1
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Gong T, McNally KL, Konanoor S, Peraza A, Bailey C, Redemann S, McNally FJ. Roles of Tubulin Concentration during Prometaphase and Ran-GTP during Anaphase of Caenorhabditis elegans Meiosis. Life Sci Alliance 2024; 7:e202402884. [PMID: 38960623 PMCID: PMC11222656 DOI: 10.26508/lsa.202402884] [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: 06/12/2024] [Revised: 06/25/2024] [Accepted: 06/26/2024] [Indexed: 07/05/2024] Open
Abstract
In many animal species, the oocyte meiotic spindle, which is required for chromosome segregation, forms without centrosomes. In some systems, Ran-GEF on chromatin initiates spindle assembly. We found that in Caenorhabditis elegans oocytes, endogenously-tagged Ran-GEF dissociates from chromatin during spindle assembly but re-associates during meiotic anaphase. Meiotic spindle assembly occurred after auxin-induced degradation of Ran-GEF, but anaphase I was faster than controls and extrusion of the first polar body frequently failed. In search of a possible alternative pathway for spindle assembly, we found that soluble tubulin concentrates in the nuclear volume during germinal vesicle breakdown. We found that the concentration of soluble tubulin in the metaphase spindle region is enclosed by ER sheets which exclude cytoplasmic organelles including mitochondria and yolk granules. Measurement of the volume occupied by yolk granules and mitochondria indicated that volume exclusion would be sufficient to explain the concentration of tubulin in the spindle volume. We suggest that this concentration of soluble tubulin may be a redundant mechanism promoting spindle assembly near chromosomes.
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Affiliation(s)
- Ting Gong
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Karen L McNally
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Siri Konanoor
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Alma Peraza
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Cynthia Bailey
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Stefanie Redemann
- https://ror.org/0153tk833 Department of Cell Biology, University of Virginia, School of Medicine, Charlottesville, VA, USA
| | - Francis J McNally
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
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2
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Wu T, Luo Y, Zhang M, Chen B, Du X, Gu H, Xie S, Pan Z, Yu R, Hai R, Niu X, Hao G, Jin L, Shi J, Sun X, Kuang Y, Li W, Sang Q, Wang L. Mechanisms of minor pole-mediated spindle bipolarization in human oocytes. Science 2024; 385:eado1022. [PMID: 39172836 DOI: 10.1126/science.ado1022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/29/2024] [Accepted: 07/02/2024] [Indexed: 08/24/2024]
Abstract
Spindle bipolarization, the process of a microtubule mass transforming into a bipolar spindle, is a prerequisite for accurate chromosome segregation. In contrast to mitotic cells, the process and mechanism of spindle bipolarization in human oocytes remains unclear. Using high-resolution imaging in more than 1800 human oocytes, we revealed a typical state of multipolar intermediates that form during spindle bipolarization and elucidated the mechanism underlying this process. We found that the minor poles formed in multiple kinetochore clusters contribute to the generation of multipolar intermediates. We further determined the essential roles of HAUS6, KIF11, and KIF18A in spindle bipolarization and identified mutations in these genes in infertile patients characterized by oocyte or embryo defects. These results provide insights into the physiological and pathological mechanisms of spindle bipolarization in human oocytes.
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Affiliation(s)
- Tianyu Wu
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Yuxi Luo
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Meiling Zhang
- Center for Reproductive Medicine and Fertility Preservation Program, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Biaobang Chen
- NHC Key Lab of Reproduction Regulation, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Fudan University, Shanghai 200032, China
| | - Xingzhu Du
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Hao Gu
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Siyuan Xie
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Zhiqi Pan
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Ran Yu
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Ruiqi Hai
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Xiangli Niu
- Reproductive Hospital of Guangxi Zhuang Autonomous Region, Nanning 530029, China
| | - Guimin Hao
- Hebei Clinical Research Center for Birth Defects, Department of Reproductive Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China
| | - Liping Jin
- Laboratory for Reproductive Immunology, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, China
| | - Juanzi Shi
- Assisted Reproduction Center, Northwest Women's and Children's Hospital, Xi'an 710003, China
| | - Xiaoxi Sun
- Shanghai JIAI Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, China
| | - Yanping Kuang
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Wen Li
- Center for Reproductive Medicine and Fertility Preservation Program, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Qing Sang
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Lei Wang
- Institute of Pediatrics, Children's Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
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3
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Blengini CS, Vaskovicova M, Schier J, Drutovic D, Schindler K. Spatio-temporal requirements of Aurora kinase A in mouse oocyte meiotic spindle building. iScience 2024; 27:110451. [PMID: 39081293 PMCID: PMC11284559 DOI: 10.1016/j.isci.2024.110451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/30/2024] [Accepted: 07/01/2024] [Indexed: 08/02/2024] Open
Abstract
Meiotic spindles are critical to ensure chromosome segregation during gamete formation. Oocytes lack centrosomes and use alternative microtubule-nucleation mechanisms for spindle building. How these mechanisms are regulated is still unknown. Aurora kinase A (AURKA) is essential for mouse oocyte meiosis because in pro-metaphase I it triggers microtubule organizing-center fragmentation and its expression compensates for the loss of the two other Aurora kinases (AURKB/AURKC). Although knockout mouse models were useful for foundational studies, AURK spatial and temporal functions are not yet resolved. We provide high-resolution analyses of AURKA/AURKC requirements during meiotic spindle-building and identify the subcellular populations that carry out these functions: 1) AURKA is required in early spindle assembly and later for spindle stability, whereas 2) AURKC is required in late pro-metaphase, and 3) Targeted AURKA constructs expressed in triple AURK knockout oocytes reveal that spindle pole-localized AURKA is the most important population controlling spindle building and stability mechanisms.
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Affiliation(s)
- Cecilia S. Blengini
- Department of Genetics, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
- Human Genetics Institute of New Jersey, Piscataway, NJ 08854, USA
| | - Michaela Vaskovicova
- Laboratory of DNA Integrity, Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Libechov, Czech Republic
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jan Schier
- The Czech Academy of Sciences, Institute of Information Theory and Automation, Piscataway, NJ 08854, USA
| | - David Drutovic
- Laboratory of DNA Integrity, Institute of Animal Physiology and Genetics of the Czech Academy of Sciences, Libechov, Czech Republic
| | - Karen Schindler
- Department of Genetics, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA
- Human Genetics Institute of New Jersey, Piscataway, NJ 08854, USA
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4
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Cantwell H, Nguyen H, Kettenbach A, Heald R. Spindle morphology changes between meiosis and mitosis driven by CK2 regulation of the Ran pathway. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.25.605073. [PMID: 39211121 PMCID: PMC11361180 DOI: 10.1101/2024.07.25.605073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The transition from meiotic divisions in the oocyte to embryonic mitoses is a critical step in animal development. Despite negligible changes to cell size and shape, following fertilization the small, barrel-shaped meiotic spindle is replaced by a large zygotic spindle that nucleates abundant astral microtubules at spindle poles. To probe underlying mechanisms, we applied a drug screening approach using Ciona eggs and found that inhibition of Casein Kinase 2 (CK2) caused a shift from meiotic to mitotic-like spindle morphology with nucleation of robust astral microtubules, an effect reproduced in cytoplasmic extracts prepared from Xenopus eggs. In both species, CK2 activity decreased at fertilization. Phosphoproteomic differences between Xenopus meiotic and mitotic extracts that also accompanied CK2 inhibition pointed to RanGTP-regulated factors as potential targets. Interfering with RanGTP-driven microtubule formation suppressed astral microtubule growth caused by CK2 inhibition. These data support a model in which CK2 activity attenuation at fertilization leads to activation of RanGTP-regulated microtubule effectors that induce mitotic spindle morphology.
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5
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Gong T, McNally KL, Konanoor S, Peraza A, Bailey C, Redemann S, McNally FJ. Roles of Tubulin Concentration during Prometaphase and Ran-GTP during Anaphase of C. elegans meiosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.19.590357. [PMID: 38659754 PMCID: PMC11042349 DOI: 10.1101/2024.04.19.590357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
In many animal species, the oocyte meiotic spindle, which is required for chromosome segregation, forms without centrosomes. In some systems, Ran-GEF on chromatin initiates spindle assembly. We found that in C. elegans oocytes, endogenously-tagged Ran-GEF dissociates from chromatin during spindle assembly but re-associates during meiotic anaphase. Meiotic spindle assembly occurred after auxin-induced degradation of Ran-GEF but anaphase I was faster than controls and extrusion of the first polar body frequently failed. In search of a possible alternative pathway for spindle assembly, we found that soluble tubulin concentrates in the nuclear volume during germinal vesicle breakdown. We found that the concentration of soluble tubulin in the metaphase spindle region is enclosed by ER sheets which exclude cytoplasmic organelles including mitochondria and yolk granules. Measurement of the volume occupied by yolk granules and mitochondria indicated that volume exclusion would be sufficient to explain the concentration of tubulin in the spindle volume. We suggest that this concentration of soluble tubulin may be a redundant mechanism promoting spindle assembly near chromosomes.
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Affiliation(s)
- Ting Gong
- Department of Molecular and Cellular Biology, university of California, Davis, Davis, CA 95616, USA
| | - Karen L McNally
- Department of Molecular and Cellular Biology, university of California, Davis, Davis, CA 95616, USA
| | - Siri Konanoor
- Department of Molecular and Cellular Biology, university of California, Davis, Davis, CA 95616, USA
| | - Alma Peraza
- Department of Molecular and Cellular Biology, university of California, Davis, Davis, CA 95616, USA
| | - Cynthia Bailey
- Department of Molecular and Cellular Biology, university of California, Davis, Davis, CA 95616, USA
| | - Stefanie Redemann
- Department of Cell Biology, University of Virginia, School of Medicine, Charlottesville, VA, USA
| | - Francis J McNally
- Department of Molecular and Cellular Biology, university of California, Davis, Davis, CA 95616, USA
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6
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Ju JQ, Zhang HL, Wang Y, Hu LL, Sun SC. Kinesin KIFC3 is essential for microtubule stability and cytokinesis in oocyte meiosis. Cell Commun Signal 2024; 22:199. [PMID: 38553728 PMCID: PMC10979585 DOI: 10.1186/s12964-024-01589-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/23/2024] [Indexed: 04/02/2024] Open
Abstract
KIFC3 is a member of Kinesin-14 family motor proteins, which play a variety of roles such as centrosome cohesion, cytokinesis, vesicles transportation and cell proliferation in mitosis. Here, we investigated the functional roles of KIFC3 in meiosis. Our findings demonstrated that KIFC3 exhibited expression and localization at centromeres during metaphase I, followed by translocation to the midbody at telophase I throughout mouse oocyte meiosis. Disruption of KIFC3 activity resulted in defective polar body extrusion. We observed aberrant meiotic spindles and misaligned chromosomes, accompanied by the loss of kinetochore-microtubule attachment, which might be due to the failed recruitment of BubR1/Bub3. Coimmunoprecipitation data revealed that KIFC3 plays a crucial role in maintaining the acetylated tubulin level mediated by Sirt2, thereby influencing microtubule stability. Additionally, our findings demonstrated an interaction between KIFC3 and PRC1 in regulating midbody formation during telophase I, which is involved in cytokinesis regulation. Collectively, these results underscore the essential contribution of KIFC3 to spindle assembly and cytokinesis during mouse oocyte meiosis.
