1
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Divyanshi, Yang J. Germ plasm dynamics during oogenesis and early embryonic development in Xenopus and zebrafish. Mol Reprod Dev 2023:10.1002/mrd.23718. [PMID: 38126950 PMCID: PMC11190040 DOI: 10.1002/mrd.23718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 11/09/2023] [Accepted: 11/12/2023] [Indexed: 12/23/2023]
Abstract
Specification of the germline and its segregation from the soma mark one of the most crucial events in the lifetime of an organism. In different organisms, this specification can occur through either inheritance or inductive mechanisms. In species such as Xenopus and zebrafish, the specification of primordial germ cells relies on the inheritance of maternal germline determinants that are synthesized and sequestered in the germ plasm during oogenesis. In this review, we discuss the formation of the germ plasm, how germline determinants are recruited into the germ plasm during oogenesis, and the dynamics of the germ plasm during oogenesis and early embryonic development.
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Affiliation(s)
- Divyanshi
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, IL, USA
| | - Jing Yang
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, IL, USA
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, IL, USA
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2
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Bogoch Y, Jamieson-Lucy A, Vejnar CE, Levy K, Giraldez AJ, Mullins MC, Elkouby YM. Stage Specific Transcriptomic Analysis and Database for Zebrafish Oogenesis. Front Cell Dev Biol 2022; 10:826892. [PMID: 35733854 PMCID: PMC9207522 DOI: 10.3389/fcell.2022.826892] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/11/2022] [Indexed: 01/21/2023] Open
Abstract
Oogenesis produces functional eggs and is essential for fertility, embryonic development, and reproduction. The zebrafish ovary is an excellent model to study oogenesis in vertebrates, and recent studies have identified multiple regulators in oocyte development through forward genetic screens, as well as reverse genetics by CRISPR mutagenesis. However, many developmental steps in oogenesis, in zebrafish and other species, remain poorly understood, and their underlying mechanisms are unknown. Here, we take a genomic approach to systematically uncover biological activities throughout oogenesis. We performed transcriptomic analysis on five stages of oogenesis, from the onset of oocyte differentiation through Stage III, which precedes oocyte maturation. These transcriptomes revealed thousands of differentially expressed genes across stages of oogenesis. We analyzed trends of gene expression dynamics along oogenesis, as well as their expression in pair-wise comparisons between stages. We determined their functionally enriched terms, identifying uniquely characteristic biological activities in each stage. These data identified two prominent developmental phases in oocyte differentiation and traced the accumulation of maternally deposited embryonic regulator transcripts in the developing oocyte. Our analysis provides the first molecular description for oogenesis in zebrafish, which we deposit online as a resource for the community. Further, the presence of multiple gene paralogs in zebrafish, and the exclusive curation by many bioinformatic tools of the single paralogs present in humans, challenge zebrafish genomic analyses. We offer an approach for converting zebrafish gene name nomenclature to the human nomenclature for supporting genomic analyses generally in zebrafish. Altogether, our work provides a valuable resource as a first step to uncover oogenesis mechanisms and candidate regulators and track accumulating transcripts of maternal regulators of embryonic development.
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Affiliation(s)
- Yoel Bogoch
- Department of Developmental Biology and Cancer Research, Hebrew University of Jerusalem Faculty of Medicine, Jerusalem, Israel
- Institute for Biomedical Research, Israel-Canada, Jerusalem, Israel
| | - Allison Jamieson-Lucy
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | | | - Karine Levy
- Department of Developmental Biology and Cancer Research, Hebrew University of Jerusalem Faculty of Medicine, Jerusalem, Israel
- Institute for Biomedical Research, Israel-Canada, Jerusalem, Israel
| | | | - Mary C. Mullins
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Yaniv M. Elkouby
- Department of Developmental Biology and Cancer Research, Hebrew University of Jerusalem Faculty of Medicine, Jerusalem, Israel
- Institute for Biomedical Research, Israel-Canada, Jerusalem, Israel
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3
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Jamieson-Lucy AH, Kobayashi M, James Aykit Y, Elkouby YM, Escobar-Aguirre M, Vejnar CE, Giraldez AJ, Mullins MC. A proteomics approach identifies novel resident zebrafish Balbiani body proteins Cirbpa and Cirbpb. Dev Biol 2022; 484:1-11. [PMID: 35065906 PMCID: PMC8967276 DOI: 10.1016/j.ydbio.2022.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 01/17/2023]
Abstract
The Balbiani body (Bb) is the first marker of polarity in vertebrate oocytes. The Bb is a conserved structure found in diverse animals including insects, fish, amphibians, and mammals. During early zebrafish oogenesis, the Bb assembles as a transient aggregate of mRNA, proteins, and membrane-bound organelles at the presumptive vegetal side of the oocyte. As the early oocyte develops, the Bb appears to grow slowly, until at the end of stage I of oogenesis it disassembles and deposits its cargo of localized mRNAs and proteins. In fish and frogs, this cargo includes the germ plasm as well as gene products required to specify dorsal tissues of the future embryo. We demonstrate that the Bb is a stable, solid structure that forms a size exclusion barrier similar to other biological hydrogels. Despite its central role in oocyte polarity, little is known about the mechanism behind the Bb's action. Analysis of the few known protein components of the Bb is insufficient to explain how the Bb assembles, translocates, and disassembles. We isolated Bbs from zebrafish oocytes and performed mass spectrometry to define the Bb proteome. We successfully identified 77 proteins associated with the Bb sample, including known Bb proteins and novel RNA-binding proteins. In particular, we identified Cirbpa and Cirbpb, which have both an RNA-binding domain and a predicted self-aggregation domain. In stage I oocytes, Cirbpa and Cirbpb localize to the Bb rather than the nucleus (as in somatic cells), indicating that they may have a specialized function in the germ line. Both the RNA-binding domain and the self-aggregation domain are sufficient to localize to the Bb, suggesting that Cirbpa and Cirbpb interact with more than just their mRNA targets within the Bb. We propose that Cirbp proteins crosslink mRNA cargo and proteinaceous components of the Bb as it grows. Beyond Cirbpa and Cirbpb, our proteomics dataset presents many candidates for further study, making it a valuable resource for building a comprehensive mechanism for Bb function at a protein level.
