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Pan MH, Zhang KH, Wu SL, Pan ZN, Sun MH, Li XH, Ju JQ, Luo SM, Ou XH, Sun SC. FMNL2 regulates actin for endoplasmic reticulum and mitochondria distribution in oocyte meiosis. eLife 2024; 12:RP92732. [PMID: 38747713 PMCID: PMC11095938 DOI: 10.7554/elife.92732] [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: 05/18/2024] Open
Abstract
During mammalian oocyte meiosis, spindle migration and asymmetric cytokinesis are unique steps for the successful polar body extrusion. The asymmetry defects of oocytes will lead to the failure of fertilization and embryo implantation. In present study, we reported that an actin nucleating factor Formin-like 2 (FMNL2) played critical roles in the regulation of spindle migration and organelle distribution in mouse and porcine oocytes. Our results showed that FMNL2 mainly localized at the oocyte cortex and periphery of spindle. Depletion of FMNL2 led to the failure of polar body extrusion and large polar bodies in oocytes. Live-cell imaging revealed that the spindle failed to migrate to the oocyte cortex, which caused polar body formation defects, and this might be due to the decreased polymerization of cytoplasmic actin by FMNL2 depletion in the oocytes of both mice and pigs. Furthermore, mass spectrometry analysis indicated that FMNL2 was associated with mitochondria and endoplasmic reticulum (ER)-related proteins, and FMNL2 depletion disrupted the function and distribution of mitochondria and ER, showing with decreased mitochondrial membrane potential and the occurrence of ER stress. Microinjecting Fmnl2-EGFP mRNA into FMNL2-depleted oocytes significantly rescued these defects. Thus, our results indicate that FMNL2 is essential for the actin assembly, which further involves into meiotic spindle migration and ER/mitochondria functions in mammalian oocytes.
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Affiliation(s)
- Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
- College of Veterinary Medicine, Northwest A&F UniversityShaanxiChina
| | - Kun-Huan Zhang
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Si-Le Wu
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Ming-Hong Sun
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Xiao-Han Li
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Jia-Qian Ju
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Shi-Ming Luo
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General HospitalGuangzhouChina
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General HospitalGuangzhouChina
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
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Rosfelter A, de Labbey G, Chenevert J, Dumollard R, Schaub S, Machaty Z, Besnardeau L, Gonzalez Suarez D, Hebras C, Turlier H, Burgess DR, McDougall A. Reduction of cortical pulling at mitotic entry facilitates aster centration. J Cell Sci 2024; 137:jcs262037. [PMID: 38469748 DOI: 10.1242/jcs.262037] [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: 02/16/2024] [Accepted: 02/23/2024] [Indexed: 03/13/2024] Open
Abstract
Equal cell division relies upon astral microtubule-based centering mechanisms, yet how the interplay between mitotic entry, cortical force generation and long astral microtubules leads to symmetric cell division is not resolved. We report that a cortically located sperm aster displaying long astral microtubules that penetrate the whole zygote does not undergo centration until mitotic entry. At mitotic entry, we find that microtubule-based cortical pulling is lost. Quantitative measurements of cortical pulling and cytoplasmic pulling together with physical simulations suggested that a wavelike loss of cortical pulling at mitotic entry leads to aster centration based on cytoplasmic pulling. Cortical actin is lost from the cortex at mitotic entry coincident with a fall in cortical tension from ∼300pN/µm to ∼100pN/µm. Following the loss of cortical force generators at mitotic entry, long microtubule-based cytoplasmic pulling is sufficient to displace the aster towards the cell center. These data reveal how mitotic aster centration is coordinated with mitotic entry in chordate zygotes.
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Affiliation(s)
- Anne Rosfelter
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Ghislain de Labbey
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR7241 / INSERM U1050, Université PSL, 75002 Paris, France
| | - Janet Chenevert
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Rémi Dumollard
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Sebastien Schaub
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Zoltan Machaty
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Lydia Besnardeau
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Daniel Gonzalez Suarez
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Céline Hebras
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
| | - Hervé Turlier
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR7241 / INSERM U1050, Université PSL, 75002 Paris, France
| | - David R Burgess
- Department of Biology, Boston College, Chestnut Hill, MA 02467, USA
| | - Alex McDougall
- Laboratoire de Biologie du Developpement de Villefranche-sur-mer, Institut de la Mer de Villefranche-sur-mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-mer, France
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3
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Tada S, Yamazaki Y, Yamamoto K, Fujii K, Yamada TG, Hiroi NF, Kimura A, Funahashi A. Switching from weak to strong cortical attachment of microtubules accounts for the transition from nuclear centration to spindle elongation in metazoans. Heliyon 2024; 10:e25494. [PMID: 38356608 PMCID: PMC10865266 DOI: 10.1016/j.heliyon.2024.e25494] [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: 08/20/2023] [Revised: 01/06/2024] [Accepted: 01/29/2024] [Indexed: 02/16/2024] Open
Abstract
The centrosome is a major microtubule organizing center in animal cells. The position of the centrosomes inside the cell is important for cell functions such as cell cycle, and thus should be tightly regulated. Theoretical models based on the forces generated along the microtubules have been proposed to account for the dynamic movements of the centrosomes during the cell cycle. These models, however, often adopted inconsistent assumptions to explain distinct but successive movements, thus preventing a unified model for centrosome positioning. For the centration of the centrosomes, weak attachment of the astral microtubules to the cell cortex was assumed. In contrast, for the separation of the centrosomes during spindle elongation, strong attachment was assumed. Here, we mathematically analyzed these processes at steady state and found that the different assumptions are proper for each process. We experimentally validated our conclusion using nematode and sea urchin embryos by manipulating their shapes. Our results suggest the existence of a molecular mechanism that converts the cortical attachment from weak to strong during the transition from centrosome centration to spindle elongation.
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Affiliation(s)
- Shohei Tada
- Center for Biosciences and Informatics, Graduate School of Fundamental Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan
| | - Yoshitaka Yamazaki
- Center for Biosciences and Informatics, Graduate School of Fundamental Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan
| | - Kazunori Yamamoto
- Cell Architecture Laboratory, Department of Chromosome Science, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Genetics Program, The Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
- Faculty of Applied Bioscience, Kanagawa Institute of Technology, Atsugi, Kanagawa, 243-0292, Japan
- Division of Developmental Physiology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0815, Japan
| | - Ken Fujii
- Cell Architecture Laboratory, Department of Chromosome Science, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Genetics Program, The Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
| | - Takahiro G. Yamada
- Center for Biosciences and Informatics, Graduate School of Fundamental Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan
- Department of Biosciences and Informatics, Keio University, Yokohama, Kanagawa, 223-8522, Japan
| | - Noriko F. Hiroi
- School of Medicine, Keio University, Shinjuku-ward, Tokyo, 160-8582, Japan
- Faculty of Creative Engineering, Kanagawa Institute of Technology, Atsugi, Kanagawa, 243-0292, Japan
| | - Akatsuki Kimura
- Cell Architecture Laboratory, Department of Chromosome Science, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Genetics Program, The Graduate University for Advanced Studies, SOKENDAI, Mishima, Shizuoka 411-8540, Japan
- Center for Data Assimilation Research and Applications, Joint Support-Center for Data Science Research, Research Organization of Information and Systems (ROIS), Tachikawa, 190-8562, Japan
| | - Akira Funahashi
- Center for Biosciences and Informatics, Graduate School of Fundamental Science and Technology, Keio University, Yokohama, Kanagawa, 223-8522, Japan
- Department of Biosciences and Informatics, Keio University, Yokohama, Kanagawa, 223-8522, Japan
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Goda M, Shribak M, Ikeda Z, Okada N, Tani T, Goshima G, Oldenbourg R, Kimura A. Live-cell imaging under centrifugation characterized the cellular force for nuclear centration in the Caenorhabditis elegans embryo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.03.574024. [PMID: 38260704 PMCID: PMC10802357 DOI: 10.1101/2024.01.03.574024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Organelles in cells are appropriately positioned, despite crowding in the cytoplasm. However, our understanding of the force required to move large organelles, such as the nucleus, inside the cytoplasm is limited, in part owing to a lack of accurate methods for measurement. We devised a novel method to apply forces to the nucleus of living, wild-type Caenorhabditis elegans embryos to measure the force generated inside the cell. We utilized a centrifuge polarizing microscope (CPM) to apply centrifugal force and orientation-independent differential interference contrast (OI-DIC) microscopy to characterize the mass density of the nucleus and cytoplasm. The cellular forces moving the nucleus toward the cell center increased linearly at ~14 pN/μm depending on the distance from the center. The frictional coefficient was ~1,100 pN s/μm. The measured values were smaller than previously reported estimates for sea urchin embryos. The forces were consistent with the centrosome-organelle mutual pulling model for nuclear centration. Frictional coefficient was reduced when microtubules were shorter or detached from nuclei in mutant embryos, demonstrating the contribution of astral microtubules. Finally, the frictional coefficient was higher than a theoretical estimate, indicating the contribution of uncharacterized properties of the cytoplasm.
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Affiliation(s)
- Makoto Goda
- Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA
- Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
- Nagoya University, Nagoya 464-8602, Japan
| | - Michael Shribak
- Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA
| | - Zenki Ikeda
- National Institute of Genetics, Mishima 411-8540, Japan
- Sokendai (Graduate University for Advanced Studies) Mishima, Mishima 411-8540, Japan
| | | | - Tomomi Tani
- Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Ikeda 563-8577, Japan
| | - Gohta Goshima
- Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA
- Nagoya University, Nagoya 464-8602, Japan
| | | | - Akatsuki Kimura
- Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA
- National Institute of Genetics, Mishima 411-8540, Japan
- Sokendai (Graduate University for Advanced Studies) Mishima, Mishima 411-8540, Japan
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5
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Kroll J, Hauschild R, Kuznetcov A, Stefanowski K, Hermann MD, Merrin J, Shafeek L, Müller‐Taubenberger A, Renkawitz J. Adaptive pathfinding by nucleokinesis during amoeboid migration. EMBO J 2023; 42:e114557. [PMID: 37987147 PMCID: PMC10711653 DOI: 10.15252/embj.2023114557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 10/31/2023] [Accepted: 11/03/2023] [Indexed: 11/22/2023] Open
Abstract
Motile cells encounter microenvironments with locally heterogeneous mechanochemical composition. Individual compositional parameters, such as chemokines and extracellular matrix pore sizes, are well known to provide guidance cues for pathfinding. However, motile cells face diverse cues at the same time, raising the question of how they respond to multiple and potentially competing signals on their paths. Here, we reveal that amoeboid cells require nuclear repositioning, termed nucleokinesis, for adaptive pathfinding in heterogeneous mechanochemical micro-environments. Using mammalian immune cells and the amoeba Dictyostelium discoideum, we discover that frequent, rapid and long-distance nucleokinesis is a basic component of amoeboid pathfinding, enabling cells to reorientate quickly between locally competing cues. Amoeboid nucleokinesis comprises a two-step polarity switch and is driven by myosin-II forces that readjust the nuclear to the cellular path. Impaired nucleokinesis distorts path adaptions and causes cellular arrest in the microenvironment. Our findings establish that nucleokinesis is required for amoeboid cell navigation. Given that many immune cells, amoebae, and some cancer cells utilize an amoeboid migration strategy, these results suggest that nucleokinesis underlies cellular navigation during unicellular biology, immunity, and disease.