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Affiliation(s)
- Jia-Qian Ju
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hao-Lin Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yue Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Lin-Lin Hu
- Key Laboratory of Research on Clinical Molecular Diagnosis for High Incidence Diseases in Western Guangxi, Reproductive Medicine, Guangxi Medical and Health Key Discipline Construction Project, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, China.
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
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7
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LaFountain JR, Seaman CE, Cohan CS, Oldenbourg R. Sliding of antiparallel microtubules drives bipolarization of monoastral spindles. Cytoskeleton (Hoboken) 2024; 81:167-183. [PMID: 37812128 PMCID: PMC11172411 DOI: 10.1002/cm.21800] [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: 08/02/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/10/2023]
Abstract
Time-lapse imaging with liquid crystal polarized light (LC-PolScope) and fluorescent speckle microscopy (FSM) enabled this study of spindle microtubules in monoastral spindles that were produced in crane-fly spermatocytes through flattening-induced centrosome displacement. Monoastral spindles are found in several other contexts: after laser ablation of one of a cell's two centrosomes (in the work of Khodjakov et al.), in Drosophila "urchin" mutants (in the works of Heck et al. and of Wilson et al.), in Sciara males (in the works of Fuge and of Metz), and in RNAi variants of Drosophila S2 cells (in the work of Goshima et al.). In all cases, just one pole has a centrosome (the astral pole); the other lacks a centrosome (the anastral pole). Thus, the question: How is the anastral half-spindle, lacking a centrosome, constructed? We learned that monoastral spindles are assembled in two phases: Phase I assembles the astral half-spindle composed of centrosomal microtubules, and Phase II assembles microtubules of the anastral half through extension of new microtubule polymerization outward from the spindle's equatorial mid-zone. That process uses plus ends of existing centrosomal microtubules as guiding templates to assemble anastral microtubules of opposite polarity. Anastral microtubules slide outward with their minus ends leading, thereby establishing proper bipolarity just like in normal biastral spindles that have two centrosomes.
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Affiliation(s)
- James R LaFountain
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, USA
| | - Catherine E Seaman
- Department of Biological Sciences, University at Buffalo, Buffalo, New York, USA
| | - Christopher S Cohan
- Department of Pathology and Anatomy, University at Buffalo, Buffalo, New York, USA
| | - Rudolf Oldenbourg
- Eugene Bell Center, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
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8
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Kiyomitsu A, Nishimura T, Hwang SJ, Ansai S, Kanemaki MT, Tanaka M, Kiyomitsu T. Ran-GTP assembles a specialized spindle structure for accurate chromosome segregation in medaka early embryos. Nat Commun 2024; 15:981. [PMID: 38302485 PMCID: PMC10834446 DOI: 10.1038/s41467-024-45251-w] [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: 07/09/2023] [Accepted: 01/19/2024] [Indexed: 02/03/2024] Open
Abstract
Despite drastic cellular changes during cleavage, a mitotic spindle assembles in each blastomere to accurately segregate duplicated chromosomes. Mechanisms of mitotic spindle assembly have been extensively studied using small somatic cells. However, mechanisms of spindle assembly in large vertebrate embryos remain little understood. Here, we establish functional assay systems in medaka (Oryzias latipes) embryos by combining CRISPR knock-in with auxin-inducible degron technology. Live imaging reveals several unexpected features of microtubule organization and centrosome positioning that achieve rapid, accurate cleavage. Importantly, Ran-GTP assembles a dense microtubule network at the metaphase spindle center that is essential for chromosome segregation in early embryos. This unique spindle structure is remodeled into a typical short, somatic-like spindle after blastula stages, when Ran-GTP becomes dispensable for chromosome segregation. We propose that despite the presence of centrosomes, the chromosome-derived Ran-GTP pathway has essential roles in functional spindle assembly in large, rapidly dividing vertebrate early embryos, similar to acentrosomal spindle assembly in oocytes.
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Affiliation(s)
- Ai Kiyomitsu
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Toshiya Nishimura
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan
- Hokkaido University Fisheries Sciences, 3-1-1, Minato-cho, Hakodate, Hokkaido, 041-8611, Japan
| | - Shiang Jyi Hwang
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Satoshi Ansai
- Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, 980-8577, Japan
- Laboratory of Genome Editing Breeding, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8507, Japan
| | - Masato T Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), and Graduate Institute for Advanced Studies, SOKENDAI, Yata 1111, Mishima, Shizuoka, 411-8540, Japan
- Department of Biological Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Minoru Tanaka
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Tomomi Kiyomitsu
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan.
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9
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Biswas L, Schindler K. Predicting Infertility: How Genetic Variants in Oocyte Spindle Genes Affect Egg Quality. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2024; 238:1-22. [PMID: 39030352 DOI: 10.1007/978-3-031-55163-5_1] [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] [Indexed: 07/21/2024]
Abstract
Successful reproduction relies on the union of a single chromosomally normal egg and sperm. Chromosomally normal eggs develop from precursor cells, called oocytes, that have undergone accurate chromosome segregation. The process of chromosome segregation is governed by the oocyte spindle, a unique cytoskeletal machine that splits chromatin content of the meiotically dividing oocyte. The oocyte spindle develops and functions in an idiosyncratic process, which is vulnerable to genetic variation in spindle-associated proteins. Human genetic variants in several spindle-associated proteins are associated with poor clinical fertility outcomes, suggesting that heritable etiologies for oocyte dysfunction leading to infertility exist and that the spindle is a crux for female fertility. This chapter examines the mammalian oocyte spindle through the lens of human genetic variation, covering the genes TUBB8, TACC3, CEP120, AURKA, AURKC, AURKB, BUB1B, and CDC20. Specifically, it explores how patient-identified variants perturb spindle development and function, and it links these molecular changes in the oocyte to their cognate clinical consequences, such as oocyte maturation arrest, elevated egg aneuploidy, primary ovarian insufficiency, and recurrent pregnancy loss. This discussion demonstrates that small genetic errors in oocyte meiosis can result in remarkably far-ranging embryonic consequences, and thus reveals the importance of the oocyte's fine machinery in sustaining life.
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Affiliation(s)
- Leelabati Biswas
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Human Genetics Institute of New Jersey, Piscataway, NJ, USA
- Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Karen Schindler
- Department of Genetics, Rutgers University, Piscataway, NJ, USA.
- Human Genetics Institute of New Jersey, Piscataway, NJ, USA.
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10
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Guo Y, Sun H, Chen H, Yang G, Wang J, Qi Z, Pang W, Chu G, Gao L. Vitrification induces a focused spindle pole in mouse MI oocytes. Theriogenology 2023; 211:232-240. [PMID: 37660475 DOI: 10.1016/j.theriogenology.2023.08.020] [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] [Received: 06/15/2023] [Revised: 08/23/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023]
Abstract
Immature oocyte (germinal vesicle stage, GV) vitrification can avoid a cycle of ovarian stimulation, which is friendly to patients with hormone-sensitive tumors. However, the in vitro maturation of vitrification-thawed GV oocyte usually results in aneuploidy, and the underlying mechanism remains unclear. Stable spindle poles are important for accurate chromosome segregation. Acentriolar microtubule-organizing centers (aMTOCs) undergo fragmentation and reaggregation to form spindle poles. Microtubule nucleation is facilitated via the perichromosome Ran after GVBD, which plays an important role in aMTOCs fragmentation. This study showed that vitrification may reduce microtubule density by decreasing perichromosomal Ran levels, which reduced the localization of pKIF11, thereby decreased the fragmentation of aMTOCs and formed a more focused spindle pole, ultimately resulted in aneuploidy. This study revealed the mechanism of abnormal spindle pole formation in vitrified oocytes and offered a theoretical support to further improve the quality of vitrified oocytes.
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Affiliation(s)
- Yaoyao Guo
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Haowei Sun
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Hui Chen
- Animal Husbandry Industry Test and Demonstration Center of Shaanxi Province, Jingyang, 713708, Shaanxi, China.
| | - Gongshe Yang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Jialun Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Zhengjun Qi
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Weijun Pang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Guiyan Chu
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Lei Gao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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11
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Pelzer D, de Plater L, Bradbury P, Eichmuller A, Bourdais A, Halet G, Maître J. Cell fragmentation in mouse preimplantation embryos induced by ectopic activation of the polar body extrusion pathway. EMBO J 2023; 42:e114415. [PMID: 37427462 PMCID: PMC10476277 DOI: 10.15252/embj.2023114415] [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: 05/02/2023] [Revised: 06/13/2023] [Accepted: 06/22/2023] [Indexed: 07/11/2023] Open
Abstract
Cell fragmentation is commonly observed in human preimplantation embryos and is associated with poor prognosis during assisted reproductive technology (ART) procedures. However, the mechanisms leading to cell fragmentation remain largely unknown. Here, light sheet microscopy imaging of mouse embryos reveals that inefficient chromosome separation due to spindle defects, caused by dysfunctional molecular motors Myo1c or dynein, leads to fragmentation during mitosis. Extended exposure of the cell cortex to chromosomes locally triggers actomyosin contractility and pinches off cell fragments. This process is reminiscent of meiosis, during which small GTPase-mediated signals from chromosomes coordinate polar body extrusion (PBE) by actomyosin contraction. By interfering with the signals driving PBE, we find that this meiotic signaling pathway remains active during cleavage stages and is both required and sufficient to trigger fragmentation. Together, we find that fragmentation happens in mitosis after ectopic activation of actomyosin contractility by signals emanating from DNA, similar to those observed during meiosis. Our study uncovers the mechanisms underlying fragmentation in preimplantation embryos and, more generally, offers insight into the regulation of mitosis during the maternal-zygotic transition.
