1
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Torres DE, Reckard AT, Klocko AD, Seidl MF. Nuclear genome organization in fungi: from gene folding to Rabl chromosomes. FEMS Microbiol Rev 2023; 47:fuad021. [PMID: 37197899 PMCID: PMC10246852 DOI: 10.1093/femsre/fuad021] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/28/2023] [Accepted: 05/08/2023] [Indexed: 05/19/2023] Open
Abstract
Comparative genomics has recently provided unprecedented insights into the biology and evolution of the fungal lineage. In the postgenomics era, a major research interest focuses now on detailing the functions of fungal genomes, i.e. how genomic information manifests into complex phenotypes. Emerging evidence across diverse eukaryotes has revealed that the organization of DNA within the nucleus is critically important. Here, we discuss the current knowledge on the fungal genome organization, from the association of chromosomes within the nucleus to topological structures at individual genes and the genetic factors required for this hierarchical organization. Chromosome conformation capture followed by high-throughput sequencing (Hi-C) has elucidated how fungal genomes are globally organized in Rabl configuration, in which centromere or telomere bundles are associated with opposite faces of the nuclear envelope. Further, fungal genomes are regionally organized into topologically associated domain-like (TAD-like) chromatin structures. We discuss how chromatin organization impacts the proper function of DNA-templated processes across the fungal genome. Nevertheless, this view is limited to a few fungal taxa given the paucity of fungal Hi-C experiments. We advocate for exploring genome organization across diverse fungal lineages to ensure the future understanding of the impact of nuclear organization on fungal genome function.
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Affiliation(s)
- David E Torres
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Laboratory of Phytopathology, Wageningen University and Research,Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - Andrew T Reckard
- Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, 234 Centennial Hall, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918 USA
| | - Andrew D Klocko
- Department of Chemistry and Biochemistry, University of Colorado Colorado Springs, 234 Centennial Hall, 1420 Austin Bluffs Pkwy, Colorado Springs, CO 80918 USA
| | - Michael F Seidl
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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2
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Ohtsuka H, Imada K, Shimasaki T, Aiba H. Sporulation: A response to starvation in the fission yeast Schizosaccharomyces pombe. Microbiologyopen 2022; 11:e1303. [PMID: 35765188 PMCID: PMC9214231 DOI: 10.1002/mbo3.1303] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/08/2022] [Accepted: 06/08/2022] [Indexed: 12/02/2022] Open
Abstract
The fission yeast Schizosaccharomyces pombe employs two main strategies to adapt to the environment and survive when starved for nutrients. The strategies employ sporulation via sexual differentiation and extension of the chronological lifespan. When a cell is exposed to nutrient starvation in the presence of a cell of the opposite sex, the cells undergo fusion through conjugation and sporulation through meiosis. S. pombe spores are highly resistant to diverse stresses and may survive for a very long time. In this minireview, among the various sexual differentiation processes induced by starvation, we focused on and summarized the findings of the molecular mechanisms of spore formation in fission yeast. Furthermore, comparative measurements of the chronological lifespan of stationary phase cells and G0 cells and the survival period of spore cells revealed that the spore cells survived for a long period, indicating the presence of an effective mechanism for survival. Currently, many molecules involved in sporulation and their functions are being discovered; however, our understanding of these is not complete. Further understanding of spores may not only deepen our comprehension of sexual differentiation but may also provide hints for sustaining life.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical SciencesNagoya UniversityChikusa‐kuNagoyaJapan
| | - Kazuki Imada
- Department of Chemistry and BiochemistryNational Institute of Technology (KOSEN), Suzuka CollegeSuzukaJapan
- Department of Biology, Graduate School of ScienceOsaka City UniversitySumiyoshi‐kuOsakaJapan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical SciencesNagoya UniversityChikusa‐kuNagoyaJapan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical SciencesNagoya UniversityChikusa‐kuNagoyaJapan
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3
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Andric V, Rougemaille M. Long Non-Coding RNAs in the Control of Gametogenesis: Lessons from Fission Yeast. Noncoding RNA 2021; 7:ncrna7020034. [PMID: 34208016 PMCID: PMC8293462 DOI: 10.3390/ncrna7020034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/03/2021] [Accepted: 06/09/2021] [Indexed: 12/21/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) contribute to cell fate decisions by modulating genome expression and stability. In the fission yeast Schizosaccharomyces pombe, the transition from mitosis to meiosis results in a marked remodeling of gene expression profiles, which ultimately ensures gamete production and inheritance of genetic information to the offspring. This key developmental process involves a set of dedicated lncRNAs that shape cell cycle-dependent transcriptomes through a variety of mechanisms, including epigenetic modifications and the modulation of transcription, post-transcriptional and post-translational regulations, and that contribute to meiosis-specific chromosomal events. In this review, we summarize the biology of these lncRNAs, from their identification to mechanism of action, and discuss their regulatory role in the control of gametogenesis.