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Affiliation(s)
- Janina Kroll
- Biomedical Center Munich (BMC), Walter Brendel Center of Experimental Medicine, Institute of Cardiovascular Physiology and Pathophysiology, University HospitalLudwig Maximilians University MunichMunichGermany
| | - Robert Hauschild
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Artur Kuznetcov
- Biomedical Center Munich (BMC), Walter Brendel Center of Experimental Medicine, Institute of Cardiovascular Physiology and Pathophysiology, University HospitalLudwig Maximilians University MunichMunichGermany
| | - Kasia Stefanowski
- Biomedical Center Munich (BMC), Walter Brendel Center of Experimental Medicine, Institute of Cardiovascular Physiology and Pathophysiology, University HospitalLudwig Maximilians University MunichMunichGermany
| | - Monika D Hermann
- Biomedical Center Munich (BMC), Walter Brendel Center of Experimental Medicine, Institute of Cardiovascular Physiology and Pathophysiology, University HospitalLudwig Maximilians University MunichMunichGermany
| | - Jack Merrin
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Lubuna Shafeek
- Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Annette Müller‐Taubenberger
- Biomedical Center Munich (BMC), Department of Cell Biology (Anatomy III)Ludwig Maximilians University MunichMunichGermany
| | - Jörg Renkawitz
- Biomedical Center Munich (BMC), Walter Brendel Center of Experimental Medicine, Institute of Cardiovascular Physiology and Pathophysiology, University HospitalLudwig Maximilians University MunichMunichGermany
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6
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Gibson C, Jönsson H, Spelman TA. Mean-field theory approach to three-dimensional nematic phase transitions in microtubules. Phys Rev E 2023; 108:064414. [PMID: 38243538 DOI: 10.1103/physreve.108.064414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 11/16/2023] [Indexed: 01/21/2024]
Abstract
Microtubules are dynamic intracellular fibers that have been observed experimentally to undergo spontaneous self-alignment. We formulate a three-dimensional (3D) mean-field theory model to analyze the nematic phase transition of microtubules growing and interacting within a 3D space, then make a comparison with computational simulations. We identify a control parameter G_{eff} and predict a unique critical value G_{eff}=1.56 for which a phase transition can occur. Furthermore, we show both analytically and using simulations that this predicted critical value does not depend on the presence of zippering. The mean-field theory developed here provides an analytical estimate of microtubule patterning characteristics without running time-consuming simulations and is a step towards bridging scales from microtubule behavior to multicellular simulations.
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Affiliation(s)
- Cameron Gibson
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, United Kingdom
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
- Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843, USA
| | - Henrik Jönsson
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, United Kingdom
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB3 0WA, United Kingdom
- Centre for Environmental and Climate Science, Lund University, SE-223 62 Lund, Sweden
| | - Tamsin A Spelman
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, United Kingdom
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Arjona MI, Najafi J, Minc N. Cytoplasm mechanics and cellular organization. Curr Opin Cell Biol 2023; 85:102278. [PMID: 37979412 DOI: 10.1016/j.ceb.2023.102278] [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: 07/13/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/20/2023]
Abstract
As cells organize spatially or divide, they translocate many micron-scale organelles in their cytoplasm. These include endomembrane vesicles, nuclei, microtubule asters, mitotic spindles, or chromosomes. Organelle motion is powered by cytoskeleton forces but is opposed by viscoelastic forces imparted by the surrounding crowded cytoplasm medium. These resistive forces associated to cytoplasm physcial properties remain generally underappreciated, yet reach significant values to slow down organelle motion or even limit their displacement by springing them back towards their original position. The cytoplasm may also be itself organized in time and space, being for example stiffer or more fluid at certain locations or during particular cell cycle phases. Thus, cytoplasm mechanics may be viewed as a labile module that contributes to organize cells. We here review emerging methods, mechanisms, and concepts to study cytoplasm mechanical properties and their function in organelle positioning, cellular organization and division.
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Affiliation(s)
- María Isabel Arjona
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France; Equipe Labellisée LIGUE Contre le Cancer, France
| | - Javad Najafi
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France; Equipe Labellisée LIGUE Contre le Cancer, France
| | - Nicolas Minc
- Université de Paris, CNRS, Institut Jacques Monod, F-75006 Paris, France; Equipe Labellisée LIGUE Contre le Cancer, France.
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Ezoe K, Miki T, Akaike H, Shimazaki K, Takahashi T, Tanimura Y, Amagai A, Sawado A, Mogi M, Kaneko S, Ueno S, Coticchio G, Cimadomo D, Borini A, Rienzi L, Kato K. Maternal age affects pronuclear and chromatin dynamics, morula compaction and cell polarity, and blastulation of human embryos. Hum Reprod 2023; 38:387-399. [PMID: 36644923 DOI: 10.1093/humrep/dead001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/07/2022] [Indexed: 01/17/2023] Open
Abstract
STUDY QUESTION Does maternal ageing impact early and late morphokinetic and cellular processes of human blastocyst formation? SUMMARY ANSWER Maternal ageing significantly affects pronuclear size and intra- and extra-nuclear dynamics during fertilization, dysregulates cell polarity during compaction, and reduces blastocoel expansion. WHAT IS KNOWN ALREADY In ART, advanced maternal age (AMA) affects oocyte yield, fertilization, and overall developmental competence. However, with the exception of chromosome segregation errors occurring during oocyte meiosis, the molecular and biochemical mechanisms responsible for AMA-related subfertility and reduced embryo developmental competence remain unclear. In particular, studies reporting morphokinetics and cellular alterations during the fertilization and pre-implantation period in women of AMA remain limited. STUDY DESIGN, SIZE, DURATION A total of 2058 fertilized oocytes were stratified by maternal age according to the Society for Assisted Reproductive Technology classification (<35, 35-37, 38-40, 41-42, and >42 years) and retrospectively analysed. AMA effects were assessed in relation to: embryo morphokinetics and morphological alterations; and the presence and distribution of cell polarity markers-Yes-associated protein (YAP) and protein kinase C-ζ (PKC-ζ)-involved in blastocyst morphogenesis. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 1050 cycles from 1050 patients met the inclusion criteria and were analysed. Microinjected oocytes were assessed using a time-lapse culture system. Immature oocytes at oocyte retrieval and mature oocytes not suitable for time-lapse monitoring, owing to an excess of residual corona cells or inadequate orientation for correct observation, were not analysed. Phenomena relevant to meiotic resumption, pronuclear dynamics, cytoplasmic/cortical modifications, cleavage patterns and embryo quality were annotated and compared among groups. Furthermore, 20 human embryos donated for research by consenting couples were used for immunofluorescence. MAIN RESULTS AND THE ROLE OF CHANCE Static microscopic observation revealed that blastocyst formation and expansion were impaired in the 41-42 and >42-year groups (P < 0.0001). The morphological grades of the inner cell mass and trophectoderm were poorer in the >42-year group than those in the <35-year group (P = 0.0022 and P < 0.0001, respectively). Time-lapse microscopic observation revealed a reduction in nucleolus precursor body alignment in female pronuclei in the 41-42 and >42-year groups (P = 0.0010). Female pronuclear area decreased and asynchronous pronuclear breakdown increased in the >42-year group (P = 0.0027 and P < 0.0122, respectively). Developmental speed at cleavage stage, incidence of irregularity of first cleavage, type and duration of blastomere movement, and number of multinucleated cells were comparable among age groups. Delayed embryonic compaction and an increased number of extruded blastomeres were observed in the >42-year group (P = 0.0002 and P = 0.0047, respectively). Blastulation and blastocyst expansion were also delayed in the 41-42 and >42-year groups (P < 0.0001 for both). YAP positivity rate in the outer cells of morulae and embryo PKC-ζ immunoflourescence decreased in the >42-year group (P < 0.0001 for both). LIMITATIONS, REASONS FOR CAUTION At the cellular level, the investigation was limited to cell polarity markers. Cell components of other developmental pathways should be studied in relation to AMA. WIDER IMPLICATIONS OF THE FINDINGS The study indicates that maternal ageing affects the key functions of embryo morphogenesis, irrespective of the well-established influence on the fidelity of oocyte meiosis. STUDY FUNDING/COMPETING INTEREST(S) This study was supported by the participating institutions. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Mai Mogi
- Kato Ladies Clinic, Tokyo, Japan
| | | | | | | | | | | | - Laura Rienzi
- Clinica Valle Giulia, GeneraLife IVF, Rome, Italy.,Department of Biomolecular Sciences, University of Urbino "Carlo Bo", Urbino, Italy
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9
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Nuclear speed and cycle length co-vary with local density during syncytial blastoderm formation in a cricket. Nat Commun 2022; 13:3889. [PMID: 35794113 PMCID: PMC9259616 DOI: 10.1038/s41467-022-31212-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 06/09/2022] [Indexed: 12/20/2022] Open
Abstract
The blastoderm is a broadly conserved stage of early animal development, wherein cells form a layer at the embryo’s periphery. The cellular behaviors underlying blastoderm formation are varied and poorly understood. In most insects, the pre-blastoderm embryo is a syncytium: nuclei divide and move throughout the shared cytoplasm, ultimately reaching the cortex. In Drosophila melanogaster, some early nuclear movements result from pulsed cytoplasmic flows that are coupled to synchronous divisions. Here, we show that the cricket Gryllus bimaculatus has a different solution to the problem of creating a blastoderm. We quantified nuclear dynamics during blastoderm formation in G. bimaculatus embryos, finding that: (1) cytoplasmic flows are unimportant for nuclear movement, and (2) division cycles, nuclear speeds, and the directions of nuclear movement are not synchronized, instead being heterogeneous in space and time. Moreover, nuclear divisions and movements co-vary with local nuclear density. We show that several previously proposed models for nuclear movements in D. melanogaster cannot explain the dynamics of G. bimaculatus nuclei. We introduce a geometric model based on asymmetric pulling forces on nuclei, which recapitulates the patterns of nuclear speeds and orientations of both unperturbed G. bimaculatus embryos, and of embryos physically manipulated to have atypical nuclear densities. Early in insect embryo development, many nuclei share one large cell, travel varied paths and self-organize into a single layer. Donoughe et al. illuminate this process with live-imaging, modeling, and experimental changes to the embryo’s shape.
