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Ohta N, Christiaen L. Cellular remodeling and JAK inhibition promote zygotic gene expression in the Ciona germline. EMBO Rep 2024; 25:2188-2201. [PMID: 38649664 PMCID: PMC11094015 DOI: 10.1038/s44319-024-00139-0] [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: 01/30/2023] [Revised: 03/22/2024] [Accepted: 03/28/2024] [Indexed: 04/25/2024] Open
Abstract
Transcription control is a major determinant of cell fate decisions in somatic tissues. By contrast, early germline fate specification in numerous vertebrate and invertebrate species relies extensively on RNA-level regulation, exerted on asymmetrically inherited maternal supplies, with little-to-no zygotic transcription. However delayed, a maternal-to-zygotic transition is nevertheless poised to complete the deployment of pre-gametic programs in the germline. Here, we focus on early germline specification in the tunicate Ciona to study zygotic genome activation. We first demonstrate that a peculiar cellular remodeling event excludes localized postplasmic Pem-1 mRNA, which encodes the general inhibitor of transcription. Subsequently, zygotic transcription begins in Pem-1-negative primordial germ cells (PGCs), as revealed by histochemical detection of elongating RNA Polymerase II, and nascent Mef2 transcripts. In addition, we uncover a provisional antagonism between JAK and MEK/BMPRI/GSK3 signaling, which controls the onset of zygotic gene expression, following cellular remodeling of PGCs. We propose a 2-step model for the onset of zygotic transcription in the Ciona germline and discuss the significance of germ plasm dislocation and remodeling in the context of developmental fate specification.
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Affiliation(s)
- Naoyuki Ohta
- Michael Sars Centre, University of Bergen, Bergen, Norway.
| | - Lionel Christiaen
- Michael Sars Centre, University of Bergen, Bergen, Norway.
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY, USA.
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2
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Zhang H, Shang R, Kim K, Zheng W, Johnson CJ, Sun L, Niu X, Liu L, Zhou J, Liu L, Zhang Z, Uyeno TA, Pei J, Fissette SD, Green SA, Samudra SP, Wen J, Zhang J, Eggenschwiler JT, Menke DB, Bronner ME, Grishin NV, Li W, Ye K, Zhang Y, Stolfi A, Bi P. Evolution of a chordate-specific mechanism for myoblast fusion. SCIENCE ADVANCES 2022; 8:eadd2696. [PMID: 36054355 PMCID: PMC10848958 DOI: 10.1126/sciadv.add2696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
Vertebrate myoblast fusion allows for multinucleated muscle fibers to compound the size and strength of mononucleated cells, but the evolution of this important process is unknown. We investigated the evolutionary origins and function of membrane-coalescing agents Myomaker and Myomixer in various groups of chordates. Here, we report that Myomaker likely arose through gene duplication in the last common ancestor of tunicates and vertebrates, while Myomixer appears to have evolved de novo in early vertebrates. Functional tests revealed a complex evolutionary history of myoblast fusion. A prevertebrate phase of muscle multinucleation driven by Myomaker was followed by the later emergence of Myomixer that enables the highly efficient fusion system of vertebrates. Evolutionary comparisons between vertebrate and nonvertebrate Myomaker revealed key structural and mechanistic insights into myoblast fusion. Thus, our findings suggest an evolutionary model of chordate fusogens and illustrate how new genes shape the emergence of novel morphogenetic traits and mechanisms.