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Affiliation(s)
- Allison H Jamieson-Lucy
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Manami Kobayashi
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Y James Aykit
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Yaniv M Elkouby
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Matias Escobar-Aguirre
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Charles E Vejnar
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Antonio J Giraldez
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Mary C Mullins
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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4
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Multiple asters organize the yolk microtubule network during dclk2-GFP zebrafish epiboly. Sci Rep 2022; 12:4072. [PMID: 35260695 PMCID: PMC8904445 DOI: 10.1038/s41598-022-07747-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/21/2022] [Indexed: 11/25/2022] Open
Abstract
It is known that the organization of microtubule (MT) networks in cells is orchestrated by subcellular structures named MT organizing centers (MTOCs). In this work, we use Light Sheet Fluorescence and Confocal Microscopy to investigate how the MT network surrounding the spherical yolk is arranged in the dclk2-GFP zebrafish transgenic line. We found that during epiboly the MT network is organized by multiple aster-like MTOCS. These structures form rings around the yolk sphere. Importantly, in wt embryos, aster-like MTOCs are only found upon pharmacological or genetic induction. Using our microscopy approach, we underscore the variability in the number of such asters in the transgenic line and report on the variety of global configurations of the yolk MT network. The asters’ morphology, dynamics, and their distribution in the yolk sphere are also analyzed. We propose that these features are tightly linked to epiboly timing and geometry. Key molecules are identified which support this asters role as MTOCs, where MT nucleation and growth take place. We conclude that the yolk MT network of dclk2-GFP transgenic embryos can be used as a model to organize microtubules in a spherical geometry by means of multiple MTOCs.
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5
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Li W, Jiang C, Zhang E. Advances in the phase separation-organized membraneless organelles in cells: a narrative review. Transl Cancer Res 2022; 10:4929-4946. [PMID: 35116344 PMCID: PMC8797891 DOI: 10.21037/tcr-21-1111] [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: 06/28/2021] [Accepted: 10/29/2021] [Indexed: 11/26/2022]
Abstract
Membraneless organelles (MLOs) are micro-compartments that lack delimiting membranes, concentrating several macro-molecules with a high local concentration in eukaryotic cells. Recent studies have shown that MLOs have pivotal roles in multiple biological processes, including gene transcription, RNA metabolism, translation, protein modification, and signal transduction. These biological processes in cells have essential functions in many diseases, such as cancer, neurodegenerative diseases, and virus-related diseases. The liquid-liquid phase separation (LLPS) microenvironment within cells is thought to be the driving force for initiating the formation of micro-compartments with a liquid-like property, becoming an important organizing principle for MLOs to mediate organism responses. In this review, we comprehensively elucidated the formation of these MLOs and the relationship between biological functions and associated diseases. The mechanisms underlying the influence of protein concentration and valency on phase separation in cells are also discussed. MLOs undergoing the LLPS process have diverse functions, including stimulation of some adaptive and reversible responses to alter the transcriptional or translational processes, regulation of the concentrations of biomolecules in living cells, and maintenance of cell morphogenesis. Finally, we highlight that the development of this field could pave the way for developing novel therapeutic strategies for the treatment of LLPS-related diseases based on the understanding of phase separation in the coming years.
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Affiliation(s)
- Weihan Li
- Department of Immunology, School of Medicine, Nantong University, Nantong, China
| | - Chenwei Jiang
- Department of Immunology, School of Medicine, Nantong University, Nantong, China
| | - Erhao Zhang
- Department of Immunology, School of Medicine, Nantong University, Nantong, China.,Laboratory of Medical Science, School of Medicine, Nantong University, Nantong, China
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Ghasemizadeh A, Christin E, Guiraud A, Couturier N, Abitbol M, Risson V, Girard E, Jagla C, Soler C, Laddada L, Sanchez C, Jaque-Fernandez FI, Jacquemond V, Thomas JL, Lanfranchi M, Courchet J, Gondin J, Schaeffer L, Gache V. MACF1 controls skeletal muscle function through the microtubule-dependent localization of extra-synaptic myonuclei and mitochondria biogenesis. eLife 2021; 10:e70490. [PMID: 34448452 PMCID: PMC8500715 DOI: 10.7554/elife.70490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/10/2021] [Indexed: 01/02/2023] Open
Abstract
Skeletal muscles are composed of hundreds of multinucleated muscle fibers (myofibers) whose myonuclei are regularly positioned all along the myofiber's periphery except the few ones clustered underneath the neuromuscular junction (NMJ) at the synaptic zone. This precise myonuclei organization is altered in different types of muscle disease, including centronuclear myopathies (CNMs). However, the molecular machinery regulating myonuclei position and organization in mature myofibers remains largely unknown. Conversely, it is also unclear how peripheral myonuclei positioning is lost in the related muscle diseases. Here, we describe the microtubule-associated protein, MACF1, as an essential and evolutionary conserved regulator of myonuclei positioning and maintenance, in cultured mammalian myotubes, in Drosophila muscle, and in adult mammalian muscle using a conditional muscle-specific knockout mouse model. In vitro, we show that MACF1 controls microtubules dynamics and contributes to microtubule stabilization during myofiber's maturation. In addition, we demonstrate that MACF1 regulates the microtubules density specifically around myonuclei, and, as a consequence, governs myonuclei motion. Our in vivo studies show that MACF1 deficiency is associated with alteration of extra-synaptic myonuclei positioning and microtubules network organization, both preceding NMJ fragmentation. Accordingly, MACF1 deficiency results in reduced muscle excitability and disorganized triads, leaving voltage-activated sarcoplasmic reticulum Ca2+ release and maximal muscle force unchanged. Finally, adult MACF1-KO mice present an improved resistance to fatigue correlated with a strong increase in mitochondria biogenesis.
