied the Caenorhabditis elegans mutant, in which the single ZnF domain is deleted. In contrast to the gene disruption allele, the top-3-ZnF mutant is viable, with no replication defects; the allele appears to be a hypomorph. The TOP-3-ZnF protein is recruited into foci but the mutant has increased numbers of crossovers along its chromosomes, with minor defects in repressing heterologous recombination, and a marked delay in the maturation/processing of recombination intermediates after loading of the RAD-51 recombinase. The ZnF domain cooperates with the RMI1 homolog RMH-2 to stabilize association of the BTR complex with recombination intermediates and to prevent recombination between heterologous DNA sequences.
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Affiliation(s)
| | - Nina Vojtassakova
- Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Vienna Biocenter, Austria
| | - Maria Velkova
- Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Vienna Biocenter, Austria
| | - Patricia Hamminger
- Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Vienna Biocenter, Austria
| | - Patricia Ulm
- Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Vienna Biocenter, Austria
| | - Verena Jantsch
- Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Vienna Biocenter, Austria
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27
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Haversat J, Woglar A, Klatt K, Akerib CC, Roberts V, Chen SY, Arur S, Villeneuve AM, Kim Y. Robust designation of meiotic crossover sites by CDK-2 through phosphorylation of the MutSγ complex. Proc Natl Acad Sci U S A 2022; 119:e2117865119. [PMID: 35576467 PMCID: PMC9173770 DOI: 10.1073/pnas.2117865119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 04/05/2022] [Indexed: 02/07/2023] Open
Abstract
Crossover formation is essential for proper segregation of homologous chromosomes during meiosis. Here, we show that Caenorhabditis elegans cyclin-dependent kinase 2 (CDK-2) partners with cyclin-like protein COSA-1 to promote crossover formation by promoting conversion of meiotic double-strand breaks into crossover–specific recombination intermediates. Further, we identify MutSγ component MSH-5 as a CDK-2 phosphorylation target. MSH-5 has a disordered C-terminal tail that contains 13 potential CDK phosphosites and is required to concentrate crossover–promoting proteins at recombination sites. Phosphorylation of the MSH-5 tail appears dispensable in a wild-type background, but when MutSγ activity is partially compromised, crossover formation and retention of COSA-1 at recombination sites are exquisitely sensitive to phosphosite loss. Our data support a model in which robustness of crossover designation reflects a positive feedback mechanism involving CDK-2–mediated phosphorylation and scaffold-like properties of the MSH5 C-terminal tail, features that combine to promote full recruitment and activity of crossover–promoting complexes.
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Affiliation(s)
- Jocelyn Haversat
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218
| | - Alexander Woglar
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Kayla Klatt
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218
| | - Chantal C. Akerib
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Victoria Roberts
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218
| | - Shin-Yu Chen
- Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030
| | - Swathi Arur
- Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030
| | - Anne M. Villeneuve
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305
| | - Yumi Kim
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218
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28
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Liu Y, Zhao Q, Nie H, Zhang F, Fu T, Zhang Z, Qi F, Wang R, Zhou J, Gao J. SYP-5 regulates meiotic thermotolerance in Caenorhabditis elegans. J Mol Cell Biol 2021; 13:662-675. [PMID: 34081106 PMCID: PMC8648394 DOI: 10.1093/jmcb/mjab035] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 11/13/2022] Open
Abstract
Meiosis produces the haploid gametes required by all sexually reproducing organisms, occurring in specific temperature ranges in different organisms. However, how meiotic thermotolerance is regulated remains largely unknown. Using the model organism Caenorhabditis elegans, here, we identified the synaptonemal complex (SC) protein SYP-5 as a critical regulator of meiotic thermotolerance. syp-5-null mutants maintained a high percentage of viable progeny at 20°C but produced significantly fewer viable progeny at 25°C, a permissive temperature in wild-type worms. Cytological analysis of meiotic events in the mutants revealed that while SC assembly and disassembly, as well as DNA double-strand break repair kinetics, were not affected by the elevated temperature, crossover designation, and bivalent formation were significantly affected. More severe homolog segregation errors were also observed at elevated temperature. A temperature switching assay revealed that late meiotic prophase events were not temperature-sensitive and that meiotic defects during pachytene stage were responsible for the reduced viability of syp-5 mutants at the elevated temperature. Moreover, SC polycomplex formation and hexanediol sensitivity analysis suggested that SYP-5 was required for the normal properties of the SC, and charge-interacting elements in SC components were involved in regulating meiotic thermotolerance. Together, these findings provide a novel molecular mechanism for meiotic thermotolerance regulation.
