1
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Yonezawa N, Shindo T, Oda H, Kimura H, Hiraoka Y, Haraguchi T, Yamagata K. Reconstruction of artificial nuclei with nuclear import activity in living mouse oocytes. Genes Cells 2024. [PMID: 39140385 DOI: 10.1111/gtc.13149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/02/2024] [Accepted: 07/17/2024] [Indexed: 08/15/2024]
Abstract
In eukaryotes, DNA is housed within the cell nucleus. Molecules required for the formation of a nucleus have been identified using in vitro systems with frog egg extracts and in vivo imaging of somatic cells. However, little is known about the physicochemical factors and conditions required for nuclear formation in mouse oocytes. In this study, using a reconstitution approach with purified DNA, we aimed to determine factors, such as the amount and timing of DNA introduction, required for the formation of nuclei with nuclear transport activity in mouse oocytes. T4 phage DNA (~166 kbp) was microinjected into strontium-activated oocytes to evaluate the conditions appropriate for nuclear formation. Microinjection of 100-500 ng/μL of T4 DNA, but not 20 ng/μL, was sufficient for the formation of nucleus-like structures. Furthermore, microinjection of DNA during metaphase II to telophase II, but not during interphase, was sufficient. Electron and fluorescence microscopy showed that T4 DNA-induced nucleus-like structures had nuclear lamina and nuclear pore complex structures similar to those of natural nuclei, as well as nuclear import activity. These results suggest that exogenous DNA can form artificial nuclei with nuclear transport functions in mouse oocytes, regardless of the sequence or source of the DNA.
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Affiliation(s)
- Nao Yonezawa
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Japan
| | - Tomoko Shindo
- Electron Microscope Laboratory, Keio University School of Medicine, Tokyo, Japan
| | - Haruka Oda
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroshi Kimura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Yasushi Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Tokuko Haraguchi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Kazuo Yamagata
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Japan
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2
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Beath EA, Bailey C, Mahantesh Magadam M, Qiu S, McNally KL, McNally FJ. Katanin, kinesin-13, and ataxin-2 inhibit premature interaction between maternal and paternal genomes in C. elegans zygotes. eLife 2024; 13:RP97812. [PMID: 39078879 PMCID: PMC11288632 DOI: 10.7554/elife.97812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024] Open
Abstract
Fertilization occurs before the completion of oocyte meiosis in the majority of animal species and sperm contents move long distances within the zygotes of mouse and C. elegans. If incorporated into the meiotic spindle, paternal chromosomes could be expelled into a polar body resulting in lethal monosomy. Through live imaging of fertilization in C. elegans, we found that the microtubule disassembling enzymes, katanin and kinesin-13 limit long-range movement of sperm contents and that maternal ataxin-2 maintains paternal DNA and paternal mitochondria as a cohesive unit that moves together. Depletion of katanin or double depletion of kinesin-13 and ataxin-2 resulted in the capture of the sperm contents by the meiotic spindle. Thus limiting movement of sperm contents and maintaining cohesion of sperm contents within the zygote both contribute to preventing premature interaction between maternal and paternal genomes.
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Affiliation(s)
- Elizabeth A Beath
- Department of Molecular and Cellular Biology, University of CaliforniaDavisUnited States
| | - Cynthia Bailey
- Department of Molecular and Cellular Biology, University of CaliforniaDavisUnited States
| | | | - Shuyan Qiu
- Department of Molecular and Cellular Biology, University of CaliforniaDavisUnited States
| | - Karen L McNally
- Department of Molecular and Cellular Biology, University of CaliforniaDavisUnited States
| | - Francis J McNally
- Department of Molecular and Cellular Biology, University of CaliforniaDavisUnited States
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3
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Beath EA, Bailey C, Magadum MM, Qiu S, McNally KL, McNally FJ. Katanin, kinesin-13 and ataxin-2 inhibit premature interaction between maternal and paternal genomes in C. elegans zygotes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.12.584242. [PMID: 38559153 PMCID: PMC10979973 DOI: 10.1101/2024.03.12.584242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Fertilization occurs before completion of oocyte meiosis in the majority of animal species and sperm contents move long distances within zygotes of mouse and C. elegans. If incorporated into the meiotic spindle, paternal chromosomes could be expelled into a polar body resulting in lethal monosomy. Through live imaging of fertilization in C. elegans, we found that the microtubule disassembling enzymes, katanin and kinesin-13 limit long range movement of sperm contents and that maternal ataxin-2 maintains paternal DNA and paternal mitochondria as a cohesive unit that moves together. Depletion of katanin or double depletion of kinesin-13 and ataxin-2 resulted in capture of the sperm contents by the meiotic spindle. Thus limiting movement of sperm contents and maintaining cohesion of sperm contents within the zygote both contribute to preventing premature interaction between maternal and paternal genomes.