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Affiliation(s)
- Haifeng Zhang
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA
| | - Renjie Shang
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Kwantae Kim
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Wei Zheng
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | | | - Lei Sun
- The Fifth People’s Hospital of Shanghai, and Shanghai Key Laboratory of Medical Epigenetics, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xiang Niu
- Tri-Institutional Program in Computational Biology and Medicine, Weill Cornell Medical College, New York, USA
| | - Liang Liu
- Department of Statistics, University of Georgia, Athens, GA, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Jingqi Zhou
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Lingshu Liu
- Department of Genetics, University of Georgia, Athens, GA, USA
| | - Zheng Zhang
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA
| | | | - Jimin Pei
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Skye D. Fissette
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA
| | - Stephen A. Green
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | | | - Junfei Wen
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA
| | - Jianli Zhang
- College of Engineering, University of Georgia, Athens, GA, USA
| | | | | | - Marianne E. Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nick V. Grishin
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weiming Li
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA
| | - Kaixiong Ye
- Department of Genetics, University of Georgia, Athens, GA, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Yang Zhang
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Pengpeng Bi
- Center for Molecular Medicine, University of Georgia, Athens, GA, USA
- Department of Genetics, University of Georgia, Athens, GA, USA
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3
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Zhang J, Dong B, Yang L. Molecular Characterization and Expression Analysis of Putative Class C (Glutamate Family) G Protein-Coupled Receptors in Ascidian Styela clava. BIOLOGY 2022; 11:782. [PMID: 35625509 PMCID: PMC9138782 DOI: 10.3390/biology11050782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
In this study, we performed the genome-wide domain analysis and sequence alignment on the genome of Styela clava, and obtained a repertoire of 204 putative GPCRs, which exhibited a highly reduced gene number compared to vertebrates and cephalochordates. In this repertoire, six Class C GPCRs, including four metabotropic glutamate receptors (Sc-GRMs), one calcium-sensing receptor (Sc-CaSR), and one gamma-aminobutyric acid (GABA) type B receptor 2-like (Sc-GABABR2-like) were identified, with the absence of type 1 taste and vomeronasal receptors. All the Sc-GRMs and Sc-CaSR contained the typical "Venus flytrap" and cysteine-rich domains required for ligand binding and subsequent propagation of conformational changes. In swimming larvae, Sc-grm3 and Sc-casr were mainly expressed at the junction of the sensory vesicle and tail nerve cord while the transcripts of Sc-grm4, Sc-grm7a, and Sc-grm7b appeared at the anterior trunk, which suggested their important functions in neurotransmission. The high expression of these Class C receptors at tail-regression and metamorphic juvenile stages hinted at their potential involvement in regulating metamorphosis. In adults, the transcripts were highly expressed in several peripheral tissues, raising the possibility that S. clava Class C GPCRs might function as neurotransmission modulators peripherally after metamorphosis. Our study systematically characterized the ancestral chordate Class C GPCRs to provide insights into the origin and evolution of these receptors in chordates and their roles in regulating physiological and morphogenetic changes relevant to the development and environmental adaption.
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Affiliation(s)
- Jin Zhang
- Sars-Fang Centre, MoE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China;
| | - Bo Dong
- Sars-Fang Centre, MoE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China;
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Likun Yang
- Sars-Fang Centre, MoE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China;
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4
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Krasovec G, Karaiskou A, Quéinnec É, Chambon JP. Comparative transcriptomic analysis reveals gene regulation mediated by caspase activity in a chordate organism. BMC Mol Cell Biol 2021; 22:51. [PMID: 34615460 PMCID: PMC8495957 DOI: 10.1186/s12860-021-00388-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Apoptosis is a caspase regulated cell death present in all metazoans defined by a conserved set of morphological features. A well-described function of apoptosis is the removal of excessive cells during development and homeostasis. Recent studies have shown an unexpected signalling property of apoptotic cells, affecting cell fate and/or behaviour of neighbouring cells. In contrast to the apoptotic function of cell elimination, this new role of apoptosis is not well understood but seems caspase-dependent. To deepen our understanding of apoptotic functions, it is necessary to work on a biological model with a predictable apoptosis pattern affecting cell fate and/or behaviour. The tunicate Ciona intestinalis has a bi-phasic life cycle with swimming larvae which undergo metamorphosis after settlement. Previously, we have shown that the tail regression step during metamorphosis, characterized by a predictable polarized apoptotic wave, ensures elimination of most tail cells and controls primordial germ cells survival and migration. RESULTS We performed differential transcriptomic analysis between control metamorphosing larvae and larvae treated with the pan-caspase inhibitor Z-VAD-fmk in order to explore the transcriptional control of apoptotic cells on neighbouring cells that survive and migrate. When caspase activity was impaired, genes known to be involved in metamorphosis were downregulated along with other implicated in cell migration and survival molecular pathways. CONCLUSION We propose these results as a confirmation that apoptotic cells can control surrounding cells fate and as a reference database to explore novel apoptotic functions in animals, including those related to migration and differentiation.