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Affiliation(s)
- Alireza Ghasemizadeh
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Emilie Christin
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Alexandre Guiraud
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Nathalie Couturier
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Marie Abitbol
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
- Université Marcy l’Etoile, VetAgro SupLyonFrance
| | - Valerie Risson
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Emmanuelle Girard
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Christophe Jagla
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Cedric Soler
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Lilia Laddada
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRSClermont-FerrandFrance
| | - Colline Sanchez
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Francisco-Ignacio Jaque-Fernandez
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Vincent Jacquemond
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Jean-Luc Thomas
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Marine Lanfranchi
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Julien Courchet
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Julien Gondin
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Laurent Schaeffer
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
| | - Vincent Gache
- Institut NeuroMyoGène, CNRS UMR5310, INSERM U1217, Faculté de Médecine Rockefeller, Université Claude Bernard Lyon ILyon CedexFrance
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7
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MACF1 promotes osteoblast differentiation by sequestering repressors in cytoplasm. Cell Death Differ 2021; 28:2160-2178. [PMID: 33664480 PMCID: PMC8257666 DOI: 10.1038/s41418-021-00744-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 01/22/2021] [Accepted: 01/28/2021] [Indexed: 02/07/2023] Open
Abstract
Osteoblast differentiation leading to bone formation requires a coordinated transcriptional program. Osteoblastic cells with low level of microtubule actin crosslinking factor 1 (MACF1) show reduced osteoblast differentiation ability, however, the comprehensive mechanism of MACF1's action remains unexplored. In the current study, we found that MACF1 knockdown suppressed osteoblast differentiation by altering the transcriptome dynamics. We further identified two MACF1-interacted proteins, cyclin-dependent kinase 12 (CDK12) and MYST/Esa1-associated factor 6 (MEAF6), and two MACF1-interacted transcription factors (TFs), transcription factor 12 (TCF12) and E2F transcription factor 6 (E2F6), which repress osteoblast differentiation by altering the expression of osteogenic TFs and genes. Moreover, we found that MACF1 regulated cytoplasmic-nuclear localization of itself, TCF12 and E2F6 in a concentration-dependent manner. MACF1 oppositely regulates the expression of TCF12 and transcription factor 7 (TCF7), two TFs that drive osteoblast differentiation to opposite directions. This study reveals that MACF1, a cytoskeletal protein, acts as a sponge for repressors of osteoblast differentiation to promote osteoblast differentiation and contributes to a novel mechanistic insight of osteoblast differentiation and transcription dynamics.
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Anderson SJ, Garamella J, Adalbert S, McGorty RJ, Robertson-Anderson RM. Subtle changes in crosslinking drive diverse anomalous transport characteristics in actin-microtubule networks. SOFT MATTER 2021; 17:4375-4385. [PMID: 33908593 PMCID: PMC8189643 DOI: 10.1039/d1sm00093d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Anomalous diffusion in crowded and complex environments is widely studied due to its importance in intracellular transport, fluid rheology and materials engineering. Specifically, diffusion through the cytoskeleton, a network comprised of semiflexible actin filaments and rigid microtubules that interact both sterically and via crosslinking, plays a principal role in viral infection, vesicle transport and targeted drug delivery. Here, we elucidate the impact of crosslinking on particle diffusion in composites of actin and microtubules with actin-actin, microtubule-microtubule and actin-microtubule crosslinking. We analyze a suite of transport metrics by coupling single-particle tracking and differential dynamic microscopy. Using these complementary techniques, we find that particles display non-Gaussian and non-ergodic subdiffusion that is markedly enhanced by cytoskeletal crosslinking, which we attribute to suppressed microtubule mobility. However, the extent to which transport deviates from normal Brownian diffusion depends strongly on the crosslinking motif - with actin-microtubule crosslinking inducing the most pronounced anomalous characteristics. Our results reveal that subtle changes to actin-microtubule interactions can have complex impacts on particle diffusion in cytoskeleton composites, and suggest that a combination of reduced filament mobility and more variance in actin mobilities leads to more strongly anomalous particle transport.
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Affiliation(s)
- S J Anderson
- Department of Physics & Biophysics, University of San Diego, San Diego, CA 92110, USA.
| | - J Garamella
- Department of Physics & Biophysics, University of San Diego, San Diego, CA 92110, USA.
| | - S Adalbert
- Department of Physics & Biophysics, University of San Diego, San Diego, CA 92110, USA.
| | - R J McGorty
- Department of Physics & Biophysics, University of San Diego, San Diego, CA 92110, USA.
