1
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Marelli E, Hughes J, Scotting PJ. SUMO-dependent transcriptional repression by Sox2 inhibits the proliferation of neural stem cells. PLoS One 2024; 19:e0298818. [PMID: 38507426 PMCID: PMC10954124 DOI: 10.1371/journal.pone.0298818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 01/30/2024] [Indexed: 03/22/2024] Open
Abstract
Sox2 is known for its roles in maintaining the stem cell state of embryonic stem cells and neural stem cells. In particular, it has been shown to slow the proliferation of these cell types. It is also known for its effects as an activating transcription factor. Despite this, analysis of published studies shows that it represses as many genes as it activates. Here, we identify a new set of target genes that Sox2 represses in neural stem cells. These genes are associated with centrosomes, centromeres and other aspects of cell cycle control. In addition, we show that SUMOylation of Sox2 is necessary for the repression of these genes and for its repressive effects on cell proliferation. Together, these data suggest that SUMO-dependent repression of this group of target genes is responsible for the role of Sox2 in regulating the proliferation of neural stem cells.
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Affiliation(s)
- Elisa Marelli
- School of Life Sciences, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
| | - Jaime Hughes
- School of Life Sciences, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
| | - Paul J. Scotting
- School of Life Sciences, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
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2
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Pluripotency factors determine gene expression repertoire at zygotic genome activation. Nat Commun 2022; 13:788. [PMID: 35145080 PMCID: PMC8831532 DOI: 10.1038/s41467-022-28434-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 01/24/2022] [Indexed: 12/28/2022] Open
Abstract
Awakening of zygotic transcription in animal embryos relies on maternal pioneer transcription factors. The interplay of global and specific functions of these proteins remains poorly understood. Here, we analyze chromatin accessibility and time-resolved transcription in single and double mutant zebrafish embryos lacking pluripotency factors Pou5f3 and Sox19b. We show that two factors modify chromatin in a largely independent manner. We distinguish four types of direct enhancers by differential requirements for Pou5f3 or Sox19b. We demonstrate that changes in chromatin accessibility of enhancers underlie the changes in zygotic expression repertoire in the double mutants. Pou5f3 or Sox19b promote chromatin accessibility of enhancers linked to the genes involved in gastrulation and ventral fate specification. The genes regulating mesendodermal and dorsal fates are primed for activation independently of Pou5f3 and Sox19b. Strikingly, simultaneous loss of Pou5f3 and Sox19b leads to premature expression of genes, involved in regulation of organogenesis and differentiation. Zygotic genome activation in zebrafish relies on pluripotency transcription factors Pou5f3 and Sox19b. Here the authors investigate how these factors interact in vivo by analyzing the changes in chromatin state and time-resolved transcription in Pou5f3 and Sox19b single and double mutant embryos.
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3
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Lebedeva T, Aman AJ, Graf T, Niedermoser I, Zimmermann B, Kraus Y, Schatka M, Demilly A, Technau U, Genikhovich G. Cnidarian-bilaterian comparison reveals the ancestral regulatory logic of the β-catenin dependent axial patterning. Nat Commun 2021; 12:4032. [PMID: 34188050 PMCID: PMC8241978 DOI: 10.1038/s41467-021-24346-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 05/30/2021] [Indexed: 11/09/2022] Open
Abstract
In animals, body axis patterning is based on the concentration-dependent interpretation of graded morphogen signals, which enables correct positioning of the anatomical structures. The most ancient axis patterning system acting across animal phyla relies on β-catenin signaling, which directs gastrulation, and patterns the main body axis. However, within Bilateria, the patterning logic varies significantly between protostomes and deuterostomes. To deduce the ancestral principles of β-catenin-dependent axial patterning, we investigate the oral–aboral axis patterning in the sea anemone Nematostella—a member of the bilaterian sister group Cnidaria. Here we elucidate the regulatory logic by which more orally expressed β-catenin targets repress more aborally expressed β-catenin targets, and progressively restrict the initially global, maternally provided aboral identity. Similar regulatory logic of β-catenin-dependent patterning in Nematostella and deuterostomes suggests a common evolutionary origin of these processes and the equivalence of the cnidarian oral–aboral and the bilaterian posterior–anterior body axes. The authors show in Nematostella that the more orally expressed β-catenin targets repress the more aborally expressed β-catenin targets, thus patterning the oral-aboral axis. This likely represents the common mechanism of β-catenin-dependent axial patterning shared by Cnidaria and Bilateria.
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Affiliation(s)
- Tatiana Lebedeva
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Andrew J Aman
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Thomas Graf
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Isabell Niedermoser
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Bob Zimmermann
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Yulia Kraus
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria.,Department of Evolutionary Biology, Faculty of Biology, Lomonosov Moscow State University, Leninskiye gory 1/12, Moscow, Russia
| | - Magdalena Schatka
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Adrien Demilly
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Ulrich Technau
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria
| | - Grigory Genikhovich
- Department of Neurosciences and Developmental Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, Vienna, Austria.
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4
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Lin CY, Lu MYJ, Yue JX, Li KL, Le Pétillon Y, Yong LW, Chen YH, Tsai FY, Lyu YF, Chen CY, Hwang SPL, Su YH, Yu JK. Molecular asymmetry in the cephalochordate embryo revealed by single-blastomere transcriptome profiling. PLoS Genet 2021; 16:e1009294. [PMID: 33382716 PMCID: PMC7806126 DOI: 10.1371/journal.pgen.1009294] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 01/13/2021] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
Studies in various animals have shown that asymmetrically localized maternal transcripts play important roles in axial patterning and cell fate specification in early embryos. However, comprehensive analyses of the maternal transcriptomes with spatial information are scarce and limited to a handful of model organisms. In cephalochordates (amphioxus), an early branching chordate group, maternal transcripts of germline determinants form a compact granule that is inherited by a single blastomere during cleavage stages. Further blastomere separation experiments suggest that other transcripts associated with the granule are likely responsible for organizing the posterior structure in amphioxus; however, the identities of these determinants remain unknown. In this study, we used high-throughput RNA sequencing of separated blastomeres to examine asymmetrically localized transcripts in two-cell and eight-cell stage embryos of the amphioxus Branchiostoma floridae. We identified 111 and 391 differentially enriched transcripts at the 2-cell stage and the 8-cell stage, respectively, and used in situ hybridization to validate the spatial distribution patterns for a subset of these transcripts. The identified transcripts could be categorized into two major groups: (1) vegetal tier/germ granule-enriched and (2) animal tier/anterior-enriched transcripts. Using zebrafish as a surrogate model system, we showed that overexpression of one animal tier/anterior-localized amphioxus transcript, zfp665, causes a dorsalization/anteriorization phenotype in zebrafish embryos by downregulating the expression of the ventral gene, eve1, suggesting a potential function of zfp665 in early axial patterning. Our results provide a global transcriptomic blueprint for early-stage amphioxus embryos. This dataset represents a rich platform to guide future characterization of molecular players in early amphioxus development and to elucidate conservation and divergence of developmental programs during chordate evolution.