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10
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Romero JJ, De Rossi MC, Oses C, Echegaray CV, Verneri P, Francia M, Guberman A, Levi V. Nucleus-cytoskeleton communication impacts on OCT4-chromatin interactions in embryonic stem cells. BMC Biol 2022; 20:6. [PMID: 34996451 PMCID: PMC8742348 DOI: 10.1186/s12915-021-01207-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/06/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The cytoskeleton is a key component of the system responsible for transmitting mechanical cues from the cellular environment to the nucleus, where they trigger downstream responses. This communication is particularly relevant in embryonic stem (ES) cells since forces can regulate cell fate and guide developmental processes. However, little is known regarding cytoskeleton organization in ES cells, and thus, relevant aspects of nuclear-cytoskeletal interactions remain elusive. RESULTS We explored the three-dimensional distribution of the cytoskeleton in live ES cells and show that these filaments affect the shape of the nucleus. Next, we evaluated if cytoskeletal components indirectly modulate the binding of the pluripotency transcription factor OCT4 to chromatin targets. We show that actin depolymerization triggers OCT4 binding to chromatin sites whereas vimentin disruption produces the opposite effect. In contrast to actin, vimentin contributes to the preservation of OCT4-chromatin interactions and, consequently, may have a pro-stemness role. CONCLUSIONS Our results suggest roles of components of the cytoskeleton in shaping the nucleus of ES cells, influencing the interactions of the transcription factor OCT4 with the chromatin and potentially affecting pluripotency and cell fate.
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Affiliation(s)
- Juan José Romero
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina
| | - María Cecilia De Rossi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina
| | - Camila Oses
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina
| | - Camila Vázquez Echegaray
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina
| | - Paula Verneri
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina
| | - Marcos Francia
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina
| | - Alejandra Guberman
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina.
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.
| | - Valeria Levi
- Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), CONICET-Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, C1428EGA, Buenos Aires, Argentina.
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EGA, Buenos Aires, Argentina.
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11
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Agsu G, Gaillard J, Cadot B, Blanchoin L, Fabre E, Théry M. Reconstituting the Interaction Between Purified Nuclei and Microtubule Network. Methods Mol Biol 2022; 2430:385-399. [PMID: 35476346 DOI: 10.1007/978-1-0716-1983-4_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The nucleus is the stiffest organelle in the cell. Several morphogenetic processes depend on its deformation such as cell migration, cell differentiation, or senescence. Recent studies have revealed various mechanisms involved in the regulation of nucleus stiffness and deformation. The implication of chromatin swelling, lamin density, actin filament, and microtubule network revealed that nucleus shape is the outcome of a fine balance between various sources of external forces and numerous means of internal resistance. In adherent cells, the actin network is the dominant player in external force production, whereas in nonadherent cells microtubules seem to take over. It is therefore important to set up reconstitution assays in order to decipher the exact contribution of each player in this mechanical balance. In this method, we describe a nucleus purification protocol that is suitable for nonadherent cells. We also show that purified nuclei can interact with microtubules and that nuclei purified from distinct cell types get differentially wrapped into the array of microtubules. A combination with a microtubule gliding assay offers the possibility to counterbalance the binding to the nucleus membrane by active motor-based forces pulling on microtubules. So this protocol allows an in-depth study of microtubule-nucleus interactions in vitro.
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Affiliation(s)
- Gökçe Agsu
- INSERM, CEA, U976 - HIPI, Institut de Recherche Saint Louis, Université de Paris, Paris, France
- CEA, INRA, CNRS, UMR5168 - LPCV, Interdisciplinary Research Institute of Grenoble, Université Grenoble-Alpes, Grenoble, France
| | - Jérémie Gaillard
- INSERM, CEA, U976 - HIPI, Institut de Recherche Saint Louis, Université de Paris, Paris, France
- CEA, INRA, CNRS, UMR5168 - LPCV, Interdisciplinary Research Institute of Grenoble, Université Grenoble-Alpes, Grenoble, France
| | - Bruno Cadot
- INSERM - Sorbonne Université UMR974 - Center for Research in Myology, Paris, France
| | - Laurent Blanchoin
- INSERM, CEA, U976 - HIPI, Institut de Recherche Saint Louis, Université de Paris, Paris, France
- CEA, INRA, CNRS, UMR5168 - LPCV, Interdisciplinary Research Institute of Grenoble, Université Grenoble-Alpes, Grenoble, France
| | - Emmanuelle Fabre
- IRSL, INSERM, U944, CNRS, UMR7212, Université de Paris, Paris, France.
| | - Manuel Théry
- INSERM, CEA, U976 - HIPI, Institut de Recherche Saint Louis, Université de Paris, Paris, France.
- CEA, INRA, CNRS, UMR5168 - LPCV, Interdisciplinary Research Institute of Grenoble, Université Grenoble-Alpes, Grenoble, France.
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12
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Hua LL, Casas C, Mikawa T. Mitotic Antipairing of Homologous Chromosomes. Results Probl Cell Differ 2022; 70:191-220. [PMID: 36348108 PMCID: PMC9731508 DOI: 10.1007/978-3-031-06573-6_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chromosome organization is highly dynamic and plays an essential role during cell function. It was recently found that pairs of the homologous chromosomes are continuously separated at mitosis and display a haploid (1n) chromosome set, or "antipairing," organization in human cells. Here, we provide an introduction to the current knowledge of homologous antipairing in humans and its implications in human disease.
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Affiliation(s)
- Lisa L. Hua
- Department of Biology, Sonoma State University, San Francisco
| | - Christian Casas
- Department of Biology, Sonoma State University, San Francisco
| | - Takashi Mikawa
- Department of Anatomy, Cardiovascular Research Institute, University of California, San Francisco,Corresponding author:
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13
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The Cytoskeleton and Its Roles in Self-Organization Phenomena: Insights from Xenopus Egg Extracts. Cells 2021; 10:cells10092197. [PMID: 34571847 PMCID: PMC8465277 DOI: 10.3390/cells10092197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/18/2021] [Accepted: 08/21/2021] [Indexed: 01/11/2023] Open
Abstract
Self-organization of and by the cytoskeleton is central to the biology of the cell. Since their introduction in the early 1980s, cytoplasmic extracts derived from the eggs of the African clawed-frog, Xenopus laevis, have flourished as a major experimental system to study the various facets of cytoskeleton-dependent self-organization. Over the years, the many investigations that have used these extracts uniquely benefited from their simplified cell cycle, large experimental volumes, biochemical tractability and cell-free nature. Here, we review the contributions of egg extracts to our understanding of the cytoplasmic aspects of self-organization by the microtubule and the actomyosin cytoskeletons as well as the importance of cytoskeletal filaments in organizing nuclear structure and function.
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14
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Ali MF, Kawashima T. Formins control dynamics of F-actin in the central cell of Arabidopsis thaliana. PLANT SIGNALING & BEHAVIOR 2021; 16:1920192. [PMID: 33944667 PMCID: PMC8244771 DOI: 10.1080/15592324.2021.1920192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/16/2021] [Accepted: 04/18/2021] [Indexed: 05/28/2023]
Abstract
In the female gamete of flowering plants, sperm nuclear migration is controlled by a constant inward movement of actin filaments (F-actin) for successful fertilization. This dynamic F-actin movement is ARP2/3-independent, raising the question of how actin nucleation and polymerization is controlled in the female gamete. Using confocal microscopy live-cell imaging in combination with a pharmacological approach, we assessed the involvement of another group of actin nucleators, formins, in F-actin inward movement in the central cell of Arabidopsis thaliana. We identify that the inhibition of the formin function, by formin inhibitor SMIFH2, significantly reduced the dynamic inward movement of F-actin in the central cell, indicating that formins play a major role in actin nucleation required for F-actin inward movement in the central cell.
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Affiliation(s)
- Mohammad Foteh Ali
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA
| | - Tomokazu Kawashima
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, USA
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15
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Ashraf S, Tay YD, Kelly DA, Sawin KE. Microtubule-independent movement of the fission yeast nucleus. J Cell Sci 2021; 134:jcs.253021. [PMID: 33602740 PMCID: PMC8015250 DOI: 10.1242/jcs.253021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 02/09/2021] [Indexed: 12/14/2022] Open
Abstract
Movement of the cell nucleus typically involves the cytoskeleton and either polymerization-based pushing forces or motor-based pulling forces. In the fission yeast Schizosaccharomyces pombe, nuclear movement and positioning are thought to depend on microtubule polymerization-based pushing forces. Here, we describe a novel, microtubule-independent, form of nuclear movement in fission yeast. Microtubule-independent nuclear movement is directed towards growing cell tips, and it is strongest when the nucleus is close to a growing cell tip, and weakest when the nucleus is far from that tip. Microtubule-independent nuclear movement requires actin cables but does not depend on actin polymerization-based pushing or myosin V-based pulling forces. The vesicle-associated membrane protein (VAMP)-associated proteins (VAPs) Scs2 and Scs22, which are critical for endoplasmic reticulum-plasma membrane contact sites in fission yeast, are also required for microtubule-independent nuclear movement. We also find that in cells in which microtubule-based pushing forces are present, disruption of actin cables leads to increased fluctuations in interphase nuclear positioning and subsequent altered septation. Our results suggest two non-exclusive mechanisms for microtubule-independent nuclear movement, which may help illuminate aspects of nuclear positioning in other cells.
