1
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Gigante ED, Piekarz KM, Gurgis A, Cohen L, Razy-Krajka F, Popsuj S, Johnson CJ, Ali HS, Mohana Sundaram S, Stolfi A. Specification and survival of post-metamorphic branchiomeric neurons in a non-vertebrate chordate. Development 2024; 151:dev202719. [PMID: 38895900 DOI: 10.1242/dev.202719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 06/10/2024] [Indexed: 06/21/2024]
Abstract
Tunicates are the sister group to the vertebrates, yet most species have a life cycle split between swimming larva and sedentary adult phases. During metamorphosis, larval neurons are replaced by adult-specific ones. The regulatory mechanisms underlying this replacement remain largely unknown. Using tissue-specific CRISPR/Cas9-mediated mutagenesis in the tunicate Ciona, we show that orthologs of conserved hindbrain and branchiomeric neuron regulatory factors Pax2/5/8 and Phox2 are required to specify the 'neck', a cellular compartment set aside in the larva to give rise to cranial motor neuron-like neurons post-metamorphosis. Using bulk and single-cell RNA-sequencing analyses, we characterize the transcriptome of the neck downstream of Pax2/5/8. We present evidence that neck-derived adult ciliomotor neurons begin to differentiate in the larva and persist through metamorphosis, contrary to the assumption that the adult nervous system is formed after settlement and the death of larval neurons during metamorphosis. Finally, we show that FGF signaling during the larval phase alters the patterning of the neck and its derivatives. Suppression of FGF converts neck cells into larval neurons that fail to survive metamorphosis, whereas prolonged FGF signaling promotes an adult neural stem cell-like fate.
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Affiliation(s)
- Eduardo D Gigante
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Katarzyna M Piekarz
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Alexandra Gurgis
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Leslie Cohen
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Florian Razy-Krajka
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Sydney Popsuj
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Christopher J Johnson
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Hussan S Ali
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Shruthi Mohana Sundaram
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Alberto Stolfi
- School of Biological Sciences, College of Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
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2
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Johnson CJ, Razy-Krajka F, Zeng F, Piekarz KM, Biliya S, Rothbächer U, Stolfi A. Specification of distinct cell types in a sensory-adhesive organ important for metamorphosis in tunicate larvae. PLoS Biol 2024; 22:e3002555. [PMID: 38478577 PMCID: PMC10962819 DOI: 10.1371/journal.pbio.3002555] [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: 05/02/2023] [Revised: 03/25/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024] Open
Abstract
The papillae of tunicate larvae contribute sensory, adhesive, and metamorphosis-regulating functions that are crucial for the biphasic lifestyle of these marine, non-vertebrate chordates. We have identified additional molecular markers for at least 5 distinct cell types in the papillae of the model tunicate Ciona, allowing us to further study the development of these organs. Using tissue-specific CRISPR/Cas9-mediated mutagenesis and other molecular perturbations, we reveal the roles of key transcription factors and signaling pathways that are important for patterning the papilla territory into a highly organized array of different cell types and shapes. We further test the contributions of different transcription factors and cell types to the production of the adhesive glue that allows for larval attachment during settlement, and to the processes of tail retraction and body rotation during metamorphosis. With this study, we continue working towards connecting gene regulation to cellular functions that control the developmental transition between the motile larva and sessile adult of Ciona.
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Affiliation(s)
- Christopher J Johnson
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Florian Razy-Krajka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Fan Zeng
- Department of Zoology, University of Innsbruck, Innsbruck, Austria
| | - Katarzyna M Piekarz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Shweta Biliya
- Molecular Evolution Core, Petit H. Parker Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Ute Rothbächer
- Department of Zoology, University of Innsbruck, Innsbruck, Austria
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
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3
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Vish KJ, Stiegler AL, Boggon TJ. Diverse p120RasGAP interactions with doubly phosphorylated partners EphB4, p190RhoGAP, and Dok1. J Biol Chem 2023; 299:105098. [PMID: 37507023 PMCID: PMC10470053 DOI: 10.1016/j.jbc.2023.105098] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/06/2023] [Accepted: 07/24/2023] [Indexed: 07/30/2023] Open
Abstract
RasGAP (p120RasGAP), the founding member of the GTPase-activating protein (GAP) family, is one of only nine human proteins to contain two SH2 domains and is essential for proper vascular development. Despite its importance, its interactions with key binding partners remains unclear. In this study we provide a detailed viewpoint of RasGAP recruitment to various binding partners and assess their impact on RasGAP activity. We reveal the RasGAP SH2 domains generate distinct binding interactions with three well-known doubly phosphorylated binding partners: p190RhoGAP, Dok1, and EphB4. Affinity measurements demonstrate a 100-fold weakened affinity for RasGAP-EphB4 binding compared to RasGAP-p190RhoGAP or RasGAP-Dok1 binding, possibly driven by single versus dual SH2 domain engagement with a dominant N-terminal SH2 interaction. Small-angle X-ray scattering reveals conformational differences between RasGAP-EphB4 binding and RasGAP-p190RhoGAP binding. Importantly, these interactions do not impact catalytic activity, implying RasGAP utilizes its SH2 domains to achieve diverse spatial-temporal regulation of Ras signaling in a previously unrecognized fashion.
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Affiliation(s)
- Kimberly J Vish
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Amy L Stiegler
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA
| | - Titus J Boggon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA; Department of Pharmacology, Yale University, New Haven, Connecticut, USA; Department of Yale Cancer Center, Yale University, New Haven, Connecticut, USA.