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Affiliation(s)
- Yuanyuan Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Qiuchen Zhao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Hui Nie
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Fengguo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Tingting Fu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Zhenguo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Feifei Qi
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Ruoxi Wang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Jun Zhou
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Jinmin Gao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
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29
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Liu H, Gordon SG, Rog O. Heterologous synapsis in C. elegans is regulated by meiotic double-strand breaks and crossovers. Chromosoma 2021; 130:237-250. [PMID: 34608541 PMCID: PMC8671313 DOI: 10.1007/s00412-021-00763-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 10/20/2022]
Abstract
Alignment of the parental chromosomes during meiotic prophase is key to the formation of genetic exchanges, or crossovers, and consequently to the successful production of gametes. In almost all studied organisms, alignment involves synapsis: the assembly of a conserved inter-chromosomal interface called the synaptonemal complex (SC). While the SC usually synapses homologous sequences, it can assemble between heterologous sequences. However, little is known about the regulation of heterologous synapsis. Here, we study the dynamics of heterologous synapsis in the nematode C. elegans. We characterize two experimental scenarios: SC assembly onto a folded-back chromosome that cannot pair with its homologous partner; and synapsis of pseudo-homologs, a fusion chromosome partnering with an unfused chromosome half its size. We observed elevated levels of heterologous synapsis when the number of meiotic double-strand breaks or crossovers were reduced, indicating that the promiscuity of synapsis is regulated by break formation or repair. In addition, our data suggests the existence of both chromosome-specific and nucleus-wide regulation on heterologous synapsis.
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Affiliation(s)
- Hanwenheng Liu
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112-0840, USA
- The Division of Biology & Biomedical Sciences, Washington University in St. Louis, 660 South Euclid Avenue, Missouri, 63110, USA
| | - Spencer G Gordon
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112-0840, USA
| | - Ofer Rog
- School of Biological Sciences and Center for Cell and Genome Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT, 84112-0840, USA.
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30
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Li J, Gao J, Wang R. Control of Chromatin Organization and Chromosome Behavior during the Cell Cycle through Phase Separation. Int J Mol Sci 2021; 22:ijms222212271. [PMID: 34830152 PMCID: PMC8621359 DOI: 10.3390/ijms222212271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 10/29/2021] [Accepted: 11/09/2021] [Indexed: 01/02/2023] Open
Abstract
Phase-separated condensates participate in various biological activities. Liquid-liquid phase separation (LLPS) can be driven by collective interactions between multivalent and intrinsically disordered proteins. The manner in which chromatin-with various morphologies and activities-is organized in a complex and small nucleus still remains to be fully determined. Recent findings support the claim that phase separation is involved in the regulation of chromatin organization and chromosome behavior. Moreover, phase separation also influences key events during mitosis and meiosis. This review elaborately dissects how phase separation regulates chromatin and chromosome organization and controls mitotic and meiotic chromosome behavior.
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31
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Zhang FG, Zhang RR, Gao JM. The organization, regulation, and biological functions of the synaptonemal complex. Asian J Androl 2021; 23:580-589. [PMID: 34528517 PMCID: PMC8577265 DOI: 10.4103/aja202153] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The synaptonemal complex (SC) is a meiosis-specific proteinaceous macromolecular structure that assembles between paired homologous chromosomes during meiosis in various eukaryotes. The SC has a highly conserved ultrastructure and plays critical roles in controlling multiple steps in meiotic recombination and crossover formation, ensuring accurate meiotic chromosome segregation. Recent studies in different organisms, facilitated by advances in super-resolution microscopy, have provided insights into the macromolecular structure of the SC, including the internal organization of the meiotic chromosome axis and SC central region, the regulatory pathways that control SC assembly and dynamics, and the biological functions exerted by the SC and its substructures. This review summarizes recent discoveries about how the SC is organized and regulated that help to explain the biological functions associated with this meiosis-specific structure.
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Affiliation(s)
- Feng-Guo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Rui-Rui Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Jin-Min Gao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
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32
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Abstract
The specialized two-stage meiotic cell division program halves a cell's chromosome complement in preparation for sexual reproduction. This reduction in ploidy requires that in meiotic prophase, each pair of homologous chromosomes (homologs) identify one another and form physical links through DNA recombination. Here, we review recent advances in understanding the complex morphological changes that chromosomes undergo during meiotic prophase to promote homolog identification and crossing over. We focus on the structural maintenance of chromosomes (SMC) family cohesin complexes and the meiotic chromosome axis, which together organize chromosomes and promote recombination. We then discuss the architecture and dynamics of the conserved synaptonemal complex (SC), which assembles between homologs and mediates local and global feedback to ensure high fidelity in meiotic recombination. Finally, we discuss exciting new advances, including mechanisms for boosting recombination on particular chromosomes or chromosomal domains and the implications of a new liquid crystal model for SC assembly and structure. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Sarah N Ur
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA; ,
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California 92093, USA; , .,Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
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33
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Pazhayam NM, Turcotte CA, Sekelsky J. Meiotic Crossover Patterning. Front Cell Dev Biol 2021; 9:681123. [PMID: 34368131 PMCID: PMC8344875 DOI: 10.3389/fcell.2021.681123] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/28/2021] [Indexed: 12/02/2022] Open
Abstract
Proper number and placement of meiotic crossovers is vital to chromosome segregation, with failures in normal crossover distribution often resulting in aneuploidy and infertility. Meiotic crossovers are formed via homologous repair of programmed double-strand breaks (DSBs). Although DSBs occur throughout the genome, crossover placement is intricately patterned, as observed first in early genetic studies by Muller and Sturtevant. Three types of patterning events have been identified. Interference, first described by Sturtevant in 1915, is a phenomenon in which crossovers on the same chromosome do not occur near one another. Assurance, initially identified by Owen in 1949, describes the phenomenon in which a minimum of one crossover is formed per chromosome pair. Suppression, first observed by Beadle in 1932, dictates that crossovers do not occur in regions surrounding the centromere and telomeres. The mechanisms behind crossover patterning remain largely unknown, and key players appear to act at all scales, from the DNA level to inter-chromosome interactions. There is also considerable overlap between the known players that drive each patterning phenomenon. In this review we discuss the history of studies of crossover patterning, developments in methods used in the field, and our current understanding of the interplay between patterning phenomena.