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Affiliation(s)
- Vedrana Andric
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
- Institute Curie, PSL Research University, CNRS UMR3215, INSERM U934, 75005 Paris, France;
| | - Mathieu Rougemaille
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France
- Correspondence:
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4
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Mittal P, Ghule K, Trakroo D, Prajapati HK, Ghosh SK. Meiosis-Specific Functions of Kinesin Motors in Cohesin Removal and Maintenance of Chromosome Integrity in Budding Yeast. Mol Cell Biol 2020; 40:e00386-19. [PMID: 31964755 PMCID: PMC7108822 DOI: 10.1128/mcb.00386-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 09/20/2019] [Accepted: 12/26/2019] [Indexed: 12/31/2022] Open
Abstract
Kinesin motors provide the molecular forces at the kinetochore-microtubule interface and along the spindle to control chromosome segregation. During meiosis with two rounds of microtubule assembly-disassembly, the roles of motor proteins remain unexplored. We observed that in contrast to mitosis, Cin8 and Kip3 together are indispensable for meiosis. While examining meiosis in cin8Δ kip3Δ cells, we detected chromosome breakage in the meiosis II cells. The double mutant exhibits a delay in cohesin removal during anaphase I. Consequently, some cells fail to undergo meiosis II and form dyads, while some, as they progress through meiosis II, cause a defect in chromosome integrity. We believe that in the latter cells, an imbalance of spindle-mediated force and the simultaneous persistence of cohesin on chromosomes cause their breakage. We provide evidence that tension generated by Cin8 and Kip3 through microtubule cross-linking is essential for signaling efficient cohesin removal and the maintenance of chromosome integrity during meiosis.
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Affiliation(s)
- Priyanka Mittal
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Komal Ghule
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai, India
| | - Deepika Trakroo
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai, India
| | - Hemant Kumar Prajapati
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Santanu K Ghosh
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai, India
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5
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Mixing and Matching Chromosomes during Female Meiosis. Cells 2020; 9:cells9030696. [PMID: 32178277 PMCID: PMC7140621 DOI: 10.3390/cells9030696] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/08/2020] [Accepted: 03/11/2020] [Indexed: 01/17/2023] Open
Abstract
Meiosis is a key event in the manufacturing of an oocyte. During this process, the oocyte creates a set of unique chromosomes by recombining paternal and maternal copies of homologous chromosomes, and by eliminating one set of chromosomes to become haploid. While meiosis is conserved among sexually reproducing eukaryotes, there is a bewildering diversity of strategies among species, and sometimes within sexes of the same species, to achieve proper segregation of chromosomes. Here, we review the very first steps of meiosis in females, when the maternal and paternal copies of each homologous chromosomes have to move, find each other and pair. We explore the similarities and differences observed in C. elegans, Drosophila, zebrafish and mouse females.
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6
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Ohyama T. New Aspects of Magnesium Function: A Key Regulator in Nucleosome Self-Assembly, Chromatin Folding and Phase Separation. Int J Mol Sci 2019; 20:ijms20174232. [PMID: 31470631 PMCID: PMC6747271 DOI: 10.3390/ijms20174232] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 02/07/2023] Open
Abstract
Metal cations are associated with many biological processes. The effects of these cations on nucleic acids and chromatin were extensively studied in the early stages of nucleic acid and chromatin research. The results revealed that some monovalent and divalent metal cations, including Mg2+, profoundly affect the conformations and stabilities of nucleic acids, the folding of chromatin fibers, and the extent of chromosome condensation. Apart from these effects, there have only been a few reports on the functions of these cations. In 2007 and 2013, however, Mg2+-implicated novel phenomena were found: Mg2+ facilitates or enables both self-assembly of identical double-stranded (ds) DNA molecules and self-assembly of identical nucleosomes in vitro. These phenomena may be deeply implicated in the heterochromatin domain formation and chromatin-based phase separation. Furthermore, a recent study showed that elevation of the intranuclear Mg2+ concentration causes unusual differentiation of mouse ES (embryonic stem) cells. All of these phenomena seem to be closely related to one another. Mg2+ seems to be a key regulator of chromatin dynamics and chromatin-based biological processes.