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16
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Jimenez AJ, Schaeffer A, De Pascalis C, Letort G, Vianay B, Bornens M, Piel M, Blanchoin L, Théry M. Acto-myosin network geometry defines centrosome position. Curr Biol 2021; 31:1206-1220.e5. [DOI: 10.1016/j.cub.2021.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 11/20/2020] [Accepted: 01/04/2021] [Indexed: 10/22/2022]
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17
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Ali MF, Fatema U, Peng X, Hacker SW, Maruyama D, Sun MX, Kawashima T. ARP2/3-independent WAVE/SCAR pathway and class XI myosin control sperm nuclear migration in flowering plants. Proc Natl Acad Sci U S A 2020; 117:32757-32763. [PMID: 33288691 PMCID: PMC7768783 DOI: 10.1073/pnas.2015550117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
After eukaryotic fertilization, gamete nuclei migrate to fuse parental genomes in order to initiate development of the next generation. In most animals, microtubules control female and male pronuclear migration in the zygote. Flowering plants, on the other hand, have evolved actin filament (F-actin)-based sperm nuclear migration systems for karyogamy. Flowering plants have also evolved a unique double-fertilization process: two female gametophytic cells, the egg and central cells, are each fertilized by a sperm cell. The molecular and cellular mechanisms of how flowering plants utilize and control F-actin for double-fertilization events are largely unknown. Using confocal microscopy live-cell imaging with a combination of pharmacological and genetic approaches, we identified factors involved in F-actin dynamics and sperm nuclear migration in Arabidopsis thaliana (Arabidopsis) and Nicotiana tabacum (tobacco). We demonstrate that the F-actin regulator, SCAR2, but not the ARP2/3 protein complex, controls the coordinated active F-actin movement. These results imply that an ARP2/3-independent WAVE/SCAR-signaling pathway regulates F-actin dynamics in female gametophytic cells for fertilization. We also identify that the class XI myosin XI-G controls active F-actin movement in the Arabidopsis central cell. XI-G is not a simple transporter, moving cargos along F-actin, but can generate forces that control the dynamic movement of F-actin for fertilization. Our results provide insights into the mechanisms that control gamete nuclear migration and reveal regulatory pathways for dynamic F-actin movement in flowering plants.
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Affiliation(s)
- Mohammad Foteh Ali
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312
| | - Umma Fatema
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312
| | - Xiongbo Peng
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, 430072 Wuhan, China
| | - Samuel W Hacker
- Agriculture and Medical Biotechnology Program, University of Kentucky, Lexington, KY 40546-0312
| | - Daisuke Maruyama
- Kihara Institute for Biological Research, Yokohama City University, 244-0813 Yokohama, Kanagawa, Japan
| | - Meng-Xiang Sun
- State Key Laboratory of Hybrid Rice, College of Life Science, Wuhan University, 430072 Wuhan, China
| | - Tomokazu Kawashima
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312;
- Agriculture and Medical Biotechnology Program, University of Kentucky, Lexington, KY 40546-0312
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18
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Starr DA. A network of nuclear envelope proteins and cytoskeletal force generators mediates movements of and within nuclei throughout Caenorhabditis elegans development. Exp Biol Med (Maywood) 2019; 244:1323-1332. [PMID: 31495194 PMCID: PMC6880151 DOI: 10.1177/1535370219871965] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Nuclear migration and anchorage, together referred to as nuclear positioning, are central to many cellular and developmental events. Nuclear positioning is mediated by a conserved network of nuclear envelope proteins that interacts with force generators in the cytoskeleton. At the heart of this network are li nker of n ucleoskeleton and c ytoskeleton (LINC) complexes made of S ad1 and UN C-84 (SUN) proteins at the inner nuclear membrane and K larsicht, A NC-1, and S yne homology (KASH) proteins in the outer nuclear membrane. LINC complexes span the nuclear envelope, maintain nuclear envelope architecture, designate the surface of nuclei distinctly from the contiguous endoplasmic reticulum, and were instrumental in the early evolution of eukaryotes. LINC complexes interact with lamins in the nucleus and with various cytoplasmic KASH effectors from the surface of nuclei. These effectors regulate the cytoskeleton, leading to a variety of cellular outputs including pronuclear migration, nuclear migration through constricted spaces, nuclear anchorage, centrosome attachment to nuclei, meiotic chromosome movements, and DNA damage repair. How LINC complexes are regulated and how they function are reviewed here. The focus is on recent studies elucidating the best-understood network of LINC complexes, those used throughout Caenorhabditis elegans development.
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Affiliation(s)
- Daniel A Starr
- Department of Molecular and Cellular Biology,
University of California, Davis, CA 95616, USA
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19
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Yanakieva I, Erzberger A, Matejčić M, Modes CD, Norden C. Cell and tissue morphology determine actin-dependent nuclear migration mechanisms in neuroepithelia. J Cell Biol 2019; 218:3272-3289. [PMID: 31420451 PMCID: PMC6781452 DOI: 10.1083/jcb.201901077] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/29/2019] [Accepted: 07/18/2019] [Indexed: 11/22/2022] Open
Abstract
Using quantitative live imaging in the developing zebrafish embryo, Yanakieva et al. show that distinct actin-dependent mechanisms position nuclei in neuroepithelia of different morphology. In curved neuroepithelia, a novel formin-dependent mechanism is discovered for which the authors propose a proof-of-principle theoretical model. Correct nuclear position is crucial for cellular function and tissue development. Depending on cell context, however, the cytoskeletal elements responsible for nuclear positioning vary. While these cytoskeletal mechanisms have been intensely studied in single cells, how nuclear positioning is linked to tissue morphology is less clear. Here, we compare apical nuclear positioning in zebrafish neuroepithelia. We find that kinetics and actin-dependent mechanisms of nuclear positioning vary in tissues of different morphology. In straight neuroepithelia, nuclear positioning is controlled by Rho-ROCK–dependent myosin contractility. In contrast, in basally constricted neuroepithelia, a novel formin-dependent pushing mechanism is found for which we propose a proof-of-principle force generation theory. Overall, our data suggest that correct nuclear positioning is ensured by the adaptability of the cytoskeleton to cell and tissue shape. This in turn leads to robust epithelial maturation across geometries. The conclusion that different nuclear positioning mechanisms are favored in tissues of different morphology highlights the importance of developmental context for the execution of intracellular processes.
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Affiliation(s)
- Iskra Yanakieva
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Anna Erzberger
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - Marija Matejčić
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Carl D Modes
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Center for Systems Biology, Dresden, Germany
| | - Caren Norden
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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20
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Ohnishi Y, Kokubu I, Kinoshita T, Okamoto T. Sperm Entry into the Egg Cell Induces the Progression of Karyogamy in Rice Zygotes. PLANT & CELL PHYSIOLOGY 2019; 60:1656-1665. [PMID: 31076767 DOI: 10.1093/pcp/pcz077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 04/16/2019] [Indexed: 05/11/2023]
Abstract
Karyogamy is a prerequisite event for plant embryogenesis, in which dynamic changes in nuclear architecture and the establishment of appropriate gene expression patterns must occur. However, the precise role of the male and female gametes in the progression of karyogamy still remains elusive. Here, we show that the sperm cell possesses the unique property to drive steady and swift nuclear fusion. When we fertilized egg cells with sperm cells in vitro, the immediate fusion of the male and female nuclei in the zygote progressed. This rapid nuclear fusion did not occur when two egg cells were artificially fused. However, the nuclear fusion of two egg nuclei could be accelerated by additional sperm entry or the exogenous application of calcium, suggesting that possible increase of cytosolic Ca2+ level via sperm entry into the egg cell efficiently can facilitate karyogamy. In contrast to zygotes, the egg-egg fusion cells failed to proliferate beyond an early developmental stage. Our transcriptional analyses also revealed the rapid activation of zygotic genes in zygotes, whereas there was no expression in fused cells without the male contribution. Thus, the male sperm cell has the ability to cause immediate karyogamy and to establish appropriate gene expression patterns in the zygote.
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Affiliation(s)
- Yukinosuke Ohnishi
- Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji, Tokyo, Japan
- Kihara Institute for Biological Research, Yokohama City University, Maioka 641-12, Totsuka, Yokohama, Kanagawa, Japan
| | - Iwao Kokubu
- Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji, Tokyo, Japan
| | - Tetsu Kinoshita
- Kihara Institute for Biological Research, Yokohama City University, Maioka 641-12, Totsuka, Yokohama, Kanagawa, Japan
| | - Takashi Okamoto
- Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji, Tokyo, Japan
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21
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Nuclear migration in budding yeasts: position before division. Curr Genet 2019; 65:1341-1346. [PMID: 31152215 DOI: 10.1007/s00294-019-01000-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 05/21/2019] [Accepted: 05/23/2019] [Indexed: 02/03/2023]
Abstract
Positioning the nucleus to a specific cellular location is a prerequisite for high-fidelity transmission of the genetic material to daughter cells. The cellular location of the nucleus just before its division is variable in budding yeast species which rely on a variety of mechanisms for nuclear division. Dynamic growth and shrinkage kinetics of microtubules (MTs) and forces exerted by the MT plus- and minus-end-directed motor proteins empower nuclear movement. Even though the overall process of nuclear migration is largely conserved across budding yeasts, in-depth molecular analyses of newly emerging model budding yeasts began to reveal striking differences from the paradigms that have been established based on the studies performed in the well-characterized budding yeast Saccharomyces cerevisiae. Here, we highlight the molecular players involved in differential nuclear migration in diverse budding yeasts.
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22
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Sallé J, Xie J, Ershov D, Lacassin M, Dmitrieff S, Minc N. Asymmetric division through a reduction of microtubule centering forces. J Cell Biol 2019; 218:771-782. [PMID: 30563876 PMCID: PMC6400563 DOI: 10.1083/jcb.201807102] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/30/2018] [Accepted: 11/30/2018] [Indexed: 01/09/2023] Open
Abstract
Asymmetric divisions are essential for the generation of cell fate and size diversity. They implicate cortical domains where minus end-directed motors, such as dynein, are activated to pull on microtubules to decenter asters attached to centrosomes, nuclei, or spindles. In asymmetrically dividing cells, aster decentration typically follows a centering phase, suggesting a time-dependent regulation in the competition between microtubule centering and decentering forces. Using symmetrically dividing sea urchin zygotes, we generated cortical domains of magnetic particles that spontaneously cluster endogenous dynein activity. These domains efficiently attract asters and nuclei, yielding marked asymmetric divisions. Remarkably, aster decentration only occurred after asters had first reached the cell center. Using intracellular force measurement and models, we demonstrate that this time-regulated imbalance results from a global reduction of centering forces rather than a local maturation of dynein activity at the domain. Those findings define a novel paradigm for the regulation of division asymmetry.