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4
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Gigante ED, Piekarz KM, Gurgis A, Cohen L, Razy-Krajka F, Popsuj S, Ali HS, Sundaram SM, Stolfi A. Specification and survival of post-metamorphic branchiomeric neurons in the hindbrain of a non-vertebrate chordate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.16.545305. [PMID: 37645866 PMCID: PMC10461979 DOI: 10.1101/2023.06.16.545305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Tunicates are the sister group to the vertebrates, yet most species have a life cycle split between swimming larva and sedentary adult phases. During metamorphosis, larval neurons are largely replaced by adult-specific ones. Yet the regulatory mechanisms underlying this neural replacement remain largely unknown. Using tissue-specific CRISPR/Cas9-mediated mutagenesis in the tunicate Ciona, we show that orthologs of conserved hindbrain and branchiomeric neuron regulatory factors Pax2/5/8 and Phox2 are required to specify the "Neck", a compartment of cells set aside in the larva to give rise to cranial motor neuron-like neurons in the adult. Using bulk and single-cell RNAseq analyses, we also characterize the transcriptome of the Neck downstream of Pax2/5/8. Surprisingly, we find that Neck-derived adult ciliomotor neurons begin to differentiate in the larva, contrary to the long-held assumption that the adult nervous system is formed only after settlement and the death of larval neurons during metamorphosis. Finally, we show that manipulating FGF signaling during the larval phase alters the patterning of the Neck and its derivatives. Suppression of FGF converts Neck cells into larval neurons that fail to survive metamorphosis, while prolonged FGF signaling promotes an adult neural stem cell-like fate instead.
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Affiliation(s)
- Eduardo D Gigante
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
| | - Katarzyna M Piekarz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
| | - Alexandra Gurgis
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
- Department of Biology, Case Western Reserve University, Cleveland, OH, 44106; USA
| | - Leslie Cohen
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
| | - Florian Razy-Krajka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
| | - Sydney Popsuj
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
| | - Hussan S Ali
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
| | | | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332; USA
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5
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Williaume G, de Buyl S, Sirour C, Haupaix N, Bettoni R, Imai KS, Satou Y, Dupont G, Hudson C, Yasuo H. Cell geometry, signal dampening, and a bimodal transcriptional response underlie the spatial precision of an ERK-mediated embryonic induction. Dev Cell 2021; 56:2966-2979.e10. [PMID: 34672970 DOI: 10.1016/j.devcel.2021.09.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 07/16/2021] [Accepted: 09/24/2021] [Indexed: 12/13/2022]
Abstract
Precise control of lineage segregation is critical for the development of multicellular organisms, but our quantitative understanding of how variable signaling inputs are integrated to activate lineage-specific gene programs remains limited. Here, we show how precisely two out of eight ectoderm cells adopt neural fates in response to ephrin and FGF signals during ascidian neural induction. In each ectoderm cell, FGF signals activate ERK to a level that mirrors its cell contact surface with FGF-expressing mesendoderm cells. This gradual interpretation of FGF inputs is followed by a bimodal transcriptional response of the immediate early gene, Otx, resulting in its activation specifically in the neural precursors. At low levels of ERK, Otx is repressed by an ETS family transcriptional repressor, ERF2. Ephrin signals are critical for dampening ERK activation levels across ectoderm cells so that only neural precursors exhibit above-threshold levels, evade ERF repression, and "switch on" Otx transcription.
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Affiliation(s)
- Géraldine Williaume
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche-sur-Mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France
| | - Sophie de Buyl
- Applied Physics Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Interuniversity Institute of Bioinformatics in Brussels, ULB-VUB, La Plaine Campus, 1050 Brussels, Belgium
| | - Cathy Sirour
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche-sur-Mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France
| | - Nicolas Haupaix
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche-sur-Mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France
| | - Rossana Bettoni
- Applied Physics Research Group, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; Interuniversity Institute of Bioinformatics in Brussels, ULB-VUB, La Plaine Campus, 1050 Brussels, Belgium; Unité de Chronobiologie Théorique, Faculté des Sciences, CP231, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Kaoru S Imai
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Geneviève Dupont
- Unité de Chronobiologie Théorique, Faculté des Sciences, CP231, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, 1050 Brussels, Belgium.
| | - Clare Hudson
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche-sur-Mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France.
| | - Hitoyoshi Yasuo
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, Institut de la Mer de Villefranche-sur-Mer, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France.
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6
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Oonuma K, Kusakabe TG. The complete cell lineage and MAPK- and Otx-dependent specification of the dopaminergic cells in the Ciona brain. Development 2021; 148:269114. [PMID: 34121117 DOI: 10.1242/dev.198754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/17/2021] [Indexed: 11/20/2022]
Abstract
The Ciona larva has served as a unique model for understanding the development of dopaminergic cells at single-cell resolution owing to the exceptionally small number of neurons in its brain and its fixed cell lineage during embryogenesis. A recent study suggested that the transcription factors Fer2 and Meis directly regulate the dopamine synthesis genes in Ciona, but the dopaminergic cell lineage and the gene regulatory networks that control the development of dopaminergic cells have not been fully elucidated. Here, we reveal that the dopaminergic cells in Ciona are derived from a bilateral pair of cells called a9.37 cells at the center of the neural plate. The a9.37 cells divide along the anterior-posterior axis, and all of the descendants of the posterior daughter cells differentiate into the dopaminergic cells. We show that the MAPK pathway and the transcription factor Otx are required for the expression of Fer2 in the dopaminergic cell lineage. Our findings establish the cellular and molecular framework for fully understanding the commitment to dopaminergic cells in the simple chordate brain.