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Affiliation(s)
- Nila M. Pazhayam
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Carolyn A. Turcotte
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jeff Sekelsky
- Curriculum in Genetics and Molecular Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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34
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Fare CM, Villani A, Drake LE, Shorter J. Higher-order organization of biomolecular condensates. Open Biol 2021; 11:210137. [PMID: 34129784 PMCID: PMC8205532 DOI: 10.1098/rsob.210137] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A guiding principle of biology is that biochemical reactions must be organized in space and time. One way this spatio-temporal organization is achieved is through liquid–liquid phase separation (LLPS), which generates biomolecular condensates. These condensates are dynamic and reactive, and often contain a complex mixture of proteins and nucleic acids. In this review, we discuss how underlying physical and chemical processes generate internal condensate architectures. We then outline the diverse condensate architectures that are observed in biological systems. Finally, we discuss how specific condensate organization is critical for specific biological functions.
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Affiliation(s)
- Charlotte M Fare
- Department of Biochemistry and Biophysics, and.,Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | | | - James Shorter
- Department of Biochemistry and Biophysics, and.,Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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35
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von Diezmann L, Rog O. Single-Molecule Tracking of Chromatin-Associated Proteins in the C. elegans Gonad. J Phys Chem B 2021; 125:6162-6170. [PMID: 34097417 DOI: 10.1021/acs.jpcb.1c03040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biomolecules are distributed within cells by molecular-scale diffusion and binding events that are invisible in standard fluorescence microscopy. These molecular search kinetics are key to understanding nuclear signaling and chromosome organization and can be directly observed by single-molecule tracking microscopy. Here, we report a method to track individual proteins within intact C. elegans gonads and apply it to study the molecular dynamics of the axis, a proteinaceous backbone that organizes meiotic chromosomes. Using either fluorescent proteins or enzymatically ligated dyes, we obtain multisecond trajectories with a localization precision of 15-25 nm in nuclei actively undergoing meiosis. Correlation with a reference channel allows for accurate measurement of protein dynamics, compensating for movements of the nuclei and chromosomes within the gonad. We find that axis proteins exhibit either static binding to chromatin or free diffusion in the nucleoplasm, and we separately quantify the motion parameters of these distinct populations. Freely diffusing axis proteins selectively explore chromatin-rich regions, suggesting they are circumventing the central phase-separated region of the nucleus. This work demonstrates that single-molecule microscopy can infer nanoscale-resolution dynamics within living tissue, expanding the possible applications of this approach.
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36
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Abstract
The formation of crossovers between homologous chromosomes is key to sexual reproduction. In most species, crossovers are spaced further apart than would be expected if they formed independently, a phenomenon termed crossover interference. Despite more than a century of study, the molecular mechanisms implementing crossover interference remain a subject of active debate. Recent findings of how signaling proteins control the formation of crossovers and about the interchromosomal interface in which crossovers form offer new insights into this process. In this Review, we present a cell biological and biophysical perspective on crossover interference, summarizing the evidence that links interference to the spatial, dynamic, mechanical and molecular properties of meiotic chromosomes. We synthesize this physical understanding in the context of prevailing mechanistic models that aim to explain how crossover interference is implemented.
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Affiliation(s)
- Lexy von Diezmann
- Center for Cell and Genome Sciences, University of Utah, Salt Lake City, UT 84112, USA.,School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Ofer Rog
- Center for Cell and Genome Sciences, University of Utah, Salt Lake City, UT 84112, USA.,School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
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37
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Loose JA, Ghazi A. Auxin treatment increases lifespan in Caenorhabditis elegans. Biol Open 2021; 10:261795. [PMID: 34184729 PMCID: PMC8186727 DOI: 10.1242/bio.058703] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 04/08/2021] [Indexed: 12/13/2022] Open
Abstract
The auxin-inducible degradation system (AID) has proven to be a highly versatile technology for rapid, robust and reversible depletion of proteins in multiple model systems. In recent years, AID has been adapted into the nematode Caenorhabditis elegans as a tool for conditional protein knockdown. Numerous transgenic strains have been created that, upon auxin exposure, undergo protein inactivation in the worm germline or somatic tissues, both during development and in young adults. Since longevity assays often involve long-term gene- and protein-manipulation, the facility for spatiotemporally precise and extended protein removal makes AID a potentially highly valuable tool for aging biology. However, whether auxins themselves impact worm longevity has not been directly addressed. Here, we show that prolonged exposure to indole 3-acetic acid (IAA), the auxin used in worm AID studies, extends lifespan. We also report that two transgenic strains expressing Arabidopsis proteins that are key components of the AID platform are longer lived than wild-type animals. Together, our results highlight the necessity for exercising caution while utilizing AID for longevity studies and in interpreting the resulting data. This article has an associated First Person interview with the first author of the paper. Summary: We report that auxin and auxin-inducible protein degradation tools alter lifespan in C. elegans.