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Affiliation(s)
- Jérémy Sallé
- Institut Jacques Monod, Centre National de la Recherche Scientifique UMR7592 and Université Paris Diderot, Paris, France
| | - Jing Xie
- Institut Jacques Monod, Centre National de la Recherche Scientifique UMR7592 and Université Paris Diderot, Paris, France
| | - Dmitry Ershov
- Institut Jacques Monod, Centre National de la Recherche Scientifique UMR7592 and Université Paris Diderot, Paris, France
| | - Milan Lacassin
- Institut Jacques Monod, Centre National de la Recherche Scientifique UMR7592 and Université Paris Diderot, Paris, France
| | - Serge Dmitrieff
- Institut Jacques Monod, Centre National de la Recherche Scientifique UMR7592 and Université Paris Diderot, Paris, France
| | - Nicolas Minc
- Institut Jacques Monod, Centre National de la Recherche Scientifique UMR7592 and Université Paris Diderot, Paris, France
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23
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Feng M, Dang N, Bai Y, Wei H, Meng L, Wang K, Zhao Z, Chen Y, Gao F, Chen Z, Li L, Zhang S. Differential expression profiles of long non‑coding RNAs during the mouse pronuclear stage under normal gravity and simulated microgravity. Mol Med Rep 2018; 19:155-164. [PMID: 30483791 PMCID: PMC6297735 DOI: 10.3892/mmr.2018.9675] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 10/19/2018] [Indexed: 01/22/2023] Open
Abstract
Pronuclear migration, which is the initial stage of embryonic development and the marker of zygote formation, is a crucial process during mammalian preimplantation embryonic development. Recent studies have revealed that long non-coding RNAs (lncRNAs) serve an important role in early embryonic development. However, the functional regulation of lncRNAs in this process has yet to be elucidated, largely due to the difficulty of assessing gene expression alterations during the very short time in which pronuclear migration occurs. It has previously been reported that migration of the pronucleus of a zygote can be obstructed by simulated microgravity. To investigate pronuclear migration in mice, a rotary cell culture system was employed, which generates simulated microgravity, in order to interfere with murine pronuclear migration. Subsequently, lncRNA sequencing was performed to investigate the mechanism underlying this process. In the present study, a comprehensive analysis of lncRNA profile during the mouse pronuclear stage was conducted, in which 3,307 lncRNAs were identified based on single-cell RNA sequencing data. Furthermore, 52 lncRNAs were identified that were significantly differentially expressed. Subsequently, 10 lncRNAs were selected for validation by reverse transcription-quantitative polymerase chain reaction, in which the same relative expression pattern was observed. The results revealed that 12 lncRNAs (lnc006745, lnc007956, lnc013100, lnc013782, lnc017097, lnc019869, lnc025838, lnc027046, lnc005454, lnc007956, lnc019410 and lnc019607), with tubulin β 4B class IVb or actinin α 4 as target genes, may be associated with the expression of microtubule and microfilament proteins. Binding association was confirmed using a dual-luciferase reporter assay. Finally, Gene Ontology analysis revealed that the target genes of the differentially expressed lncRNAs participated in cellular processes associated with protein transport, binding, catalytic activity, membrane-bounded organelle, protein complex and the cortical cytoskeleton. These findings suggested that these lncRNAs may be associated with migration of the mouse pronucleus.
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Affiliation(s)
- Meiying Feng
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Nannan Dang
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Yinshan Bai
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Hengxi Wei
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Li Meng
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Kai Wang
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Zhihong Zhao
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Yun Chen
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Fenglei Gao
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Zhilin Chen
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Li Li
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
| | - Shouquan Zhang
- College of Animal Science, National Engineering Research Center for Breeding Swine Industry, Guangdong Provincial Key Lab of Agro‑Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong 510642, P.R. China
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24
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Uraji J, Scheffler K, Schuh M. Functions of actin in mouse oocytes at a glance. J Cell Sci 2018; 131:131/22/jcs218099. [PMID: 30467138 DOI: 10.1242/jcs.218099] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Gametes undergo a specialized and reductional cell division termed meiosis. Female gametes (oocytes) undergo two rounds of meiosis; the first meiotic division produces the fertilizable egg, while the second meiotic division occurs upon fertilization. Both meiotic divisions are highly asymmetric, producing a large egg and small polar bodies. Actin takes over various essential function during oocyte meiosis, many of which commonly rely on microtubules in mitotic cells. Specifically, the actin network has been linked to long-range vesicle transport, nuclear positioning, spindle migration and anchorage, polar body extrusion and accurate chromosome segregation in mammalian oocytes. In this Cell Science at a Glance article and the accompanying poster, we summarize the many functions of the actin cytoskeleton in oocytes, with a focus on findings from the mouse model system.
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Affiliation(s)
- Julia Uraji
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Kathleen Scheffler
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Melina Schuh
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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25
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Saade M, Blanco-Ameijeiras J, Gonzalez-Gobartt E, Martí E. A centrosomal view of CNS growth. Development 2018; 145:145/21/dev170613. [DOI: 10.1242/dev.170613] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
ABSTRACT
Embryonic development of the central nervous system (CNS) requires the proliferation of neural progenitor cells to be tightly regulated, allowing the formation of an organ with the right size and shape. This includes regulation of both the spatial distribution of mitosis and the mode of cell division. The centrosome, which is the main microtubule-organizing centre of animal cells, contributes to both of these processes. Here, we discuss the impact that centrosome-mediated control of cell division has on the shape of the overall growing CNS. We also review the intrinsic properties of the centrosome, both in terms of its molecular composition and its signalling capabilities, and discuss the fascinating notion that intrinsic centrosomal asymmetries in dividing neural progenitor cells are instructive for neurogenesis. Finally, we discuss the genetic links between centrosome dysfunction during development and the aetiology of microcephaly.
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Affiliation(s)
- Murielle Saade
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Parc Científic de Barcelona, Baldiri i Reixac 20, Barcelona 08028, Spain
| | - Jose Blanco-Ameijeiras
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Parc Científic de Barcelona, Baldiri i Reixac 20, Barcelona 08028, Spain
| | - Elena Gonzalez-Gobartt
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Parc Científic de Barcelona, Baldiri i Reixac 20, Barcelona 08028, Spain
| | - Elisa Martí
- Department of Developmental Biology, Instituto de Biología Molecular de Barcelona, Parc Científic de Barcelona, Baldiri i Reixac 20, Barcelona 08028, Spain
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26
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Duan X, Sun SC. Actin cytoskeleton dynamics in mammalian oocyte meiosis†. Biol Reprod 2018; 100:15-24. [DOI: 10.1093/biolre/ioy163] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 07/11/2018] [Indexed: 12/12/2022] Open
Affiliation(s)
- Xing Duan
- 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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27
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Haupt A, Minc N. How cells sense their own shape - mechanisms to probe cell geometry and their implications in cellular organization and function. J Cell Sci 2018; 131:131/6/jcs214015. [PMID: 29581183 DOI: 10.1242/jcs.214015] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cells come in a variety of shapes that most often underlie their functions. Regulation of cell morphogenesis implies that there are mechanisms for shape sensing that still remain poorly appreciated. Global and local cell geometry features, such as aspect ratio, size or membrane curvature, may be probed by intracellular modules, such as the cytoskeleton, reaction-diffusion systems or molecular complexes. In multicellular tissues, cell shape emerges as an important means to transduce tissue-inherent chemical and mechanical cues into intracellular organization. One emergent paradigm is that cell-shape sensing is most often based upon mechanisms of self-organization, rather than determinism. Here, we review relevant work that has elucidated some of the core principles of how cellular geometry may be conveyed into spatial information to guide processes, such as polarity, signaling, morphogenesis and division-plane positioning.
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Affiliation(s)
- Armin Haupt
- Institut Jacques Monod, CNRS UMR7592 and Université Paris Diderot, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
| | - Nicolas Minc
- Institut Jacques Monod, CNRS UMR7592 and Université Paris Diderot, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
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28
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De Simone A, Spahr A, Busso C, Gönczy P. Uncovering the balance of forces driving microtubule aster migration in C. elegans zygotes. Nat Commun 2018; 9:938. [PMID: 29507295 PMCID: PMC5838244 DOI: 10.1038/s41467-018-03118-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 01/18/2018] [Indexed: 11/09/2022] Open
Abstract
Microtubule asters must be positioned precisely within cells. How forces generated by molecular motors such as dynein are integrated in space and time to enable such positioning remains unclear. In particular, whereas aster movements depend on the drag caused by cytoplasm viscosity, in vivo drag measurements are lacking, precluding a thorough understanding of the mechanisms governing aster positioning. Here, we investigate this fundamental question during the migration of asters and pronuclei in C. elegans zygotes, a process essential for the mixing of parental genomes. Detailed quantification of these movements using the female pronucleus as an in vivo probe establish that the drag coefficient of the male-asters complex is approximately five times that of the female pronucleus. Further analysis of embryos lacking cortical dynein, the connection between asters and male pronucleus, or the male pronucleus altogether, uncovers the balance of dynein-driven forces that accurately position microtubule asters in C. elegans zygotes. Microtubule asters are positioned precisely within cells by forces generated by molecular motors, but it is unclear how these are integrated in space and time. Here the authors perform in vivo drag measurements and genetic manipulations to determine the balance of forces that position microtubule asters in C. elegans zygotes.
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Affiliation(s)
- A De Simone
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015, Lausanne, Switzerland.,Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - A Spahr
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - C Busso
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - P Gönczy
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), 1015, Lausanne, Switzerland.
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29
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Xiang X. Nuclear movement in fungi. Semin Cell Dev Biol 2017; 82:3-16. [PMID: 29241689 DOI: 10.1016/j.semcdb.2017.10.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/17/2017] [Accepted: 10/23/2017] [Indexed: 12/22/2022]
Abstract
Nuclear movement within a cell occurs in a variety of eukaryotic organisms including yeasts and filamentous fungi. Fungal molecular genetic studies identified the minus-end-directed microtubule motor cytoplasmic dynein as a critical protein for nuclear movement or orientation of the mitotic spindle contained in the nucleus. Studies in the budding yeast first indicated that dynein anchored at the cortex via its anchoring protein Num1 exerts pulling force on an astral microtubule to orient the anaphase spindle across the mother-daughter axis before nuclear division. Prior to anaphase, myosin V interacts with the plus end of an astral microtubule via Kar9-Bim1/EB1 and pulls the plus end along the actin cables to move the nucleus/spindle close to the bud neck. In addition, pushing or pulling forces generated from cortex-linked polymerization or depolymerization of microtubules drive nuclear movements in yeasts and possibly also in filamentous fungi. In filamentous fungi, multiple nuclei within a hyphal segment undergo dynein-dependent back-and-forth movements and their positioning is also influenced by cytoplasmic streaming toward the hyphal tip. In addition, nuclear movement occurs at various stages of fungal development and fungal infection of plant tissues. This review discusses our current understanding on the mechanisms of nuclear movement in fungal organisms, the importance of nuclear positioning and the regulatory strategies that ensure the proper positioning of nucleus/spindle.