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Affiliation(s)
- Kouhei Oonuma
- Institute for Integrative Neurobiology and Department of Biology, Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
| | - Takehiro G Kusakabe
- Institute for Integrative Neurobiology and Department of Biology, Faculty of Science and Engineering, Konan University, Kobe 658-8501, Japan
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7
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Guignard L, Fiúza UM, Leggio B, Laussu J, Faure E, Michelin G, Biasuz K, Hufnagel L, Malandain G, Godin C, Lemaire P. Contact area-dependent cell communication and the morphological invariance of ascidian embryogenesis. Science 2020; 369:369/6500/eaar5663. [PMID: 32646972 DOI: 10.1126/science.aar5663] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 04/29/2020] [Indexed: 12/18/2022]
Abstract
Marine invertebrate ascidians display embryonic reproducibility: Their early embryonic cell lineages are considered invariant and are conserved between distantly related species, despite rapid genomic divergence. Here, we address the drivers of this reproducibility. We used light-sheet imaging and automated cell segmentation and tracking procedures to systematically quantify the behavior of individual cells every 2 minutes during Phallusia mammillata embryogenesis. Interindividual reproducibility was observed down to the area of individual cell contacts. We found tight links between the reproducibility of embryonic geometries and asymmetric cell divisions, controlled by differential sister cell inductions. We combined modeling and experimental manipulations to show that the area of contact between signaling and responding cells is a key determinant of cell communication. Our work establishes the geometric control of embryonic inductions as an alternative to classical morphogen gradients and suggests that the range of cell signaling sets the scale at which embryonic reproducibility is observed.
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Affiliation(s)
- Léo Guignard
- CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France.,Virtual Plants, Université de Montpellier, CIRAD, INRA, Inria, 34095 Montpellier, France.,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Ulla-Maj Fiúza
- CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Bruno Leggio
- CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France.,Virtual Plants, Université de Montpellier, CIRAD, INRA, Inria, 34095 Montpellier, France.,Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Inria, 69342 Lyon, France
| | - Julien Laussu
- CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Emmanuel Faure
- CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France.,Virtual Plants, Université de Montpellier, CIRAD, INRA, Inria, 34095 Montpellier, France.,Institut de Recherche en Informatique de Toulouse (IRIT), Universités Toulouse I et III, CNRS, INPT, ENSEEIHT, 31071 Toulouse, France
| | - Gaël Michelin
- Morpheme, Université Côte d'Azur, Inria, CNRS, I3S, France
| | - Kilian Biasuz
- CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Lars Hufnagel
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | | | - Christophe Godin
- Virtual Plants, Université de Montpellier, CIRAD, INRA, Inria, 34095 Montpellier, France. .,Laboratoire Reproduction et Développement des Plantes, Université de Lyon, ENS de Lyon, UCB Lyon 1, CNRS, INRA, Inria, 69342 Lyon, France
| | - Patrick Lemaire
- CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France.
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8
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Liu B, Satou Y. The genetic program to specify ectodermal cells in ascidian embryos. Dev Growth Differ 2020; 62:301-310. [PMID: 32130723 DOI: 10.1111/dgd.12660] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/11/2020] [Accepted: 02/21/2020] [Indexed: 12/18/2022]
Abstract
The ascidian belongs to the sister group of vertebrates and shares many features with them. The gene regulatory network (GRN) controlling gene expression in ascidian embryonic development leading to the tadpole larva has revealed evolutionarily conserved gene circuits between ascidians and vertebrates. These conserved mechanisms are indeed useful to infer the original developmental programs of the ancestral chordates. Simultaneously, these studies have revealed which gene circuits are missing in the ascidian GRN; these gene circuits may have been acquired in the vertebrate lineage. In particular, the GRN responsible for gene expression in ectodermal cells of ascidian embryos has revealed the genetic programs that regulate the regionalization of the brain, formation of palps derived from placode-like cells, and differentiation of sensory neurons derived from neural crest-like cells. We here discuss how these studies have given insights into the evolution of these traits.
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Affiliation(s)
- Boqi Liu
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan
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9
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Satou Y. A gene regulatory network for cell fate specification in Ciona embryos. Curr Top Dev Biol 2020; 139:1-33. [DOI: 10.1016/bs.ctdb.2020.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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10
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Razy-Krajka F, Stolfi A. Regulation and evolution of muscle development in tunicates. EvoDevo 2019; 10:13. [PMID: 31249657 PMCID: PMC6589888 DOI: 10.1186/s13227-019-0125-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 06/08/2019] [Indexed: 12/16/2022] Open
Abstract
For more than a century, studies on tunicate muscle formation have revealed many principles of cell fate specification, gene regulation, morphogenesis, and evolution. Here, we review the key studies that have probed the development of all the various muscle cell types in a wide variety of tunicate species. We seize this occasion to explore the implications and questions raised by these findings in the broader context of muscle evolution in chordates.
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Affiliation(s)
- Florian Razy-Krajka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, USA
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, USA
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11
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Abstract
The extracellular signal-regulated kinase (ERK) pathway leads to activation of the effector molecule ERK, which controls downstream responses by phosphorylating a variety of substrates, including transcription factors. Crucial insights into the regulation and function of this pathway came from studying embryos in which specific phenotypes arise from aberrant ERK activation. Despite decades of research, several important questions remain to be addressed for deeper understanding of this highly conserved signaling system and its function. Answering these questions will require quantifying the first steps of pathway activation, elucidating the mechanisms of transcriptional interpretation and measuring the quantitative limits of ERK signaling within which the system must operate to avoid developmental defects.