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Petrushko MP, Buderatska NO, Gontar JV, Yurchuk TO. Morphological and Molecular Cytogenetic Characteristics of Giant Human Oocytes. CYTOL GENET+ 2021. [DOI: 10.3103/s0095452721020110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Mytlis A, Elkouby YM. Live and Time-Lapse Imaging of Early Oogenesis and Meiotic Chromosomal Dynamics in Cultured Juvenile Zebrafish Ovaries. Methods Mol Biol 2021; 2218:137-155. [PMID: 33606229 DOI: 10.1007/978-1-0716-0970-5_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Oocyte production is crucial for sexual reproduction. Recent findings in zebrafish and other established model organisms emphasize that the early steps of oogenesis involve the coordination of simultaneous and tightly sequential processes across cellular compartments and between sister cells. To fully understand the mechanistic framework of these coordinated processes, cellular and morphological analysis in high temporal resolution is required. Here, we provide a protocol for four-dimensional live time-lapse analysis of cultured juvenile zebrafish ovaries. We describe how multiple-stage oocytes can be simultaneously analyzed in single ovaries, and several ovaries can be processed in single experiments. In addition, we detail adequate conditions for quantitative image acquisition. Finally, we demonstrate that using this protocol, we successfully capture rapid meiotic chromosomal movements in early prophase for the first time in zebrafish oocytes, in four dimensions and in vivo. Our protocol expands the use of the zebrafish as a model system to understand germ cell and ovarian development in postembryonic stages.
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Affiliation(s)
- Avishag Mytlis
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem, Faculty of Medicine, Institute for Medical Research - Israel-Canada (IMRIC), Jerusalem, Israel
| | - Yaniv M Elkouby
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem, Faculty of Medicine, Institute for Medical Research - Israel-Canada (IMRIC), Jerusalem, Israel.
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11
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So C, Cheng S, Schuh M. Phase Separation during Germline Development. Trends Cell Biol 2021; 31:254-268. [PMID: 33455855 DOI: 10.1016/j.tcb.2020.12.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 02/07/2023]
Abstract
Phase separation has emerged as a new key principle of intracellular organization. Phase-separated structures play diverse roles in various biological processes and pathogenesis of protein aggregation diseases. Recent work has revealed crucial functions for phase separation during germline development. Phase separation controls the assembly and segregation of germ granules that determine which embryonic cells become germ cells. Phase separation promotes the formation of the Balbiani body, a structure that stores organelles and RNAs during the prolonged prophase arrest of oocytes. Phase separation also facilitates meiotic recombination that prepares homologous chromosomes for segregation, and drives the formation of a liquid-like spindle domain that promotes spindle assembly in mammalian oocytes. We review how phase separation drives these essential steps during germline development.
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Affiliation(s)
- Chun So
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Shiya Cheng
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Melina Schuh
- Department of Meiosis, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
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12
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Fuentes R, Tajer B, Kobayashi M, Pelliccia JL, Langdon Y, Abrams EW, Mullins MC. The maternal coordinate system: Molecular-genetics of embryonic axis formation and patterning in the zebrafish. Curr Top Dev Biol 2020; 140:341-389. [PMID: 32591080 DOI: 10.1016/bs.ctdb.2020.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Axis specification of the zebrafish embryo begins during oogenesis and relies on proper formation of well-defined cytoplasmic domains within the oocyte. Upon fertilization, maternally-regulated cytoplasmic flow and repositioning of dorsal determinants establish the coordinate system that will build the structure and developmental body plan of the embryo. Failure of specific genes that regulate the embryonic coordinate system leads to catastrophic loss of body structures. Here, we review the genetic principles of axis formation and discuss how maternal factors orchestrate axis patterning during zebrafish early embryogenesis. We focus on the molecular identity and functional contribution of genes controlling critical aspects of oogenesis, egg activation, blastula, and gastrula stages. We examine how polarized cytoplasmic domains form in the oocyte, which set off downstream events such as animal-vegetal polarity and germ line development. After gametes interact and form the zygote, cytoplasmic segregation drives the animal-directed reorganization of maternal determinants through calcium- and cell cycle-dependent signals. We also summarize how maternal genes control dorsoventral, anterior-posterior, mesendodermal, and left-right cell fate specification and how signaling pathways pattern these axes and tissues during early development to instruct the three-dimensional body plan. Advances in reverse genetics and phenotyping approaches in the zebrafish model are revealing positional patterning signatures at the single-cell level, thus enhancing our understanding of genotype-phenotype interactions in axis formation. Our emphasis is on the genetic interrogation of novel and specific maternal regulatory mechanisms of axis specification in the zebrafish.
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Affiliation(s)
- Ricardo Fuentes
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile.
| | - Benjamin Tajer
- Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
| | - Manami Kobayashi
- Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
| | - Jose L Pelliccia
- Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States
| | | | - Elliott W Abrams
- Department of Biology, Purchase College, State University of New York, Harrison, NY, United States
| | - Mary C Mullins
- Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, United States.
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13
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Mesenchymal MACF1 Facilitates SMAD7 Nuclear Translocation to Drive Bone Formation. Cells 2020; 9:cells9030616. [PMID: 32143362 PMCID: PMC7140458 DOI: 10.3390/cells9030616] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 02/27/2020] [Accepted: 02/29/2020] [Indexed: 02/07/2023] Open
Abstract
Microtubule actin crosslinking factor 1 (MACF1) is a large crosslinker that contributes to cell integrity and cell differentiation. Recent studies show that MACF1 is involved in multiple cellular functions such as neuron development and epidermal migration, and is the molecular basis for many degenerative diseases. MACF1 is highly abundant in bones, especially in mesenchymal stem cells; however, its regulatory role is still less understood in bone formation and degenerative bone diseases. In this study, we found MACF1 expression in mesenchymal stem cells (MSCs) of osteoporotic bone specimens was significantly lower. By conditional gene targeting to delete the mesenchymal Macf1 gene in mice, we observed in MSCs decreased osteogenic differentiation capability. During early stage bone development, the MACF1 conditional knockout (cKO) mice exhibit significant ossification retardation in skull and hindlimb, and by adulthood, mesenchymal loss of MACF1 attenuated bone mass, bone microarchitecture, and bone formation capability significantly. Further, we showed that MACF1 interacts directly with SMAD family member 7 (SMAD7) and facilitates SMAD7 nuclear translocation to initiate downstream osteogenic pathways. Hopefully these findings will expand the biological scope of the MACF1 gene, and provide an experimental basis for targeting MACF1 in degenerative bone diseases such as osteoporosis.