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Affiliation(s)
- Che-Yi Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Mei-Yeh Jade Lu
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Jia-Xing Yue
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Kun-Lung Li
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yann Le Pétillon
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Luok Wen Yong
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Hua Chen
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Fu-Yu Tsai
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yu-Feng Lyu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Yi Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Sheng-Ping L. Hwang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yi-Hsien Su
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- * E-mail: (Y-HS); (J-KY)
| | - Jr-Kai Yu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
- Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, Yilan, Taiwan
- * E-mail: (Y-HS); (J-KY)
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5
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Gaynor KU, Grigorieva IV, Mirczuk SM, Piret SE, Kooblall KG, Stevenson M, Rizzoti K, Bowl MR, Nesbit MA, Christie PT, Fraser WD, Hough T, Whyte MP, Lovell-Badge R, Thakker RV. Studies of mice deleted for Sox3 and uc482: relevance to X-linked hypoparathyroidism. Endocr Connect 2020; 9:EC-19-0478.R1. [PMID: 31961795 PMCID: PMC7040864 DOI: 10.1530/ec-19-0478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/20/2020] [Indexed: 12/18/2022]
Abstract
Hypoparathyroidism is genetically heterogeneous and characterized by low plasma calcium and parathyroid hormone (PTH) concentrations. X-linked hypoparathyroidism (XLHPT) in two American families, is associated with interstitial deletion-insertions involving deletions of chromosome Xq27.1 downstream of SOX3 and insertions of predominantly non-coding DNA from chromosome 2p25.3. These could result in loss, gain, or movement of regulatory elements, which include ultraconserved element uc482, that could alter SOX3 expression,. To investigate this, we analysed SOX3 expression in EBV-transformed lymphoblastoid cells from 3 affected males, 3 unaffected males, and 4 carrier females from one XLHPT family. SOX3 expression was similar in all individuals, indicating that the spatiotemporal effect of the interstitial deletion-insertion on SOX3 expression postulated to occur in developing parathyroids did not manifest in lymphoblastoids. Expression of SNTG2, which is duplicated and inserted into the X chromosome, and ATP11C, which is moved telomerically, were also similarly expressed in all individuals. Investigation of male hemizygous (Sox3-/Y and uc482-/Y) and female heterozygous (Sox3+/- and uc482+/-) knock-out mice, together with wild-type littermates (male Sox3+/Y and uc482+/Y, and female Sox3+/+ and uc482+/+), revealed Sox3-/Y, Sox3+/-, uc482-/Y, and uc482+/- mice to have normal plasma biochemistry, compared to their respective wild-type littermates. When challenged with a low calcium diet, all mice had hypocalcaemia, and elevated plasma PTH concentrations and alkaline phosphatase activities, and Sox3-/Y, Sox3+/-, uc482-/Y, and uc482+/- mice had similar plasma biochemistry, compared to wild-type littermates. Thus, these results indicate that absence of Sox3 or uc482 does not cause hypoparathyroidism, and that XLHPT likely reflects a more complex mechanism.
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Affiliation(s)
- Katherine U Gaynor
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Irina V Grigorieva
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Samantha M Mirczuk
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Sian E Piret
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Kreepa G Kooblall
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Mark Stevenson
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | | | - Michael R Bowl
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - M Andrew Nesbit
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - Paul T Christie
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
| | - William D Fraser
- Norwich Medical School, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK
| | - Tertius Hough
- MRC Mammalian Genetics Unit, MRC Harwell Institute, Harwell Science and Innovation Campus, Oxfordshire, UK
| | - Michael P Whyte
- Washington University in St Louis School of Medicine, Center for Metabolic Bone Disease and Molecular Research, St Louis, Missouri, USA
| | | | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, UK
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6
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Li X, Zhou W, Li X, Gao M, Ji S, Tian W, Ji G, Du J, Hao A. SOX19b regulates the premature neuronal differentiation of neural stem cells through EZH2-mediated histone methylation in neural tube development of zebrafish. Stem Cell Res Ther 2019; 10:389. [PMID: 31842983 PMCID: PMC6915949 DOI: 10.1186/s13287-019-1495-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/29/2019] [Accepted: 11/14/2019] [Indexed: 12/15/2022] Open
Abstract
Objective Neural tube defects (NTDs) are the most serious and common birth defects in the clinic. The SRY-related HMG box B1 (SoxB1) gene family has been implicated in different processes of early embryogenesis. Sox19b is a maternally expressed gene in the SoxB1 family that is found in the region of the presumptive central nervous system (CNS), but its role and mechanism in embryonic neural stem cells (NSCs) during neural tube development have not yet been explored. Considering that Sox19b is specific to bony fish, we intended to investigate the role and mechanism of Sox19b in neural tube development in zebrafish embryos. Material and methods Morpholino (MO) antisense oligonucleotides were used to construct a Sox19b loss-of-function zebrafish model. The phenotype and the expression of related genes were analysed by in situ hybridization and immunolabelling. Epigenetic modifications were detected by western blot and chromatin immunoprecipitation. Results In this study, we found that zebrafish embryos exhibited a reduced or even deleted forebrain phenotype after the expression of the Sox19b gene was inhibited. Moreover, we found for the first time that knockdown of Sox19b reduced the proliferation of NSCs; increased the transcription levels of Ngn1, Ascl1, HuC, Islet1, and cyclin-dependent kinase (CDK) inhibitors; and led to premature differentiation of NSCs. Finally, we found that knockdown of Sox19b decreased the levels of EZH2/H3K27me3 and decreased the level of H3K27me3 at the promoters of Ngn1 and ascl1a. Conclusion Together, our data demonstrate that Sox19b plays an essential role in early NSC proliferation and differentiation through EZH2-mediated histone methylation in neural tube development. This study established the role of transcription factor Sox19b and epigenetic factor EZH2 regulatory network on NSC development, which provides new clues and theoretical guidance for the clinical treatment of neural tube defects.
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Affiliation(s)
- Xian Li
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China.,Foot and Ankle Surgery Center of Shandong University and Department of Hand and Foot Surgery, The Second Hospital of Shandong University, Jinan, Shandong, China
| | - Wenjuan Zhou
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Xinyue Li
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Ming Gao
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China.,National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Center for Reproductive Medicine, Shandong University, Jinan, China
| | - Shufang Ji
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Wenyu Tian
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Guangyu Ji
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Jingyi Du
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China
| | - Aijun Hao
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Human Anatomy and Histoembryology, School of Basic Medical Sciences, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, China.