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Affiliation(s)
- Julia A Loose
- Department of Pediatrics, University of Pittsburgh School of Medicine, Rangos Research Center, Children's Hospital of Pittsburgh, 15224 PA, USA
| | - Arjumand Ghazi
- Department of Pediatrics, University of Pittsburgh School of Medicine, Rangos Research Center, Children's Hospital of Pittsburgh, 15224 PA, USA.,Departments of Developmental Biology and Cell Biology and Physiology, University of Pittsburgh School of Medicine, Rangos Research Center, Children's Hospital of Pittsburgh, 15224 PA, USA
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38
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Brandt JN, Hussey KA, Kim Y. Spatial and temporal control of targeting Polo-like kinase during meiotic prophase. J Cell Biol 2021; 219:152136. [PMID: 32997737 PMCID: PMC7594494 DOI: 10.1083/jcb.202006094] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/19/2020] [Accepted: 08/28/2020] [Indexed: 12/17/2022] Open
Abstract
Polo-like kinases (PLKs) play widely conserved roles in orchestrating meiotic chromosome dynamics. However, how PLKs are targeted to distinct subcellular localizations during meiotic progression remains poorly understood. Here, we demonstrate that the cyclin-dependent kinase CDK-1 primes the recruitment of PLK-2 to the synaptonemal complex (SC) through phosphorylation of SYP-1 in C. elegans. SYP-1 phosphorylation by CDK-1 occurs just before meiotic onset. However, PLK-2 docking to the SC is prevented by the nucleoplasmic HAL-2/3 complex until crossover designation, which constrains PLK-2 to special chromosomal regions known as pairing centers to ensure proper homologue pairing and synapsis. PLK-2 is targeted to crossover sites primed by CDK-1 and spreads along the SC by reinforcing SYP-1 phosphorylation on one side of each crossover only when threshold levels of crossovers are generated. Thus, the integration of chromosome-autonomous signaling and a nucleus-wide crossover-counting mechanism partitions holocentric chromosomes relative to the crossover site, which ultimately defines the pattern of chromosome segregation during meiosis I.
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Affiliation(s)
- James N Brandt
- Department of Biology, Johns Hopkins University, Baltimore, MD
| | | | - Yumi Kim
- Department of Biology, Johns Hopkins University, Baltimore, MD
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39
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Almanzar DE, Gordon SG, Rog O. Meiotic sister chromatid exchanges are rare in C. elegans. Curr Biol 2021; 31:1499-1507.e3. [PMID: 33740426 DOI: 10.1016/j.cub.2020.11.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/08/2020] [Accepted: 11/05/2020] [Indexed: 11/16/2022]
Abstract
Sexual reproduction shuffles the parental genomes to generate new genetic combinations. To achieve that, the genome is subjected to numerous double-strand breaks, the repair of which involves two crucial decisions: repair pathway and repair template.1 Use of crossover pathways with the homologous chromosome as template exchanges genetic information and directs chromosome segregation. Crossover repair, however, can compromise the integrity of the repair template and is therefore tightly regulated. The extent to which crossover pathways are used during sister-directed repair is unclear because the identical sister chromatids are difficult to distinguish. Nonetheless, indirect assays have led to the suggestion that inter-sister crossovers, or sister chromatid exchanges (SCEs), are quite common.2-11 Here we devised a technique to directly score physiological SCEs in the C. elegans germline using selective sister chromatid labeling with the thymidine analog 5-ethynyl-2'-deoxyuridine (EdU). Surprisingly, we find SCEs to be rare in meiosis, accounting for <2% of repair events. SCEs remain rare even when the homologous chromosome is unavailable, indicating that almost all sister-directed repair is channeled into noncrossover pathways. We identify two mechanisms that limit SCEs. First, SCEs are elevated in the absence of the RecQ helicase BLMHIM-6. Second, the synaptonemal complex-a conserved interface that promotes crossover repair12,13-promotes SCEs when localized between the sisters. Our data suggest that crossover pathways in C. elegans are only used to generate the single necessary link between the homologous chromosomes. Noncrossover pathways repair almost all other breaks, regardless of the repair template.
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Affiliation(s)
- David E Almanzar
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112-0840, USA
| | - Spencer G Gordon
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112-0840, USA
| | - Ofer Rog
- School of Biological Sciences, University of Utah, 257 South 1400 East, Salt Lake City, UT 84112-0840, USA.
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40
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Zhang Z, Xie S, Wang R, Guo S, Zhao Q, Nie H, Liu Y, Zhang F, Chen M, Liu L, Meng X, Liu M, Zhao L, Colaiácovo MP, Zhou J, Gao J. Multivalent weak interactions between assembly units drive synaptonemal complex formation. J Cell Biol 2021; 219:151585. [PMID: 32211900 PMCID: PMC7199860 DOI: 10.1083/jcb.201910086] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 01/22/2020] [Accepted: 02/26/2020] [Indexed: 12/28/2022] Open
Abstract
The synaptonemal complex (SC) is an ordered but highly dynamic structure assembled between homologous chromosomes to control interhomologous crossover formation, ensuring accurate meiotic chromosome segregation. However, the mechanisms regulating SC assembly and dynamics remain unclear. Here, we identified two new SC components, SYP-5 and SYP-6, in Caenorhabditis elegans that have distinct expression patterns and form distinct SC assembly units with other SYPs through stable interactions. SYP-5 and SYP-6 exhibit diverse in vivo SC regulatory functions and distinct phase separation properties in cells. Charge-interacting elements (CIEs) are enriched in SC intrinsically disordered regions (IDRs), and IDR deletion or CIE removal confirmed a requirement for these elements in SC regulation. Our data support the theory that multivalent weak interactions between the SC units drive SC formation and that CIEs confer multivalency to the assembly units.