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14
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Wang X, Qi Y, Zhou X, Zhang G, Fu C. Alteration of scaffold: Possible role of MACF1 in Alzheimer's disease pathogenesis. Med Hypotheses 2019; 130:109259. [PMID: 31383338 DOI: 10.1016/j.mehy.2019.109259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/27/2019] [Accepted: 06/04/2019] [Indexed: 02/09/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease, with the sign of sensory or motor function loss, memory decline, and dementia. Histopathological study shows AD neuron has irregular cytoskeleton and aberrant synapse. Amyloid-β (Aβ) is believed as the trigger of AD, however, the detailed pathogenesis is not fully elucidated. Microtubule-actin crosslinking factor 1 (MACF1) is a unique giant molecule which can bind to all three types of cytoskeleton fibers, different linkers/adaptors, as well as various functional proteins. MACF1 is a critical scaffold for orchestrating the complex 3D structure, and is essential for correct synaptic function. MACF1's binding ability to microtubule depends on Glycogen synthase kinase 3 Bate (GSK3β) mediated phosphorylation. While GSK3β can be regulated by the binding of Aβ and the receptor Paired immunoglobulin-like receptor B (PirB), possibly via Protein phosphatase 2A (PP2A). So based on literature search and logic analysis, we propose a hypothesis: Aβ binds to its receptor PirB, and triggers cytosol PP2A, which might activate GSK3β. GSK3β might further phosphorylates microtubule-binding domain (MTBD) of MACF1, causes the separation of microtubule and MACF1. Thus MACF1 might lose the control of the whole cytoskeleton system, synapse might change and AD might develop. That is Aβ-PirB-PP2A-GSK3β-MACF1 axis might give rise to AD. We hope our hypothesis might provide new clue and evidence to AD pathogenesis.
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Affiliation(s)
- Xiaolong Wang
- School of Basic Medical Sciences & Shaanxi Key Laboratory of Brain Disorders, Xi'an Medical University, Xi'an 710021, China.
| | - Yangyang Qi
- School of Clinical Medicine, Xi'an Medical University, Xi'an 710021, China
| | - Xin Zhou
- School of Clinical Medicine, Xi'an Medical University, Xi'an 710021, China
| | - Geyang Zhang
- School of Clinical Medicine, Xi'an Medical University, Xi'an 710021, China
| | - Caiyu Fu
- School of Clinical Medicine, Xi'an Medical University, Xi'an 710021, China
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15
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Oury J, Liu Y, Töpf A, Todorovic S, Hoedt E, Preethish-Kumar V, Neubert TA, Lin W, Lochmüller H, Burden SJ. MACF1 links Rapsyn to microtubule- and actin-binding proteins to maintain neuromuscular synapses. J Cell Biol 2019; 218:1686-1705. [PMID: 30842214 PMCID: PMC6504910 DOI: 10.1083/jcb.201810023] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 01/07/2019] [Accepted: 02/07/2019] [Indexed: 12/20/2022] Open
Abstract
Oury et al. show that the scaffolding protein MACF1 links Rapsyn, which binds acetylcholine receptors, to the microtubule- and actin-network at neuromuscular synapses. MACF1 thereby plays a role in synaptic maturation in mice, and mutations of MACF1 are associated with congenital myasthenia in humans. Complex mechanisms are required to form neuromuscular synapses, direct their subsequent maturation, and maintain the synapse throughout life. Transcriptional and post-translational pathways play important roles in synaptic differentiation and direct the accumulation of the neurotransmitter receptors, acetylcholine receptors (AChRs), to the postsynaptic membrane, ensuring for reliable synaptic transmission. Rapsyn, an intracellular peripheral membrane protein that binds AChRs, is essential for synaptic differentiation, but how Rapsyn acts is poorly understood. We screened for proteins that coisolate with AChRs in a Rapsyn-dependent manner and show that microtubule actin cross linking factor 1 (MACF1), a scaffolding protein with binding sites for microtubules (MT) and actin, is concentrated at neuromuscular synapses, where it binds Rapsyn and serves as a synaptic organizer for MT-associated proteins, EB1 and MAP1b, and the actin-associated protein, Vinculin. MACF1 plays an important role in maintaining synaptic differentiation and efficient synaptic transmission in mice, and variants in MACF1 are associated with congenital myasthenia in humans.
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Affiliation(s)
- Julien Oury
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University Medical School, New York, NY
| | - Yun Liu
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Slobodanka Todorovic
- Clinic for Neurology and Psychiatry for Children and Youth, Belgrade, Serbia and Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Esthelle Hoedt
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University Medical School, New York, NY
| | | | - Thomas A Neubert
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University Medical School, New York, NY
| | - Weichun Lin
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX
| | - Hanns Lochmüller
- Department of Neuropediatrics and Muscle Disorders, Medical Center, University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Centro Nacional de Análisis Genómico, Center for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain.,Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Canada.,Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada
| | - Steven J Burden
- Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University Medical School, New York, NY
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16
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Lee KL, Marlow FL. Visualizing the Balbiani Body in Zebrafish Oocytes. Methods Mol Biol 2019; 1920:277-293. [PMID: 30737697 DOI: 10.1007/978-1-4939-9009-2_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Approaches to visualize the Balbiani body of zebrafish primary oocytes using protein, RNA, and mitochondrial markers are described. The method involves isolation, histology, staining, and microscopic examination of early zebrafish oocytes. These techniques can be applied to visualize gene products that are localized to the Balbiani body, and when applied to mutants can be used to decipher molecular and genetic pathways acting in Balbiani body development in early oocytes.