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Affiliation(s)
- Gabriel Krasovec
- Institut de Systématique, Evolution, Biodiversité (ISYEB), UMR 7205, Sorbonne Université, Muséum National d'histoire Naturelle, CNRS, EPHE, 7 Quai St-Bernard, F-75252, Paris Cedex 05, France. .,Center for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
| | - Anthi Karaiskou
- INSERM UMRS_938, Centre de recherche Saint-Antoine (CRSA), Sorbonne Université, Paris, France
| | - Éric Quéinnec
- Institut de Systématique, Evolution, Biodiversité (ISYEB), UMR 7205, Sorbonne Université, Muséum National d'histoire Naturelle, CNRS, EPHE, 7 Quai St-Bernard, F-75252, Paris Cedex 05, France
| | - Jean-Philippe Chambon
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), Montpellier Univ., CNRS, 34000, Montpellier, France
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5
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Marotta P, Salatiello F, Ambrosino L, Berruto F, Chiusano ML, Locascio A. The Ascidia Ciona robusta Provides Novel Insights on the Evolution of the AP-1 Transcriptional Complex. Front Cell Dev Biol 2021; 9:709696. [PMID: 34414189 PMCID: PMC8369891 DOI: 10.3389/fcell.2021.709696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/12/2021] [Indexed: 11/13/2022] Open
Abstract
The Activator Protein-1 transcription factor family (AP-1) transcriptional complex is historically defined as an early response group of transcription factors formed by dimeric complexes of the Jun, Fos, Atf, and Maf bZIP proteins that control cell proliferation and differentiation by regulating gene expression. It has been greatly investigated in many model organisms across metazoan evolution. Nevertheless, its complexity and variability of action made its multiple functions difficult to be defined. Here, we place the foundations for understanding the complexity of AP-1 transcriptional members in tunicates. We investigated the gene members of this family in the ascidian Ciona robusta and identified single copies of Jun, Fos, Atf3, Atf2/7, and Maf bZIP-related factors that could have a role in the formation of the AP-1 complex. We highlight that mesenchyme is a common cellular population where all these factors are expressed during embryonic development, and that, moreover, Fos shows a wider pattern of expression including also notochord and neural cells. By ectopic expression in transgenic embryos of Jun and Fos genes alone or in combination, we investigated the phenotypic alterations induced by these factors and highlighted a degree of functional conservation of the AP-1 complex between Ciona and vertebrates. The lack of gene redundancy and the first pieces of evidence of conserved functions in the control of cell movements and structural organization exerted by these factors open the way for using Ciona as a helpful model system to uncover the multiple potentialities of this highly complex family of bZIP transcription factors.
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Affiliation(s)
- Pina Marotta
- Stazione Zoologica Anton Dohrn, Department of Integrative Marine Ecology, Naples, Italy.,Stazione Zoologica Anton Dohrn, Department of Research Infrastructures for Marine Biological Resources, Naples, Italy
| | - Federica Salatiello
- Stazione Zoologica Anton Dohrn, Department of Biology and Evolution of Marine Organisms, Naples, Italy
| | - Luca Ambrosino
- Stazione Zoologica Anton Dohrn, Department of Research Infrastructures for Marine Biological Resources, Naples, Italy
| | - Federica Berruto
- Stazione Zoologica Anton Dohrn, Department of Biology and Evolution of Marine Organisms, Naples, Italy
| | - Maria Luisa Chiusano
- Stazione Zoologica Anton Dohrn, Department of Research Infrastructures for Marine Biological Resources, Naples, Italy.,Department of Agriculture, Università degli Studi di Napoli Federico II, Portici, Italy
| | - Annamaria Locascio
- Stazione Zoologica Anton Dohrn, Department of Biology and Evolution of Marine Organisms, Naples, Italy
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6
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Coppola U, Kamal AK, Stolfi A, Ristoratore F. The Cis-Regulatory Code for Kelch-like 21/30 Specific Expression in Ciona robusta Sensory Organs. Front Cell Dev Biol 2020; 8:569601. [PMID: 33043001 PMCID: PMC7517041 DOI: 10.3389/fcell.2020.569601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/17/2020] [Indexed: 12/18/2022] Open
Abstract
The tunicate Ciona robusta is an emerging model system to study the evolution of the nervous system. Due to their small embryos and compact genomes, tunicates, like Ciona robusta, have great potential to comprehend genetic circuitry underlying cell specific gene repertoire, among different neuronal cells. Their simple larvae possess a sensory vesicle comprising two pigmented sensory organs, the ocellus and the otolith. We focused here on Klhl21/30, a gene belonging to Kelch family, that, in Ciona robusta, starts to be expressed in pigmented cell precursors, becoming specifically maintained in the otolith precursor during embryogenesis. Evolutionary analyses demonstrated the conservation of Klhl21/30 in all the chordates. Cis-regulatory analyses and CRISPR/Cas9 mutagenesis of potential upstream factors, revealed that Klhl21/30 expression is controlled by the combined action of three transcription factors, Mitf, Dmrt, and Msx, which are downstream of FGF signaling. The central role of Mitf is consistent with its function as a fundamental regulator of vertebrate pigment cell development. Moreover, our results unraveled a new function for Dmrt and Msx as transcriptional co-activators in the context of the Ciona otolith.