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Affiliation(s)
- Elizabeth A Beath
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95618, USA
| | - Cynthia Bailey
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95618, USA
| | | | - Shuyan Qiu
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95618, USA
| | - Karen L McNally
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95618, USA
| | - Francis J McNally
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95618, USA
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4
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Bourdais A, Dehapiot B, Halet G. MRCK activates mouse oocyte myosin II for spindle rotation and male pronucleus centration. J Cell Biol 2023; 222:e202211029. [PMID: 37651121 PMCID: PMC10470461 DOI: 10.1083/jcb.202211029] [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: 11/08/2022] [Revised: 06/24/2023] [Accepted: 08/09/2023] [Indexed: 09/01/2023] Open
Abstract
Asymmetric meiotic divisions in oocytes rely on spindle positioning in close vicinity to the cortex. In metaphase II mouse oocytes, eccentric spindle positioning triggers cortical polarization, including the build-up of an actin cap surrounded by a ring of activated myosin II. While the role of the actin cap in promoting polar body formation is established, ring myosin II activation mechanisms and functions have remained elusive. Here, we show that ring myosin II activation requires myotonic dystrophy kinase-related Cdc42-binding kinase (MRCK), downstream of polarized Cdc42. MRCK inhibition resulted in spindle rotation defects during anaphase II, precluding polar body extrusion. Remarkably, disengagement of segregated chromatids from the anaphase spindle could rescue rotation. We further show that the MRCK/myosin II pathway is activated in the fertilization cone and is required for male pronucleus migration toward the center of the zygote. These findings provide novel insights into the mechanism of myosin II activation in oocytes and its role in orchestrating asymmetric division and pronucleus centration.
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Affiliation(s)
- Anne Bourdais
- University of Rennes, CNRS - UMR 6290, Institute of Genetics and Development of Rennes, Rennes, France
| | - Benoit Dehapiot
- University of Rennes, CNRS - UMR 6290, Institute of Genetics and Development of Rennes, Rennes, France
| | - Guillaume Halet
- University of Rennes, CNRS - UMR 6290, Institute of Genetics and Development of Rennes, Rennes, France
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5
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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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6
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Frolikova M, Sur VP, Novotny I, Blazikova M, Vondrakova J, Simonik O, Ded L, Valaskova E, Koptasikova L, Benda A, Postlerova P, Horvath O, Komrskova K. Juno and CD9 protein network organization in oolemma of mouse oocyte. Front Cell Dev Biol 2023; 11:1110681. [PMID: 37635875 PMCID: PMC10450504 DOI: 10.3389/fcell.2023.1110681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 07/18/2023] [Indexed: 08/29/2023] Open
Abstract
Juno and CD9 protein, expressed in oolemma, are known to be essential for sperm-oocyte binding and fusion. Although evidence exists that these two proteins cooperate, their interaction has not yet been demonstrated. Here in, we present Juno and CD9 mutual localization over the surface of mouse metaphase II oocytes captured using the 3D STED super-resolution technique. The precise localization of examined proteins was identified in different compartments of oolemma such as the microvillar membrane, planar membrane between individual microvilli, and the membrane of microvilli-free region. Observed variance in localization of Juno and CD9 was confirmed by analysis of transmission and scanning electron microscopy images, which showed a significant difference in the presence of proteins between selected membrane compartments. Colocalization analysis of super-resolution images based on Pearson's correlation coefficient supported evidence of Juno and CD9 mutual position in the oolemma, which was identified by proximity ligation assay. Importantly, the interaction between Juno and CD9 was detected by co-immunoprecipitation and mass spectrometry in HEK293T/17 transfected cell line. For better understanding of experimental data, mouse Juno and CD9 3D structure were prepared by comparative homology modelling and several protein-protein flexible sidechain dockings were performed using the ClusPro server. The dynamic state of the proteins was studied in real-time at atomic level by molecular dynamics (MD) simulation. Docking and MD simulation predicted Juno-CD9 interactions and stability also suggesting an interactive mechanism. Using the multiscale approach, we detected close proximity of Juno and CD9 within microvillar oolemma however, not in the planar membrane or microvilli-free region. Our findings show yet unidentified Juno and CD9 interaction within the mouse oolemma protein network prior to sperm attachment. These results suggest that a Juno and CD9 interactive network could assist in primary Juno binding to sperm Izumo1 as a prerequisite to subsequent gamete membrane fusion.