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Affiliation(s)
- KathyAnn L Lee
- Department of Cell Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Florence L Marlow
- Department of Cell Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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17
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Jamieson-Lucy A, Mullins MC. Isolation of Zebrafish Balbiani Bodies for Proteomic Analysis. Methods Mol Biol 2019; 1920:295-302. [PMID: 30737698 DOI: 10.1007/978-1-4939-9009-2_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Proteomic characterization of isolated organelles can provide insight into the functional components of the structure and novel targets for further testing. Germplasm in developing oocytes is difficult to isolate for protein identification because not all types of germplasm are stable outside of the cytoplasm. In zebrafish, the Balbiani body forms a proteinaceous aggregate that contains the germplasm and we found is stable outside of the oocyte. Here we present a manual isolation protocol that collects intact Balbiani bodies from stage I zebrafish oocytes. We lysed oocytes by passing them through a syringe, and then used a fine injection needle to wick up Balbiani bodies by capillary action with minimal buffer solution. Using this protocol we collected sufficient material for proteomic analysis of the zebrafish Balbiani body.
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Affiliation(s)
- Allison Jamieson-Lucy
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mary C Mullins
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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18
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Jamieson-Lucy A, Mullins MC. The vertebrate Balbiani body, germ plasm, and oocyte polarity. Curr Top Dev Biol 2019; 135:1-34. [DOI: 10.1016/bs.ctdb.2019.04.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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19
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Fuentes R, Letelier J, Tajer B, Valdivia LE, Mullins MC. Fishing forward and reverse: Advances in zebrafish phenomics. Mech Dev 2018; 154:296-308. [PMID: 30130581 PMCID: PMC6289646 DOI: 10.1016/j.mod.2018.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 08/06/2018] [Accepted: 08/17/2018] [Indexed: 12/15/2022]
Abstract
Understanding how the genome instructs the phenotypic characteristics of an organism is one of the major scientific endeavors of our time. Advances in genetics have progressively deciphered the inheritance, identity and biological relevance of genetically encoded information, contributing to the rise of several, complementary omic disciplines. One of them is phenomics, an emergent area of biology dedicated to the systematic multi-scale analysis of phenotypic traits. This discipline provides valuable gene function information to the rapidly evolving field of genetics. Current molecular tools enable genome-wide analyses that link gene sequence to function in multi-cellular organisms, illuminating the genome-phenome relationship. Among vertebrates, zebrafish has emerged as an outstanding model organism for high-throughput phenotyping and modeling of human disorders. Advances in both systematic mutagenesis and phenotypic analyses of embryonic and post-embryonic stages in zebrafish have revealed the function of a valuable collection of genes and the general structure of several complex traits. In this review, we summarize multiple large-scale genetic efforts addressing parental, embryonic, and adult phenotyping in the zebrafish. The genetic and quantitative tools available in the zebrafish model, coupled with the broad spectrum of phenotypes that can be assayed, make it a powerful model for phenomics, well suited for the dissection of genotype-phenotype associations in development, physiology, health and disease.
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Affiliation(s)
- Ricardo Fuentes
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Joaquín Letelier
- Centro Andaluz de Biología del Desarrollo (CSIC/UPO/JA), Seville, Spain; Center for Integrative Biology, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Benjamin Tajer
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Leonardo E Valdivia
- Center for Integrative Biology, Facultad de Ciencias, Universidad Mayor, Santiago, Chile.
| | - Mary C Mullins
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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20
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Burg L, Palmer N, Kikhi K, Miroshnik ES, Rueckert H, Gaddy E, MacPherson Cunningham C, Mattonet K, Lai SL, Marín-Juez R, Waring RB, Stainier DYR, Balciunas D. Conditional mutagenesis by oligonucleotide-mediated integration of loxP sites in zebrafish. PLoS Genet 2018; 14:e1007754. [PMID: 30427827 PMCID: PMC6261631 DOI: 10.1371/journal.pgen.1007754] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 11/28/2018] [Accepted: 10/10/2018] [Indexed: 02/07/2023] Open
Abstract
Many eukaryotic genes play essential roles in multiple biological processes in several different tissues. Conditional mutants are needed to analyze genes with such pleiotropic functions. In vertebrates, conditional gene inactivation has only been feasible in the mouse, leaving other model systems to rely on surrogate experimental approaches such as overexpression of dominant negative proteins and antisense-based tools. Here, we have developed a simple and straightforward method to integrate loxP sequences at specific sites in the zebrafish genome using the CRISPR/Cas9 technology and oligonucleotide templates for homology directed repair. We engineered conditional (floxed) mutants of tbx20 and fleer, and demonstrate excision of exons flanked by loxP sites using tamoxifen-inducible CreERT2 recombinase. To demonstrate broad applicability of our method, we also integrated loxP sites into two additional genes, aldh1a2 and tcf21. The ease of this approach will further expand the use of zebrafish to study various aspects of vertebrate biology, especially post-embryonic processes such as regeneration. Some genes are expressed and function in a single tissue, and the effect of their loss on that tissue can be readily determined. Frequently, however, genes that are necessary for the development or maintenance of one tissue are also important for other tissues or cell types. Genes of the latter type are difficult to analyze because of the complications resulting from an organism having multiple defects in different tissues. The solution pioneered by mouse geneticists is to inactivate the gene of interest in only one tissue at a time. This elegant approach requires the ability to make specific edits to the genome, a technology that was not readily available to zebrafish researchers until recently. Using the CRISPR/Cas9 genome editing tool, we have developed a simple, reliable, and efficient method to insert DNA sequences into the zebrafish genome that enable conditional gene inactivation. Our methodology will be useful not only for the study of genes that play important roles in multiple tissues, but also for the genetic analysis of biological processes which occur in adult animals.