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Affiliation(s)
- Takashi Ohyama
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
- Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
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7
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Wallen RM, Perlin MH. An Overview of the Function and Maintenance of Sexual Reproduction in Dikaryotic Fungi. Front Microbiol 2018; 9:503. [PMID: 29619017 PMCID: PMC5871698 DOI: 10.3389/fmicb.2018.00503] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/05/2018] [Indexed: 12/11/2022] Open
Abstract
Sexual reproduction likely evolved as protection from environmental stresses, specifically, to repair DNA damage, often via homologous recombination. In higher eukaryotes, meiosis and the production of gametes with allelic combinations different from parental type provides the side effect of increased genetic variation. In fungi it appears that while the maintenance of meiosis is paramount for success, outcrossing is not a driving force. In the subkingdom Dikarya, fungal members are characterized by existence of a dikaryon for extended stages within the life cycle. Such fungi possess functional or, in some cases, relictual, loci that govern sexual reproduction between members of their own species. All mating systems identified so far in the Dikarya employ a pheromone/receptor system for haploid organisms to recognize a compatible mating partner, although the paradigm in the Ascomycota, e.g., Saccharomyces cerevisiae, is that genes for the pheromone precursor and receptor are not found in the mating-type locus but rather are regulated by its products. Similarly, the mating systems in the Ascomycota are bipolar, with two non-allelic idiomorphs expressed in cells of opposite mating type. In contrast, for the Basidiomycota, both bipolar and tetrapolar mating systems have been well characterized; further, at least one locus directly encodes the pheromone precursor and the receptor for the pheromone of a different mating type, while a separate locus encodes proteins that may regulate the first locus and/or additional genes required for downstream events. Heterozygosity at both of two unlinked loci is required for cells to productively mate in tetrapolar systems, whereas in bipolar systems the two loci are tightly linked. Finally, a trade-off exists in wild fungal populations between sexual reproduction and the associated costs, with adverse conditions leading to mating. For fungal mammal pathogens, the products of sexual reproduction can be targets for the host immune system. The opposite appears true for phytopathogenic fungi, where mating and pathogenicity are inextricably linked. Here, we explore, compare, and contrast different strategies used among the Dikarya, both saprophytic and pathogenic fungi, and highlight differences between pathogens of mammals and pathogens of plants, providing context for selective pressures acting on this interesting group of fungi.
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Affiliation(s)
| | - Michael H. Perlin
- Department of Biology, University of Louisville, Louisville, KY, United States
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8
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Multiple Transcriptional and Post-transcriptional Pathways Collaborate to Control Sense and Antisense RNAs of Tf2 Retroelements in Fission Yeast. Genetics 2016; 205:621-632. [PMID: 28007890 DOI: 10.1534/genetics.116.193870] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/21/2016] [Indexed: 01/06/2023] Open
Abstract
Retrotransposons are mobile genetic elements that colonize eukaryotic genomes by replicating through an RNA intermediate. As retrotransposons can move within the host genome, defense mechanisms have evolved to repress their potential mutagenic activities. In the fission yeast Schizosaccharomyces pombe, the mRNA of Tf2 long terminal repeat retrotransposons is targeted for degradation by the 3'-5' exonucleolytic activity of the exosome-associated protein Rrp6. Here, we show that the nuclear poly(A)-binding protein Pab2 functions with Rrp6 to negatively control Tf2 mRNA accumulation. Furthermore, we found that Pab2/Rrp6-dependent RNA elimination functions redundantly to the transcriptional silencing mediated by the CENP-B homolog, Abp1, in the suppression of antisense Tf2 RNA accumulation. Interestingly, the absence of Pab2 attenuated the derepression of Tf2 transcription and the increased frequency of Tf2 mobilization caused by the deletion of abp1 Our data also reveal that the expression of antisense Tf2 transcripts is developmentally regulated and correlates with decreased levels of Tf2 mRNA. Our findings suggest that transcriptional and post-transcriptional pathways cooperate to control sense and antisense RNAs expressed from Tf2 retroelements.