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Affiliation(s)
- Michaela Frolikova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
| | - Vishma Pratap Sur
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
| | - Ivan Novotny
- Light Microscopy Core Facility, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Michaela Blazikova
- Light Microscopy Core Facility, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Jana Vondrakova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
| | - Ondrej Simonik
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
| | - Lukas Ded
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
| | - Eliska Valaskova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
| | - Lenka Koptasikova
- Imaging Methods Core Facility at BIOCEV, Faculty of Science, Charles University, Vestec, Czechia
| | - Ales Benda
- Imaging Methods Core Facility at BIOCEV, Faculty of Science, Charles University, Vestec, Czechia
| | - Pavla Postlerova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
- Department of Veterinary Sciences, Faculty of Agrobiology, Food and Natural Resources, University of Life Sciences Prague, Prague, Czechia
| | - Ondrej Horvath
- Light Microscopy Core Facility, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Katerina Komrskova
- Laboratory of Reproductive Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Vestec, Czechia
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
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7
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Silva DM, Akera T. Meiotic drive of noncentromeric loci in mammalian meiosis II eggs. Curr Opin Genet Dev 2023; 81:102082. [PMID: 37406428 PMCID: PMC10527070 DOI: 10.1016/j.gde.2023.102082] [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: 01/23/2023] [Revised: 06/02/2023] [Accepted: 06/08/2023] [Indexed: 07/07/2023]
Abstract
The germline produces haploid gametes through a specialized cell division called meiosis. In general, homologous chromosomes from each parent segregate randomly to the daughter cells during meiosis, providing parental alleles with an equal chance of transmission. Meiotic drivers are selfish elements who cheat this process to increase their transmission rate. In female meiosis, selfish centromeres and noncentromeric drivers cheat by preferentially segregating to the egg cell. Selfish centromeres cheat in meiosis I (MI), while noncentromeric drivers can cheat in both meiosis I and meiosis II (MII). Here, we highlight recent advances on our understanding of the molecular mechanisms underlying these genetic cheating strategies, especially focusing on mammalian systems, and discuss new models of how noncentromeric selfish drivers can cheat in MII eggs.
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Affiliation(s)
- Duilio Mza Silva
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Takashi Akera
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
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8
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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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9
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Wang J, Liu X, Wang H, Qin L, Feng A, Qi D, Wang H, Zhao Y, Kong L, Wang H, Wang L, Hu Z, Xu X. JMJD1C Regulates Megakaryopoiesis in In Vitro Models through the Actin Network. Cells 2022; 11:cells11223660. [PMID: 36429088 PMCID: PMC9688414 DOI: 10.3390/cells11223660] [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: 10/25/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/19/2022] Open
Abstract
The histone demethylase JMJD1C is associated with human platelet counts. The JMJD1C knockout in zebrafish and mice leads to the ablation of megakaryocyte-erythroid lineage anemia. However, the specific expression, function, and mechanism of JMJD1C in megakaryopoiesis remain unknown. Here, we used cell line models, cord blood cells, and thrombocytopenia samples, to detect the JMJD1C expression. ShRNA of JMJD1C and a specific peptide agonist of JMJD1C, SAH-JZ3, were used to explore the JMJD1C function in the cell line models. The actin ratio in megakaryopoiesis for the JMJDC modulation was also measured. Mass spectrometry was used to identify the JMJD1C-interacting proteins. We first show the JMJD1C expression difference in the PMA-induced cell line models, the thrombopoietin (TPO)-induced megakaryocyte differentiation of the cord blood cells, and also the thrombocytopenia patients, compared to the normal controls. The ShRNA of JMJD1C and SAH-JZ3 showed different effects, which were consistent with the expression of JMJD1C in the cell line models. The effort to find the underlying mechanism of JMJD1C in megakaryopoiesis, led to the discovery that SAH-JZ3 decreases F-actin in K562 cells and increases F-actin in MEG-01 cells. We further performed mass spectrometry to identify the potential JMJD1C-interacting proteins and found that the important Ran GTPase interacts with JMJD1C. To sum up, JMJD1C probably regulates megakaryopoiesis by influencing the actin network.
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Affiliation(s)
- Jialing Wang
- Laboratory for Stem Cell and Regenerative Medicine, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Xiaodan Liu
- Laboratory for Stem Cell and Regenerative Medicine, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
| | - Haixia Wang
- Department of Blood Transfusion, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Lili Qin
- Department of Hematology, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Anhua Feng
- Department of Hematology, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Daoxin Qi
- Laboratory for Stem Cell and Regenerative Medicine, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Haihua Wang
- Laboratory for Stem Cell and Regenerative Medicine, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Yao Zhao
- Laboratory for Stem Cell and Regenerative Medicine, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Lihua Kong
- Department of Hematology, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Haiying Wang
- Department of Hematology, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Lin Wang
- The School of Physics and Electronic Information, Weifang University, Weifang 261061, China
| | - Zhenbo Hu
- Laboratory for Stem Cell and Regenerative Medicine, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
- Correspondence: (Z.H.); (X.X.)
| | - Xin Xu
- Laboratory for Stem Cell and Regenerative Medicine, the Affiliated Hospital of Weifang Medical University, Weifang 261031, China
- School of Life Science and Technology, Weifang Medical University, Weifang 261053, China
- Correspondence: (Z.H.); (X.X.)