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Affiliation(s)
- Leonard Burg
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Nicholas Palmer
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Khrievono Kikhi
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Evgeniya S. Miroshnik
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Helen Rueckert
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Eleanor Gaddy
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Carlee MacPherson Cunningham
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Kenny Mattonet
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Shih-Lei Lai
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Rubén Marín-Juez
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Richard B. Waring
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Didier Y. R. Stainier
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Darius Balciunas
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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21
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Krishnakumar P, Riemer S, Perera R, Lingner T, Goloborodko A, Khalifa H, Bontems F, Kaufholz F, El-Brolosy MA, Dosch R. Functional equivalence of germ plasm organizers. PLoS Genet 2018; 14:e1007696. [PMID: 30399145 PMCID: PMC6219760 DOI: 10.1371/journal.pgen.1007696] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 09/16/2018] [Indexed: 11/18/2022] Open
Abstract
The proteins Oskar (Osk) in Drosophila and Bucky ball (Buc) in zebrafish act as germ plasm organizers. Both proteins recapitulate germ plasm activities but seem to be unique to their animal groups. Here, we discover that Osk and Buc show similar activities during germ cell specification. Drosophila Osk induces additional PGCs in zebrafish. Surprisingly, Osk and Buc do not show homologous protein motifs that would explain their related function. Nonetheless, we detect that both proteins contain stretches of intrinsically disordered regions (IDRs), which seem to be involved in protein aggregation. IDRs are known to rapidly change their sequence during evolution, which might obscure biochemical interaction motifs. Indeed, we show that Buc binds to the known Oskar interactors Vasa protein and nanos mRNA indicating conserved biochemical activities. These data provide a molecular framework for two proteins with unrelated sequence but with equivalent function to assemble a conserved core-complex nucleating germ plasm. Multicellular organisms use gametes for their propagation. Gametes are formed from germ cells, which are specified during embryogenesis in some animals by the inheritance of RNP granules known as germ plasm. Transplantation of germ plasm induces extra germ cells, whereas germ plasm ablation leads to the loss of gametes and sterility. Therefore, germ plasm is key for germ cell formation and reproduction. However, the molecular mechanisms of germ cell specification by germ plasm in the vertebrate embryo remain an unsolved question. Proteins, which assemble the germ plasm, are known as germ plasm organizers. Here, we show that the two germ plasm organizers Oskar from the fly and Bucky ball from the fish show similar functions by using a cross species approach. Both are intrinsically disordered proteins, which rapidly changed their sequence during evolution. Moreover, both proteins still interact with conserved components of the germ cell specification pathway. These data might provide a first example of two proteins with the same biological role, but distinct sequence.
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Affiliation(s)
- Pritesh Krishnakumar
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Stephan Riemer
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Roshan Perera
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Thomas Lingner
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Alexander Goloborodko
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Hazem Khalifa
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Franck Bontems
- Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Switzerland
| | - Felix Kaufholz
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Mohamed A. El-Brolosy
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
| | - Roland Dosch
- Institute for Developmental Biochemistry, University Medical Center, Göttingen, Germany
- Institute of Human Genetics, University Medical Center, Göttingen, Germany
- * E-mail:
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22
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Fuentes R, Mullins MC, Fernández J. Formation and dynamics of cytoplasmic domains and their genetic regulation during the zebrafish oocyte-to-embryo transition. Mech Dev 2018; 154:259-269. [PMID: 30077623 DOI: 10.1016/j.mod.2018.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 08/01/2018] [Indexed: 12/13/2022]
Abstract
Establishment and movement of cytoplasmic domains is of great importance for the emergence of cell polarity, germline segregation, embryonic axis specification and correct sorting of organelles and macromolecules into different embryonic cells. The zebrafish oocyte, egg and zygote are valuable material for the study of cytoplasmic domains formation and dynamics during development. In this review we examined how cytoplasmic domains form and are relocated during zebrafish early embryogenesis. Distinct cortical cytoplasmic domains (also referred to as ectoplasm domains) form first during early oogenesis by the localization of mRNAs to the vegetal or animal poles of the oocyte or radially throughout the cortex. Cytoplasmic segregation in the late oocyte relocates non-cortical cytoplasm (endoplasm) into the preblastodisc and yolk cell. The preblastodisc is a precursor to the blastodisc, which gives rise to the blastoderm and most the future embryo. After egg activation, the blastodisc enlarges by transport of cytoplasm from the yolk cell to the animal pole, along defined pathways or streamers that include a complex cytoskeletal meshwork and cytoplasmic movement at different speeds. A powerful actin ring, assembled at the margin of the blastodisc, appears to drive the massive streaming of cytoplasm. The fact that the mechanism(s) leading to the formation and relocation of cytoplasmic domains are affected in maternal-effect mutants indicates that these processes are under maternal control. Here, we also discuss why these mutants represent outstanding genetic entry points to investigate the genetic basis of cytoplasmic segregation. Functional studies, combined with the analysis of zebrafish mutants, generated by forward and reverse genetic strategies, are expected to decipher the molecular mechanism(s) by which the maternal factors regulate cytoplasmic movements during early vertebrate development.