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Affiliation(s)
- Aleena L Patel
- Lewis Sigler Institute for Integrative Genomics, Department of Chemical Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Stanislav Y Shvartsman
- Lewis Sigler Institute for Integrative Genomics, Department of Chemical Engineering, Princeton University, Princeton, NJ 08544, USA
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12
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Abstract
Ascidians are tunicates, which constitute the sister group of vertebrates. The ascidian genome contains two Zic genes, called Zic-r.a (also called Macho-1) and Zic-r.b (ZicL). The latter is a multi-copy gene, and the precise copy number has not yet been determined. Zic-r.a is maternally expressed, and soon after fertilization Zic-r.a mRNA is localized in the posterior pole of the zygote. Zic-r.a protein is translated there and is involved in specification of posterior fate; in particular it is important for specification of muscle fate. Zic-r.a is also expressed zygotically in neural cells of the tailbud stage. On the other hand, Zic-r.b is first expressed in marginal cells of the vegetal hemisphere of 32-cell embryos and then in neural cells that contribute to the central nervous system during gastrulation. Zic-r.b is required first for specification of mesodermal tissues and then for specification of the central nervous system. Their upstream and downstream genetic pathways have been studied extensively by functional assays, which include gene knockdown and chromatin immunoprecipitation assays. Thus, ascidian Zic genes play central roles in specification of mesodermal and neural fates.
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Affiliation(s)
- Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University, Kyoto, Japan.
| | - Kaoru S Imai
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
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13
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Kobayashi K, Maeda K, Tokuoka M, Mochizuki A, Satou Y. Controlling Cell Fate Specification System by Key Genes Determined from Network Structure. iScience 2018; 4:281-293. [PMID: 30240747 PMCID: PMC6147236 DOI: 10.1016/j.isci.2018.05.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 04/19/2018] [Accepted: 05/07/2018] [Indexed: 11/25/2022] Open
Abstract
Network structures describing regulation between biomolecules have been determined in many biological systems. Dynamics of molecular activities based on such networks are considered to be the origin of many biological functions. Recently, it has been proved mathematically that key nodes for controlling dynamics in networks are identified from network structure alone. Here, we applied this theory to a gene regulatory network for the cell fate specification of seven tissues in the ascidian embryo and found that this network, which consisted of 92 factors, had five key molecules. By controlling the activities of these key molecules, the specific gene expression of six of seven tissues observed in the embryo was successfully reproduced. Since this method is applicable to all nonlinear dynamic systems, we propose this method as a tool for controlling gene regulatory networks and reprogramming cell fates.
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Affiliation(s)
- Kenji Kobayashi
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan; CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Kazuki Maeda
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan; Department of Mathematical Sciences, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Miki Tokuoka
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan; CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Atsushi Mochizuki
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan; Theoretical Biology Laboratory, RIKEN, Wako, Saitama 351-0198, Japan; Institute for Frontier Life and Medical Sciences, Kyoto University, Sakyo, Kyoto 606-8507, Japan.
| | - Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan; CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
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14
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Tokuoka M, Kobayashi K, Satou Y. Distinct regulation of Snail in two muscle lineages of the ascidian embryo achieves temporal coordination of muscle development. Development 2018; 145:dev.163915. [PMID: 29764858 DOI: 10.1242/dev.163915] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 05/03/2018] [Indexed: 01/29/2023]
Abstract
The transcriptional repressor Snail is required for proper differentiation of the tail muscle of ascidian tadpole larvae. Two muscle lineages (B5.1 and B6.4) contribute to the anterior tail muscle cells, and are consecutively separated from a transcriptionally quiescent germ cell lineage at the 16- and 32-cell stages. Concomitantly, cells of these lineages begin to express Tbx6.b (Tbx6-r.b) at the 16- and 32-cell stages, respectively. Meanwhile, Snail expression begins in these two lineages simultaneously at the 32-cell stage. Here, we show that Snail expression is regulated differently between these two lineages. In the B5.1 lineage, Snail was activated through Tbx6.b, which is activated by maternal factors, including Zic-r.a. In the B6.4 lineage, the MAPK pathway was cell-autonomously activated by a constitutively active form of Raf, enabling Zic-r.a to activate Snail independently of Tbx6.b As a result, Snail begins to be expressed at the 32-cell stage simultaneously in these two lineages. Such shortcuts might be required for coordinating developmental programs in embryos in which cells become separated progressively from stem cells, including germline cells.
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Affiliation(s)
- Miki Tokuoka
- Department of Zoology, Graduate School of Science, Kyoto University Sakyo, Kyoto, 606-8502, Japan
| | - Kenji Kobayashi
- Department of Zoology, Graduate School of Science, Kyoto University Sakyo, Kyoto, 606-8502, Japan
| | - Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University Sakyo, Kyoto, 606-8502, Japan
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15
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Practical Guide for Ascidian Microinjection: Phallusia mammillata. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018. [PMID: 29542077 DOI: 10.1007/978-981-10-7545-2_3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Phallusia mammillata has recently emerged as a new ascidian model. Its unique characteristics, including the optical transparency of eggs and embryos and efficient translation of exogenously introduced mRNA in eggs, make the Phallusia system suitable for fluorescent protein (FP)-based imaging approaches. In addition, genomic and transcriptomic resources are readily available for this ascidian species, facilitating functional gene studies. Microinjection is probably the most versatile technique for introducing exogenous molecules such as plasmids, mRNAs, and proteins into ascidian eggs/embryos. However, it is not practiced widely within the community; presumably, because the system is rather laborious to set up and it requires practice. Here, we describe in as much detail as possible two microinjection methods that we use daily in the laboratory: one based on an inverted microscope and the other on a stereomicroscope. Along the stepwise description of system setup and injection procedure, we provide practical tips in the hope that this chapter might be a useful guide for introducing or improving a microinjection setup.