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Affiliation(s)
- Xin Xiang
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences - F. Edward Hébert School of Medicine, Bethesda, MD, USA.
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30
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Lee YL, Burke B. LINC complexes and nuclear positioning. Semin Cell Dev Biol 2017; 82:67-76. [PMID: 29191370 DOI: 10.1016/j.semcdb.2017.11.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 12/14/2022]
Abstract
One of the characteristics of eukaryotic cells is their structural plasticity associated with the ability to carry out a broad range of complex functions, both autonomously and as components of tissues and organs. Major cellular rearrangements can be observed in various systems from meiosis in fission yeast, through dermal differentiation in nematodes, to muscle and neuronal development in vertebrates. Each of these processes involves oftentimes dramatic relocation of the nucleus within the cell. During the last decade it has become apparent that the nuclear periphery represents a nexus of cytoskeletal interactions that are involved not only in nuclear movement but also in the distribution and dissemination of mechanical forces throughout the cell. Nucleocytoskeletal coupling is mediated in large part by SUN- and KASH-domain proteins of the nuclear membranes, that together assemble to form LINC (Linker of the Nucleoskeleton and Cytoskeleton) complexes. In this review we will describe how the LINC complex repertoire contributes to nuclear positioning and chromosome dynamics in a variety of cellular contexts.
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Affiliation(s)
- Yin Loon Lee
- Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore
| | - Brian Burke
- Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
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31
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Nazockdast E, Rahimian A, Needleman D, Shelley M. Cytoplasmic flows as signatures for the mechanics of mitotic positioning. Mol Biol Cell 2017; 28:3261-3270. [PMID: 28331070 PMCID: PMC5687028 DOI: 10.1091/mbc.e16-02-0108] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 02/27/2017] [Accepted: 03/16/2017] [Indexed: 12/03/2022] Open
Abstract
The proper positioning of mitotic spindle in the single-cell Caenorhabditis elegans embryo is achieved initially by the migration and rotation of the pronuclear complex (PNC) and its two associated astral microtubules (MTs). Pronuclear migration produces global cytoplasmic flows that couple the mechanics of all MTs, the PNC, and the cell periphery with each other through their hydrodynamic interactions (HIs). We present the first computational study that explicitly accounts for detailed HIs between the cytoskeletal components and demonstrate the key consequences of HIs for the mechanics of pronuclear migration. First, we show that, because of HIs between the MTs, the cytoplasm-filled astral MTs behave like a porous medium, with its permeability decreasing with increasing the number of MTs. We then directly study the dynamics of PNC migration under various force-transduction models, including the pushing or pulling of MTs at the cortex and the pulling of MTs by cytoplasmically bound force generators. Although achieving proper position and orientation on reasonable time scales does not uniquely choose a model, we find that each model produces a different signature in its induced cytoplasmic flow. We suggest that cytoplasmic flows can be used to differentiate between mechanisms.
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Affiliation(s)
- Ehssan Nazockdast
- Center for Computational Biology, Flatiron Institute, New York, NY 10010
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012
| | - Abtin Rahimian
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012
| | - Daniel Needleman
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138
| | - Michael Shelley
- Center for Computational Biology, Flatiron Institute, New York, NY 10010
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012
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32
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Zhao ZL, Liu ZY, Du J, Xu GK, Feng XQ. A Dynamic Biochemomechanical Model of Geometry-Confined Cell Spreading. Biophys J 2017; 112:2377-2386. [PMID: 28591610 DOI: 10.1016/j.bpj.2017.04.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 04/11/2017] [Accepted: 04/13/2017] [Indexed: 01/09/2023] Open
Abstract
Cell spreading is involved in many physiological and pathological processes. The spreading behavior of a cell significantly depends on its microenvironment, but the biochemomechanical mechanisms of geometry-confined cell spreading remain unclear. A dynamic model is here established to investigate the spreading of cells confined in a finite region with different geometries, e.g., rectangle, ellipse, triangle, and L-shape. This model incorporates both biophysical and biochemical mechanisms, including actin polymerization, integrin-mediated binding, plasma viscoelasticity, and the elasticity of membranes and microtubules. We simulate the dynamic configurational evolution of a cell under different geometric microenvironments, including the angular distribution of microtubule forces and the deformation of the nucleus. The results indicate that the positioning of the cell-division plane is affected by its boundary confinement: a cell divides in a plane perpendicular to its minimal principal axis of inertia of area. In addition, the effects of such physical factors as the adhesive bond density, membrane tension, and microtubule number are examined on the cell spreading dynamics. The theoretical predictions show a good agreement with relevant experimental results. This work sheds light on the geometry-confined spreading dynamics of cells and holds potential applications in regulating cell division and designing cell-based sensors.
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Affiliation(s)
- Zi-Long Zhao
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China
| | - Zong-Yuan Liu
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China
| | - Jing Du
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China
| | - Guang-Kui Xu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, China
| | - Xi-Qiao Feng
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China.
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33
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Abstract
Moving the nucleus to a specific position within the cell is an important event during many cell and developmental processes. Several different molecular mechanisms exist to position nuclei in various cell types. In this Commentary, we review the recent progress made in elucidating mechanisms of nuclear migration in a variety of important developmental models. Genetic approaches to identify mutations that disrupt nuclear migration in yeast, filamentous fungi, Caenorhabditis elegans, Drosophila melanogaster and plants led to the identification of microtubule motors, as well as Sad1p, UNC-84 (SUN) domain and Klarsicht, ANC-1, Syne homology (KASH) domain proteins (LINC complex) that function to connect nuclei to the cytoskeleton. We focus on how these proteins and various mechanisms move nuclei during vertebrate development, including processes related to wound healing of fibroblasts, fertilization, developing myotubes and the developing central nervous system. We also describe how nuclear migration is involved in cells that migrate through constricted spaces. On the basis of these findings, it is becoming increasingly clear that defects in nuclear positioning are associated with human diseases, syndromes and disorders.
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Affiliation(s)
- Courtney R Bone
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Daniel A Starr
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
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34
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New nuclear and perinuclear functions of formins. Biochem Soc Trans 2017; 44:1701-1708. [PMID: 27913680 DOI: 10.1042/bst20160187] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/29/2016] [Accepted: 09/02/2016] [Indexed: 12/12/2022]
Abstract
Formin family proteins (formins) represent an evolutionary conserved protein family encoded in the genome of a wide range of eukaryotes. Formins are hallmarked by a formin homology 1 (FH1) domain juxtaposed to an FH2 domain whereby they control actin and microtubule dynamics. Not surprisingly, formins are best known as key regulators of the cytoskeleton in a variety of morphogenetic processes. However, mounting evidence implicates several formins in the assembly and organization of actin within and around the nucleus. In addition, actin-independent roles for formins have recently been discovered. In this mini-review, we summarize these findings and highlight the novel nuclear and perinulcear functions of formins. In light of the emerging new biology of formins, we also discuss the fundamental principles governing the versatile activity and multimodal regulation of these proteins.
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35
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She ZY, Yang WX. Molecular mechanisms of kinesin-14 motors in spindle assembly and chromosome segregation. J Cell Sci 2017; 130:2097-2110. [DOI: 10.1242/jcs.200261] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
ABSTRACT
During eukaryote cell division, molecular motors are crucial regulators of microtubule organization, spindle assembly, chromosome segregation and intracellular transport. The kinesin-14 motors are evolutionarily conserved minus-end-directed kinesin motors that occur in diverse organisms from simple yeasts to higher eukaryotes. Members of the kinesin-14 motor family can bind to, crosslink or slide microtubules and, thus, regulate microtubule organization and spindle assembly. In this Commentary, we present the common subthemes that have emerged from studies of the molecular kinetics and mechanics of kinesin-14 motors, particularly with regard to their non-processive movement, their ability to crosslink microtubules and interact with the minus- and plus-ends of microtubules, and with microtubule-organizing center proteins. In particular, counteracting forces between minus-end-directed kinesin-14 and plus-end-directed kinesin-5 motors have recently been implicated in the regulation of microtubule nucleation. We also discuss recent progress in our current understanding of the multiple and fundamental functions that kinesin-14 motors family members have in important aspects of cell division, including the spindle pole, spindle organization and chromosome segregation.
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Affiliation(s)
- Zhen-Yu She
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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36
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Barbosa DJ, Duro J, Prevo B, Cheerambathur DK, Carvalho AX, Gassmann R. Dynactin binding to tyrosinated microtubules promotes centrosome centration in C. elegans by enhancing dynein-mediated organelle transport. PLoS Genet 2017; 13:e1006941. [PMID: 28759579 PMCID: PMC5552355 DOI: 10.1371/journal.pgen.1006941] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/10/2017] [Accepted: 07/25/2017] [Indexed: 12/01/2022] Open
Abstract
The microtubule-based motor dynein generates pulling forces for centrosome centration and mitotic spindle positioning in animal cells. How the essential dynein activator dynactin regulates these functions of the motor is incompletely understood. Here, we dissect the role of dynactin's microtubule binding activity, located in the p150 CAP-Gly domain and an adjacent basic patch, in the C. elegans zygote. Analysis of p150 mutants engineered by genome editing suggests that microtubule tip tracking of dynein-dynactin is dispensable for targeting the motor to the cell cortex and for generating robust cortical pulling forces. Instead, mutations in p150's CAP-Gly domain inhibit cytoplasmic pulling forces responsible for centration of centrosomes and attached pronuclei. The centration defects are mimicked by mutations of α-tubulin's C-terminal tyrosine, and both p150 CAP-Gly and tubulin tyrosine mutants decrease the frequency of early endosome transport from the cell periphery towards centrosomes during centration. Our results suggest that p150 GAP-Gly domain binding to tyrosinated microtubules promotes initiation of dynein-mediated organelle transport in the dividing one-cell embryo, and that this function of p150 is critical for generating cytoplasmic pulling forces for centrosome centration.