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9
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Illner D, Lorenz A, Scherthan H. Meiotic chromosome mobility in fission yeast is resistant to environmental stress. Sci Rep 2016; 6:24222. [PMID: 27074839 PMCID: PMC4831013 DOI: 10.1038/srep24222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 03/22/2016] [Indexed: 02/06/2023] Open
Abstract
The formation of healthy gametes requires pairing of homologous chromosomes (homologs) as a prerequisite for their correct segregation during meiosis. Initially, homolog alignment is promoted by meiotic chromosome movements feeding into intimate homolog pairing by homologous recombination and/or synaptonemal complex formation. Meiotic chromosome movements in the fission yeast, Schizosaccharomyces pombe, depend on astral microtubule dynamics that drag the nucleus through the zygote; known as horsetail movement. The response of microtubule-led meiotic chromosome movements to environmental stresses such as ionizing irradiation (IR) and associated reactive oxygen species (ROS) is not known. Here, we show that, in contrast to budding yeast, the horsetail movement is largely radiation-resistant, which is likely mediated by a potent antioxidant defense. IR exposure of sporulating S. pombe cells induced misrepair and irreparable DNA double strand breaks causing chromosome fragmentation, missegregation and gamete death. Comparing radiation outcome in fission and budding yeast, and studying meiosis with poisoned microtubules indicates that the increased gamete death after IR is innate to fission yeast. Inhibition of meiotic chromosome mobility in the face of IR failed to influence the course of DSB repair, indicating that paralysis of meiotic chromosome mobility in a genotoxic environment is not a universal response among species.
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Affiliation(s)
- Doris Illner
- Institut für Radiobiologie der Bundeswehr in Verbindung mit der Universität Ulm, Neuherbergstr. 11, D-80937 München, Germany
| | - Alexander Lorenz
- Institute of Medical Sciences (IMS), University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Harry Scherthan
- Institut für Radiobiologie der Bundeswehr in Verbindung mit der Universität Ulm, Neuherbergstr. 11, D-80937 München, Germany
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10
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Lin YT, Frömberg D, Huang W, Delivani P, Chacón M, Tolić IM, Jülicher F, Zaburdaev V. Pulled Polymer Loops as a Model for the Alignment of Meiotic Chromosomes. PHYSICAL REVIEW LETTERS 2015; 115:208102. [PMID: 26613475 DOI: 10.1103/physrevlett.115.208102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Indexed: 06/05/2023]
Abstract
During recombination, the DNA of parents exchange their genetic information to give rise to a genetically unique offspring. For recombination to occur, homologous chromosomes need to find each other and align with high precision. Fission yeast solves this problem by folding chromosomes in loops and pulling them through the viscous nucleoplasm. We propose a theory of pulled polymer loops to quantify the effect of drag forces on the alignment of chromosomes. We introduce an external force field to the concept of a Brownian bridge and thus solve for the statistics of loop configurations in space.
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Affiliation(s)
- Yen Ting Lin
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, D-01187 Dresden, Germany
| | - Daniela Frömberg
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, D-01187 Dresden, Germany
| | - Wenwen Huang
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, D-01187 Dresden, Germany
| | - Petrina Delivani
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
| | - Mariola Chacón
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
| | - Iva M Tolić
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany
- Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, D-01187 Dresden, Germany
| | - Vasily Zaburdaev
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, D-01187 Dresden, Germany
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11
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Gladyshev E, Kleckner N. Direct recognition of homology between double helices of DNA in Neurospora crassa. Nat Commun 2014; 5:3509. [PMID: 24699390 PMCID: PMC4000310 DOI: 10.1038/ncomms4509] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 02/25/2014] [Indexed: 12/11/2022] Open
Abstract
Chromosomal regions of identical or nearly identical DNA sequence can preferentially associate with one another in the apparent absence of DNA breakage. Molecular mechanism(s) underlying such homology-dependent pairing phenomena remain(s) unknown. Using Neurospora crassa repeat-induced point mutation (RIP) as a model system, we show that a pair of DNA segments can be recognized as homologous if they share triplets of base pairs arrayed with the matching periodicity of 11 or 12 base pairs. This pattern suggests direct interactions between slightly underwound co-aligned DNA duplexes engaging once per turn and over many consecutive turns. The process occurs in the absence of MEI3, the only RAD51/DMC1 protein in N. crassa, demonstrating independence from the canonical homology recognition pathway. A new perspective is thus provided for further analysis of the breakage-independent recognition of homology that underlies RIP and, potentially, other processes where sequence-specific pairing of intact chromosomes is involved.