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7
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Abstract
Soon after fertilization the zebrafish embryo generates the pool of cells that will give rise to the germline and the three somatic germ layers of the embryo (ectoderm, mesoderm and endoderm). As the basic body plan of the vertebrate embryo emerges, evolutionarily conserved developmental signaling pathways, including Bmp, Nodal, Wnt, and Fgf, direct the nearly totipotent cells of the early embryo to adopt gene expression profiles and patterns of cell behavior specific to their eventual fates. Several decades of molecular genetics research in zebrafish has yielded significant insight into the maternal and zygotic contributions and mechanisms that pattern this vertebrate embryo. This new understanding is the product of advances in genetic manipulations and imaging technologies that have allowed the field to probe the cellular, molecular and biophysical aspects underlying early patterning. The current state of the field indicates that patterning is governed by the integration of key signaling pathways and physical interactions between cells, rather than a patterning system in which distinct pathways are deployed to specify a particular cell fate. This chapter focuses on recent advances in our understanding of the genetic and molecular control of the events that impart cell identity and initiate the patterning of tissues that are prerequisites for or concurrent with movements of gastrulation.
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Affiliation(s)
- Florence L Marlow
- Icahn School of Medicine Mount Sinai Department of Cell, Developmental and Regenerative Biology, New York, NY, United States.
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8
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Reisser M, Palmer A, Popp AP, Jahn C, Weidinger G, Gebhardt JCM. Single-molecule imaging correlates decreasing nuclear volume with increasing TF-chromatin associations during zebrafish development. Nat Commun 2018; 9:5218. [PMID: 30523256 PMCID: PMC6283880 DOI: 10.1038/s41467-018-07731-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 11/21/2018] [Indexed: 11/08/2022] Open
Abstract
Zygotic genome activation (ZGA), the onset of transcription after initial quiescence, is a major developmental step in many species, which occurs after ten cell divisions in zebrafish embryos. How transcription factor (TF)-chromatin interactions evolve during early development to support ZGA is largely unknown. We establish single molecule tracking in live developing zebrafish embryos using reflected light-sheet microscopy to visualize two fluorescently labeled TF species, mEos2-TBP and mEos2-Sox19b. We further develop a data acquisition and analysis scheme to extract quantitative information on binding kinetics and bound fractions during fast cell cycles. The chromatin-bound fraction of both TFs increases during early development, as expected from a physical model of TF-chromatin interactions including a decreasing nuclear volume and increasing DNA accessibility. For Sox19b, data suggests the increase is mainly due to the shrinking nucleus. Our single molecule approach provides quantitative insight into changes of TF-chromatin associations during the developmental period embracing ZGA.
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Affiliation(s)
- Matthias Reisser
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Anja Palmer
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Achim P Popp
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Christopher Jahn
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Gilbert Weidinger
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - J Christof M Gebhardt
- Institute of Biophysics, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
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9
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Klum S, Zaouter C, Alekseenko Z, Björklund ÅK, Hagey DW, Ericson J, Muhr J, Bergsland M. Sequentially acting SOX proteins orchestrate astrocyte- and oligodendrocyte-specific gene expression. EMBO Rep 2018; 19:embr.201846635. [PMID: 30166336 DOI: 10.15252/embr.201846635] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/24/2018] [Accepted: 08/07/2018] [Indexed: 12/30/2022] Open
Abstract
SOX transcription factors have important roles during astrocyte and oligodendrocyte development, but how glial genes are specified and activated in a sub-lineage-specific fashion remains unknown. Here, we define glial-specific gene expression in the developing spinal cord using single-cell RNA-sequencing. Moreover, by ChIP-seq analyses we show that these glial gene sets are extensively preselected already in multipotent neural precursor cells through prebinding by SOX3. In the subsequent lineage-restricted glial precursor cells, astrocyte genes become additionally targeted by SOX9 at DNA regions strongly enriched for Nfi binding motifs. Oligodendrocyte genes instead are prebound by SOX9 only, at sites which during oligodendrocyte maturation are targeted by SOX10. Interestingly, reporter gene assays and functional studies in the spinal cord reveal that SOX3 binding represses the synergistic activation of astrocyte genes by SOX9 and NFIA, whereas oligodendrocyte genes are activated in a combinatorial manner by SOX9 and SOX10. These genome-wide studies demonstrate how sequentially expressed SOX proteins act on lineage-specific regulatory DNA elements to coordinate glial gene expression both in a temporal and in a sub-lineage-specific fashion.
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Affiliation(s)
- Susanne Klum
- Ludwig Institute for Cancer Research, Karolinska Institutet, Stockholm, Sweden.,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Cécile Zaouter
- Ludwig Institute for Cancer Research, Karolinska Institutet, Stockholm, Sweden.,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Zhanna Alekseenko
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Åsa K Björklund
- National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Daniel W Hagey
- Ludwig Institute for Cancer Research, Karolinska Institutet, Stockholm, Sweden.,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Johan Ericson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jonas Muhr
- Ludwig Institute for Cancer Research, Karolinska Institutet, Stockholm, Sweden .,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Bergsland
- Ludwig Institute for Cancer Research, Karolinska Institutet, Stockholm, Sweden .,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
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10
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Abstract
TGF-β family ligands function in inducing and patterning many tissues of the early vertebrate embryonic body plan. Nodal signaling is essential for the specification of mesendodermal tissues and the concurrent cellular movements of gastrulation. Bone morphogenetic protein (BMP) signaling patterns tissues along the dorsal-ventral axis and simultaneously directs the cell movements of convergence and extension. After gastrulation, a second wave of Nodal signaling breaks the symmetry between the left and right sides of the embryo. During these processes, elaborate regulatory feedback between TGF-β ligands and their antagonists direct the proper specification and patterning of embryonic tissues. In this review, we summarize the current knowledge of the function and regulation of TGF-β family signaling in these processes. Although we cover principles that are involved in the development of all vertebrate embryos, we focus specifically on three popular model organisms: the mouse Mus musculus, the African clawed frog of the genus Xenopus, and the zebrafish Danio rerio, highlighting the similarities and differences between these species.