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Affiliation(s)
- Diane Pelzer
- Institut CuriePSL Research University, CNRS UMR 3215, INSERM U934ParisFrance
| | - Ludmilla de Plater
- Institut CuriePSL Research University, CNRS UMR 3215, INSERM U934ParisFrance
| | - Peta Bradbury
- Institut CuriePSL Research University, CNRS UMR 3215, INSERM U934ParisFrance
| | - Adrien Eichmuller
- Institut CuriePSL Research University, CNRS UMR 3215, INSERM U934ParisFrance
| | - Anne Bourdais
- Institut de Génétique et Développement de RennesUniversité de Rennes, CNRS UMR 6290RennesFrance
| | - Guillaume Halet
- Institut de Génétique et Développement de RennesUniversité de Rennes, CNRS UMR 6290RennesFrance
| | - Jean‐Léon Maître
- Institut CuriePSL Research University, CNRS UMR 3215, INSERM U934ParisFrance
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12
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Valdez VA, Neahring L, Petry S, Dumont S. Mechanisms underlying spindle assembly and robustness. Nat Rev Mol Cell Biol 2023; 24:523-542. [PMID: 36977834 PMCID: PMC10642710 DOI: 10.1038/s41580-023-00584-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2023] [Indexed: 03/30/2023]
Abstract
The microtubule-based spindle orchestrates chromosome segregation during cell division. Following more than a century of study, many components and pathways contributing to spindle assembly have been described, but how the spindle robustly assembles remains incompletely understood. This process involves the self-organization of a large number of molecular parts - up to hundreds of thousands in vertebrate cells - whose local interactions give rise to a cellular-scale structure with emergent architecture, mechanics and function. In this Review, we discuss key concepts in our understanding of spindle assembly, focusing on recent advances and the new approaches that enabled them. We describe the pathways that generate the microtubule framework of the spindle by driving microtubule nucleation in a spatially controlled fashion and present recent insights regarding the organization of individual microtubules into structural modules. Finally, we discuss the emergent properties of the spindle that enable robust chromosome segregation.
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Affiliation(s)
| | - Lila Neahring
- Department of Bioengineering & Therapeutic Sciences, UCSF, San Francisco, CA, USA
- Developmental & Stem Cell Biology Graduate Program, UCSF, San Francisco, CA, USA
| | - Sabine Petry
- Molecular Biology, Princeton University, Princeton, NJ, USA.
| | - Sophie Dumont
- Department of Bioengineering & Therapeutic Sciences, UCSF, San Francisco, CA, USA.
- Developmental & Stem Cell Biology Graduate Program, UCSF, San Francisco, CA, USA.
- Department of Biochemistry & Biophysics, UCSF, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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13
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Gouveia B, Setru SU, King MR, Hamlin A, Stone HA, Shaevitz JW, Petry S. Acentrosomal spindles assemble from branching microtubule nucleation near chromosomes in Xenopus laevis egg extract. Nat Commun 2023; 14:3696. [PMID: 37344488 DOI: 10.1038/s41467-023-39041-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/08/2023] [Indexed: 06/23/2023] Open
Abstract
Microtubules are generated at centrosomes, chromosomes, and within spindles during cell division. Whereas microtubule nucleation at the centrosome is well characterized, much remains unknown about where, when, and how microtubules are nucleated at chromosomes. To address these questions, we reconstitute microtubule nucleation from purified chromosomes in meiotic Xenopus egg extract and find that chromosomes alone can form spindles. We visualize microtubule nucleation near chromosomes using total internal reflection fluorescence microscopy to find that this occurs through branching microtubule nucleation. By inhibiting molecular motors, we find that the organization of the resultant polar branched networks is consistent with a theoretical model where the effectors for branching nucleation are released by chromosomes, forming a concentration gradient that spatially biases branching microtbule nucleation. In the presence of motors, these branched networks are ultimately organized into functional spindles, where the number of emergent spindle poles scales with the number of chromosomes and total chromatin area.
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Affiliation(s)
- Bernardo Gouveia
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Sagar U Setru
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
| | - Matthew R King
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Aaron Hamlin
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Joshua W Shaevitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
- Department of Physics, Princeton University, Princeton, NJ, 08544, USA
| | - Sabine Petry
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
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14
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Jiang Y, Adhikari D, Li C, Zhou X. Spatiotemporal regulation of maternal mRNAs during vertebrate oocyte meiotic maturation. Biol Rev Camb Philos Soc 2023; 98:900-930. [PMID: 36718948 DOI: 10.1111/brv.12937] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 02/01/2023]
Abstract
Vertebrate oocytes face a particular challenge concerning the regulation of gene expression during meiotic maturation. Global transcription becomes quiescent in fully grown oocytes, remains halted throughout maturation and fertilization, and only resumes upon embryonic genome activation. Hence, the oocyte meiotic maturation process is largely regulated by protein synthesis from pre-existing maternal messenger RNAs (mRNAs) that are transcribed and stored during oocyte growth. Rapidly developing genome-wide techniques have greatly expanded our insights into the global translation changes and possible regulatory mechanisms during oocyte maturation. The storage, translation, and processing of maternal mRNAs are thought to be regulated by factors interacting with elements in the mRNA molecules. Additionally, posttranscriptional modifications of mRNAs, such as methylation and uridylation, have recently been demonstrated to play crucial roles in maternal mRNA destabilization. However, a comprehensive understanding of the machineries that regulate maternal mRNA fate during oocyte maturation is still lacking. In particular, how the transcripts of important cell cycle components are stabilized, recruited at the appropriate time for translation, and eliminated to modulate oocyte meiotic progression remains unclear. A better understanding of these mechanisms will provide invaluable insights for the preconditions of developmental competence acquisition, with important implications for the treatment of infertility. This review discusses how the storage, localization, translation, and processing of oocyte mRNAs are regulated, and how these contribute to oocyte maturation progression.
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Affiliation(s)
- Yanwen Jiang
- College of Animal Science, Jilin University, 5333 Xian Road, Changchun, 130062, China
| | - Deepak Adhikari
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, 19 Innovation Walk, Melbourne, VIC, 3800, Australia
| | - Chunjin Li
- College of Animal Science, Jilin University, 5333 Xian Road, Changchun, 130062, China
| | - Xu Zhou
- College of Animal Science, Jilin University, 5333 Xian Road, Changchun, 130062, China
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15
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Crozet F, Letort G, Bulteau R, Da Silva C, Eichmuller A, Tortorelli AF, Blévinal J, Belle M, Dumont J, Piolot T, Dauphin A, Coulpier F, Chédotal A, Maître JL, Verlhac MH, Clarke HJ, Terret ME. Filopodia-like protrusions of adjacent somatic cells shape the developmental potential of oocytes. Life Sci Alliance 2023; 6:e202301963. [PMID: 36944420 PMCID: PMC10029974 DOI: 10.26508/lsa.202301963] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/07/2023] [Accepted: 03/07/2023] [Indexed: 03/23/2023] Open
Abstract
The oocyte must grow and mature before fertilization, thanks to a close dialogue with the somatic cells that surround it. Part of this communication is through filopodia-like protrusions, called transzonal projections (TZPs), sent by the somatic cells to the oocyte membrane. To investigate the contribution of TZPs to oocyte quality, we impaired their structure by generating a full knockout mouse of the TZP structural component myosin-X (MYO10). Using spinning disk and super-resolution microscopy combined with a machine-learning approach to phenotype oocyte morphology, we show that the lack of Myo10 decreases TZP density during oocyte growth. Reduction in TZPs does not prevent oocyte growth but impairs oocyte-matrix integrity. Importantly, we reveal by transcriptomic analysis that gene expression is altered in TZP-deprived oocytes and that oocyte maturation and subsequent early embryonic development are partially affected, effectively reducing mouse fertility. We propose that TZPs play a role in the structural integrity of the germline-somatic complex, which is essential for regulating gene expression in the oocyte and thus its developmental potential.
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Affiliation(s)
- Flora Crozet
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Paris, France
| | - Gaëlle Letort
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Department of Developmental and Stem Cell Biology, Institut Pasteur, CNRS UMR 3738, Université Paris Cité, Paris, France
| | - Rose Bulteau
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Christelle Da Silva
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Adrien Eichmuller
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | - Anna Francesca Tortorelli
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | | | - Morgane Belle
- Institut de la Vision, UMRS968/UMR7210/UM80, Paris, France
| | - Julien Dumont
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Tristan Piolot
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Aurélien Dauphin
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | - Fanny Coulpier
- Genomics Core Facility, Institut de Biologie de l'ENS, Département de biologie, Ecole normale supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Alain Chédotal
- Institut de la Vision, UMRS968/UMR7210/UM80, Paris, France
| | - Jean-Léon Maître
- Institut Curie, PSL Research University, Sorbonne Université, CNRS UMR 3215, INSERM U934, Paris, France
| | - Marie-Hélène Verlhac
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Hugh J Clarke
- Department of Obstetrics and Gynecology, McGill University, Montreal, Canada
| | - Marie-Emilie Terret
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Université PSL, Paris, France
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16
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Qiao FX, Sun MX, Xu ZR, Liu YC, Chen YZ, Wang HL, Qi ZQ, Xu CL, Liu Y. Chloroacetonitrile exposure induces endoplasmic reticulum stress and affects spindle assembly in mouse oocytes. Food Chem Toxicol 2023; 176:113736. [PMID: 36940772 DOI: 10.1016/j.fct.2023.113736] [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: 02/03/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/23/2023]
Abstract
Chloroacetonitrile (CAN) is a halogenated acetonitrile often produced while disinfecting drinking water. Previous studies have shown that maternal exposure to CAN interferes with fetal development; however, the adverse effects on maternal oocytes remain unknown. In this study, in vitro exposure of mouse oocytes to CAN reduced maturation significantly. Transcriptomics analysis showed that CAN altered the expression of multiple oocyte genes, especially those associated with the protein folding process. CAN exposure induced reactive oxygen species production, accompanied by endoplasmic reticulum (ER) stress and increased glucose regulated protein 78, C/EBP homologous protein and activating transcription factor 6 expression. Moreover, our results indicated that spindle morphology was impaired after CAN exposure. CAN disrupted polo-like kinase 1, pericentrin and p-Aurora A distribution, which may be an origin inducer that disrupts spindle assemble. Furthermore, exposure to CAN in vivo impaired follicular development. Taken together, our findings indicate that CAN exposure induces ER stress and affects spindle assembly in mouse oocytes.