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16
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Laussu J, Audouard C, Kischel A, Assis-Nascimento P, Escalas N, Liebl DJ, Soula C, Davy A. Eph/Ephrin Signaling Controls Progenitor Identities In The Ventral Spinal Cord. Neural Dev 2017; 12:10. [PMID: 28595615 PMCID: PMC5463316 DOI: 10.1186/s13064-017-0087-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/31/2017] [Indexed: 02/01/2023] Open
Abstract
Background In the vertebrate spinal cord, motor neurons (MN) are generated in stereotypical numbers from a pool of dedicated progenitors (pMN) whose number depends on signals that control their specification but also their proliferation and differentiation rates. Although the initial steps of pMN specification have been extensively studied, how pMN numbers are regulated over time is less well characterized. Results Here, we show that ephrinB2 and ephrinB3 are differentially expressed in progenitor domains in the ventral spinal cord with several Eph receptors more broadly expressed. Genetic loss-of-function analyses show that ephrinB2 and ephrinB3 inversely control pMN numbers and that these changes in progenitor numbers correlate with changes in motor neuron numbers. Detailed phenotypic analyses by immunostaining and genetic interaction studies between ephrinB2 and Shh indicate that changes in pMN numbers in ephrin mutants are due to alteration in progenitor identity at late stages of development. Conclusions Altogether our data reveal that Eph:ephrin signaling is required to control progenitor identities in the ventral spinal cord. Electronic supplementary material The online version of this article (doi:10.1186/s13064-017-0087-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julien Laussu
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France.,Present address: CRBM, 1919 route de Mende, 34293, Montpellier, France
| | - Christophe Audouard
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Anthony Kischel
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Poincyane Assis-Nascimento
- University of Miami Miller School of Medicine, The Miami Project to Cure Paralysis, 1095 NW 14th Terrace, Miami, FL, R-48, USA
| | - Nathalie Escalas
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Daniel J Liebl
- University of Miami Miller School of Medicine, The Miami Project to Cure Paralysis, 1095 NW 14th Terrace, Miami, FL, R-48, USA
| | - Cathy Soula
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Alice Davy
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France.
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17
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Abstract
Asymmetric cell division during embryogenesis contributes to cell diversity by generating daughter cells that adopt distinct developmental fates. In this chapter, we summarize current knowledge of three examples of asymmetric cell division occurring in ascidian early embryos: (1) Three successive cell divisions that are asymmetric in terms of cell fate and unequal in cell size in the germline lineage at the embryo posterior pole. A subcellular structure, the centrosome-attracting body (CAB), and maternal PEM mRNAs localized within it control both the positioning of the cell division planes and segregation of the germ cell fates. (2) Asymmetric cell divisions involving endoderm and mesoderm germ layer separation. Asymmetric partitioning of zygotically expressed mRNA for Not, a homeodomain transcription factor, promotes the mesoderm fate and suppresses the endoderm fate. This asymmetric partitioning is mediated by transient nuclear migration toward the mesodermal pole of the mother cell, where the mRNA is delivered. In this case, there is no special regulation of cleavage plane orientation. (3) Asymmetric cell divisions in the marginal region of the vegetal hemisphere. The directed extracellular FGF and ephrin signals polarize the mother cells, inducing distinct fates in a pair of daughter cells (nerve versus notochord and mesenchyme versus muscle). The directions of cell division are regulated and oriented but independently of FGF and ephrin signaling. In these examples, polarization of the mother cells is facilitated by localized maternal factors, by delivery of transcripts from the nucleus to one pole of each cell, and by directed extracellular signals. Two cellular processes-asymmetric fate allocation and orientation of the cell division plane-are coupled by a single factor in the first example, but these processes are regulated independently in the third example. Thus, various modes of asymmetric cell division operate even at the early developmental stages in this single type of organism.
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Affiliation(s)
- Takefumi Negishi
- Division of Morphogenesis, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi, 444-8585, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-Cho, Toyonaka, Osaka, 560-0043, Japan.
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18
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The central nervous system of ascidian larvae. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:538-61. [DOI: 10.1002/wdev.239] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/05/2016] [Accepted: 04/09/2016] [Indexed: 11/07/2022]
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19
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Kodama H, Miyata Y, Kuwajima M, Izuchi R, Kobayashi A, Gyoja F, Onuma TA, Kumano G, Nishida H. Redundant mechanisms are involved in suppression of default cell fates during embryonic mesenchyme and notochord induction in ascidians. Dev Biol 2016; 416:162-172. [PMID: 27265866 DOI: 10.1016/j.ydbio.2016.05.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/28/2016] [Accepted: 05/30/2016] [Indexed: 11/30/2022]
Abstract
During embryonic induction, the responding cells invoke an induced developmental program, whereas in the absence of an inducing signal, they assume a default uninduced cell fate. Suppression of the default fate during the inductive event is crucial for choice of the binary cell fate. In contrast to the mechanisms that promote an induced cell fate, those that suppress the default fate have been overlooked. Upon induction, intracellular signal transduction results in activation of genes encoding key transcription factors for induced tissue differentiation. It is elusive whether an induced key transcription factor has dual functions involving suppression of the default fates and promotion of the induced fate, or whether suppression of the default fate is independently regulated by other factors that are also downstream of the signaling cascade. We show that during ascidian embryonic induction, default fates were suppressed by multifold redundant mechanisms. The key transcription factor, Twist-related.a, which is required for mesenchyme differentiation, and another independent transcription factor, Lhx3, which is dispensable for mesenchyme differentiation, sequentially and redundantly suppress the default muscle fate in induced mesenchyme cells. Similarly in notochord induction, Brachyury, which is required for notochord differentiation, and other factors, Lhx3 and Mnx, are likely to suppress the default nerve cord fate redundantly. Lhx3 commonly suppresses the default fates in two kinds of induction. Mis-activation of the autonomously executed default program in induced cells is detrimental to choice of the binary cell fate. Multifold redundant mechanisms would be required for suppression of the default fate to be secure.