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Affiliation(s)
- Joseph Zinski
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Benjamin Tajer
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Mary C Mullins
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
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11
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SOX2 regulates common and specific stem cell features in the CNS and endoderm derived organs. PLoS Genet 2018; 14:e1007224. [PMID: 29432416 PMCID: PMC5825159 DOI: 10.1371/journal.pgen.1007224] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 02/23/2018] [Accepted: 01/25/2018] [Indexed: 11/29/2022] Open
Abstract
Stem cells are defined by their capacities to self-renew and generate progeny of multiple lineages. The transcription factor SOX2 has key roles in the regulation of stem cell characteristics, but whether SOX2 achieves these functions through similar mechanisms in distinct stem cell populations is not known. To address this question, we performed RNA-seq and SOX2 ChIP-seq on embryonic mouse cortex, spinal cord, stomach and lung/esophagus. We demonstrate that, although SOX2 binds a similar motif in the different cell types, its target regions are primarily cell-type-specific and enriched for the distinct binding motifs of appropriately expressed interacting co-factors. Furthermore, cell-type-specific SOX2 binding in endodermal and neural cells is most often found around genes specifically expressed in the corresponding tissue. Consistent with this, we demonstrate that SOX2 target regions can act as cis-regulatory modules capable of directing reporter expression to appropriate tissues in a zebrafish reporter assay. In contrast, SOX2 binding sites found in both endodermal and neural tissues are associated with genes regulating general stem cell features, such as proliferation. Notably, we provide evidence that SOX2 regulates proliferation through conserved mechanisms and target genes in both germ layers examined. Together, these findings demonstrate how SOX2 simultaneously regulates cell-type-specific, as well as core transcriptional programs in neural and endodermal stem cells. The fine-tuned activities of stem cells are essential for embryonic development and organ maintenance. All types of stem cells share the abilities to self-renew and differentiate into specific cell-types, though the stem cells of different organs have distinct gene expression profiles and competences. Despite these unifying properties, to what extent diverse populations of stem cells utilize similar regulatory mechanisms remains unclear. To address this issue, we map the binding pattern of the key stem cell transcription factor SOX2 in the developing cortex, spinal cord, stomach and lung/esophagus. We find that, even though the core DNA-sequence it targets is similar in all tissues, its binding location is highly divergent and reflects the gene expression profile of each cell type. Moreover, DNA-regions targeted by SOX2 are enriched for binding motifs of distinct co-factors in each tissue, which we demonstrate can physically and functionally interact with SOX2. Consistent with these findings, DNA-regions bound specifically in cells of one germ layer are capable of driving fluorescent reporter gene expression in corresponding zebrafish tissues. Finally, we demonstrate that proliferation genes are bound by SOX2 in all examined tissues, and that cell division is controlled via a common mechanism in neural and endodermal cells. These findings provide a striking example of how a single transcription factor regulates both core and specific stem cell processes in multiple cellular contexts.
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12
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Kiecker C, Bates T, Bell E. Molecular specification of germ layers in vertebrate embryos. Cell Mol Life Sci 2016; 73:923-47. [PMID: 26667903 PMCID: PMC4744249 DOI: 10.1007/s00018-015-2092-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/11/2015] [Accepted: 11/09/2015] [Indexed: 11/17/2022]
Abstract
In order to generate the tissues and organs of a multicellular organism, different cell types have to be generated during embryonic development. The first step in this process of cellular diversification is the formation of the three germ layers: ectoderm, endoderm and mesoderm. The ectoderm gives rise to the nervous system, epidermis and various neural crest-derived tissues, the endoderm goes on to form the gastrointestinal, respiratory and urinary systems as well as many endocrine glands, and the mesoderm will form the notochord, axial skeleton, cartilage, connective tissue, trunk muscles, kidneys and blood. Classic experiments in amphibian embryos revealed the tissue interactions involved in germ layer formation and provided the groundwork for the identification of secreted and intracellular factors involved in this process. We will begin this review by summarising the key findings of those studies. We will then evaluate them in the light of more recent genetic studies that helped clarify which of the previously identified factors are required for germ layer formation in vivo, and to what extent the mechanisms identified in amphibians are conserved across other vertebrate species. Collectively, these studies have started to reveal the gene regulatory network (GRN) underlying vertebrate germ layer specification and we will conclude our review by providing examples how our understanding of this GRN can be employed to differentiate stem cells in a targeted fashion for therapeutic purposes.
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Affiliation(s)
- Clemens Kiecker
- MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK
| | - Thomas Bates
- MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Esther Bell
- MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK.
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13
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Sox2 Acts in a Dose-Dependent Fashion to Regulate Proliferation of Cortical Progenitors. Cell Rep 2014; 9:1908-1920. [DOI: 10.1016/j.celrep.2014.11.013] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 09/25/2014] [Accepted: 11/08/2014] [Indexed: 12/17/2022] Open
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14
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McAninch D, Thomas P. Identification of highly conserved putative developmental enhancers bound by SOX3 in neural progenitors using ChIP-Seq. PLoS One 2014; 9:e113361. [PMID: 25409526 PMCID: PMC4237438 DOI: 10.1371/journal.pone.0113361] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/22/2014] [Indexed: 11/29/2022] Open
Abstract
The transcription factor SOX3 is expressed within most neural progenitor (NP) cells of the vertebrate central nervous system (CNS) and is essential for normal brain development in mice and humans. However, despite the widespread expression of Sox3, CNS defects in null mice are relatively mild due to functional redundancy with the other SOXB1 sub-group members Sox1 and Sox2. To further understand the molecular function of SOX3, we investigated the genome-wide binding profile of endogenous SOX3 in NP cells using ChIP-seq. SOX3 binding was identified at over 8,000 sites, most of which were intronic or intergeneic and were significantly associated with neurodevelopmental genes. The majority of binding sites were moderately or highly conserved (phastCons scores >0.1 and 0.5, respectively) and included the previously characterised, SOXB1-binding Nestin NP cell enhancer. Comparison of SOX3 and published ChIP-Seq data for the co-activator P300 in embryonic brain identified hundreds of highly conserved putative enhancer elements. In addition, we identified a subset of highly conserved putative enhancers for CNS development genes common to SOXB1 members in NP cells, all of which contained the SOX consensus motif (ACAAWR). Together these data implicate SOX3 in the direct regulation of hundreds of NP genes and provide molecular insight into the overlapping roles of SOXB1 proteins in CNS development.
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Affiliation(s)
- Dale McAninch
- Department of Biochemistry, School of Molecular & Biomedical Science and Robinson Research Institute, The University of Adelaide, Adelaide, Australia
| | - Paul Thomas
- Department of Biochemistry, School of Molecular & Biomedical Science and Robinson Research Institute, The University of Adelaide, Adelaide, Australia
- * E-mail:
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15
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The transcription factor hairy/E(spl)-related 2 induces proliferation of neural progenitors and regulates neurogenesis and gliogenesis. Dev Biol 2014; 397:116-28. [PMID: 25446033 DOI: 10.1016/j.ydbio.2014.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 10/15/2014] [Accepted: 10/21/2014] [Indexed: 02/06/2023]
Abstract
The study of molecular regulation in neural development provides information to understand how diverse neural cells are generated. It also helps to establish therapeutic strategies for the treatment of neural degenerative disorders and brain tumors. The Hairy/E(spl) family members are potential targets of Notch signaling, which is fundamental to neural cell maintenance, cell fate decisions, and compartment boundary formation. In this study, we isolated a zebrafish homolog of Hairy/E(spl), her2, and showed that this gene is expressed in neural progenitor cells and in the developing nervous system. The expression of her2 required Notch activation, as revealed by a Notch-defective mutant and a chemical inhibitor, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT). The endogenous expression of Her2 was altered by both overexpression and morpholino-knockdown approaches, and the results demonstrated that Her2 was both necessary and sufficient to promote the proliferation of neural progenitors by inhibiting the transcription of the cell cycle inhibitors cdkn1a, cdkn1ba, and cdkn1bb. Her2 knockdown caused premature neuronal differentiation, which indicates that Her2 is essential for inhibiting neuronal differentiation. At a later stage of neural development, Her2 could induce glial differentiation. The overexpression of Her2 constructs lacking the bHLH or WRPW domain phenocopied the effect of the morpholino knockdown, demonstrating the essential function of these two domains and further confirming the knockdown specificity. In conclusion, our data reveal that Her2 promotes progenitor proliferation and maintains progenitor characteristics by inhibiting neuronal differentiation. Together, these two mechanisms ensure the proper development of the neural progenitor cell pool.