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Affiliation(s)
- Zhenguo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Songbo Xie
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Ruoxi Wang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Shuqun Guo
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Qiuchen Zhao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Hui Nie
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Yuanyuan Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Fengguo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Miao Chen
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Libo Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Xiaoqian Meng
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Min Liu
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
| | - Li Zhao
- Department of Pathology, Harvard Medical School, Dana-Farber/Harvard Cancer Center, Boston, MA.,Department of Laboratory Medicine, Children's Hospital Boston, Boston, MA
| | | | - Jun Zhou
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China.,State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jinmin Gao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan, Shandong, China
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41
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Gartner A, Engebrecht J. DNA repair, recombination, and damage signaling. Genetics 2021; 220:6522877. [PMID: 35137093 PMCID: PMC9097270 DOI: 10.1093/genetics/iyab178] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/10/2021] [Indexed: 01/09/2023] Open
Abstract
DNA must be accurately copied and propagated from one cell division to the next, and from one generation to the next. To ensure the faithful transmission of the genome, a plethora of distinct as well as overlapping DNA repair and recombination pathways have evolved. These pathways repair a large variety of lesions, including alterations to single nucleotides and DNA single and double-strand breaks, that are generated as a consequence of normal cellular function or by external DNA damaging agents. In addition to the proteins that mediate DNA repair, checkpoint pathways have also evolved to monitor the genome and coordinate the action of various repair pathways. Checkpoints facilitate repair by mediating a transient cell cycle arrest, or through initiation of cell suicide if DNA damage has overwhelmed repair capacity. In this chapter, we describe the attributes of Caenorhabditis elegans that facilitate analyses of DNA repair, recombination, and checkpoint signaling in the context of a whole animal. We review the current knowledge of C. elegans DNA repair, recombination, and DNA damage response pathways, and their role during development, growth, and in the germ line. We also discuss how the analysis of mutational signatures in C. elegans is helping to inform cancer mutational signatures in humans.
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Affiliation(s)
- Anton Gartner
- Department for Biological Sciences, IBS Center for Genomic Integrity, Ulsan National Institute of Science and Technology, Ulsan 689-798, Republic of Korea,Corresponding author: (A.G.); (J.E.)
| | - JoAnne Engebrecht
- Department of Molecular and Cellular Biology, University of California Davis, Davis, CA 95616, USA,Corresponding author: (A.G.); (J.E.)
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42
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Hatkevich T, Miller DE, Turcotte CA, Miller MC, Sekelsky J. A pathway for error-free non-homologous end joining of resected meiotic double-strand breaks. Nucleic Acids Res 2021; 49:879-890. [PMID: 33406239 PMCID: PMC7826270 DOI: 10.1093/nar/gkaa1205] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/22/2020] [Accepted: 11/25/2020] [Indexed: 12/31/2022] Open
Abstract
Programmed DNA double-strand breaks (DSBs) made during meiosis are repaired by recombination with the homologous chromosome to generate, at selected sites, reciprocal crossovers that are critical for the proper separation of homologs in the first meiotic division. Backup repair processes can compensate when the normal meiotic recombination processes are non-functional. We describe a novel backup repair mechanism that occurs when the homologous chromosome is not available in Drosophila melanogaster meiosis. In the presence of a previously described mutation (Mcm5A7) that disrupts chromosome pairing, DSB repair is initiated by homologous recombination but is completed by non-homologous end joining (NHEJ). Remarkably, this process yields precise repair products. Our results provide support for a recombination intermediate recently proposed in mouse meiosis, in which an oligonucleotide bound to the Spo11 protein that catalyzes DSB formation remains bound after resection. We propose that this oligonucleotide functions as a primer for fill-in synthesis to allow scarless repair by NHEJ. We argue that this is a conserved repair mechanism that is likely to be invoked to overcome occasional challenges in normal meiosis.