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Affiliation(s)
- Feng-Xin Qiao
- Medical College, Guangxi University, Nanning, Guangxi, 530004, China
| | - Ming-Xin Sun
- Medical College, Guangxi University, Nanning, Guangxi, 530004, China
| | - Zhi-Ran Xu
- Translational Medicine Research Center, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, Guangxi, 530011, China
| | - Yue-Cen Liu
- Medical College, Guangxi University, Nanning, Guangxi, 530004, China
| | - Yan-Zhu Chen
- Medical College, Guangxi University, Nanning, Guangxi, 530004, China
| | - Hai-Long Wang
- Department of Basic Medicine, School of Medicine, Xiamen University, Xiamen, Fujian, 361102, China
| | - Zhong-Quan Qi
- Medical College, Guangxi University, Nanning, Guangxi, 530004, China
| | - Chang-Long Xu
- Reproductive Medical Center of Nanning Second People's Hospital, Nanning, Guangxi, 530031, China.
| | - Yu Liu
- Medical College, Guangxi University, Nanning, Guangxi, 530004, China.
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17
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Akera T. Tubulin post-translational modifications in meiosis. Semin Cell Dev Biol 2023; 137:38-45. [PMID: 34836784 PMCID: PMC9124733 DOI: 10.1016/j.semcdb.2021.11.014] [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: 06/09/2021] [Revised: 10/22/2021] [Accepted: 11/14/2021] [Indexed: 11/18/2022]
Abstract
Haploid gametes are produced from diploid parents through meiosis, a process inherent to all sexually reproducing eukaryotes. Faithful chromosome segregation in meiosis is essential for reproductive success, although it is less clear how the meiotic spindle achieves this compared to the mitotic spindle. It is becoming increasingly clear that tubulin post-translational modifications (PTMs) play critical roles in regulating microtubule functions in many biological processes, and meiosis is no exception. Here, I review recent advances in the understanding of tubulin PTMs in meiotic spindles, especially focusing on their roles in spindle integrity, oocyte aging, and non-Mendelian transmission.
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Affiliation(s)
- Takashi Akera
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda 20892, MD, USA.
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18
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Yuen WS, Zhang QH, Bourdais A, Adhikari D, Halet G, Carroll J. Polo-like kinase 1 promotes Cdc42-induced actin polymerization for asymmetric division in oocytes. Open Biol 2023; 13:220326. [PMID: 36883283 PMCID: PMC9993042 DOI: 10.1098/rsob.220326] [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: 03/09/2023] Open
Abstract
Polo-like kinase I (Plk1) is a highly conserved seronine/threonine kinase essential in meiosis and mitosis for spindle formation and cytokinesis. Here, through temporal application of Plk1 inhibitors, we identify a new role for Plk1 in the establishment of cortical polarity essential for highly asymmetric cell divisions of oocyte meiosis. Application of Plk1 inhibitors in late metaphase I abolishes pPlk1 from spindle poles and prevents the induction of actin polymerization at the cortex through inhibition of local recruitment of Cdc42 and Neuronal Wiskott-Aldrich Syndrome protein (N-WASP). By contrast, an already established polar actin cortex is insensitive to Plk1 inhibitors, but if the polar cortex is first depolymerized, Plk1 inhibitors completely prevent its restoration. Thus, Plk1 is essential for establishment but not maintenance of cortical actin polarity. These findings indicate that Plk1 regulates recruitment of Cdc42 and N-Wasp to coordinate cortical polarity and asymmetric cell division.
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Affiliation(s)
- Wai Shan Yuen
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Qing Hua Zhang
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Anne Bourdais
- University of Rennes, CNRS, IGDR - UMR 6290, F-35000 Rennes, France
| | - Deepak Adhikari
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Guillaume Halet
- University of Rennes, CNRS, IGDR - UMR 6290, F-35000 Rennes, France
| | - John Carroll
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
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19
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KYOGOKU H, KITAJIMA TS. The large cytoplasmic volume of oocyte. J Reprod Dev 2023; 69:1-9. [PMID: 36436912 PMCID: PMC9939283 DOI: 10.1262/jrd.2022-101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The study of the size of cells and organelles has a long history, dating back to the 1600s when cells were defined. In particular, various methods have elucidated the size of the nucleus and the mitotic spindle in several species. However, little research has been conducted on oocyte size and organelles in mammals, and many questions remain to be answered. The appropriate size is essential to cell function properly. Oocytes have a very large cytoplasm, which is more than 100 times larger than that of general somatic cells in mammals. In this review, we discuss how oocytes acquire an enormous cytoplasmic size and the adverse effects of a large cytoplasmic size on cellular functions.
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Affiliation(s)
- Hirohisa KYOGOKU
- Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan,Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
| | - Tomoya S KITAJIMA
- Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan
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20
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Bypassing Mendel's First Law: Transmission Ratio Distortion in Mammals. Int J Mol Sci 2023; 24:ijms24021600. [PMID: 36675116 PMCID: PMC9863905 DOI: 10.3390/ijms24021600] [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: 11/29/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023] Open
Abstract
Mendel's law of segregation states that the two alleles at a diploid locus should be transmitted equally to the progeny. A genetic segregation distortion, also referred to as transmission ratio distortion (TRD), is a statistically significant deviation from this rule. TRD has been observed in several mammal species and may be due to different biological mechanisms occurring at diverse time points ranging from gamete formation to lethality at post-natal stages. In this review, we describe examples of TRD and their possible mechanisms in mammals based on current knowledge. We first focus on the differences between TRD in male and female gametogenesis in the house mouse, in which some of the most well studied TRD systems have been characterized. We then describe known TRD in other mammals, with a special focus on the farmed species and in the peculiar common shrew species. Finally, we discuss TRD in human diseases. Thus far, to our knowledge, this is the first time that such description is proposed. This review will help better comprehend the processes involved in TRD. A better understanding of these molecular mechanisms will imply a better comprehension of their impact on fertility and on genome evolution. In turn, this should allow for better genetic counseling and lead to better care for human families.
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21
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Charalambous C, Webster A, Schuh M. Aneuploidy in mammalian oocytes and the impact of maternal ageing. Nat Rev Mol Cell Biol 2023; 24:27-44. [PMID: 36068367 DOI: 10.1038/s41580-022-00517-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2022] [Indexed: 11/09/2022]
Abstract
During fertilization, the egg and the sperm are supposed to contribute precisely one copy of each chromosome to the embryo. However, human eggs frequently contain an incorrect number of chromosomes - a condition termed aneuploidy, which is much more prevalent in eggs than in either sperm or in most somatic cells. In turn, aneuploidy in eggs is a leading cause of infertility, miscarriage and congenital syndromes. Aneuploidy arises as a consequence of aberrant meiosis during egg development from its progenitor cell, the oocyte. In human oocytes, chromosomes often segregate incorrectly. Chromosome segregation errors increase in women from their mid-thirties, leading to even higher levels of aneuploidy in eggs from women of advanced maternal age, ultimately causing age-related infertility. Here, we cover the two main areas that contribute to aneuploidy: (1) factors that influence the fidelity of chromosome segregation in eggs of women from all ages and (2) factors that change in response to reproductive ageing. Recent discoveries reveal new error-causing pathways and present a framework for therapeutic strategies to extend the span of female fertility.
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Affiliation(s)
- Chloe Charalambous
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Alexandre Webster
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Melina Schuh
- Department of Meiosis, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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22
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Zhang Y, Fan B, Li X, Tang Y, Shao J, Liu L, Ren Y, Yang Y, Xu B. Phosphorylation of adducin-1 by TPX2 promotes interpolar microtubule homeostasis and precise chromosome segregation in mouse oocytes. Cell Biosci 2022; 12:205. [PMID: 36539904 PMCID: PMC9769001 DOI: 10.1186/s13578-022-00943-y] [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: 10/24/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND ADD1 (adducin-1) and TPX2 (targeting protein for Xklp2) are centrosomal proteins and regulate mitotic spindle assembly. Mammalian oocytes that segregate homologous chromosomes in Meiosis I and sister chromatids in Meiosis II with a spindle lacking centrosomes are more prone to chromosome segregation errors than in mitosis. However, the regulatory mechanisms of oocyte spindle assembly and the functions of ADD1 and TPX2 in this process remain elusive. RESULT We found that the expression levels and localization of ADD1, S726 phosphorylated ADD1 (p-ADD1), and TPX2 proteins exhibited spindle assembly-dependent dynamic changes during mouse oocyte meiosis. Taxol treatment, which stabilizes the microtubule polymer and protects it from disassembly, made the signals of ADD1, p-ADD1, and TPX2 present in the microtubule organizing centers of small asters and spindles. Knockdown of approximately 60% of ADD1 protein levels destabilized interpolar microtubules in the meiotic spindle, resulting in aberrant chromosome alignment, reduced first polar body extrusion, and increased aneuploidy in metaphase II oocytes, but did not affect K-fiber homeostasis and the expression and localization of TPX2. Strikingly, TPX2 deficiency caused increased protein content of ADD1, but decreased expression and detachment of p-ADD1 from the spindle, thereby arresting mouse oocytes at the metaphase I stage with collapsed spindles. CONCLUSION Phosphorylation of ADD1 at S726 by TPX2 mediates acentriolar spindle assembly and precise chromosome segregation in mouse oocytes.
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Affiliation(s)
- Ying Zhang
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China
| | - Bingfeng Fan
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China
| | - Xiaoxia Li
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China ,College of Animal Science and Technology, Jilin Agriculture Science and Technology University, Jilin, China
| | - Yu Tang
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China
| | - Jing Shao
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China
| | - Lixiang Liu
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China
| | - Yuhe Ren
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China
| | - Yifeng Yang
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China
| | - Baozeng Xu
- grid.410727.70000 0001 0526 1937Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, #4899 Juye Street, Jingyue District, Changchun, 130112 Jilin China ,grid.410727.70000 0001 0526 1937State Key Laboratory for Molecular Biology of Special Economic Animals, Institute of Special Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun, Jilin China
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23
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Effects of Ran-GTP/importin β inhibition on the meiotic division of porcine oocytes. Histochem Cell Biol 2022; 158:571-582. [PMID: 35930054 DOI: 10.1007/s00418-022-02134-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2022] [Indexed: 12/13/2022]
Abstract
The Ran-GTP/importin β pathway has been implicated in a diverse array of mitotic functions in somatic mitosis; however, the possible meiotic roles of Ran-GTP/importin β in mammalian oocyte meiosis are still not fully understood. In the present study, importazole (IPZ), a small molecule inhibitor of the interaction between Ran and importin β was used to explore the potential meiotic roles of Ran-GTP/importin β in porcine oocytes undergoing meiosis. After IPZ treatment, the extrusion rate of the first polar body (PB1) was significantly decreased, and a higher proportion of the oocytes were arrested at the germinal vesicle breakdown (GVBD) stage. Moreover, IPZ treatment led to severe defects in metaphase I (MI) spindle assembly and chromosome alignment during the germinal vesicle (GV)-to-MI stage, as well as failure of metaphase II (MII) spindle reassembly and homologous chromosome segregation during the MI-to-MII stage. Notably, IPZ treatment decreased TPX2 expression and abnormal subcellular localization. Furthermore, the expression levels of aurora kinase A (AURKA) and transforming acidic coiled-coil 3 (TACC3) were significantly reduced after IPZ treatment. Collectively, these data indicate that the interaction of Ran-GTP and importin β is essential for proper spindle assembly and successful chromosome segregation during two consecutive meiotic divisions in porcine oocytes, and regulation of this complex might be related to its effect on the TPX2 signaling cascades.