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16
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Liu YR, Laghari ZA, Novoa CA, Hughes J, Webster JRM, Goodwin PE, Wheatley SP, Scotting PJ. Sox2 acts as a transcriptional repressor in neural stem cells. BMC Neurosci 2014; 15:95. [PMID: 25103589 PMCID: PMC4148960 DOI: 10.1186/1471-2202-15-95] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/30/2014] [Indexed: 12/30/2022] Open
Abstract
Background The transcription factor, Sox2, is central to the behaviour of neural stem cells. It is also one of the key embryonic stem cell factors that, when overexpressed can convert somatic cells into induced pluripotent cells. Although generally studied as a transcriptional activator, recent evidence suggests that it might also repress gene expression. Results We show that in neural stem cells Sox2 represses as many genes as it activates. We found that Sox2 interacts directly with members of the groucho family of corepressors and that repression of several target genes required this interaction. Strikingly, where many of the genes activated by Sox2 encode transcriptional regulators, no such genes were repressed. Finally, we found that a mutant form of Sox2 that was unable to bind groucho was no longer able to inhibit differentiation of neural stem cells to the same extent as the wild type protein. Conclusions These data reveal a major new mechanism of action for this key transcription factor. In the context of our understanding of endogenous stem cells, this highlights the need to determine how such a central regulator can distinguish which genes to activate and which to repress. Electronic supplementary material The online version of this article (doi:10.1186/1471-2202-15-95) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | - Paul J Scotting
- Centre for Genetics and Genomics, School of Life Sciences, Queen's Medical Centre, Nottingham NG7 2UH, England.
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17
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Popovic J, Stanisavljevic D, Schwirtlich M, Klajn A, Marjanovic J, Stevanovic M. Expression analysis of SOX14 during retinoic acid induced neural differentiation of embryonal carcinoma cells and assessment of the effect of its ectopic expression on SOXB members in HeLa cells. PLoS One 2014; 9:e91852. [PMID: 24637840 PMCID: PMC3956720 DOI: 10.1371/journal.pone.0091852] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 02/17/2014] [Indexed: 12/01/2022] Open
Abstract
SOX14 is a member of the SOXB2 subgroup of transcription factors implicated in neural development. Although the first SOX14 gene in vertebrates was cloned and characterized more than a decade ago and its expression profile during development was revealed in various animal model systems, the role of this gene during neural development is largely unknown. In the present study we analyzed the expression of SOX14 in human NT2/D1 and mouse P19 pluripotent embryonal carcinoma cells. We demonstrated that it is expressed in both cell lines and upregulated during retinoic acid induced neural differentiation. We showed that SOX14 was expressed in both neuronal and non-neuronal differentiated derivatives, as revealed by immunocytochemistry. Since it was previously proposed that increased SOXB2 proteins level interfere with the activity of SOXB1 counteracting partners, we compared expression patterns of SOXB members during retinoic acid induction of embryonal carcinoma cells. We revealed that upregulation of SOX14 expression is accompanied by alterations in the expression patterns of SOXB1 members. In order to analyze the potential cross-talk between them, we generated SOX14 expression construct. The ectopic expression of SOX14 was demonstrated at the mRNA level in NT2/D1, P19 and HeLa cells, while an increased level of SOX14 protein was detected in HeLa cells only. By transient transfection experiments in HeLa cells we showed for the first time that ectopic expression of SOX14 repressed SOX1 expression, whereas no significant effect on SOX2, SOX3 and SOX21 was observed. Data presented here provide an insight into SOX14 expression during in vitro neural differentiation of embryonal carcinoma cells and demonstrate the effect of its ectopic expression on protein levels of SOXB members in HeLa cells. Obtained results contribute to better understanding the role of one of the most conserved SOX proteins.
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Affiliation(s)
- Jelena Popovic
- Laboratory for Human Molecular Genetics, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
- * E-mail:
| | - Danijela Stanisavljevic
- Laboratory for Human Molecular Genetics, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Marija Schwirtlich
- Laboratory for Human Molecular Genetics, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Andrijana Klajn
- Laboratory for Human Molecular Genetics, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Jelena Marjanovic
- Laboratory for Human Molecular Genetics, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Milena Stevanovic
- Laboratory for Human Molecular Genetics, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
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18
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Scerbo P, Coen L. [Pluripotency and induced nuclear reprogramming in vertebrates: new perspectives]. Biol Aujourdhui 2013; 207:201-17. [PMID: 24330973 DOI: 10.1051/jbio/2013016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Indexed: 11/14/2022]
Abstract
Pluripotency is a transitory state during vertebrate development. A pluripotent cell can theoretically acquire all cell fates of the organism. During ontogenetic dynamics, loss of pluripotency is associated with a progressive acquisition of a specific genetic program, which is determined both by instructions received and by cell position in the whole organism. Pluripotent embryonic stem cells can be isolated and cultured in vitro indefinitely. Using mammalian embryonic stem cells (ESCs), it has been possible to identify the factors involved in the establishment and maintenance of pluripotency state. In this review, we will describe recent scientific advances in the understanding of pluripotency, the molecular actors involved in such a regulation and their functional conservation during evolution. We shall focus on new concepts, obtained from the study of vertebrate model organisms, to shed light on the cell transition from pluripotency to differentiated state, and shall recapitulate fundamental and clinical applications of pluripotent cells, of "somatic cell nuclear transfer" (SCNT), of induced nuclear reprogramming in vitro and future perspectives of in vivo applications. Our results, in the xenopus, concerning the first in vivo induced nuclear reprogramming might open new perspectives about the understanding of cell plasticity in an integrated context. Our analyses sought to encourage new and alternative clinical approaches to achieve in situ tissue regeneration.