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Affiliation(s)
- Eugene Gladyshev
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Room NW140, Cambridge, Massachusetts 02138, USA
| | - Nancy Kleckner
- Department of Molecular and Cellular Biology, Harvard University, 52 Oxford Street, Room NW140, Cambridge, Massachusetts 02138, USA
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12
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Da Ines O, Gallego ME, White CI. Recombination-independent mechanisms and pairing of homologous chromosomes during meiosis in plants. MOLECULAR PLANT 2014; 7:492-501. [PMID: 24375719 DOI: 10.1093/mp/sst172] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Meiosis is the specialized eukaryotic cell division that permits the halving of ploidy necessary for gametogenesis in sexually reproducing organisms. This involves a single round of DNA replication followed by two successive divisions. To ensure balanced segregation, homologous chromosome pairs must migrate to opposite poles at the first meiotic division and this means that they must recognize and pair with each other beforehand. Although understanding of the mechanisms by which meiotic chromosomes find and pair with their homologs has greatly advanced, it remains far from being fully understood. With some notable exceptions such as male Drosophila, the recognition and physical linkage of homologs at the first meiotic division involves homologous recombination. However, in addition to this, it is clear that many organisms, including plants, have also evolved a series of recombination-independent mechanisms to facilitate homolog recognition and pairing. These implicate chromosome structure and dynamics, telomeres, centromeres, and, most recently, small RNAs. With a particular focus on plants, we present here an overview of understanding of these early, recombination-independent events that act in the pairing of homologous chromosomes during the first meiotic division.
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Affiliation(s)
- Olivier Da Ines
- Génétique, Reproduction et Développement, UMR CNRS 6293, Clermont Université, INSERM U1103, 63171 Aubière, France
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13
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Sun W, Lorenz A, Osman F, Whitby MC. A failure of meiotic chromosome segregation in a fbh1Delta mutant correlates with persistent Rad51-DNA associations. Nucleic Acids Res 2010; 39:1718-31. [PMID: 21149262 PMCID: PMC3061084 DOI: 10.1093/nar/gkq977] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The F-box DNA helicase Fbh1 constrains homologous recombination in vegetative cells, most likely through an ability to displace the Rad51 recombinase from DNA. Here, we provide the first evidence that Fbh1 also serves a vital meiotic role in fission yeast to promote normal chromosome segregation. In the absence of Fbh1, chromosomes remain entangled or segregate unevenly during meiosis, and genetic and cytological data suggest that this results in part from a failure to efficiently dismantle Rad51 nucleofilaments that form during meiotic double-strand break repair.
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Affiliation(s)
- Weili Sun
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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14
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Fungal meiosis and parasexual reproduction--lessons from pathogenic yeast. Curr Opin Microbiol 2009; 12:599-607. [PMID: 19892588 DOI: 10.1016/j.mib.2009.09.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 09/09/2009] [Accepted: 09/14/2009] [Indexed: 12/15/2022]
Abstract
Meiosis is an integral part of sexual reproduction in eukaryotic species. It performs the dual functions of halving the genetic content in the cell, as well as increasing genetic diversity by promoting recombination between chromosome homologs. Despite extensive studies of meiosis in model yeast, it is now apparent that both the regulation of meiosis and the machinery mediating recombination have significantly diverged, even between closely related species. To highlight this, we discuss new studies on sex in Candida species, a diverse collection of hemiascomycetes that are related to Saccharomyces cerevisiae and are important human pathogens. These provide new insights into the most conserved, as well as the most plastic, aspects of meiosis, meiotic recombination, and related parasexual processes.