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Wu T, Dong J, Fu J, Kuang Y, Chen B, Gu H, Luo Y, Gu R, Zhang M, Li W, Dong X, Sun X, Sang Q, Wang L. The mechanism of acentrosomal spindle assembly in human oocytes. Science 2022; 378:eabq7361. [DOI: 10.1126/science.abq7361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Meiotic spindle assembly ensures proper chromosome segregation in oocytes. However, the mechanisms behind spindle assembly in human oocytes remain largely unknown. We used three-dimensional high-resolution imaging of more than 2000 human oocytes to identify a structure that we named the human oocyte microtubule organizing center (huoMTOC). The proteins TACC3, CCP110, CKAP5, and DISC1 were found to be essential components of the huoMTOC. The huoMTOC arises beneath the oocyte cortex and migrates adjacent to the nuclear envelope before nuclear envelope breakdown (NEBD). After NEBD, the huoMTOC fragments and relocates on the kinetochores to initiate microtubule nucleation and spindle assembly. Disrupting the huoMTOC led to spindle assembly defects and oocyte maturation arrest. These results reveal a physiological mechanism of huoMTOC-regulated spindle assembly in human oocytes.
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Affiliation(s)
- Tianyu Wu
- Institute of Pediatrics, Children’s Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Jie Dong
- Institute of Pediatrics, Children’s Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Jing Fu
- Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, China
| | - Yanping Kuang
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China
| | - Biaobang Chen
- NHC Key Lab of Reproduction Regulation, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Fudan University, Shanghai 200032, China
| | - Hao Gu
- Institute of Pediatrics, Children’s Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Yuxi Luo
- Institute of Pediatrics, Children’s Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Ruihuan Gu
- Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, China
| | - Meiling Zhang
- Center for Reproductive Medicine and Fertility Preservation Program, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Wen Li
- Center for Reproductive Medicine and Fertility Preservation Program, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Xi Dong
- Reproductive Medicine Center, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xiaoxi Sun
- Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, China
| | - Qing Sang
- Institute of Pediatrics, Children’s Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
| | - Lei Wang
- Institute of Pediatrics, Children’s Hospital of Fudan University, State Key Laboratory of Genetic Engineering, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, Fudan University, Shanghai 200032, China
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Cohesin is required for meiotic spindle assembly independent of its role in cohesion in C. elegans. PLoS Genet 2022; 18:e1010136. [PMID: 36279281 PMCID: PMC9632809 DOI: 10.1371/journal.pgen.1010136] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 11/03/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022] Open
Abstract
Accurate chromosome segregation requires a cohesin-mediated physical attachment between chromosomes that are to be segregated apart, and a bipolar spindle with microtubule plus ends emanating from exactly two poles toward the paired chromosomes. We asked whether the striking bipolar structure of C. elegans meiotic chromosomes is required for bipolarity of acentriolar female meiotic spindles by time-lapse imaging of mutants that lack cohesion between chromosomes. Both a spo-11 rec-8 coh-4 coh-3 quadruple mutant and a spo-11 rec-8 double mutant entered M phase with separated sister chromatids lacking any cohesion. However, the quadruple mutant formed an apolar spindle whereas the double mutant formed a bipolar spindle that segregated chromatids into two roughly equal masses. Residual non-cohesive COH-3/4-dependent cohesin on separated sister chromatids of the double mutant was sufficient to recruit haspin-dependent Aurora B kinase, which mediated bipolar spindle assembly in the apparent absence of chromosomal bipolarity. We hypothesized that cohesin-dependent Aurora B might activate or inhibit spindle assembly factors in a manner that would affect their localization on chromosomes and found that the chromosomal localization patterns of KLP-7 and CLS-2 correlated with Aurora B loading on chromosomes. These results demonstrate that cohesin is essential for spindle assembly and chromosome segregation independent of its role in sister chromatid cohesion.
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Repton C, Cullen CF, Costa MFA, Spanos C, Rappsilber J, Ohkura H. The phospho-docking protein 14-3-3 regulates microtubule-associated proteins in oocytes including the chromosomal passenger Borealin. PLoS Genet 2022; 18:e1009995. [PMID: 35666772 PMCID: PMC9203013 DOI: 10.1371/journal.pgen.1009995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 06/16/2022] [Accepted: 04/27/2022] [Indexed: 11/18/2022] Open
Abstract
Global regulation of spindle-associated proteins is crucial in oocytes due to the absence of centrosomes and their very large cytoplasmic volume, but little is known about how this is achieved beyond involvement of the Ran-importin pathway. We previously uncovered a novel regulatory mechanism in Drosophila oocytes, in which the phospho-docking protein 14-3-3 suppresses microtubule binding of Kinesin-14/Ncd away from chromosomes. Here we report systematic identification of microtubule-associated proteins regulated by 14-3-3 from Drosophila oocytes. Proteins from ovary extract were co-sedimented with microtubules in the presence or absence of a 14-3-3 inhibitor. Through quantitative mass-spectrometry, we identified proteins or complexes whose ability to bind microtubules is suppressed by 14-3-3, including the chromosomal passenger complex (CPC), the centralspindlin complex and Kinesin-14/Ncd. We showed that 14-3-3 binds to the disordered region of Borealin, and this binding is regulated differentially by two phosphorylations on Borealin. Mutations at these two phospho-sites compromised normal Borealin localisation and centromere bi-orientation in oocytes, showing that phospho-regulation of 14-3-3 binding is important for Borealin localisation and function.
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Affiliation(s)
- Charlotte Repton
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - C. Fiona Cullen
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Mariana F. A. Costa
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Christos Spanos
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Juri Rappsilber
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
- Chair of Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Hiroyuki Ohkura
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
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He Y, Peng L, Li J, Li Q, Chu Y, Lin Q, Rui R, Ju S. TPX2 deficiency leads to spindle abnormity and meiotic impairment in porcine oocytes. Theriogenology 2022; 187:164-172. [DOI: 10.1016/j.theriogenology.2022.04.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 10/18/2022]
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McKim KS. Highway to hell-thy meiotic divisions: Chromosome passenger complex functions driven by microtubules: CPC interactions with both the chromosomes and microtubules are important for spindle assembly and function: CPC interactions with both the chromosomes and microtubules are important for spindle assembly and function. Bioessays 2022; 44:e2100202. [PMID: 34821405 PMCID: PMC8688318 DOI: 10.1002/bies.202100202] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 01/03/2023]
Abstract
The chromosome passenger complex (CPC) localizes to chromosomes and microtubules, sometimes simultaneously. The CPC also has multiple domains for interacting with chromatin and microtubules. Interactions between the CPC and both the chromatin and microtubules is important for spindle assembly and error correction. Such dual chromatin-microtubule interactions may increase the concentration of the CPC necessary for efficient kinase activity while also making it responsive to specific conditions or structures in the cell. CPC-microtubule dependent functions are considered in the context of the first meiotic division. Acentrosomal spindle assembly is a process that depends on transfer of the CPC from the chromosomes to the microtubules. Furthermore, transfer to the microtubules is not only to position the CPC for a later role in cytokinesis; metaphase I error correction and subsequent bi-orientation of bivalents may depend on microtubule associated CPC interacting with the kinetochores.
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Affiliation(s)
- Kim S McKim
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, New Jersey, USA
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Blengini CS, Schindler K. Acentriolar spindle assembly in mammalian female meiosis and the consequences of its perturbations on human reproduction. Biol Reprod 2021; 106:253-263. [PMID: 34791041 DOI: 10.1093/biolre/ioab210] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/26/2021] [Accepted: 11/11/2021] [Indexed: 12/18/2022] Open
Abstract
The purpose of meiosis is to generate developmentally competent, haploid gametes with the correct number of chromosomes. For reasons not completely understood, female meiosis is more prone to chromosome segregation errors than meiosis in males, leading to an abnormal number of chromosomes, or aneuploidy, in gametes. Meiotic spindles are the cellular machinery essential for the proper segregation of chromosomes. One unique feature of spindle structures in female meiosis is spindles poles that lack centrioles. The process of building a meiotic spindle without centrioles is complex and requires precise coordination of different structural components, assembly factors, motor proteins, and signaling molecules at specific times and locations to regulate each step. In this review, we discuss the basics of spindle formation during oocyte meiotic maturation focusing on mouse and human studies. Finally, we review different factors that could alter the process of spindle formation and its stability. We conclude with a discussion of how different assisted reproductive technologies (ART) could affect spindles and the consequences these perturbations may have for subsequent embryo development.
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Affiliation(s)
- Cecilia S Blengini
- Rutgers University, Human Genetics Institute of New Jersey, Piscataway, NJ 08854 USA
| | - Karen Schindler
- Rutgers University, Human Genetics Institute of New Jersey, Piscataway, NJ 08854 USA
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Verlhac MH. Preventing aneuploidy: The groom must wait until the bride is ready. J Cell Biol 2021; 220:e202108030. [PMID: 34505874 PMCID: PMC8438638 DOI: 10.1083/jcb.202108030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Fertilization often triggers the final step of haploidization of the female gamete genome. In this issue, Mori et al. (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202012001) identify two successive actin-dependent mechanisms that delay fusion of maternal and paternal chromosomes, preventing inadvertent elimination of paternal chromosomes together with maternal ones.