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Affiliation(s)
- Pierluigi Scerbo
- Institut de Biologie du Développement de Marseille Luminy, CNRS UMR 7288, case 907, campus de Luminy, 13009 Marseille, France - Département Régulations, Développement et Diversité Moléculaire, CNRS UMR 7221, Muséum National d'Histoire Naturelle (MNHN), CP No. 32, 7 rue Cuvier, 75231 Paris Cedex 5, France
| | - Laurent Coen
- Département Régulations, Développement et Diversité Moléculaire, CNRS UMR 7221, Muséum National d'Histoire Naturelle (MNHN), CP No. 32, 7 rue Cuvier, 75231 Paris Cedex 5, France
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19
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Kamachi Y, Kondoh H. Sox proteins: regulators of cell fate specification and differentiation. Development 2013; 140:4129-44. [PMID: 24086078 DOI: 10.1242/dev.091793] [Citation(s) in RCA: 417] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sox transcription factors play widespread roles during development; however, their versatile funtions have a relatively simple basis: the binding of a Sox protein alone to DNA does not elicit transcriptional activation or repression, but requires binding of a partner transcription factor to an adjacent site on the DNA. Thus, the activity of a Sox protein is dependent upon the identity of its partner factor and the context of the DNA sequence to which it binds. In this Primer, we provide an mechanistic overview of how Sox family proteins function, as a paradigm for transcriptional regulation of development involving multi-transcription factor complexes, and we discuss how Sox factors can thus regulate diverse processes during development.
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Affiliation(s)
- Yusuke Kamachi
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
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20
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Milivojevic M, Petrovic I, Kovacevic-Grujicic N, Popovic J, Mojsin M, Stevanovic M. Construction and functional analysis of novel dominant-negative mutant of human SOX18 protein. BIOCHEMISTRY (MOSCOW) 2013; 78:1287-92. [DOI: 10.1134/s0006297913110096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Ramel MC, Hill CS. The ventral to dorsal BMP activity gradient in the early zebrafish embryo is determined by graded expression of BMP ligands. Dev Biol 2013; 378:170-82. [PMID: 23499658 PMCID: PMC3899928 DOI: 10.1016/j.ydbio.2013.03.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/26/2013] [Accepted: 03/04/2013] [Indexed: 12/26/2022]
Abstract
In the early zebrafish embryo, a ventral to dorsal gradient of bone morphogenetic protein (BMP) activity is established, which is essential for the specification of cell fates along this axis. To visualise and mechanistically determine how this BMP activity gradient forms, we have used a transgenic zebrafish line that expresses monomeric red fluorescent protein (mRFP) under the control of well-characterised BMP responsive elements. We demonstrate that mRFP expression in this line faithfully reports BMP and GDF signalling at both early and late stages of development. Taking advantage of the unstable nature of mRFP transcripts, we use in situ hybridisation to reveal the dynamic spatio-temporal pattern of BMP activity and establish the timing and sequence of events that lead to the formation of the BMP activity gradient. We show that the BMP transcriptional activity gradient is established between 30% and 40% epiboly stages and that it is preceded by graded mRNA expression of the BMP ligands. Both Dharma and FGF signalling contribute to graded bmp transcription during these early stages and it is subsequently maintained through autocrine BMP signalling. We show that BMP2B protein is also expressed in a gradient as early as blastula stages, but do not find any evidence of diffusion of this BMP to generate the BMP transcriptional activity gradient. Thus, in contrast to diffusion/transport-based models of BMP gradient formation in Drosophila, our results indicate that the establishment of the BMP activity gradient in early zebrafish embryos is determined by graded expression of the BMP ligands.
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Affiliation(s)
| | - Caroline S. Hill
- Laboratory of Developmental Signalling, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3LY, United Kingdom
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22
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Hoffman JA, Wu CI, Merrill BJ. Tcf7l1 prepares epiblast cells in the gastrulating mouse embryo for lineage specification. Development 2013; 140:1665-75. [PMID: 23487311 DOI: 10.1242/dev.087387] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The core gene regulatory network (GRN) in embryonic stem cells (ESCs) integrates activities of the pro-self-renewal factors Oct4 (Pou5f1), Sox2 and Nanog with that of an inhibitor of self-renewal, Tcf7l1 (Tcf3). The inhibitor function of Tcf7l1 causes dependence on extracellular Wnt/β-catenin signaling activity, making its embryonic role within the ESC GRN unclear. By analyzing intact mouse embryos, we demonstrate that the function of Tcf7l1 is necessary for specification of cell lineages to occur concomitantly with the elaboration of a three-dimensional body plan during gastrulation. In Tcf7l1(-/-) embryos, specification of mesoderm is delayed, effectively uncoupling it from the induction of the primitive streak. Tcf7l1 repressor activity is necessary for a rapid switch in the response of pluripotent cells to Wnt/β-catenin stimulation, from one of self-renewal to a mesoderm specification response. These results identify Tcf7l1 as a unique factor that is necessary in pluripotent cells to prepare them for lineage specification. We suggest that the role of Tcf7l1 in mammals is to inhibit the GRN to ensure the coordination of lineage specification with the dynamic cellular events occurring during gastrulation.
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Affiliation(s)
- Jackson A Hoffman
- Department of Biochemistry and Molecular Genetics, University of Illinois, Chicago, IL 60607, USA
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23
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Kuo CL, Lam CM, Hewitt JE, Scotting PJ. Formation of the embryonic organizer is restricted by the competitive influences of Fgf signaling and the SoxB1 transcription factors. PLoS One 2013; 8:e57698. [PMID: 23469052 PMCID: PMC3585176 DOI: 10.1371/journal.pone.0057698] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 01/23/2013] [Indexed: 11/18/2022] Open
Abstract
The organizer is one of the earliest structures to be established during vertebrate development and is crucial to subsequent patterning of the embryo. We have previously shown that the SoxB1 transcription factor, Sox3, plays a central role as a transcriptional repressor of zebrafish organizer gene expression. Recent data suggest that Fgf signaling has a positive influence on organizer formation, but its role remains to be fully elucidated. In order to better understand how Fgf signaling fits into the complex regulatory network that determines when and where the organizer forms, the relationship between the positive effects of Fgf signaling and the repressive effects of the SoxB1 factors must be resolved. This study demonstrates that both fgf3 and fgf8 are required for expression of the organizer genes, gsc and chd, and that SoxB1 factors (Sox3, and the zebrafish specific factors, Sox19a and Sox19b) can repress the expression of both fgf3 and fgf8. However, we also find that these SoxB1 factors inhibit the expression of gsc and chd independently of their repression of fgf expression. We show that ectopic expression of organizer genes induced solely by the inhibition of SoxB1 function is dependent upon the activation of fgf expression. These data allow us to describe a comprehensive signaling network in which the SoxB1 factors restrict organizer formation by inhibiting Fgf, Nodal and Wnt signaling, as well as independently repressing the targets of that signaling. The organizer therefore forms only where Nodal-induced Fgf signaling overlaps with Wnt signaling and the SoxB1 proteins are absent.