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Affiliation(s)
- Hitoshi Kodama
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yoshimasa Miyata
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Mami Kuwajima
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Ryoichi Izuchi
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Ayumi Kobayashi
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Fuki Gyoja
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa 904-0495, Japan
| | - Takeshi A Onuma
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Gaku Kumano
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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20
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EphrinB2/EphB4 pathway in postnatal angiogenesis: a potential therapeutic target for ischemic cardiovascular disease. Angiogenesis 2016; 19:297-309. [PMID: 27216867 DOI: 10.1007/s10456-016-9514-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 05/13/2016] [Indexed: 01/12/2023]
Abstract
Ischemic cardiovascular disease remains one of the leading causes of morbidity and mortality in the world. Proangiogenic therapy appears to be a promising and feasible strategy for the patients with ischemic cardiovascular disease, but the results of preclinical and clinical trials are limited due to the complicated mechanisms of angiogenesis. Facilitating the formation of functional vessels is important in rescuing the ischemic cardiomyocytes. EphrinB2/EphB4, a novel pathway in angiogenesis, plays a critical role in both microvascular growth and neovascular maturation. Hence, investigating the mechanisms of EphrinB2/EphB4 pathway in angiogenesis may contribute to the development of novel therapeutics for ischemic cardiovascular disease. Previous reviews mainly focused on the role of EphrinB2/EphB4 pathway in embryo vascular development, but their role in postnatal angiogenesis in ischemic heart disease has not been fully illustrated. Here, we summarized the current knowledge of EphrinB2/EphB4 in angiogenesis and their interaction with other angiogenic pathways in ischemic cardiovascular disease.
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21
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Ricci L, Cabrera F, Lotito S, Tiozzo S. Redeployment of germ layers related TFs shows regionalized expression during two non-embryonic developments. Dev Biol 2016; 416:235-248. [PMID: 27208394 DOI: 10.1016/j.ydbio.2016.05.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 11/26/2022]
Abstract
In all non-vertebrate metazoan phyla, species that evolved non-embryonic developmental pathways as means of propagation or regeneration can be found. In this context, new bodies arise through asexual reproduction processes (such as budding) or whole body regeneration, that lack the familiar temporal and spatial cues classically associated with embryogenesis, like maternal determinants, or gastrulation. The molecular mechanisms underlying those non-embryonic developments (i.e., regeneration and asexual reproduction), and their relationship to those deployed during embryogenesis are poorly understood. We have addressed this question in the colonial ascidian Botryllus schlosseri, which undergoes an asexual reproductive process via palleal budding (PB), as well as a whole body regeneration by vascular budding (VB). We identified early regenerative structures during VB and then followed the fate of differentiating tissues during both non-embryonic developments (PB and VB) by monitoring the expression of genes known to play key functions in germ layer specification with well conserved expression patterns in solitary ascidian embryogenesis. The expression patterns of FoxA1, GATAa, GATAb, Otx, Bra, Gsc and Tbx2/3 were analysed during both PB and VB. We found that the majority of these transcription factors were expressed during both non-embryonic developmental processes, revealing a regionalization of the palleal and vascular buds. Knockdown of GATAa by siRNA in palleal buds confirmed that preventing the correct development of one of these regions blocks further tissue specification. Our results indicate that during both normal and injury-induced budding, a similar alternative developmental program operates via early commitment of epithelial regions.
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Affiliation(s)
- Lorenzo Ricci
- Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), 06230 Villefranche sur-mer, France
| | - Fabien Cabrera
- Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), 06230 Villefranche sur-mer, France
| | - Sonia Lotito
- Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), 06230 Villefranche sur-mer, France
| | - Stefano Tiozzo
- Sorbonne Universités, UPMC Univ. Paris 06, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), 06230 Villefranche sur-mer, France.