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10
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Brukman NG, Nakajima KP, Valansi C, Flyak K, Li X, Higashiyama T, Podbilewicz B. A novel function for the sperm adhesion protein IZUMO1 in cell-cell fusion. J Cell Biol 2022; 222:213693. [PMID: 36394541 PMCID: PMC9671554 DOI: 10.1083/jcb.202207147] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/11/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022] Open
Abstract
Mammalian sperm-egg adhesion depends on the trans-interaction between the sperm-specific type I glycoprotein IZUMO1 and its oocyte-specific GPI-anchored receptor JUNO. However, the mechanisms and proteins (fusogens) that mediate the following step of gamete fusion remain unknown. Using live imaging and content mixing assays in a heterologous system and structure-guided mutagenesis, we unveil an unexpected function for IZUMO1 in cell-to-cell fusion. We show that IZUMO1 alone is sufficient to induce fusion, and that this ability is retained in a mutant unable to bind JUNO. On the other hand, a triple mutation in exposed aromatic residues prevents this fusogenic activity without impairing JUNO interaction. Our findings suggest a second function for IZUMO1 as a unilateral mouse gamete fusogen.
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Affiliation(s)
- Nicolas G. Brukman
- Department of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Kohdai P. Nakajima
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Clari Valansi
- Department of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Kateryna Flyak
- Department of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Xiaohui Li
- Department of Biology, Technion - Israel Institute of Technology, Haifa, Israel
| | - Tetsuya Higashiyama
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan,Institute of Transformative Bio-Molecules, Nagoya University, Nagoya, Aichi, Japan,Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan
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11
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Yanagimachi R. Mysteries and unsolved problems of mammalian fertilization and related topics. Biol Reprod 2022; 106:644-675. [PMID: 35292804 PMCID: PMC9040664 DOI: 10.1093/biolre/ioac037] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/10/2022] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
Mammalian fertilization is a fascinating process that leads to the formation of a new individual. Eggs and sperm are complex cells that must meet at the appropriate time and position within the female reproductive tract for successful fertilization. I have been studying various aspects of mammalian fertilization over 60 years. In this review, I discuss many different aspects of mammalian fertilization, some of my laboratory's contribution to the field, and discuss enigmas and mysteries that remain to be solved.
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Affiliation(s)
- Ryuzo Yanagimachi
- Institute for Biogenesis Research, University of Hawaii Medical School, Honolulu, Hawaii, USA
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12
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Brukman NG, Li X, Podbilewicz B. Fusexins, HAP2/GCS1 and Evolution of Gamete Fusion. Front Cell Dev Biol 2022; 9:824024. [PMID: 35083224 PMCID: PMC8784728 DOI: 10.3389/fcell.2021.824024] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 12/21/2021] [Indexed: 12/14/2022] Open
Abstract
Gamete fusion is the climax of fertilization in all sexually reproductive organisms, from unicellular fungi to humans. Similarly to other cell-cell fusion events, gamete fusion is mediated by specialized proteins, named fusogens, that overcome the energetic barriers during this process. In recent years, HAPLESS 2/GENERATIVE CELL-SPECIFIC 1 (HAP2/GCS1) was identified as the fusogen mediating sperm-egg fusion in flowering plants and protists, being both essential and sufficient for the membrane merger in some species. The identification of HAP2/GCS1 in invertebrates, opens the possibility that a similar fusogen may be used in vertebrate fertilization. HAP2/GCS1 proteins share a similar structure with two distinct families of exoplasmic fusogens: the somatic Fusion Family (FF) proteins discovered in nematodes, and class II viral glycoproteins (e.g., rubella and dengue viruses). Altogether, these fusogens form the Fusexin superfamily. While some attributes are shared among fusexins, for example the overall structure and the possibility of assembly into trimers, some other characteristics seem to be specific, such as the presence or not of hydrophobic loops or helices at the distal tip of the protein. Intriguingly, HAP2/GCS1 or other fusexins have neither been identified in vertebrates nor in fungi, raising the question of whether these genes were lost during evolution and were replaced by other fusion machinery or a significant divergence makes their identification difficult. Here, we discuss the biology of HAP2/GCS1, its involvement in gamete fusion and the structural, mechanistic and evolutionary relationships with other fusexins.
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Affiliation(s)
- Nicolas G Brukman
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
| | - Xiaohui Li
- Department of Biology, Technion- Israel Institute of Technology, Haifa, Israel
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13
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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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