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Affiliation(s)
- Talia Hatkevich
- Curriculum in Genetics and Molecular Biology, 120 Mason Farm Road, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Danny E Miller
- Department of Pediatrics, Division of Medical Genetics, University of Washington, Seattle, Washington and Seattle Children's Hospital, Seattle, WA 98105, USA
| | - Carolyn A Turcotte
- Curriculum in Genetics and Molecular Biology, 120 Mason Farm Road, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Margaret C Miller
- Department of Biology, University of North Carolina, 120 South Road, Chapel Hill, NC 27599, USA
| | - Jeff Sekelsky
- Curriculum in Genetics and Molecular Biology, 120 Mason Farm Road, University of North Carolina, Chapel Hill, NC 27599, USA.,Department of Biology, University of North Carolina, 120 South Road, Chapel Hill, NC 27599, USA.,Integrative Program in Biological and Genome Sciences, 250 Bell Tower Drive, University of North Carolina, Chapel Hill, NC 27599, USA
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43
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Russo AE, Nelson CR, Bhalla N. Mutating two putative phosphorylation sites on ZHP-3 does not affect its localization or function during meiotic chromosome segregation. MICROPUBLICATION BIOLOGY 2021; 2021. [PMID: 33490887 PMCID: PMC7816088 DOI: 10.17912/micropub.biology.000354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Meiotic chromosome segregation depends on crossover recombination to link homologous chromosomes together and promote accurate segregation in the first meiotic division. In Caenorhabditis elegans, a conserved RING finger protein, ZHP-3, is essential for meiotic recombination and localizes to sites of crossover formation. Whether ZHP-3 is regulated to promote recombination remains poorly understood. In vitro analysis identified two putative CHK-1 kinase phosphorylation sites on ZHP-3. However, mutation of the phosphorylation sites identified in vitro had no effect on meiotic recombination or localization of ZHP-3. Thus, these two phosphorylation sites appear to be dispensable for ZHP-3’s role in meiotic recombination or its localization.
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Affiliation(s)
- Anna E Russo
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Christian R Nelson
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Needhi Bhalla
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
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44
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Sato-Carlton A, Nakamura-Tabuchi C, Li X, Boog H, Lehmer MK, Rosenberg SC, Barroso C, Martinez-Perez E, Corbett KD, Carlton PM. Phosphoregulation of HORMA domain protein HIM-3 promotes asymmetric synaptonemal complex disassembly in meiotic prophase in Caenorhabditis elegans. PLoS Genet 2020; 16:e1008968. [PMID: 33175901 PMCID: PMC7717579 DOI: 10.1371/journal.pgen.1008968] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 12/04/2020] [Accepted: 10/17/2020] [Indexed: 11/27/2022] Open
Abstract
In the two cell divisions of meiosis, diploid genomes are reduced into complementary haploid sets through the discrete, two-step removal of chromosome cohesion, a task carried out in most eukaryotes by protecting cohesion at the centromere until the second division. In eukaryotes without defined centromeres, however, alternative strategies have been innovated. The best-understood of these is found in the nematode Caenorhabditis elegans: after the single off-center crossover divides the chromosome into two segments, or arms, several chromosome-associated proteins or post-translational modifications become specifically partitioned to either the shorter or longer arm, where they promote the correct timing of cohesion loss through as-yet unknown mechanisms. Here, we investigate the meiotic axis HORMA-domain protein HIM-3 and show that it becomes phosphorylated at its C-terminus, within the conserved “closure motif” region bound by the related HORMA-domain proteins HTP-1 and HTP-2. Binding of HTP-2 is abrogated by phosphorylation of the closure motif in in vitro assays, strongly suggesting that in vivo phosphorylation of HIM-3 likely modulates the hierarchical structure of the chromosome axis. Phosphorylation of HIM-3 only occurs on synapsed chromosomes, and similarly to other previously-described phosphorylated proteins of the synaptonemal complex, becomes restricted to the short arm after designation of crossover sites. Regulation of HIM-3 phosphorylation status is required for timely disassembly of synaptonemal complex central elements from the long arm, and is also required for proper timing of HTP-1 and HTP-2 dissociation from the short arm. Phosphorylation of HIM-3 thus plays a role in establishing the identity of short and long arms, thereby contributing to the robustness of the two-step chromosome segregation. To segregate properly in meiosis, cohesion between replicated chromosomes must remain after the first meiotic cell division, so chromosomes can be held together until they finally separate in the second division. While the majority of organisms use centromeres to protect chromosome cohesion in the first division, the nematode worm C. elegans, which lacks single centromeres, instead protects cohesion only on a segment of the chromosome known as the “long arm”. The long arm (and its complement, the short arm) are known to accumulate specific proteins and protein modifications, but it is not known how the short and long arms are first distinguished, nor how their separate functions are carried out. We report here that the chromosome axis protein HIM-3 and its modification by phosphorylation is important for ensuring the robust establishment of short and long arm functions. We show that phosphorylated HIM-3 partitions to the short arms after crossover recombination sites are designated, and HIM-3 mutants that mimic constitutive phosphorylation delay the normal establishment of the two complementary arm domains. Our findings reveal another layer of regulation to an outstanding mystery in chromosome biology.