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Affiliation(s)
- Marie-Hélène Verlhac
- Center for Interdisciplinary Research in Biology, Collège de France, UMR7241/U1050, Paris Sciences et Lettres Research University, Paris, France
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31
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Dehapiot B, Clément R, Bourdais A, Carrière V, Huet S, Halet G. RhoA- and Cdc42-induced antagonistic forces underlie symmetry breaking and spindle rotation in mouse oocytes. PLoS Biol 2021; 19:e3001376. [PMID: 34491981 PMCID: PMC8448345 DOI: 10.1371/journal.pbio.3001376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 09/17/2021] [Accepted: 07/30/2021] [Indexed: 11/25/2022] Open
Abstract
Mammalian oocyte meiotic divisions are highly asymmetric and produce a large haploid gamete and 2 small polar bodies. This relies on the ability of the cell to break symmetry and position its spindle close to the cortex before anaphase occurs. In metaphase II–arrested mouse oocytes, the spindle is actively maintained close and parallel to the cortex, until fertilization triggers sister chromatid segregation and the rotation of the spindle. The latter must indeed reorient perpendicular to the cortex to enable cytokinesis ring closure at the base of the polar body. However, the mechanisms underlying symmetry breaking and spindle rotation have remained elusive. In this study, we show that spindle rotation results from 2 antagonistic forces. First, an inward contraction of the cytokinesis furrow dependent on RhoA signaling, and second, an outward attraction exerted on both sets of chromatids by a Ran/Cdc42-dependent polarization of the actomyosin cortex. By combining live segmentation and tracking with numerical modeling, we demonstrate that this configuration becomes unstable as the ingression progresses. This leads to spontaneous symmetry breaking, which implies that neither the rotation direction nor the set of chromatids that eventually gets discarded are biologically predetermined. Mammalian oocyte meiotic divisions are highly asymmetric and produce a large haploid gamete and two small polar bodies, but the mechanisms underlying the required symmetry breaking and spindle rotation have remained elusive. This study shows that spindle rotation in activated mouse oocytes relies on spontaneous symmetry breaking resulting from an unstable configuration generated by cleavage furrow ingression and cortical chromosome attraction.
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Affiliation(s)
- Benoit Dehapiot
- Aix Marseille Université, CNRS, IBDM-UMR7288, Turing Center for Living Systems, Marseille, France
- Univ Rennes, CNRS, IGDR—UMR 6290, Rennes, France
- * E-mail: (BD); (GH)
| | - Raphaël Clément
- Aix Marseille Université, CNRS, IBDM-UMR7288, Turing Center for Living Systems, Marseille, France
| | | | | | | | - Guillaume Halet
- Univ Rennes, CNRS, IGDR—UMR 6290, Rennes, France
- * E-mail: (BD); (GH)
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Pajpach F, Wu T, Shearwin-Whyatt L, Jones K, Grützner F. Flavors of Non-Random Meiotic Segregation of Autosomes and Sex Chromosomes. Genes (Basel) 2021; 12:genes12091338. [PMID: 34573322 PMCID: PMC8471020 DOI: 10.3390/genes12091338] [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: 07/15/2021] [Revised: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 12/14/2022] Open
Abstract
Segregation of chromosomes is a multistep process occurring both at mitosis and meiosis to ensure that daughter cells receive a complete set of genetic information. Critical components in the chromosome segregation include centromeres, kinetochores, components of sister chromatid and homologous chromosomes cohesion, microtubule organizing centres, and spindles. Based on the cytological work in the grasshopper Brachystola, it has been accepted for decades that segregation of homologs at meiosis is fundamentally random. This ensures that alleles on chromosomes have equal chance to be transmitted to progeny. At the same time mechanisms of meiotic drive and an increasing number of other examples of non-random segregation of autosomes and sex chromosomes provide insights into the underlying mechanisms of chromosome segregation but also question the textbook dogma of random chromosome segregation. Recent advances provide a better understanding of meiotic drive as a prominent force where cellular and chromosomal changes allow autosomes to bias their segregation. Less understood are mechanisms explaining observations that autosomal heteromorphism may cause biased segregation and regulate alternating segregation of multiple sex chromosome systems or translocation heterozygotes as an extreme case of non-random segregation. We speculate that molecular and cytological mechanisms of non-random segregation might be common in these cases and that there might be a continuous transition between random and non-random segregation which may play a role in the evolution of sexually antagonistic genes and sex chromosome evolution.
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Affiliation(s)
- Filip Pajpach
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (F.P.); (L.S.-W.)
| | - Tianyu Wu
- Department of Central Laboratory, Clinical Laboratory, Jing’an District Centre Hospital of Shanghai and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China;
| | - Linda Shearwin-Whyatt
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (F.P.); (L.S.-W.)
| | - Keith Jones
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton BN1 9RH, UK;
| | - Frank Grützner
- School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; (F.P.); (L.S.-W.)
- Correspondence:
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33
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Wang X, Baumann C, De La Fuente R, Viveiros MM. Loss of acentriolar MTOCs disrupts spindle pole Aurora A and assembly of the liquid-like meiotic spindle domain in oocytes. J Cell Sci 2021; 134:jcs256297. [PMID: 34152366 PMCID: PMC8325960 DOI: 10.1242/jcs.256297] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 06/14/2021] [Indexed: 11/20/2022] Open
Abstract
Oocyte-specific knockdown of pericentrin (PCNT) in transgenic (Tg) mice disrupts acentriolar microtubule-organizing center (aMTOC) formation, leading to spindle instability and error-prone meiotic division. Here, we show that PCNT-depleted oocytes lack phosphorylated Aurora A (pAURKA) at spindle poles, while overall levels are unaltered. To test aMTOC-associated AURKA function, metaphase II (MII) control (WT) and Tg oocytes were briefly exposed to a specific AURKA inhibitor (MLN8237). Similar defects were observed in Tg and MLN8237-treated WT oocytes, including altered spindle structure, increased chromosome misalignment and impaired microtubule regrowth. Yet, AURKA inhibition had a limited effect on Tg oocytes, revealing a critical role for aMTOC-associated AURKA in regulating spindle stability. Notably, spindle instability was associated with disrupted γ-tubulin and lack of the liquid-like meiotic spindle domain (LISD) in Tg oocytes. Analysis of this Tg model provides the first evidence that LISD assembly depends expressly on aMTOC-associated AURKA, and that Ran-mediated spindle formation ensues without the LISD. These data support that loss of aMTOC-associated AURKA and failure of LISD assembly contribute to error-prone meiotic division in PCNT-depleted oocytes, underscoring the essential role of aMTOCs for spindle stability.
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Affiliation(s)
- Xiaotian Wang
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia,Athens, GA 30602, USA
| | - Claudia Baumann
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia,Athens, GA 30602, USA
| | - Rabindranath De La Fuente
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia,Athens, GA 30602, USA
- Regenerative Biosciences Center (RBC), University of Georgia,Athens, GA 30602, USA
| | - Maria M. Viveiros
- Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia,Athens, GA 30602, USA
- Regenerative Biosciences Center (RBC), University of Georgia,Athens, GA 30602, USA
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Abstract
An investigation of how mitotic spindle size scales with cell size in early zebrafish embryos reveals fundamental principles of spindle organization. Spindle size depends primarily on microtubule number, which is regulated by a reaction-diffusion system when cells are large, and by signals from the plasma membrane when they are small.
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Affiliation(s)
- T J Mitchison
- Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
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35
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Wang LI, DeFosse T, Jang JK, Battaglia RA, Wagner VF, McKim KS. Borealin directs recruitment of the CPC to oocyte chromosomes and movement to the microtubules. J Cell Biol 2021; 220:211972. [PMID: 33836043 PMCID: PMC8185691 DOI: 10.1083/jcb.202006018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 01/17/2021] [Accepted: 03/11/2021] [Indexed: 12/25/2022] Open
Abstract
The chromosomes in the oocytes of many animals appear to promote bipolar spindle assembly. In Drosophila oocytes, spindle assembly requires the chromosome passenger complex (CPC), which consists of INCENP, Borealin, Survivin, and Aurora B. To determine what recruits the CPC to the chromosomes and its role in spindle assembly, we developed a strategy to manipulate the function and localization of INCENP, which is critical for recruiting the Aurora B kinase. We found that an interaction between Borealin and the chromatin is crucial for the recruitment of the CPC to the chromosomes and is sufficient to build kinetochores and recruit spindle microtubules. HP1 colocalizes with the CPC on the chromosomes and together they move to the spindle microtubules. We propose that the Borealin interaction with HP1 promotes the movement of the CPC from the chromosomes to the microtubules. In addition, within the central spindle, rather than at the centromeres, the CPC and HP1 are required for homologous chromosome bi-orientation.
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Affiliation(s)
- Lin-Ing Wang
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ
| | - Tyler DeFosse
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ
| | - Janet K Jang
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ
| | - Rachel A Battaglia
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ
| | - Victoria F Wagner
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ
| | - Kim S McKim
- Waksman Institute and Department of Genetics, Rutgers, the State University of New Jersey, Piscataway, NJ
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Crozet F, Da Silva C, Verlhac MH, Terret ME. Myosin-X is dispensable for spindle morphogenesis and positioning in the mouse oocyte. Development 2021; 148:dev.199364. [PMID: 33722900 PMCID: PMC8077531 DOI: 10.1242/dev.199364] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/02/2021] [Indexed: 01/08/2023]
Abstract
Off-center spindle positioning in mammalian oocytes enables asymmetric divisions in size, which are important for subsequent embryogenesis. The migration of the meiosis I spindle from the oocyte center to its cortex is mediated by F-actin. Specifically, an F-actin cage surrounds the microtubule spindle and applies forces to it. To better understand how F-actin transmits forces to the spindle, we studied a potential direct link between F-actin and microtubules. For this, we tested the implication of myosin-X, a known F-actin and microtubule binder involved in spindle morphogenesis and/or positioning in somatic cells, amphibian oocytes and embryos. Using a mouse strain conditionally invalidated for myosin-X in oocytes and by live-cell imaging, we show that myosin-X is not localized on the spindle, and is dispensable for spindle and F-actin assembly. It is not required for force transmission as spindle migration and chromosome alignment occur normally. More broadly, myosin-X is dispensable for oocyte developmental potential and female fertility. We therefore exclude a role for myosin-X in transmitting F-actin-mediated forces to the spindle, opening new perspectives regarding this mechanism in mouse oocytes, which differ from most mitotic cells. Summary: Cortical spindle positioning in mammalian oocytes relies on the interplay between actin and the microtubule spindle. Myosin-X, an obvious candidate for linking these two cytoskeletal elements, is dispensable in mouse oocytes.