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22
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Ohta N, Waki K, Mochizuki A, Satou Y. A Boolean Function for Neural Induction Reveals a Critical Role of Direct Intercellular Interactions in Patterning the Ectoderm of the Ascidian Embryo. PLoS Comput Biol 2015; 11:e1004687. [PMID: 26714026 PMCID: PMC4695095 DOI: 10.1371/journal.pcbi.1004687] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 12/01/2015] [Indexed: 01/12/2023] Open
Abstract
A complex system of multiple signaling molecules often produce differential gene expression patterns in animal embryos. In the ascidian embryo, four signaling ligands, Ephrin-A.d (Efna.d), Fgf9/16/20, Admp, and Gdf1/3-r, coordinately induce Otx expression in the neural lineage at the 32-cell stage. However, it has not been determined whether differential inputs of all of these signaling pathways are really necessary. It is possible that differential activation of one of these signaling pathways is sufficient and the remaining signaling pathways are activated in all cells at similar levels. To address this question, we developed a parameter-free method for determining a Boolean function for Otx expression in the present study. We treated activities of signaling pathways as Boolean values, and we also took all possible patterns of signaling gradients into consideration. We successfully determined a Boolean function that explains Otx expression in the animal hemisphere of wild-type and morphant embryos at the 32-cell stage. This Boolean function was not inconsistent with three sensing patterns, which represented whether or not individual cells received sufficient amounts of the signaling molecules. These sensing patterns all indicated that differential expression of Otx in the neural lineage is primarily determined by Efna.d, but not by differential inputs of Fgf9/16/20, Admp, and Gdf1/3-r signaling. To confirm this hypothesis experimentally, we simultaneously knocked-down Admp, Gdf1/3-r, and Fgf9/16/20, and treated this triple morphant with recombinant bFGF and BMP4 proteins, which mimic Fgf9/16/20 and Admp/Gdf1/3-r activity, respectively. Although no differential inputs of Admp, Gdf1/3-r and Fgf9/16/20 signaling were expected under this experimental condition, Otx was expressed specifically in the neural lineage. Thus, direct cell–cell interactions through Efna.d play a critical role in patterning the ectoderm of the early ascidian embryo. It is often difficult to understand a complex system of multiple signaling molecules in animal embryos only with experimental procedures. Although theoretical analysis might solve this problem, it is often difficult to precisely determine parameters for signaling gradients and kinetics of signaling molecules. In the present study, we developed a parameter-free method for determining a Boolean function for understanding a complex signaling system using gene expression patterns of signaling molecules and geometrical configurations of individual cells within the embryo. In the ascidian embryo, four signaling ligands, Ephrin-A.d (Efna.d), Fgf9/16/20, Admp, and Gdf1/3-r, coordinately induce Otx expression in the neural lineage at the 32-cell stage. In addition to determining a Boolean function, our method determined sensing patterns, which represented whether or not individual cells received sufficient amounts of the signaling molecules. The sensing patterns predicted that differential expression of Otx in the neural lineage is primarily determined by Efna.d, but not by differential inputs of Fgf9/16/20, Admp, and Gdf1/3-r. We confirmed this prediction by an experiment. As a result, we found that only Efna.d signaling pathway is differentially activated between ectodermal cells and the remaining signaling pathways are activated in all ectodermal cells at similar levels.
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Affiliation(s)
- Naoyuki Ohta
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, Japan
| | - Kana Waki
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, Japan
| | - Atsushi Mochizuki
- RIKEN Advanced Science Institute, Wako, Saitama, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
| | - Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan
- * E-mail:
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23
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Abdul-Wajid S, Morales-Diaz H, Khairallah SM, Smith WC. T-type Calcium Channel Regulation of Neural Tube Closure and EphrinA/EPHA Expression. Cell Rep 2015; 13:829-839. [PMID: 26489462 DOI: 10.1016/j.celrep.2015.09.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 08/06/2015] [Accepted: 09/11/2015] [Indexed: 10/22/2022] Open
Abstract
A major class of human birth defects arise from aberrations during neural tube closure (NTC). We report on a NTC signaling pathway requiring T-type calcium channels (TTCCs) that is conserved between primitive chordates (Ciona) and Xenopus. With loss of TTCCs, there is a failure to seal the anterior neural folds. Accompanying loss of TTCCs is an upregulation of EphrinA effectors. Ephrin signaling is known to be important in NTC, and ephrins can affect both cell adhesion and repulsion. In Ciona, ephrinA-d expression is downregulated at the end of neurulation, whereas, with loss of TTCC, ephrinA-d remains elevated. Accordingly, overexpression of ephrinA-d phenocopied TTCC loss of function, while overexpression of a dominant-negative Ephrin receptor was able to rescue NTC in a Ciona TTCC mutant. We hypothesize that signaling through TTCCs is necessary for proper anterior NTC through downregulation of ephrins, and possibly elimination of a repulsive signal.
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Affiliation(s)
- Sarah Abdul-Wajid
- Department of Molecular, Cell and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Heidi Morales-Diaz
- Department of Molecular, Cell and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Stephanie M Khairallah
- Department of Molecular, Cell and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - William C Smith
- Department of Molecular, Cell and Developmental Biology, and Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
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24
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Abstract
There is increasing evidence that in addition to having major roles in morphogenesis, in some tissues Eph receptor and ephrin signaling regulates the differentiation of cells. In one mode of deployment, cell contact dependent Eph-ephrin activation induces a distinct fate of cells at the interface of their expression domains, for example in early ascidian embryos and in the vertebrate hindbrain. In another mode, overlapping Eph receptor and ephrin expression underlies activation within a cell population, which promotes or inhibits cell differentiation in bone remodelling, neural progenitors and keratinocytes. Eph-ephrin activation also contributes to formation of the appropriate number of progenitor cells by increasing or decreasing cell proliferation. These multiple roles of Eph receptor and ephrin signaling may enable a coupling between morphogenesis and the differentiation and proliferation of cells.