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Affiliation(s)
| | | | - Xuan Li
- Kyoto University, Graduate School of Biostudies, Japan
| | - Hendrik Boog
- Kyoto University, Graduate School of Biostudies, Japan
| | - Madison K. Lehmer
- Department of Chemistry and Biochemistry, University of California, San Diego, United States of America
| | - Scott C. Rosenberg
- Department of Chemistry and Biochemistry, University of California, San Diego, United States of America
| | - Consuelo Barroso
- MRC London Institute of Medical Sciences, Imperial College, London
| | | | - Kevin D. Corbett
- Department of Chemistry and Biochemistry, University of California, San Diego, United States of America
- Department of Cellular and Molecular Medicine, University of California, San Diego, United States of America
- Ludwig Institute for Cancer Research, San Diego Branch, United States of America
| | - Peter Mark Carlton
- Kyoto University, Graduate School of Biostudies, Japan
- Kyoto University, Radiation Biology Center, Japan
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Japan
- * E-mail:
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45
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Hollis JA, Glover ML, Schlientz AJ, Cahoon CK, Bowerman B, Wignall SM, Libuda DE. Excess crossovers impede faithful meiotic chromosome segregation in C. elegans. PLoS Genet 2020; 16:e1009001. [PMID: 32886661 PMCID: PMC7508374 DOI: 10.1371/journal.pgen.1009001] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 09/22/2020] [Accepted: 07/21/2020] [Indexed: 12/19/2022] Open
Abstract
During meiosis, diploid organisms reduce their chromosome number by half to generate haploid gametes. This process depends on the repair of double strand DNA breaks as crossover recombination events between homologous chromosomes, which hold homologs together to ensure their proper segregation to opposite spindle poles during the first meiotic division. Although most organisms are limited in the number of crossovers between homologs by a phenomenon called crossover interference, the consequences of excess interfering crossovers on meiotic chromosome segregation are not well known. Here we show that extra interfering crossovers lead to a range of meiotic defects and we uncover mechanisms that counteract these errors. Using chromosomes that exhibit a high frequency of supernumerary crossovers in Caenorhabditis elegans, we find that essential chromosomal structures are mispatterned in the presence of multiple crossovers, subjecting chromosomes to improper spindle forces and leading to defects in metaphase alignment. Additionally, the chromosomes with extra interfering crossovers often exhibited segregation defects in anaphase I, with a high incidence of chromatin bridges that sometimes created a tether between the chromosome and the first polar body. However, these anaphase I bridges were often able to resolve in a LEM-3 nuclease dependent manner, and chromosome tethers that persisted were frequently resolved during Meiosis II by a second mechanism that preferentially segregates the tethered sister chromatid into the polar body. Altogether these findings demonstrate that excess interfering crossovers can severely impact chromosome patterning and segregation, highlighting the importance of limiting the number of recombination events between homologous chromosomes for the proper execution of meiosis.
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Affiliation(s)
- Jeremy A. Hollis
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Marissa L. Glover
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, OR, United States of America
| | - Aleesa J. Schlientz
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, OR, United States of America
| | - Cori K. Cahoon
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, OR, United States of America
| | - Bruce Bowerman
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, OR, United States of America
| | - Sarah M. Wignall
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
- * E-mail: (SMW); (DEL)
| | - Diana E. Libuda
- Institute of Molecular Biology, Department of Biology, University of Oregon, Eugene, OR, United States of America
- * E-mail: (SMW); (DEL)
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46
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Alternative Synaptonemal Complex Structures: Too Much of a Good Thing? Trends Genet 2020; 36:833-844. [PMID: 32800626 DOI: 10.1016/j.tig.2020.07.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/10/2020] [Accepted: 07/10/2020] [Indexed: 12/21/2022]
Abstract
The synaptonemal complex (SC), a highly conserved structure built between homologous meiotic chromosomes, is required for crossover formation and ensuring proper chromosome segregation. In many organisms, SC components can also form alternative structures, including repeating SC structures that are known as polycomplexes (PCs), and extensively modified SC structures that are maintained late in meiosis. PCs display differences in their ability to localize with lateral element proteins, recombination machinery, and DNA. They can be created by defects in post-translational modification, suggesting that these modifications have roles in preventing alternate SC structures. These SC-like structures provide insight into the rules for building and maintaining the SC by offering an 'in vivo laboratory' for models of SC assembly, structure, and disassembly. Here, we discuss what these structures can tell us about the rules for building the SC and the roles of the SC in meiotic processes.
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47
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Liquid-liquid phase separation in biology: mechanisms, physiological functions and human diseases. SCIENCE CHINA. LIFE SCIENCES 2020; 63:953-985. [PMID: 32548680 DOI: 10.1007/s11427-020-1702-x] [Citation(s) in RCA: 151] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/20/2020] [Indexed: 02/06/2023]
Abstract
Cells are compartmentalized by numerous membrane-enclosed organelles and membraneless compartments to ensure that a wide variety of cellular activities occur in a spatially and temporally controlled manner. The molecular mechanisms underlying the dynamics of membrane-bound organelles, such as their fusion and fission, vesicle-mediated trafficking and membrane contactmediated inter-organelle interactions, have been extensively characterized. However, the molecular details of the assembly and functions of membraneless compartments remain elusive. Mounting evidence has emerged recently that a large number of membraneless compartments, collectively called biomacromolecular condensates, are assembled via liquid-liquid phase separation (LLPS). Phase-separated condensates participate in various biological activities, including higher-order chromatin organization, gene expression, triage of misfolded or unwanted proteins for autophagic degradation, assembly of signaling clusters and actin- and microtubule-based cytoskeletal networks, asymmetric segregations of cell fate determinants and formation of pre- and post-synaptic density signaling assemblies. Biomacromolecular condensates can transition into different material states such as gel-like structures and solid aggregates. The material properties of condensates are crucial for fulfilment of their distinct functions, such as biochemical reaction centers, signaling hubs and supporting architectures. Cells have evolved multiple mechanisms to ensure that biomacromolecular condensates are assembled and disassembled in a tightly controlled manner. Aberrant phase separation and transition are causatively associated with a variety of human diseases such as neurodegenerative diseases and cancers. This review summarizes recent major progress in elucidating the roles of LLPS in various biological pathways and diseases.