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15
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Dorsett M, Schedl T. A role for dynein in the inhibition of germ cell proliferative fate. Mol Cell Biol 2009; 29:6128-39. [PMID: 19752194 PMCID: PMC2772574 DOI: 10.1128/mcb.00815-09] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 07/24/2009] [Accepted: 09/08/2009] [Indexed: 01/30/2023] Open
Abstract
During normal development as well as in diseased states such as cancer, extracellular "niches" often provide cues to proximal cells and activate intracellular pathways. Activation of such signaling pathways in turn instructs cellular proliferation and differentiation. In the Caenorhabditis elegans gonad, GLP-1/Notch signaling instructs germ line stem cells to self-renew through mitotic cell division. As germ cells progressively move out of the niche, they differentiate by entering meiosis and eventually form gametes. In this model system, we uncovered an unexpected role for the dynein motor complex in promoting normal differentiation of proliferating germ cells. We demonstrate that dynein light chain 1 (DLC-1) and its partner, dynein heavy chain 1, inhibit the proliferative cell fate, in part through regulation of METT-10, a conserved putative methyltransferase. We show that DLC-1 physically interacts with METT-10 and promotes both its overall levels and nuclear accumulation. Our results add a new dimension to the processes controlled by the dynein motor complex, demonstrating that dynein can act as an antiproliferative factor.
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Affiliation(s)
- Maia Dorsett
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, 63110
| | - Tim Schedl
- Department of Genetics, Washington University School of Medicine, Saint Louis, Missouri, 63110
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16
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Koszul R, Kleckner N. Dynamic chromosome movements during meiosis: a way to eliminate unwanted connections? Trends Cell Biol 2009; 19:716-24. [PMID: 19854056 DOI: 10.1016/j.tcb.2009.09.007] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 09/15/2009] [Accepted: 09/22/2009] [Indexed: 01/14/2023]
Abstract
Dramatic chromosome motion is a characteristic of mid-prophase of meiosis that is observed across broadly divergent eukaryotic phyla. Although the specific mechanisms underlying chromosome motions vary among organisms studied to date, the outcome is similar in all cases: vigorous back-and-forth movement (as fast as approximately 1mum/sec for budding yeast), led by chromosome ends (or near-end regions), and directed by cytoskeletal components via direct association through the nuclear envelope. The exact role(s) of these movements remains unknown, although an idea gaining currency is that movement serves as a stringency factor, eliminating unwanted inter-chromosomal associations or entanglements that have arisen as part of the homolog pairing process and, potentially, unwanted associations of chromatin with the nuclear envelope. Turbulent chromosome movements observed during bipolar orientation of chromosomes for segregation could also serve similar roles during mitosis. Recent advances shed light on the contribution of protein complexes involved in the meiotic movements in chromosome dynamics during the mitotic program.
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Affiliation(s)
- Romain Koszul
- CNRS URA2171, Institut Pasteur, Unité de Génétique Moléculaire des Levures, 25 rue du Dr. Roux, 75015 Paris, France
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Wahls WP, Davidson MK. Low-copy episomal vector pFY20 and high-saturation coverage genomic libraries for the fission yeast Schizosaccharomyces pombe. Yeast 2008; 25:643-50. [PMID: 18613214 DOI: 10.1002/yea.1605] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In fission yeast, as in many organisms, episomally replicating plasmid DNA molecules can be used for a wide variety of applications. However, replicating plasmids described previously are each propagated at a high copy number per cell. Plasmid fission yeast twenty (pFY20) contains the ura4(+) gene for positive and negative selection, an origin of replication (ars1) and a stability element (stb). Although this plasmid does not have a centromere, it is propagated with a copy number of about two plasmids per haploid genome equivalent and it is transmitted with relatively high fidelity in mitosis and meiosis. This low-copy vector is useful for screens and mutational studies where overexpression (e.g. from high copy plasmids) is undesirable. We therefore constructed multiple partial-digest, size-fractionated, fission yeast genomic DNA libraries in pFY20 and in the cloning vector pBluescript KS(+). These libraries have sufficient complexity (average of 2100 genome equivalents each) for saturation screening by complementation, plasmid shuffle or hybridization.