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Affiliation(s)
- Ugo Coppola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Naples, Italy.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Ashwani Kumar Kamal
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Naples, Italy
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Filomena Ristoratore
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, Naples, Italy
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7
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Coppola U, Olivo P, D’Aniello E, Johnson CJ, Stolfi A, Ristoratore F. Rimbp, a New Marker for the Nervous System of the Tunicate Ciona robusta. Genes (Basel) 2020; 11:genes11091006. [PMID: 32867148 PMCID: PMC7565545 DOI: 10.3390/genes11091006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/16/2020] [Accepted: 08/25/2020] [Indexed: 12/12/2022] Open
Abstract
Establishment of presynaptic mechanisms by proteins that regulate neurotransmitter release in the presynaptic active zone is considered a fundamental step in animal evolution. Rab3 interacting molecule-binding proteins (Rimbps) are crucial components of the presynaptic active zone and key players in calcium homeostasis. Although Rimbp involvement in these dynamics has been described in distantly related models such as fly and human, the role of this family in most invertebrates remains obscure. To fill this gap, we defined the evolutionary history of Rimbp family in animals, from sponges to mammals. We report, for the first time, the expression of the two isoforms of the unique Rimbp family member in Ciona robusta in distinct domains of the larval nervous system. We identify intronic enhancers that are able to drive expression in different nervous system territories partially corresponding to Rimbp endogenous expression. The analysis of gene expression patterns and the identification of regulatory elements of Rimbp will positively impact our understanding of this family of genes in the context of Ciona embryogenesis.
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Affiliation(s)
- Ugo Coppola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy; (U.C.); (P.O.); (E.D.)
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Paola Olivo
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy; (U.C.); (P.O.); (E.D.)
| | - Enrico D’Aniello
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy; (U.C.); (P.O.); (E.D.)
| | | | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- Correspondence: (A.S.); (F.R.)
| | - Filomena Ristoratore
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy; (U.C.); (P.O.); (E.D.)
- Correspondence: (A.S.); (F.R.)
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8
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Sepe RM, Ghiron JHL, Zucchetti I, Caputi L, Tarallo R, Crocetta F, De Santis R, D'Aniello S, Sordino P. The EJC component Magoh in non-vertebrate chordates. Dev Genes Evol 2020; 230:295-304. [PMID: 32632492 DOI: 10.1007/s00427-020-00664-7] [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: 10/17/2019] [Accepted: 07/01/2020] [Indexed: 11/26/2022]
Abstract
Earliest craniates possess a newly enlarged, elaborated forebrain with new cell types and neuronal networks. A key question in vertebrate evolution is when and how this cerebral expansion took place. The exon-junction complex (EJC) plays an essential role in mRNA processing of all Eukarya. Recently, it has been proposed that the EJC represses recursive RNA splicing in Deuterostomes, with implication in human brain diseases like microcephaly and depression. However, the EJC or EJC subunit contribution to brain development in non-vertebrate Deuterostomes remained unknown. Being interested in the evolution of chordate characters, we focused on the model species, Branchiostoma lanceolatum (Cephalochordata) and Ciona robusta (Tunicata), with the aim to investigate the ancestral and the derived expression state of Magoh orthologous genes. This study identifies that Magoh is part of a conserved syntenic group exclusively in vertebrates and suggests that Magoh has experienced duplication and loss events in mammals. During early development in amphioxus and ascidian, maternal contribution and zygotic expression of Magoh genes in various types of progenitor cells and tissues are consistent with the condition observed in other Bilateria. Later in development, we also show expression of Magoh in the brain of cephalochordate and ascidian larvae. Collectively, these results provide a basis to further define what functional role(s) Magoh exerted during nervous system development and evolution.