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48
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ASY1 acts as a dosage-dependent antagonist of telomere-led recombination and mediates crossover interference in Arabidopsis. Proc Natl Acad Sci U S A 2020; 117:13647-13658. [PMID: 32499315 PMCID: PMC7306779 DOI: 10.1073/pnas.1921055117] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During meiosis, interhomolog recombination produces crossovers and noncrossovers to create genetic diversity. Meiotic recombination frequency varies at multiple scales, with high subtelomeric recombination and suppressed centromeric recombination typical in many eukaryotes. During recombination, sister chromatids are tethered as loops to a polymerized chromosome axis, which, in plants, includes the ASY1 HORMA domain protein and REC8-cohesin complexes. Using chromatin immunoprecipitation, we show an ascending telomere-to-centromere gradient of ASY1 enrichment, which correlates strongly with REC8-cohesin ChIP-seq data. We mapped crossovers genome-wide in the absence of ASY1 and observe that telomere-led recombination becomes dominant. Surprisingly, asy1/+ heterozygotes also remodel crossovers toward subtelomeric regions at the expense of the pericentromeres. Telomeric recombination increases in asy1/+ occur in distal regions where ASY1 and REC8 ChIP enrichment are lowest in wild type. In wild type, the majority of crossovers show interference, meaning that they are more widely spaced along the chromosomes than expected by chance. To measure interference, we analyzed double crossover distances, MLH1 foci, and fluorescent pollen tetrads. Interestingly, while crossover interference is normal in asy1/+, it is undetectable in asy1 mutants, indicating that ASY1 is required to mediate crossover interference. Together, this is consistent with ASY1 antagonizing telomere-led recombination and promoting spaced crossover formation along the chromosomes via interference. These findings provide insight into the role of the meiotic axis in patterning recombination frequency within plant genomes.
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49
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Smith GR, Nambiar M. New Solutions to Old Problems: Molecular Mechanisms of Meiotic Crossover Control. Trends Genet 2020; 36:337-346. [PMID: 32294414 PMCID: PMC7162993 DOI: 10.1016/j.tig.2020.02.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/10/2020] [Accepted: 02/12/2020] [Indexed: 01/25/2023]
Abstract
During scientific investigations, the explanation of remarkably interesting phenomena must often await development of new methods or accrual of new observations that in retrospect can lead to lucid answers to the initial problem. A case in point is the control of genetic recombination during meiosis, which leads to crossovers between chromosomes critical for production of healthy offspring. Crossovers must be properly placed along meiotic chromosomes for their accurate segregation. Here, we review observations on two aspects of meiotic crossover control - crossover interference and repression of crossovers near centromeres, both observed more than 85 years ago. Only recently have relatively simple molecular mechanisms for these phenomena become clear through advances in both methods and understanding the molecular basis of meiotic recombination.
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Affiliation(s)
- Gerald R Smith
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
| | - Mridula Nambiar
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA; Department of Biology, Indian Institute of Science Education and Research, Pune, India
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50
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Sanders DW, Kedersha N, Lee DSW, Strom AR, Drake V, Riback JA, Bracha D, Eeftens JM, Iwanicki A, Wang A, Wei MT, Whitney G, Lyons SM, Anderson P, Jacobs WM, Ivanov P, Brangwynne CP. Competing Protein-RNA Interaction Networks Control Multiphase Intracellular Organization. Cell 2020; 181:306-324.e28. [PMID: 32302570 PMCID: PMC7816278 DOI: 10.1016/j.cell.2020.03.050] [Citation(s) in RCA: 452] [Impact Index Per Article: 113.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 10/24/2019] [Accepted: 03/20/2020] [Indexed: 12/22/2022]
Abstract
Liquid-liquid phase separation (LLPS) mediates formation of membraneless condensates such as those associated with RNA processing, but the rules that dictate their assembly, substructure, and coexistence with other liquid-like compartments remain elusive. Here, we address the biophysical mechanism of this multiphase organization using quantitative reconstitution of cytoplasmic stress granules (SGs) with attached P-bodies in human cells. Protein-interaction networks can be viewed as interconnected complexes (nodes) of RNA-binding domains (RBDs), whose integrated RNA-binding capacity determines whether LLPS occurs upon RNA influx. Surprisingly, both RBD-RNA specificity and disordered segments of key proteins are non-essential, but modulate multiphase condensation. Instead, stoichiometry-dependent competition between protein networks for connecting nodes determines SG and P-body composition and miscibility, while competitive binding of unconnected proteins disengages networks and prevents LLPS. Inspired by patchy colloid theory, we propose a general framework by which competing networks give rise to compositionally specific and tunable condensates, while relative linkage between nodes underlies multiphase organization.
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Affiliation(s)
- David W Sanders
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Nancy Kedersha
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Daniel S W Lee
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Amy R Strom
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Victoria Drake
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Joshua A Riback
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Dan Bracha
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Jorine M Eeftens
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Allana Iwanicki
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Alicia Wang
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Ming-Tzo Wei
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Gena Whitney
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Shawn M Lyons
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
| | - Paul Anderson
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - William M Jacobs
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Pavel Ivanov
- Division of Rheumatology, Inflammation, and Immunity, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Princeton, NJ 08544, USA.
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