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Affiliation(s)
- Wayne P Wahls
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205-7199, USA
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Davis L, Rozalén AE, Moreno S, Smith GR, Martín-Castellanos C. Rec25 and Rec27, novel linear-element components, link cohesin to meiotic DNA breakage and recombination. Curr Biol 2008; 18:849-54. [PMID: 18514516 PMCID: PMC3119532 DOI: 10.1016/j.cub.2008.05.025] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 04/18/2008] [Accepted: 05/02/2008] [Indexed: 01/12/2023]
Abstract
Meiosis is a specialized nuclear division by which sexually reproducing diploid organisms generate haploid gametes. Recombination between homologous chromosomes facilitates accurate meiotic chromosome segregation and is initiated by DNA double-strand breaks (DSBs) made by the conserved topoisomerase-like protein Spo11 (Rec12 in fission yeast), but DSBs are not evenly distributed across the genome. In Schizosaccharomyces pombe, proteinaceous structures known as linear elements (LinEs) are formed during meiotic prophase. The meiosis-specific cohesin subunits Rec8 and Rec11 are essential for DSB formation in some regions of the genome, as well as for formation of LinEs or the related synaptonemal complex (SC) in other eukaryotes. Proteins required for DSB formation decorate LinEs, and mutants lacking Rec10, a major component of LinEs, are completely defective for recombination. Although recombination may occur in the context of LinEs, it is not well understood how Rec10 is loaded onto chromosomes. We describe two novel components of LinEs in fission yeast, Rec25 and Rec27. Comparisons of rec25Delta, rec27Delta, and rec10Delta mutants suggest multiple pathways to load Rec10. In the major pathway, Rec10 is loaded, together with Rec25 and Rec27, in a Rec8-dependent manner with subsequent region-specific effects on recombination.
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Affiliation(s)
- Luther Davis
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, U.S.A
| | - Ana E. Rozalén
- Instituto de Biología Molecular y Celular del Cáncer, CSIC/Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Sergio Moreno
- Instituto de Biología Molecular y Celular del Cáncer, CSIC/Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Gerald R. Smith
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, U.S.A
| | - Cristina Martín-Castellanos
- Instituto de Biología Molecular y Celular del Cáncer, CSIC/Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
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The anaphase-promoting complex/cyclosome controls repair and recombination by ubiquitylating Rhp54 in fission yeast. Mol Cell Biol 2008; 28:3905-16. [PMID: 18426916 DOI: 10.1128/mcb.02116-07] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Homologous recombination (HR) is important for maintaining genome integrity and for the process of meiotic chromosome segregation and the generation of variation. HR is regulated throughout the cell cycle, being prevalent in the S and G2 phases and suppressed in the G1 phase. Here we show that the anaphase-promoting complex/cyclosome (APC/C) regulates homologous recombination in the fission yeast Schizosaccharomyces pombe by ubiquitylating Rhp54 (an ortholog of Rad54). We show that Rhp54 is a novel APC/C substrate that is destroyed in G1 phase in a KEN-box- and Ste9/Fizzy-related manner. The biological consequences of failing to temporally regulate HR via Rhp54 degradation are seen in haploid cells only in the absence of antirecombinase Srs2 function and are more extensive in diploid cells, which become sensitive to a range of DNA-damaging agents, including hydroxyurea, methyl methanesulfonate, bleomycin, and UV. During meiosis, expression of nondegradable Rhp54 inhibits interhomolog recombination and stimulates sister chromatid recombination. We thus propose that it is critical to control levels of Rhp54 in G1 to suppress HR repair of double-strand breaks and during meiosis to coordinate interhomolog recombination.
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20
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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21
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Wells JL, Pryce DW, Estreicher A, Loidl J, McFarlane RJ. Linear element-independent meiotic recombination in Schizosaccharomyces pombe. Genetics 2006; 174:1105-14. [PMID: 16980386 PMCID: PMC1667095 DOI: 10.1534/genetics.106.063818] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Most organisms form protein-rich, linear, ladder-like structures associated with chromosomes during early meiosis, the synaptonemal complex. In Schizosaccharomyces pombe, linear elements (LinEs) are thread-like, proteinacious chromosome-associated structures that form during early meiosis. LinEs are related to axial elements, the synaptonemal complex precursors of other organisms. Previous studies have led to the suggestion that axial structures are essential to mediate meiotic recombination. Rec10 protein is a major component of S. pombe LinEs and is required for their development. In this report we study recombination in a number of rec10 mutants, one of which (rec10-155) does not form LinEs, but is predicted to encode a truncated Rec10 protein. This mutant has levels of crossing over and gene conversion substantially higher than a rec10 null mutant (rec10-175) and forms cytologically detectable Rad51 foci indicative of meiotic recombination intermediates. These data demonstrate that while Rec10 is required for meiotic recombination, substantial meiotic recombination can occur in rec10 mutants that do not form LinEs, indicating that LinEs per se are not essential for all meiotic recombination.
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Affiliation(s)
- Jennifer L Wells
- North West Research Fund Institute, University of Wales, Bangor, UK
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