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Affiliation(s)
- Ricardo Fuentes
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mary C Mullins
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Juan Fernández
- Department of Biology, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
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23
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Kaufman OH, Lee K, Martin M, Rothhämel S, Marlow FL. rbpms2 functions in Balbiani body architecture and ovary fate. PLoS Genet 2018; 14:e1007489. [PMID: 29975683 PMCID: PMC6049948 DOI: 10.1371/journal.pgen.1007489] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 07/17/2018] [Accepted: 06/13/2018] [Indexed: 12/20/2022] Open
Abstract
The most prominent developmental regulators in oocytes are RNA-binding proteins (RNAbps) that assemble their targets into ribonucleoprotein granules where they are stored, transported and translationally regulated. RNA-binding protein of multiple splice forms 2, or Rbpms2, interacts with molecules that are essential to reproduction and egg patterning, including bucky ball, a key factor for Bb formation. Rbpms2 is localized to germ granules in primordial germ cells (PGCs) and to the Balbiani body (Bb) of oocytes, although the mechanisms regulating Rbpms2 localization to these structures are unknown. Using mutant Rbpms2 proteins, we show that Rbpms2 requires distinct protein domains to localize within germ cells and somatic cells. Accumulation and localization to subcellular compartments in the germline requires an intact RNA binding domain. Whereas in zebrafish somatic blastula cells, the conserved C-terminal domain promotes localization to the bipolar centrosomes/spindle. To investigate Rbpms2 functions, we mutated the duplicated and functionally redundant zebrafish rbpms2 genes. The gonads of rbpms2a;2b (rbpms2) mutants initially contain early oocytes, however definitive oogenesis ultimately fails during sexual differentiation and, rbpms2 mutants develop as fertile males. Unlike other genes that promote oogenesis, failure to maintain oocytes in rbpms2 mutants was not suppressed by mutation of Tp53. These findings reveal a novel and essential role for rbpms2 in oogenesis. Ultrastructural and immunohistochemical analyses revealed that rbpms2 is not required for the asymmetric accumulation of mitochondria and Buc protein in oocytes, however its absence resulted in formation of abnormal Buc aggregates and atypical electron-dense cytoplasmic inclusions. Our findings reveal novel and essential roles for rbpms2 in Buc organization and oocyte differentiation. Oocyte development relies on posttranscriptional regulation by RNA binding proteins (RNAbps). RNAbps form large multi-molecular structures called RNPs (ribonucleoproteins) that further aggregate into regulatory granules within germ cells. In zebrafish primary oocytes, a large transient RNP aggregate called the Balbiani body (Bb) is essential for localizing patterning molecules and germline determinants within oocytes. RNA-binding protein of multiple splice forms 2, or Rbpms2, localizes to germ granules and the Bb, and interacts with bucky ball, a key factor for Bb formation. We show that Rbpms2 requires RNA binding for localization within germ cells, and that the C-term and RRM contribute to Rbpms2 subcellular localization in distinct somatic cell types. To investigate Rbpms2 functions we mutated the duplicated zebrafish rbpms2 genes. Consistent with redundant functions, rbpms2a and rbpms2b gene expression overlaps, and single mutants have no discernible phenotypes. Although rbpms2a;2b double mutants have cardiac phenotypes, those that reach adulthood are exclusively fertile males. Genetic analysis shows that rbpms2 mutant oocytes are not maintained even when Tp53, a regulator of cell death is absent. Initial oocyte polarity is established in rbpms2 mutants based on asymmetric distribution of Buc protein and mitochondria; however, abnormal Buc structures and atypical cytoplasmic inclusions form. This work reveals independent Rbpms2 functions in promoting Bb integrity, and as a novel regulator of ovary fate.
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Affiliation(s)
- Odelya H. Kaufman
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - KathyAnn Lee
- Department of Cell, Developmental and Regenerative Biology Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Manon Martin
- Department of Cell, Developmental and Regenerative Biology Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Sophie Rothhämel
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Florence L. Marlow
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Cell, Developmental and Regenerative Biology Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Department of Neuroscience. Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail:
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24
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Marlow FL. Recent advances in understanding oogenesis: interactions with the cytoskeleton, microtubule organization, and meiotic spindle assembly in oocytes. F1000Res 2018; 7. [PMID: 29755732 PMCID: PMC5911934 DOI: 10.12688/f1000research.13837.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/12/2018] [Indexed: 01/16/2023] Open
Abstract
Maternal control of development begins with production of the oocyte during oogenesis. All of the factors necessary to complete oocyte maturation, meiosis, fertilization, and early development are produced in the transcriptionally active early oocyte. Active transcription of the maternal genome is a mechanism to ensure that the oocyte and development of the early embryo begin with all of the factors needed for successful embryonic development. To achieve the maximum maternal store, only one functional cell is produced from the meiotic divisions that produce the oocyte. The oocyte receives the bulk of the maternal cytoplasm and thus is significantly larger than its sister cells, the tiny polar bodies, which receive a copy of the maternal genome but essentially none of the maternal cytoplasm. This asymmetric division is accomplished by an enormous cell that is depleted of centrosomes in early oogenesis; thus, meiotic divisions in oocytes are distinct from those of mitotic cells. Therefore, these cells must partition the chromosomes faithfully to ensure euploidy by using mechanisms that do not rely on a conventional centrosome-based mitotic spindle. Several mechanisms that contribute to assembly and maintenance of the meiotic spindle in oocytes have been identified; however, none is fully understood. In recent years, there have been many exciting and significant advances in oogenesis, contributed by studies using a myriad of systems. Regrettably, I cannot adequately cover all of the important advances here and so I apologize to those whose beautiful work has not been included. This review focuses on a few of the most recent studies, conducted by several groups, using invertebrate and vertebrate systems, that have provided mechanistic insight into how microtubule assembly and meiotic spindle morphogenesis are controlled in the absence of centrosomes.
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Affiliation(s)
- Florence L Marlow
- Department of Cell Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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