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Key Words
- Eph receptor
- Eph receptor, Erythropoietin-producing hepatocellular carcinoma cell receptor
- FGF, Fibroblast growth factor
- IGF-1, Insulin-like growth factor-1
- JNK, c-Jun N-terminal kinase
- MAPK, Mitogen activated protein kinase
- NFAT, Nuclear factor of activated T-cells
- RGS3, Regulator of G-protein signaling 3
- STAT3, Signal transducer and activator of transcription 3
- TAZ, Tafazzin
- TCR, T cell receptor
- TEC, Thymic epithelial cell
- TGF, Transforming growth factor
- ZHX2, Zinc fingers and homeoboxes 2
- ascidian development
- bone
- cell proliferation
- differentiation
- ephrin
- ephrin, Eph receptor interacting protein
- hindbrain
- keratinocytes
- neural progenitors
- p120GAP, GTPase activating protein
- thymocytes
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Affiliation(s)
- David G Wilkinson
- a Division of Developmental Neurobiology; MRC National Institute for Medical Research ; London , UK
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25
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Lim B, Dsilva CJ, Levario TJ, Lu H, Schüpbach T, Kevrekidis IG, Shvartsman SY. Dynamics of Inductive ERK Signaling in the Drosophila Embryo. Curr Biol 2015; 25:1784-90. [PMID: 26096970 DOI: 10.1016/j.cub.2015.05.039] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 05/14/2015] [Accepted: 05/20/2015] [Indexed: 12/11/2022]
Abstract
Transient activation of the highly conserved extracellular-signal-regulated kinase (ERK) establishes precise patterns of cell fates in developing tissues. Quantitative parameters of these transients are essentially unknown, but a growing number of studies suggest that changes in these parameters can lead to a broad spectrum of developmental abnormalities. We provide a detailed quantitative picture of an ERK-dependent inductive signaling event in the early Drosophila embryo, an experimental system that offers unique opportunities for high-throughput studies of developmental signaling. Our analysis reveals a spatiotemporal pulse of ERK activation that is consistent with a model in which transient production of a short-ranged ligand feeds into a simple signal interpretation system. The pulse of ERK signaling acts as a switch in controlling the expression of the ERK target gene. The quantitative approach that led to this model, based on the integration of data from fixed embryos and live imaging, can be extended to other developmental systems patterned by transient inductive signals.
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Affiliation(s)
- Bomyi Lim
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Carmeline J Dsilva
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Thomas J Levario
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Trudi Schüpbach
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Ioannis G Kevrekidis
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Program in Applied and Computational Mathematics, Princeton University, Princeton, NJ 08544, USA
| | - Stanislav Y Shvartsman
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
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26
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Satou Y, Imai KS. Gene regulatory systems that control gene expression in the Ciona embryo. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2015; 91:33-51. [PMID: 25748582 PMCID: PMC4406867 DOI: 10.2183/pjab.91.33] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/05/2014] [Indexed: 06/04/2023]
Abstract
Transcriptional control of gene expression is one of the most important regulatory systems in animal development. Specific gene expression is basically determined by combinatorial regulation mediated by multiple sequence-specific transcription factors. The decoding of animal genomes has provided an opportunity for us to systematically examine gene regulatory networks consisting of successive layers of control of gene expression. It remains to be determined to what extent combinatorial regulation encoded in gene regulatory networks can explain spatial and temporal gene-expression patterns. The ascidian Ciona intestinalis is one of the animals in which the gene regulatory network has been most extensively studied. In this species, most specific gene expression patterns in the embryo can be explained by combinations of upstream regulatory genes encoding transcription factors and signaling molecules. Systematic scrutiny of gene expression patterns and regulatory interactions at the cellular resolution have revealed incomplete parts of the network elucidated so far, and have identified novel regulatory genes and novel regulatory mechanisms.
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Affiliation(s)
- Yutaka Satou
- Department of Zoology, Graduate School of Science, Kyoto University; CREST, JST, Saitama, Japan.
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27
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Haupaix N, Abitua PB, Sirour C, Yasuo H, Levine M, Hudson C. Ephrin-mediated restriction of ERK1/2 activity delimits the number of pigment cells in the Ciona CNS. Dev Biol 2014; 394:170-80. [PMID: 25062608 DOI: 10.1016/j.ydbio.2014.07.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 07/04/2014] [Accepted: 07/10/2014] [Indexed: 12/31/2022]
Abstract
Recent evidence suggests that ascidian pigment cells are related to neural crest-derived melanocytes of vertebrates. Using live-imaging, we determine a revised cell lineage of the pigment cells in Ciona intestinalis embryos. The neural precursors undergo successive rounds of anterior-posterior (A-P) oriented cell divisions, starting at the blastula 64-cell stage. A previously unrecognized fourth A-P oriented cell division in the pigment cell lineage leads to the generation of the post-mitotic pigment cell precursors. We provide evidence that MEK/ERK signals are required for pigment cell specification until approximately 30min after the final cell division has taken place. Following each of the four A-P oriented cell divisions, ERK1/2 is differentially activated in the posterior sister cells, into which the pigment cell lineage segregates. Eph/ephrin signals are critical during the third A-P oriented cell division to spatially restrict ERK1/2 activation to the posterior daughter cell. Targeted inhibition of Eph/ephrin signals results in, at neurula stages, anterior expansion of both ERK1/2 activation and a pigment cell lineage marker and subsequently, at larval stages, supernumerary pigment cells. We discuss the implications of these findings with respect to the evolution of the vertebrate neural crest.
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Affiliation(s)
- Nicolas Haupaix
- CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France; Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France; Université de Nice Sophia Antipolis, Nice, France
| | - Philip B Abitua
- Center for Integrative Genomics, Division of Genetics, Genomics and Development, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Cathy Sirour
- CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France; Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France
| | - Hitoyoshi Yasuo
- CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France; Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France
| | - Michael Levine
- Center for Integrative Genomics, Division of Genetics, Genomics and Development, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Clare Hudson
- CNRS, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France; Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Biologie du Développement de Villefranche-sur-mer, Observatoire Océanologique, 06230 Villefranche-sur-mer, France.
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