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Affiliation(s)
- Cheng-Liang Kuo
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, QMC, Nottingham, United Kingdom
| | - Chi Man Lam
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, QMC, Nottingham, United Kingdom
| | - Jane E. Hewitt
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, QMC, Nottingham, United Kingdom
| | - Paul J. Scotting
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, QMC, Nottingham, United Kingdom
- * E-mail:
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24
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Telias M, Segal M, Ben-Yosef D. Neural differentiation of Fragile X human Embryonic Stem Cells reveals abnormal patterns of development despite successful neurogenesis. Dev Biol 2012; 374:32-45. [PMID: 23219959 DOI: 10.1016/j.ydbio.2012.11.031] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/24/2012] [Accepted: 11/28/2012] [Indexed: 12/23/2022]
Abstract
Fragile X Syndrome (FXS) is the most common form of inherited intellectual disability, caused by developmentally regulated inactivation of FMR1, leading to the absence of its encoded protein FMRP. We have previously shown that undifferentiated Fragile X human Embryonic Stem Cells (FX-hESCs) express FMRP, despite the presence of the full FMR1 mutation (>200 CGG repeats). We describe here, for the first time, in-vitro differentiation of FX-hESCs into neurons progressively inactivating FMR1. Abnormal neurogenesis and aberrant gene expression were found already during early stages of differentiation, leading to poor neuronal maturation and high gliogenic development. Human FX neurons fired action potentials but displayed poor spontaneous synaptic activity and lacked reactivity to glutamate. Our dynamic FX-hESCs model can contribute to the understanding of the sequence of developmental events taking place during neurogenesis and how they are altered in FXS individuals, leading to intellectual disability. Furthermore, it may shed light over the striking phenotypic features characterizing FXS in human.
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Affiliation(s)
- Michael Telias
- Stem Cell Research Lab, Racine IVF Unit, Lis Maternity Hospital, Tel-Aviv Sourasky Medical Center, 6 Weizmann St., 64239 Tel-Aviv, Israel
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25
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Lee K, Tan J, Morris MB, Rizzoti K, Hughes J, Cheah PS, Felquer F, Liu X, Piltz S, Lovell-Badge R, Thomas PQ. Congenital hydrocephalus and abnormal subcommissural organ development in Sox3 transgenic mice. PLoS One 2012; 7:e29041. [PMID: 22291885 PMCID: PMC3266892 DOI: 10.1371/journal.pone.0029041] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 11/18/2011] [Indexed: 12/24/2022] Open
Abstract
Congenital hydrocephalus (CH) is a life-threatening medical condition in which excessive accumulation of CSF leads to ventricular expansion and increased intracranial pressure. Stenosis (blockage) of the Sylvian aqueduct (Aq; the narrow passageway that connects the third and fourth ventricles) is a common form of CH in humans, although the genetic basis of this condition is unknown. Mouse models of CH indicate that Aq stenosis is associated with abnormal development of the subcommmissural organ (SCO) a small secretory organ located at the dorsal midline of the caudal diencephalon. Glycoproteins secreted by the SCO generate Reissner's fibre (RF), a thread-like structure that descends into the Aq and is thought to maintain its patency. However, despite the importance of SCO function in CSF homeostasis, the genetic program that controls SCO development is poorly understood. Here, we show that the X-linked transcription factor SOX3 is expressed in the murine SCO throughout its development and in the mature organ. Importantly, overexpression of Sox3 in the dorsal diencephalic midline of transgenic mice induces CH via a dose-dependent mechanism. Histological, gene expression and cellular proliferation studies indicate that Sox3 overexpression disrupts the development of the SCO primordium through inhibition of diencephalic roof plate identity without inducing programmed cell death. This study provides further evidence that SCO function is essential for the prevention of hydrocephalus and indicates that overexpression of Sox3 in the dorsal midline alters progenitor cell differentiation in a dose-dependent manner.
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Affiliation(s)
- Kristie Lee
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Jacqueline Tan
- Pituitary Research Unit, Murdoch Childrens Research Institute, Melbourne, Australia
| | - Michael B. Morris
- Bosch Institute and Physiology, University of Sydney, Sydney, Australia
- Kolling Institute of Medical Research and Sydney Centre for Development and Regenerative Medicine, Royal North Shore Hospital, Sydney, Australia
| | - Karine Rizzoti
- Division of Stem Cell Biology and Developmental Genetics, Medical Research Council National Institute for Medical Research, London, United Kingdom
| | - James Hughes
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Pike See Cheah
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
- Department of Human Anatomy, Universiti Putra Malaysia, Serdang, Malaysia
| | - Fernando Felquer
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Xuan Liu
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Sandra Piltz
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - Robin Lovell-Badge
- Division of Stem Cell Biology and Developmental Genetics, Medical Research Council National Institute for Medical Research, London, United Kingdom
| | - Paul Q. Thomas
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
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Hu SN, Yu H, Zhang YB, Wu ZL, Yan YC, Li YX, Li YY, Li YP. Splice blocking of zygotic sox31 leads to developmental arrest shortly after Mid-Blastula Transition and induces apoptosis in zebrafish. FEBS Lett 2011; 586:222-8. [PMID: 22209980 DOI: 10.1016/j.febslet.2011.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 11/29/2011] [Accepted: 12/06/2011] [Indexed: 10/14/2022]
Abstract
Here we report that splice blocking morpholinos (Sb MO) against zebrafish sox31 elicit developmental arrest, likely through creating a series of dominant negative splicing variants. Embryos injected with the Sb MO develop normally before the Mid-Blastula Transition (MBT); however, they do not initiate epiboly. Microarray analysis of mRNAs collected at the dome stage revealed that the Sb MO impairs activation of a large set of zygotic genes and reduces degradation of maternal mRNA during MBT. Furthermore, an apoptotic response occurs in Sb morphants at about 6hpf. SoxB1 family genes including sox31 thus play an essential role for early embryos traversing the transitional stage.
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Affiliation(s)
- Sheng-Nan Hu
- State Key Laboratory of Cell Biology, Shanghai Key Laboratory for Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Acloque H, Ocaña OH, Matheu A, Rizzoti K, Wise C, Lovell-Badge R, Nieto MA. Reciprocal repression between Sox3 and snail transcription factors defines embryonic territories at gastrulation. Dev Cell 2011; 21:546-58. [PMID: 21920318 PMCID: PMC3256632 DOI: 10.1016/j.devcel.2011.07.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 05/19/2011] [Accepted: 07/10/2011] [Indexed: 01/05/2023]
Abstract
In developing amniote embryos, the first epithelial-to-mesenchymal transition (EMT) occurs at gastrulation, when a subset of epiblast cells moves to the primitive streak and undergoes EMT to internalize and generate the mesoderm and the endoderm. We show that in the chick embryo this decision to internalize is mediated by reciprocal transcriptional repression of Snail2 and Sox3 factors. We also show that the relationship between Sox3 and Snail is conserved in the mouse embryo and in human cancer cells. In the embryo, Snail-expressing cells ingress at the primitive streak, whereas Sox3-positive cells, which are unable to ingress, ensure the formation of ectodermal derivatives. Thus, the subdivision of the early embryo into the two main territories, ectodermal and mesendodermal, is regulated by changes in cell behavior mediated by the antagonistic relationship between Sox3 and Snail transcription factors.