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Affiliation(s)
- Rosa Maria Sepe
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy
| | - Jung Hee Levialdi Ghiron
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy
| | - Ivana Zucchetti
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy
| | - Luigi Caputi
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy
| | - Raffaella Tarallo
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy
| | - Fabio Crocetta
- Department of Integrated Marine Ecology, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy
| | - Rosaria De Santis
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy
| | - Salvatore D'Aniello
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy.
| | - Paolo Sordino
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn Napoli, 80121, Naples, Italy.
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9
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Sladitschek HL, Fiuza UM, Pavlinic D, Benes V, Hufnagel L, Neveu PA. MorphoSeq: Full Single-Cell Transcriptome Dynamics Up to Gastrulation in a Chordate. Cell 2020; 181:922-935.e21. [PMID: 32315617 PMCID: PMC7237864 DOI: 10.1016/j.cell.2020.03.055] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 02/25/2020] [Accepted: 03/24/2020] [Indexed: 11/10/2022]
Abstract
Single-cell RNA sequencing (scRNA-seq) provides a leap forward in resolving cellular diversity and developmental trajectories but fails to comprehensively delineate the spatial organization and precise cellular makeup of individual embryos. Here, we reconstruct from scRNA-seq and light sheet imaging data a canonical digital embryo that captures the genome-wide gene expression trajectory of every single cell at every cell division in the 18 lineages up to gastrulation in the ascidian Phallusia mammillata. By using high-coverage scRNA-seq, we devise a computational framework that stratifies single cells of individual embryos into cell types without prior knowledge. Unbiased transcriptome data analysis mapped each cell’s physical position and lineage history, yielding the complete history of gene expression at the genome-wide level for every single cell in a developing embryo. A comparison of individual embryos reveals both extensive reproducibility between symmetric embryo sides and a large inter-embryonic variability due to small differences in embryogenesis timing. Integration of scRNA-seq and imaging data yield a canonical digital embryo Cell type classification without prior knowledge De novo reconstruction of the lineage history and spatial organization of the embryo Timing differences contribute to inter-embryo variability in gene expression
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Affiliation(s)
- Hanna L Sladitschek
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; Department of Molecular Medicine, University of Padua School of Medicine, 35126 Padua, Italy
| | - Ulla-Maj Fiuza
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Dinko Pavlinic
- Genomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Vladimir Benes
- Genomics Core Facility, European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Lars Hufnagel
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
| | - Pierre A Neveu
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
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10
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Fiuza UM, Negishi T, Rouan A, Yasuo H, Lemaire P. A Nodal/Eph signalling relay drives the transition from apical constriction to apico-basal shortening in ascidian endoderm invagination. Development 2020; 147:dev.186965. [DOI: 10.1242/dev.186965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 07/02/2020] [Indexed: 01/13/2023]
Abstract
Gastrulation is the first major morphogenetic event during animal embryogenesis. Ascidian gastrulation starts with the invagination of 10 endodermal precursor cells between the 64- and late 112-cell stages. This process occurs in the absence of endodermal cell division and in two steps, driven by myosin-dependent contractions of the acto-myosin network. First, endoderm precursors constrict their apex. Second, they shorten apico-basally, while retaining small apical surfaces, thereby causing invagination. The mechanisms that prevent endoderm cell division, trigger the transition between step 1 and step 2, and drive apico-basal shortening have remained elusive. Here, we demonstrate a conserved role for Nodal and Eph signalling during invagination in two distantly related ascidian species, Phallusia mammillata and Ciona intestinalis. Specifically, we show that the transition to step 2 is triggered by Nodal relayed by Eph signalling. Additionally, our results indicate that Eph signalling lengthens the endodermal cell cycle, independently of Nodal. Finally, we find that both Nodal and Eph signals are dispensable for endoderm fate specification. These results illustrate commonalities as well as differences in the action of Nodal during ascidian and vertebrate gastrulation.