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Affiliation(s)
- Flora Crozet
- CIRB, Collège de France, UMR7241/U1050, 75005 Paris, France
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Kiyomitsu T, Boerner S. The Nuclear Mitotic Apparatus (NuMA) Protein: A Key Player for Nuclear Formation, Spindle Assembly, and Spindle Positioning. Front Cell Dev Biol 2021; 9:653801. [PMID: 33869212 PMCID: PMC8047419 DOI: 10.3389/fcell.2021.653801] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/10/2021] [Indexed: 01/10/2023] Open
Abstract
The nuclear mitotic apparatus (NuMA) protein is well conserved in vertebrates, and dynamically changes its subcellular localization from the interphase nucleus to the mitotic/meiotic spindle poles and the mitotic cell cortex. At these locations, NuMA acts as a key structural hub in nuclear formation, spindle assembly, and mitotic spindle positioning, respectively. To achieve its variable functions, NuMA interacts with multiple factors, including DNA, microtubules, the plasma membrane, importins, and cytoplasmic dynein. The binding of NuMA to dynein via its N-terminal domain drives spindle pole focusing and spindle positioning, while multiple interactions through its C-terminal region define its subcellular localizations and functions. In addition, NuMA can self-assemble into high-ordered structures which likely contribute to spindle positioning and nuclear formation. In this review, we summarize recent advances in NuMA’s domains, functions and regulations, with a focus on human NuMA, to understand how and why vertebrate NuMA participates in these functions in comparison with invertebrate NuMA-related proteins.
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Affiliation(s)
- Tomomi Kiyomitsu
- Cell Division Dynamics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan
| | - Susan Boerner
- Cell Division Dynamics Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan
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Métivier M, Gallaud E, Thomas A, Pascal A, Gagné JP, Poirier GG, Chrétien D, Gibeaux R, Richard-Parpaillon L, Benaud C, Giet R. Drosophila Tubulin-Specific Chaperone E Recruits Tubulin around Chromatin to Promote Mitotic Spindle Assembly. Curr Biol 2021; 31:684-695.e6. [PMID: 33259793 DOI: 10.1016/j.cub.2020.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 09/29/2020] [Accepted: 11/03/2020] [Indexed: 12/31/2022]
Abstract
Proper assembly of mitotic spindles requires microtubule nucleation not only at the centrosomes but also around chromatin. In this study, we found that the Drosophila tubulin-specific chaperone dTBCE is required for the enrichment of tubulin in the nuclear space after nuclear envelope breakdown and for subsequent promotion of spindle microtubule nucleation. These events depend on the CAP-Gly motif found in dTBCE and are regulated by Ran and lamin proteins. Our data suggest that during early mitosis, dTBCE and nuclear pore proteins become enriched in the nucleus, where they interact with the Ran GTPase to promote dynamic tubulin enrichment. We propose that this novel mechanism enhances microtubule nucleation around chromatin, thereby facilitating mitotic spindle assembly.
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Affiliation(s)
- Mathieu Métivier
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Emmanuel Gallaud
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Alexandre Thomas
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Aude Pascal
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Jean-Philippe Gagné
- Centre de Recherche du Centre Hospitalier Universitaire de Québec - Pavillon CHUL, Université Laval, Québec City, QC, Canada
| | - Guy G Poirier
- Centre de Recherche du Centre Hospitalier Universitaire de Québec - Pavillon CHUL, Université Laval, Québec City, QC, Canada
| | - Denis Chrétien
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Romain Gibeaux
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Laurent Richard-Parpaillon
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Christelle Benaud
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France
| | - Régis Giet
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes) - UMR 6290, F-35000 Rennes, France.
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So C, Cheng S, Schuh M. Phase Separation during Germline Development. Trends Cell Biol 2021; 31:254-268. [PMID: 33455855 DOI: 10.1016/j.tcb.2020.12.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 02/07/2023]
Abstract
Phase separation has emerged as a new key principle of intracellular organization. Phase-separated structures play diverse roles in various biological processes and pathogenesis of protein aggregation diseases. Recent work has revealed crucial functions for phase separation during germline development. Phase separation controls the assembly and segregation of germ granules that determine which embryonic cells become germ cells. Phase separation promotes the formation of the Balbiani body, a structure that stores organelles and RNAs during the prolonged prophase arrest of oocytes. Phase separation also facilitates meiotic recombination that prepares homologous chromosomes for segregation, and drives the formation of a liquid-like spindle domain that promotes spindle assembly in mammalian oocytes. We review how phase separation drives these essential steps during germline development.
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Affiliation(s)
- Chun So
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Shiya Cheng
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Melina Schuh
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
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Tsuchiya K, Hayashi H, Nishina M, Okumura M, Sato Y, Kanemaki MT, Goshima G, Kiyomitsu T. Ran-GTP Is Non-essential to Activate NuMA for Mitotic Spindle-Pole Focusing but Dynamically Polarizes HURP Near Chromosomes. Curr Biol 2021; 31:115-127.e3. [DOI: 10.1016/j.cub.2020.09.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/25/2020] [Accepted: 09/30/2020] [Indexed: 12/27/2022]
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Role of PB1 Midbody Remnant Creating Tethered Polar Bodies during Meiosis II. Genes (Basel) 2020; 11:genes11121394. [PMID: 33255457 PMCID: PMC7760350 DOI: 10.3390/genes11121394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/17/2020] [Accepted: 11/21/2020] [Indexed: 01/30/2023] Open
Abstract
Polar body (PB) formation is an extreme form of unequal cell division that occurs in oocytes due to the eccentric position of the small meiotic spindle near the oocyte cortex. Prior to PB formation, a chromatin-centered process causes the cortex overlying the meiotic chromosomes to become polarized. This polarized cortical subdomain marks the site where a cortical protrusion or outpocket forms at the oocyte surface creating the future PBs. Using ascidians, we observed that PB1 becomes tethered to the fertilized egg via PB2, indicating that the site of PB1 cytokinesis directed the precise site for PB2 emission. We therefore studied whether the midbody remnant left behind following PB1 emission was involved, together with the egg chromatin, in defining the precise cortical site for PB2 emission. During outpocketing of PB2 in ascidians, we discovered that a small structure around 1 µm in diameter protruded from the cortical outpocket that will form the future PB2, which we define as the “polar corps”. As emission of PB2 progressed, this small polar corps became localized between PB2 and PB1 and appeared to link PB2 to PB1. We tested the hypothesis that this small polar corps on the surface of the forming PB2 outpocket was the midbody remnant from the previous round of PB1 cytokinesis. We had previously discovered that Plk1::Ven labeled midbody remnants in ascidian embryos. We therefore used Plk1::Ven to follow the dynamics of the PB1 midbody remnant during meiosis II. Plk1::Ven strongly labeled the small polar corps that formed on the surface of the cortical outpocket that created PB2. Following emission of PB2, this polar corps was rich in Plk1::Ven and linked PB2 to PB1. By labelling actin (with TRITC-Phalloidin) we also demonstrated that actin accumulates at the midbody remnant and also forms a cortical cap around the midbody remnant in meiosis II that prefigured the precise site of cortical outpocketing during PB2 emission. Phalloidin staining of actin and immunolabelling of anti-phospho aPKC during meiosis II in fertilized eggs that had PB1 removed suggested that the midbody remnant remained within the fertilized egg following emission of PB1. Dynamic imaging of microtubules labelled with Ens::3GFP, MAP7::GFP or EB3::3GFP showed that one pole of the second meiotic spindle was located near the midbody remnant while the other pole rotated away from the cortex during outpocketing. Finally, we report that failure of the second meiotic spindle to rotate can lead to the formation of two cortical outpockets at anaphase II, one above each set of chromatids. It is not known whether the midbody remnant of PB1 is involved in directing the precise location of PB2 since our data are correlative in ascidians. However, a review of the literature indicates that PB1 is tethered to the egg surface via PB2 in several species including members of the cnidarians, lophotrochozoa and echinoids, suggesting that the midbody remnant formed during PB1 emission may be involved in directing the precise site of PB2 emission throughout the invertebrates.
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Prc1-rich kinetochores are required for error-free acentrosomal spindle bipolarization during meiosis I in mouse oocytes. Nat Commun 2020; 11:2652. [PMID: 32461611 PMCID: PMC7253481 DOI: 10.1038/s41467-020-16488-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 05/01/2020] [Indexed: 12/18/2022] Open
Abstract
Acentrosomal meiosis in oocytes represents a gametogenic challenge, requiring spindle bipolarization without predefined bipolar cues. While much is known about the structures that promote acentrosomal microtubule nucleation, less is known about the structures that mediate spindle bipolarization in mammalian oocytes. Here, we show that in mouse oocytes, kinetochores are required for spindle bipolarization in meiosis I. This process is promoted by oocyte-specific, microtubule-independent enrichment of the antiparallel microtubule crosslinker Prc1 at kinetochores via the Ndc80 complex. In contrast, in meiosis II, cytoplasm that contains upregulated factors including Prc1 supports kinetochore-independent pathways for spindle bipolarization. The kinetochore-dependent mode of spindle bipolarization is required for meiosis I to prevent chromosome segregation errors. Human oocytes, where spindle bipolarization is reportedly error prone, exhibit no detectable kinetochore enrichment of Prc1. This study reveals an oocyte-specific function of kinetochores in acentrosomal spindle bipolarization in mice, and provides insights into the error-prone nature of human oocytes. Oocyte meiosis must achieve spindle bipolarization without predefined spatial cues. Yoshida et al. demonstrate that spindle bipolarization during meiosis I in mouse oocytes requires kinetochores to prevent chromosome segregation errors, a phenomenon that does not occur in error-prone human oocytes.
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Abstract
The Ran pathway has a well-described function in nucleocytoplasmic transport, where active Ran dissociates importin/karyopherin-bound cargo containing a nuclear localization signal (NLS) in the nucleus. As cells enter mitosis, the nuclear envelope breaks down and a gradient of active Ran forms where levels are highest near chromatin. This gradient plays a crucial role in regulating mitotic spindle assembly, where active Ran binds to and releases importins from NLS-containing spindle assembly factors. An emerging theme is that the Ran gradient also regulates the actomyosin cortex for processes including polar body extrusion during meiosis, and cytokinesis. For these events, active Ran could play an inhibitory role, where importin-binding may help promote or stabilize a conformation or interaction that favours the recruitment and function of cortical regulators. For either spindle assembly or cortical polarity, the gradient of active Ran determines the extent of importin-binding, the effects of which could vary for different proteins.