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Affiliation(s)
- Hervé Acloque
- Instituto de Neurociencias, CSIC-UMH, San Juan de Alicante 03550, Spain
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28
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Abstract
Vertebrate development begins with precise molecular, cellular, and morphogenetic controls to establish the basic body plan of the embryo. In zebrafish, these tightly regulated processes begin during oogenesis and proceed through gastrulation to establish and pattern the axes of the embryo. During oogenesis a maternal factor is localized to the vegetal pole of the oocyte that is a determinant of dorsal tissues. Following fertilization this vegetally localized dorsal determinant is asymmetrically translocated in the egg and initiates formation of the dorsoventral axis. Dorsoventral axis formation and patterning is then mediated by maternal and zygotic factors acting through Wnt, BMP (bone morphogenetic protein), Nodal, and FGF (fibroblast growth factor) signaling pathways, each of which is required to establish and/or pattern the dorsoventral axis. This review addresses recent advances in our understanding of the molecular factors and mechanisms that establish and pattern the dorsoventral axis of the zebrafish embryo, including establishment of the animal-vegetal axis as it relates to formation of the dorsoventral axis.
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Affiliation(s)
- Yvette G Langdon
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
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Zebrafish Her8a is activated by Su(H)-dependent Notch signaling and is essential for the inhibition of neurogenesis. PLoS One 2011; 6:e19394. [PMID: 21541299 PMCID: PMC3082574 DOI: 10.1371/journal.pone.0019394] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 04/04/2011] [Indexed: 12/22/2022] Open
Abstract
Understanding how diversity of neural cells is generated is one of the main tasks of developmental biology. The Hairy/E(spl) family members are potential targets of Notch signaling, which has been shown to be fundamental to neural cell maintenance, cell fate decisions, and compartment boundary formation. However, their response to Notch signaling and their roles in neurogenesis are still not fully understood. In the present study, we isolated a zebrafish homologue of hairy/E(spl), her8a, and showed this gene is specifically expressed in the developing nervous system. her8a is positively regulated by Su(H)-dependent Notch signaling as revealed by a Notch-defective mutant and injection of variants of the Notch intracellular regulator, Su(H). Morpholino knockdown of Her8a resulted in upregulation of proneural and post-mitotic neuronal markers, indicating that Her8a is essential for the inhibition of neurogenesis. In addition, markers for glial precursors and mature glial cells were down-regulated in Her8a morphants, suggesting Her8a is required for gliogenesis. The role of Her8a and its response to Notch signaling is thus similar to mammalian HES1, however this is the converse of what is seen for the more closely related mammalian family member, HES6. This study not only provides further understanding of how the fundamental signaling pathway, Notch signaling, and its downstream genes mediate neural development and differentiation, but also reveals evolutionary diversity in the role of H/E(spl) genes.
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Laronda MM, Jameson JL. Sox3 functions in a cell-autonomous manner to regulate spermatogonial differentiation in mice. Endocrinology 2011; 152:1606-15. [PMID: 21248142 PMCID: PMC3060639 DOI: 10.1210/en.2010-1249] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The X-linked Sox3 gene encodes a member of the Sry high-mobility group box proteins, which play a role in many developmental processes including neurogenesis and testis development. This study further examined the role of Sox3 in spermatogenesis. Males without Sox3 expression exhibited a similar number of germ cell nuclear antigen-positive germ cells at 1, 5, and 10 d postpartum (dpp) compared to their wild-type littermates, but there was significant germ cell depletion by 20 dpp. However, spermatogenesis later resumed and postmeiotic germ cells were observed by 56 dpp. The VasaCre transgene was used to generate a germ cell-specific deletion of Sox3. The phenotype of the germ cell-specific Sox3 knockout was similar to the ubiquitous knockout, indicating an intrinsic role for Sox3 in germ cells. The residual germ cells in 20 dpp Sox3(-/Y) males were spermatogonia as indicated by their expression of neurogenin3 but not synaptonemal complex protein 3, which is expressed within cells undergoing meiosis. RNA expression analyses corroborated the histological analyses and revealed a gradual transition from relatively increased expression of spermatogonia genes at 20 dpp to near normal expression of genes characteristic of undifferentiated and meiotic germ cells by 84 dpp. Fluorescent-activated cell sorting of undifferentiated (ret tyrosine kinase receptor positive) and differentiated (kit receptor tyrosine kinase-positive) spermatogonia revealed depletion of differentiated spermatogonia in Sox3(-/Y) tubules. These results indicate that Sox3 functions in an intrinsic manner to promote differentiation of spermatogonia in prepubertal mice but it is not required for ongoing spermatogenesis in adults. The Sox3(-/Y) males provide a unique model for studying the mechanism of germ cell differentiation in prepubertal testes.
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Affiliation(s)
- Monica M Laronda
- Department of Medicine, Northwestern University, Feinberg School of Medicine, 420 East Superior Street, Chicago, Illinois 60611, USA
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Ro H, Dawid IB. Lnx-2b restricts gsc expression to the dorsal mesoderm by limiting Nodal and Bozozok activity. Biochem Biophys Res Commun 2010; 402:626-30. [PMID: 20971071 DOI: 10.1016/j.bbrc.2010.10.070] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 10/17/2010] [Indexed: 11/18/2022]
Abstract
Coordinated Nodal-related signals and Bozozok (Boz) activity are critical for the initial specification of dorsal mesoderm and anterior neuroectoderm during zebrafish embryogenesis. Overexpression of Boz expands gsc expression into the ventro-lateral marginal blastomeres where Nodal signaling is active, but is insufficient to induce ectopic gsc expression in the animal region. We found that overexpression of Boz together with depletion of Lnx-2b (previously named Lnx-like, Lnx-l), but not each manipulation alone, causes robust gsc expression in all blastomeres. Furthermore, nodal-related signals are required for gsc expression in embryos with elevated Boz activity. Through targeted injection into single cells at the 128-cell stage we illustrate the role of maternally deposited Lnx-2b to restrict the expansion of gsc expression into the presumptive ectodermal region. This report provides a novel mechanism for limiting dorsal organizer specification to a defined region of the early zebrafish embryo.
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Affiliation(s)
- Hyunju Ro
- Laboratory of Molecular Genetics, Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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