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Affiliation(s)
- Daniel J. Barbosa
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
| | - Joana Duro
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
| | - Bram Prevo
- Ludwig Institute for Cancer Research/Dept of Cellular & Molecular Medicine UCSD, La Jolla, CA, United States of America
| | - Dhanya K. Cheerambathur
- Ludwig Institute for Cancer Research/Dept of Cellular & Molecular Medicine UCSD, La Jolla, CA, United States of America
| | - Ana X. Carvalho
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
| | - Reto Gassmann
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
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37
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Tariq Z, Zhang H, Chia-Liu A, Shen Y, Gete Y, Xiong ZM, Tocheny C, Campanello L, Wu D, Losert W, Cao K. Lamin A and microtubules collaborate to maintain nuclear morphology. Nucleus 2017; 8:433-446. [PMID: 28557611 DOI: 10.1080/19491034.2017.1320460] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Lamin A (LA) is a critical structural component of the nuclear lamina. Mutations within the LA gene (LMNA) lead to several human disorders, most striking of which is Hutchinson-Gilford Progeria Syndrome (HGPS), a premature aging disorder. HGPS cells are best characterized by an abnormal nuclear morphology known as nuclear blebbing, which arises due to the accumulation of progerin, a dominant mutant form of LA. The microtubule (MT) network is known to mediate changes in nuclear morphology in the context of specific events such as mitosis, cell polarization, nucleus positioning and cellular migration. What is less understood is the role of the microtubule network in determining nuclear morphology during interphase. In this study, we elucidate the role of the cytoskeleton in regulation and misregulation of nuclear morphology through perturbations of both the lamina and the microtubule network. We found that LA knockout cells exhibit a crescent shape morphology associated with the microtubule-organizing center. Furthermore, this crescent shape ameliorates upon treatment with MT drugs, Nocodazole or Taxol. Expression of progerin, in LA knockout cells also rescues the crescent shape, although the response to Nocodazole or Taxol treatment is altered in comparison to cells expressing LA. Together these results describe a collaborative effort between LA and the MT network to maintain nuclear morphology.
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Affiliation(s)
- Zeshan Tariq
- a Department of Cell Biology and Molecular Genetics , University of Maryland , College Park , MD , USA
| | - Haoyue Zhang
- a Department of Cell Biology and Molecular Genetics , University of Maryland , College Park , MD , USA
| | - Alexander Chia-Liu
- b Department of Physics , University of Maryland , College Park , MD , USA
| | - Yang Shen
- b Department of Physics , University of Maryland , College Park , MD , USA
| | - Yantenew Gete
- a Department of Cell Biology and Molecular Genetics , University of Maryland , College Park , MD , USA
| | - Zheng-Mei Xiong
- a Department of Cell Biology and Molecular Genetics , University of Maryland , College Park , MD , USA
| | - Claire Tocheny
- c Department of Biology , The College of William and Mary , Williamsburg , VA , USA
| | - Leonard Campanello
- b Department of Physics , University of Maryland , College Park , MD , USA
| | - Di Wu
- a Department of Cell Biology and Molecular Genetics , University of Maryland , College Park , MD , USA
| | - Wolfgang Losert
- b Department of Physics , University of Maryland , College Park , MD , USA
| | - Kan Cao
- a Department of Cell Biology and Molecular Genetics , University of Maryland , College Park , MD , USA
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38
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Stroud MJ, Feng W, Zhang J, Veevers J, Fang X, Gerace L, Chen J. Nesprin 1α2 is essential for mouse postnatal viability and nuclear positioning in skeletal muscle. J Cell Biol 2017; 216:1915-1924. [PMID: 28533284 PMCID: PMC5496623 DOI: 10.1083/jcb.201612128] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 03/08/2017] [Accepted: 04/18/2017] [Indexed: 12/13/2022] Open
Abstract
Defects in nuclear positioning occur in muscle diseases and correlate with muscle dysfunction. In this study, Stroud et al. show that nesprin 1α2 is the fundamental nesprin 1 isoform for nuclear positioning, skeletal muscle function, and postnatal viability. The position of the nucleus in a cell is controlled by interactions between the linker of nucleoskeleton and cytoskeleton (LINC) complex and the cytoskeleton. Defects in nuclear positioning and abnormal aggregation of nuclei occur in many muscle diseases and correlate with muscle dysfunction. Nesprin 1, which includes multiple isoforms, is an integral component of the LINC complex, critical for nuclear positioning and anchorage in skeletal muscle, and is thought to provide an essential link between nuclei and actin. However, previous studies have yet to identify which isoform is responsible. To elucidate this, we generated a series of nesprin 1 mutant mice. We showed that the actin-binding domains of nesprin 1 were dispensable, whereas nesprin 1α2, which lacks actin-binding domains, was crucial for postnatal viability, nuclear positioning, and skeletal muscle function. Furthermore, we revealed that kinesin 1 was displaced in fibers of nesprin 1α2–knockout mice, suggesting that this interaction may play an important role in positioning of myonuclei and functional skeletal muscle.
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Affiliation(s)
- Matthew J Stroud
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Wei Feng
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Jianlin Zhang
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Jennifer Veevers
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Xi Fang
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Larry Gerace
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA
| | - Ju Chen
- Department of Medicine, University of California, San Diego, La Jolla, CA
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39
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Ohnishi Y, Okamoto T. Nuclear migration during karyogamy in rice zygotes is mediated by continuous convergence of actin meshwork toward the egg nucleus. JOURNAL OF PLANT RESEARCH 2017; 130:339-348. [PMID: 27995374 DOI: 10.1007/s10265-016-0892-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/10/2016] [Indexed: 05/20/2023]
Abstract
Fertilization is comprised of two sequential fusion processes; plasmogamy and karyogamy. Karyogamy completes with migration and fusion of the male and female nuclei in the fused cell. In animals, microtubules organized by the centrosome control female/male pronuclei migration. In contrast, the nuclear migration in fused gametes of angiosperms is controlled by actin filaments, but the mechanism that regulates actin filament-dependent nuclear migration is not clear. In this study, we prepared fused rice (Oryza sativa L.) gametes/zygotes using in vitro fertilization and observed the spatial and temporal movements of actin filaments and sperm nuclei. Our results show that actin filaments in egg cells form a meshwork structure surrounding the nuclei. Quantitative analysis of the actin meshwork dynamics suggests that actin meshwork converges toward the egg nucleus. In egg cells fused with sperm cells, actin filaments appeared to interact with a portion of the sperm nuclear membrane. The velocity of the actin filaments was positively correlated with the velocity of the sperm nucleus during karyogamy. These results suggest that sperm nuclear membrane and actin filaments physically interact with each other during karyogamy, and that the sperm nucleus migrates toward the egg nucleus through the convergence of the actin meshwork. Interestingly, actin filament velocity increased promptly after gamete fusion and was further elevated during nuclear fusion. In addition to the migration of gamete nuclei, convergence of actin meshwork may also be critical during early zygotic developments.
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Affiliation(s)
- Yukinosuke Ohnishi
- Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji, Tokyo, 192-0397, Japan.
| | - Takashi Okamoto
- Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji, Tokyo, 192-0397, Japan
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40
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Peng X, Yan T, Sun M. The WASP-Arp2/3 complex signal cascade is involved in actin-dependent sperm nuclei migration during double fertilization in tobacco and maize. Sci Rep 2017; 7:43161. [PMID: 28225074 PMCID: PMC5320560 DOI: 10.1038/srep43161] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/20/2017] [Indexed: 12/14/2022] Open
Abstract
Sperm nuclear migration during fertilization in Arabidopsis and rice has recently been found to be actin-dependent, but the driving force behind this actin cytoskeleton-dependent motion is unclear. Here, we confirmed that the actin-dependent sperm nuclei migration during fertilization is a conserved mechanism in plants. Using in vitro fertilization systems, we showed that a functional actin is also essential in maize and tobacco for sperm nuclei migration after gamete membrane fusion. Cytoskeleton depolymerization inhibitor treatments supported the view that sperm nuclei migration is actin-dependent but microtubule-independent in both egg cell and central cell during double fertilization. We further revealed that the actin-based motor myosin is not the driving force for sperm nuclear migration in maize and tobacco. The WASP-Arp2/3 complex signal cascade is shown here to be involved in the regulation of sperm nuclear migration in maize and tobacco. It is interesting that sperm nuclei migration within somatic cell also need WASP-Arp2/3 complex signal cascade and actin, suggesting that the mechanism of sperm nuclear migration is not gamete specific.
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Affiliation(s)
- Xiongbo Peng
- State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Tingting Yan
- State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Mengxiang Sun
- State Key Laboratory for Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
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41
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Tekleyohans DG, Mao Y, Kägi C, Stierhof YD, Groß-Hardt R. Polyspermy barriers: a plant perspective. CURRENT OPINION IN PLANT BIOLOGY 2017; 35:131-137. [PMID: 27951463 PMCID: PMC7610644 DOI: 10.1016/j.pbi.2016.11.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 05/19/2023]
Abstract
A common denominator of sexual reproduction in many eukaryotic species is the exposure of an egg to excess sperm to maximize the chances of reproductive success. To avoid potential harmful or deleterious consequences of supernumerary sperm fusion to a single female gamete (polyspermy), many eukaryotes, including plants, have evolved barriers preventing polyspermy. Typically, these checkpoints are implemented at different stages in the reproduction process. The virtual absence of unambiguous reports of naturally occurring egg cell polyspermy in flowering plants is likely reflecting the success of this multiphasic strategy and highlights the difficulty to trace this presumably rare event. We here focus on potential polyspermy avoidance mechanisms in plants and discuss them in light of analogous processes in animals.
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Affiliation(s)
- Dawit G Tekleyohans
- Bremen University, Molecular Genetics, Leobenerstr. 5, 28359, Bremen, Germany
| | - Yanbo Mao
- Bremen University, Molecular Genetics, Leobenerstr. 5, 28359, Bremen, Germany
| | - Christina Kägi
- Federal Office for Agriculture FOAG, Mattenhofstr. 5, 3003 Bern, Switzerland
| | | | - Rita Groß-Hardt
- Bremen University, Molecular Genetics, Leobenerstr. 5, 28359, Bremen, Germany.