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Affiliation(s)
- Imge Ozugergin
- Department of Biology, Concordia University, Montreal, QC, Canada
| | - Alisa Piekny
- Department of Biology, Concordia University, Montreal, QC, Canada
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Chinen T, Yamamoto S, Takeda Y, Watanabe K, Kuroki K, Hashimoto K, Takao D, Kitagawa D. NuMA assemblies organize microtubule asters to establish spindle bipolarity in acentrosomal human cells. EMBO J 2020; 39:e102378. [PMID: 31782546 PMCID: PMC6960446 DOI: 10.15252/embj.2019102378] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 11/11/2019] [Accepted: 11/12/2019] [Indexed: 12/11/2022] Open
Abstract
In most animal cells, mitotic spindle formation is mediated by coordination of centrosomal and acentrosomal pathways. At the onset of mitosis, centrosomes promote spindle bipolarization. However, the mechanism through which the acentrosomal pathways facilitate the establishment of spindle bipolarity in early mitosis is not completely understood. In this study, we show the critical roles of nuclear mitotic apparatus protein (NuMA) in the generation of spindle bipolarity in acentrosomal human cells. In acentrosomal human cells, we found that small microtubule asters containing NuMA formed at the time of nuclear envelope breakdown. In addition, these asters were assembled by dynein and the clustering activity of NuMA. Subsequently, NuMA organized the radial array of microtubules, which incorporates Eg5, and thus facilitated spindle bipolarization. Importantly, in cells with centrosomes, we also found that NuMA promoted the initial step of spindle bipolarization in early mitosis. Overall, these data suggest that canonical centrosomal and NuMA-mediated acentrosomal pathways redundantly promote spindle bipolarity in human cells.
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Affiliation(s)
- Takumi Chinen
- Division of Centrosome BiologyDepartment of Molecular GeneticsNational Institute of GeneticsMishimaShizuokaJapan
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
| | - Shohei Yamamoto
- Division of Centrosome BiologyDepartment of Molecular GeneticsNational Institute of GeneticsMishimaShizuokaJapan
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
- Graduate Program in BioscienceGraduate School of ScienceUniversity of TokyoHongoTokyoJapan
| | - Yutaka Takeda
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
| | - Koki Watanabe
- Division of Centrosome BiologyDepartment of Molecular GeneticsNational Institute of GeneticsMishimaShizuokaJapan
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
- Department of GeneticsSchool of Life ScienceThe Graduate University for Advanced Studies (SOKENDAI)HayamaKanagawaJapan
| | - Kanako Kuroki
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
| | - Kaho Hashimoto
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
| | - Daisuke Takao
- Division of Centrosome BiologyDepartment of Molecular GeneticsNational Institute of GeneticsMishimaShizuokaJapan
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
| | - Daiju Kitagawa
- Division of Centrosome BiologyDepartment of Molecular GeneticsNational Institute of GeneticsMishimaShizuokaJapan
- Department of Physiological ChemistryGraduate School of Pharmaceutical ScienceThe University of TokyoBunkyoTokyoJapan
- Department of GeneticsSchool of Life ScienceThe Graduate University for Advanced Studies (SOKENDAI)HayamaKanagawaJapan
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Drutovic D, Duan X, Li R, Kalab P, Solc P. RanGTP and importin β regulate meiosis I spindle assembly and function in mouse oocytes. EMBO J 2020; 39:e101689. [PMID: 31617608 PMCID: PMC6939199 DOI: 10.15252/embj.2019101689] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 12/21/2022] Open
Abstract
Homologous chromosome segregation during meiosis I (MI) in mammalian oocytes is carried out by the acentrosomal MI spindles. Whereas studies in human oocytes identified Ran GTPase as a crucial regulator of the MI spindle function, experiments in mouse oocytes questioned the generality of this notion. Here, we use live-cell imaging with fluorescent probes and Förster resonance energy transfer (FRET) biosensors to monitor the changes in Ran and importin β signaling induced by perturbations of Ran in mouse oocytes while examining the MI spindle dynamics. We show that unlike RanT24N employed in previous studies, a RanT24N, T42A double mutant inhibits RanGEF without perturbing cargo binding to importin β and disrupts MI spindle function in chromosome segregation. Roles of Ran and importin β in the coalescence of microtubule organizing centers (MTOCs) and MI spindle assembly are further supported by the use of the chemical inhibitor importazole, whose effects are partially rescued by the GTP hydrolysis-resistant RanQ69L mutant. These results indicate that RanGTP is essential for MI spindle assembly and function both in humans and mice.
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Affiliation(s)
- David Drutovic
- Institute of Animal Physiology and Genetics of the Czech Academy of SciencesLibechovCzech Republic
| | - Xing Duan
- Department of Chemical and Biomolecular EngineeringWhiting School of EngineeringBaltimoreMDUSA
- Center for Cell DynamicsDepartment of Cell BiologyJohns Hopkins University School of MedicineBaltimoreMDUSA
| | - Rong Li
- Department of Chemical and Biomolecular EngineeringWhiting School of EngineeringBaltimoreMDUSA
- Center for Cell DynamicsDepartment of Cell BiologyJohns Hopkins University School of MedicineBaltimoreMDUSA
| | - Petr Kalab
- Department of Chemical and Biomolecular EngineeringWhiting School of EngineeringBaltimoreMDUSA
| | - Petr Solc
- Institute of Animal Physiology and Genetics of the Czech Academy of SciencesLibechovCzech Republic
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Abstract
Chromosome segregation errors in human oocytes lead to aneuploid embryos that cause infertility and birth defects. Here we provide an overview of the chromosome-segregation process in the mammalian oocyte, highlighting mechanistic differences between oocytes and somatic cells that render oocytes so prone to segregation error. These differences include the extremely large size of the oocyte cytoplasm, the unique geometry of meiosis-I chromosomes, idiosyncratic function of the spindle assembly checkpoint, and dramatically altered oocyte cell-cycle control and spindle assembly, as compared to typical somatic cells. We summarise recent work suggesting that aging leads to a further deterioration in fidelity of chromosome segregation by impacting multiple components of the chromosome-segregation machinery. In addition, we compare and contrast recent results from mouse and human oocytes, which exhibit overlapping defects to differing extents. We conclude that the striking propensity of the oocyte to mis-segregate chromosomes reflects the unique challenges faced by the spindle in a highly unusual cellular environment.
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Affiliation(s)
- Aleksandar I Mihajlović
- Centre Recherche CHUM and Department OBGYN, Université de Montreal, Montreal, Quebec, Canada
| | - Greg FitzHarris
- Centre Recherche CHUM and Department OBGYN, Université de Montreal, Montreal, Quebec, Canada.
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Active Fluctuations of the Nuclear Envelope Shape the Transcriptional Dynamics in Oocytes. Dev Cell 2019; 51:145-157.e10. [DOI: 10.1016/j.devcel.2019.09.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 06/14/2019] [Accepted: 09/13/2019] [Indexed: 01/03/2023]
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48
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Jin Z, Suk N, Kim N. TP53BP1 regulates chromosome alignment and spindle bipolarity in mouse oocytes. Mol Reprod Dev 2019; 86:1126-1137. [DOI: 10.1002/mrd.23228] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 06/01/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Zhe‐Long Jin
- Department of Animal SciencesChungbuk National UniversityCheongju Korea
| | - Namgoong Suk
- Department of Animal SciencesChungbuk National UniversityCheongju Korea
| | - Nam‐Hyung Kim
- Department of Animal SciencesChungbuk National UniversityCheongju Korea
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49
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Namgoong S, Kim NH. Meiotic spindle formation in mammalian oocytes: implications for human infertility. Biol Reprod 2019; 98:153-161. [PMID: 29342242 DOI: 10.1093/biolre/iox145] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 12/27/2017] [Indexed: 12/12/2022] Open
Abstract
In the final stage of oogenesis, mammalian oocytes generate a meiotic spindle and undergo chromosome segregation to yield an egg that is ready for fertilization. Herein, we describe the recent advances in understanding the mechanisms controlling formation of the meiotic spindle in metaphase I (MI) and metaphase II (MII) in mammalian oocytes, and focus on the differences between mouse and human oocytes. Unlike mitotic cells, mammalian oocytes lack typical centrosomes that consist of two centrioles and the surrounding pericentriolar matrix proteins, which serve as microtubule-organizing centers (MTOCs) in most somatic cells. Instead, oocytes rely on different mechanisms for the formation of microtubules in MI spindles. Two different mechanisms have been described for MI spindle formation in mammalian oocytes. Chromosome-mediated microtubule formation, including RAN-mediated spindle formation and chromosomal passenger complex-mediated spindle elongation, controls the growth of microtubules from chromatin, while acentriolar MTOC-mediated microtubule formation contributes to spindle formation. Mouse oocytes utilize both chromatin- and MTOC-mediated pathways for microtubule formation. The existence of both pathways may provide a fail-safe mechanism to ensure high fidelity of chromosome segregation during meiosis. Unlike mouse oocytes, human oocytes considered unsuitable for clinical in vitro fertilization procedures, lack MTOCs; this may explain why meiosis in human oocytes is often error-prone. Understanding the mechanisms of MI/MII spindle formation, spindle assembly checkpoint, and chromosome segregation, in mammalian oocytes, will provide valuable insights into the molecular mechanisms of human infertility.
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Affiliation(s)
| | - Nam-Hyung Kim
- Department of Animal Science, Chungbuk National University, Cheong-Ju, Chungbuk, Republic of Korea
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50
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Zhang Y, Wan X, Wang HH, Pan MH, Pan ZN, Sun SC. RAB35 depletion affects spindle formation and actin-based spindle migration in mouse oocyte meiosis. ACTA ACUST UNITED AC 2019; 25:359-372. [DOI: 10.1093/molehr/gaz027] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/28/2019] [Accepted: 05/17/2019] [Indexed: 12/16/2022]
Abstract
Abstract
Mammalian oocyte maturation involves a unique asymmetric cell division, in which meiotic spindle formation and actin filament-mediated spindle migration to the oocyte cortex are key processes. Here, we report that the vesicle trafficking regulator, RAB35 GTPase, is involved in regulating cytoskeleton dynamics in mouse oocytes. RAB35 GTPase mainly accumulated at the meiotic spindle periphery and cortex during oocyte meiosis. Depletion of RAB35 by morpholino microinjection led to aberrant polar body extrusion and asymmetric division defects in almost half the treated oocytes. We also found that RAB35 affected SIRT2 and αTAT for tubulin acetylation, which further modulated microtubule stability and meiotic spindle formation. Additionally, we found that RAB35 associated with RHOA in oocytes and modulated the ROCK–cofilin pathway for actin assembly, which further facilitated spindle migration for oocyte asymmetric division. Importantly, microinjection of Myc-Rab35 cRNA into RAB35-depleted oocytes could significantly rescue these defects. In summary, our results suggest that RAB35 GTPase has multiple roles in spindle stability and actin-mediated spindle migration in mouse oocyte meiosis.
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Affiliation(s)
- Yu Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xiang Wan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Hong-Hui Wang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
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