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42
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Wu HY, Nazockdast E, Shelley MJ, Needleman DJ. Forces positioning the mitotic spindle: Theories, and now experiments. Bioessays 2016; 39. [PMID: 28026040 DOI: 10.1002/bies.201600212] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The position of the spindle determines the position of the cleavage plane, and is thus crucial for cell division. Although spindle positioning has been extensively studied, the underlying forces ultimately responsible for moving the spindle remain poorly understood. A recent pioneering study by Garzon-Coral et al. uses magnetic tweezers to perform the first direct measurements of the forces involved in positioning the mitotic spindle. Combining this with molecular perturbations and geometrical effects, they use their data to argue that the forces that keep the spindle in its proper position for cell division arise from astral microtubules growing and pushing against the cell's cortex. Here, we review these ground-breaking experiments, the various biomechanical models for spindle positioning that they seek to differentiate, and discuss new questions raised by these measurements.
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Affiliation(s)
- Hai-Yin Wu
- Department of Physics, Harvard University, Cambridge, MA, USA
- Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA, USA
| | - Ehssan Nazockdast
- Center for Computational Biology, Simons Foundation, New York, NY, USA
| | - Michael J Shelley
- Center for Computational Biology, Simons Foundation, New York, NY, USA
- Courant Institute of Mathematical Sciences, New York University, New York, NY, USA
| | - Daniel J Needleman
- Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA, USA
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
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43
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He L, Chen W, Wu PH, Jimenez A, Wong BS, San A, Konstantopoulos K, Wirtz D. Local 3D matrix confinement determines division axis through cell shape. Oncotarget 2016; 7:6994-7011. [PMID: 26515603 PMCID: PMC4872764 DOI: 10.18632/oncotarget.5848] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/03/2015] [Indexed: 12/24/2022] Open
Abstract
How the division axis is determined in mammalian cells embedded in three-dimensional (3D) matrices remains elusive, despite that many types of cells divide in 3D environments. Cells on two-dimensional (2D) substrates typically round up completely to divide. Here, we show that in 3D collagen matrices, mammalian cells such as HT1080 human fibrosarcoma and MDA-MB-231 breast cancer cells exhibit division modes distinct from their Counterparts on 2D substrates, with a markedly higher fraction of cells remaining highly elongated through mitosis in 3D matrices. The long axis of elongated mitotic cells accurately predicts the division axis, independently of matrix density and cell-matrix interactions. This 3D-specific elongated division mode is determined by the local confinement produced by the matrix and the ability of cells to protrude and locally remodel the matrix via β1 integrin. Elongated division is readily recapitulated using collagen-coated microfabricated channels. Cells depleted of β1 integrin still divide in the elongated mode in microchannels, suggesting that 3D confinement is sufficient to induce the elongated cell-division phenotype.
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Affiliation(s)
- Lijuan He
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Weitong Chen
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Pei-Hsun Wu
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Angela Jimenez
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Bin Sheng Wong
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Angela San
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Konstantinos Konstantopoulos
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Departments of Oncology and Pathology and Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Denis Wirtz
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Johns Hopkins Physical Sciences - Oncology Center, The Johns Hopkins University, Baltimore, Maryland 21218, USA.,Departments of Oncology and Pathology and Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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44
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Wu CH, Zong Q, Du AL, Zhang W, Yao HC, Yu XQ, Wang YF. Knockdown of Dynamitin in testes significantly decreased male fertility in Drosophila melanogaster. Dev Biol 2016; 420:79-89. [DOI: 10.1016/j.ydbio.2016.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 10/09/2016] [Accepted: 10/09/2016] [Indexed: 10/20/2022]
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45
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Gullekson C, Walker M, Harden JL, Pelling AE. Measuring mechanodynamics in an unsupported epithelial monolayer grown at an air-water interface. Mol Biol Cell 2016; 28:111-119. [PMID: 28035043 PMCID: PMC5221614 DOI: 10.1091/mbc.e16-05-0300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 10/11/2016] [Accepted: 11/02/2016] [Indexed: 01/08/2023] Open
Abstract
A new method is presented for measuring the mechanodynamics of epithelial monolayers by culturing cells at an air–liquid interface. These model monolayers are grown in the absence of any supporting structures, removing cell–substrate effects. Actomyosin contraction and relaxation in a monolayer is a fundamental biophysical process in development and homeostasis. Current methods used to characterize the mechanodynamics of monolayers often involve cells grown on solid supports such as glass or gels. The results of these studies are fundamentally influenced by these supporting structures. Here we describe a new method for measuring the mechanodynamics of epithelial monolayers by culturing cells at an air–liquid interface. These model monolayers are grown in the absence of any supporting structures, removing cell–substrate effects. This method’s potential was evaluated by observing and quantifying the generation and release of internal stresses upon actomyosin contraction (800 ± 100 Pa) and relaxation (600 ± 100 Pa) in response to chemical treatments. Although unsupported monolayers exhibited clear major and minor strain axes, they were not correlated with nuclear alignment as observed when the monolayers were grown on soft deformable gels. It was also observed that both gels and glass substrates led to the promotion of long-range cell nuclei alignment not seen in the hanging-drop model. This new approach provides us with a picture of basal actomyosin mechanodynamics in a simplified system, allowing us to infer how the presence of a substrate affects contractility and long-range multicellular organization and dynamics.
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Affiliation(s)
- Corinne Gullekson
- Centre for Interdisciplinary NanoPhysics, Department of Physics, University of Ottawa, Ottawa, ON K1N5N5, Canada
| | - Matthew Walker
- Department of Biology, University of Ottawa, Ottawa, ON K1N5N5, Canada
| | - James L Harden
- Centre for Interdisciplinary NanoPhysics, Department of Physics, University of Ottawa, Ottawa, ON K1N5N5, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON K1N5N5, Canada
| | - Andrew E Pelling
- Centre for Interdisciplinary NanoPhysics, Department of Physics, University of Ottawa, Ottawa, ON K1N5N5, Canada .,Department of Biology, University of Ottawa, Ottawa, ON K1N5N5, Canada.,Institute for Science Society and Policy, University of Ottawa, Ottawa, ON K1N5N5, Canada.,SymbioticA, School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA 6009, Australia
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46
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Abstract
Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals.
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Affiliation(s)
- Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany.
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany
| | - Gary M Wessel
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA
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47
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Cadot B, Gache V, Gomes ER. Moving and positioning the nucleus in skeletal muscle - one step at a time. Nucleus 2016; 6:373-81. [PMID: 26338260 DOI: 10.1080/19491034.2015.1090073] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Nuclear movement and positioning within cells has become an area of great interest in the past few years due to the identification of different molecular mechanisms and functions in distinct organisms and contexts. One extreme example occurs during skeletal muscle development and regeneration. Skeletal muscles are composed of individual multinucleated myofibers with nuclei positioned at their periphery. Myofibers are formed by fusion of mononucleated myoblasts and during their development, successive nuclear movements and positioning events have been described. The position of the nuclei in myofibers is important for muscle function. Interestingly, during muscle regeneration and in some muscular diseases, nuclei are positioned in the center of the myofiber. In this review, we discuss the multiple mechanisms of nuclear positioning that occur during myofiber formation and regeneration. We also discuss the role of nuclear positioning for skeletal muscle function.
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Affiliation(s)
- Bruno Cadot
- a Center of Research in Myology; INSERM UPMC UMR974; CNRS FRE3617 ; Paris , France
| | - Vincent Gache
- b Ecole Normale Superieure de Lyon; CNRS UMR5239 ; Lyon , France
| | - Edgar R Gomes
- a Center of Research in Myology; INSERM UPMC UMR974; CNRS FRE3617 ; Paris , France.,c Instituto de Medicina Molecular; Faculdade de Medicina; Universidade de Lisboa ; Lisbon, Portugal
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48
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Fudge DS, Schorno S. The Hagfish Gland Thread Cell: A Fiber-Producing Cell Involved in Predator Defense. Cells 2016; 5:cells5020025. [PMID: 27258313 PMCID: PMC4931674 DOI: 10.3390/cells5020025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 12/18/2022] Open
Abstract
Fibers are ubiquitous in biology, and include tensile materials produced by specialized glands (such as silks), extracellular fibrils that reinforce exoskeletons and connective tissues (such as chitin and collagen), as well as intracellular filaments that make up the metazoan cytoskeleton (such as F-actin, microtubules, and intermediate filaments). Hagfish gland thread cells are unique in that they produce a high aspect ratio fiber from cytoskeletal building blocks within the confines of their cytoplasm. These threads are elaborately coiled into structures that readily unravel when they are ejected into seawater from the slime glands. In this review we summarize what is currently known about the structure and function of gland thread cells and we speculate about the mechanism that these cells use to produce a mechanically robust fiber that is almost one hundred thousand times longer than it is wide. We propose that a key feature of this mechanism involves the unidirectional rotation of the cell’s nucleus, which would serve to twist disorganized filaments into a coherent thread and impart a torsional stress on the thread that would both facilitate coiling and drive energetic unravelling in seawater.
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Affiliation(s)
- Douglas S Fudge
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G-2W1, Canada.
| | - Sarah Schorno
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G-2W1, Canada.
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49
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De Simone A, Nédélec F, Gönczy P. Dynein Transmits Polarized Actomyosin Cortical Flows to Promote Centrosome Separation. Cell Rep 2016; 14:2250-2262. [DOI: 10.1016/j.celrep.2016.01.077] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/23/2015] [Accepted: 01/27/2016] [Indexed: 01/27/2023] Open
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50
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Chang W, Antoku S, Gundersen GG. Wound-Healing Assays to Study Mechanisms of Nuclear Movement in Fibroblasts and Myoblasts. Methods Mol Biol 2016; 1411:255-267. [PMID: 27147048 DOI: 10.1007/978-1-4939-3530-7_17] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The rearward positioning of the nucleus is a characteristic feature of most migrating cells. Studies using wounded monolayers of fibroblasts and myoblasts have shown that this positioning is actively established before migration by the coupling of dorsal actin cables to the nuclear envelope through nesprin-2G and SUN2 linker of nucleoskeleton and cytoskeleton (LINC) complexes. During nuclear movement, these LINC complexes cluster along the actin cables to form adhesive structures known as transmembrane actin-associated nuclear (TAN) lines. Here we described experimental procedures for studying nuclear movement and TAN lines using wounded monolayers of fibroblasts and myoblasts, the acquisition of data using immunofluorescence microscopy and live-cell imaging, and methods for data analysis and quantification.
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Affiliation(s)
- Wakam Chang
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, P&S 15-420, 630 West 168th Street, New York, NY, 10032, USA
| | - Susumu Antoku
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, P&S 15-420, 630 West 168th Street, New York, NY, 10032, USA
| | - Gregg G Gundersen
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, P&S 15-420, 630 West 168th Street, New York, NY, 10032, USA.
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