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Affiliation(s)
- Ulla-Maj Fiuza
- CRBM, University of Montpellier, CNRS, Montpellier, France
| | - Takefumi Negishi
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, CNRS, Sorbonne Universités, 06230 Villefranche-sur-Mer, France
| | - Alice Rouan
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, CNRS, Sorbonne Universités, 06230 Villefranche-sur-Mer, France
| | - Hitoyoshi Yasuo
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, CNRS, Sorbonne Universités, 06230 Villefranche-sur-Mer, France
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11
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Racioppi C, Wiechecki KA, Christiaen L. Combinatorial chromatin dynamics foster accurate cardiopharyngeal fate choices. eLife 2019; 8:49921. [PMID: 31746740 PMCID: PMC6952182 DOI: 10.7554/elife.49921] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/18/2019] [Indexed: 12/22/2022] Open
Abstract
During embryogenesis, chromatin accessibility profiles control lineage-specific gene expression by modulating transcription, thus impacting multipotent progenitor states and subsequent fate choices. Subsets of cardiac and pharyngeal/head muscles share a common origin in the cardiopharyngeal mesoderm, but the chromatin landscapes that govern multipotent progenitors competence and early fate choices remain largely elusive. Here, we leveraged the simplicity of the chordate model Ciona to profile chromatin accessibility through stereotyped transitions from naive Mesp+ mesoderm to distinct fate-restricted heart and pharyngeal muscle precursors. An FGF-Foxf pathway acts in multipotent progenitors to establish cardiopharyngeal-specific patterns of accessibility, which govern later heart vs. pharyngeal muscle-specific expression profiles, demonstrating extensive spatiotemporal decoupling between early cardiopharyngeal enhancer accessibility and late cell-type-specific activity. We found that multiple cis-regulatory elements, with distinct chromatin accessibility profiles and motif compositions, are required to activate Ebf and Tbx1/10, two key determinants of cardiopharyngeal fate choices. We propose that these 'combined enhancers' foster spatially and temporally accurate fate choices, by increasing the repertoire of regulatory inputs that control gene expression, through either accessibility and/or activity.
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Affiliation(s)
- Claudia Racioppi
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Keira A Wiechecki
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
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12
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Krasovec G, Robine K, Quéinnec E, Karaiskou A, Chambon J. Ci-hox12 tail gradient precedes and participates in the control of the apoptotic-dependent tail regression during Ciona larva metamorphosis. Dev Biol 2019; 448:237-246. [DOI: 10.1016/j.ydbio.2018.12.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 12/11/2018] [Accepted: 12/11/2018] [Indexed: 01/20/2023]
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13
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Prünster MM, Ricci L, Brown FD, Tiozzo S. Modular co-option of cardiopharyngeal genes during non-embryonic myogenesis. EvoDevo 2019; 10:3. [PMID: 30867897 PMCID: PMC6399929 DOI: 10.1186/s13227-019-0116-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 02/15/2019] [Indexed: 01/03/2023] Open
Abstract
Background In chordates, cardiac and body muscles arise from different embryonic origins. In addition, myogenesis can be triggered in adult organisms, during asexual development or regeneration. In non-vertebrate chordates like ascidians, muscles originate from embryonic precursors regulated by a conserved set of genes that orchestrate cell behavior and dynamics during development. In colonial ascidians, besides embryogenesis and metamorphosis, an adult can propagate asexually via blastogenesis, skipping embryo and larval stages, and form anew the adult body, including the complete body musculature. Results To investigate the cellular origin and mechanisms that trigger non-embryonic myogenesis, we followed the expression of ascidian myogenic genes during Botryllus schlosseri blastogenesis and reconstructed the dynamics of muscle precursors. Based on the expression dynamics of Tbx1/10, Ebf, Mrf, Myh3 for body wall and of FoxF, Tbx1/10, Nk4, Myh2 for heart development, we show that the embryonic factors regulating myogenesis are only partially co-opted in blastogenesis, and that markers for muscle precursors are expressed in two separate domains: the dorsal tube and the ventral mesenchyma. Conclusions Regardless of the developmental pathway, non-embryonic myogenesis shares a similar molecular and anatomical setup as embryonic myogenesis, but implements a co-option and loss of molecular modules. We then propose that the cellular precursors contributing to heart and body muscles may have different origins and may be coordinated by different developmental pathways. Electronic supplementary material The online version of this article (10.1186/s13227-019-0116-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maria Mandela Prünster
- 1Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), CNRS, Sorbonne Université, 06230 Villefranche sur Mer, France
| | - Lorenzo Ricci
- 1Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), CNRS, Sorbonne Université, 06230 Villefranche sur Mer, France.,2Department of Organismic and Evolutionary Biology, Harvard University, 52 Oxford Street, Cambridge, MA 02138 USA
| | - Federico D Brown
- 3Departamento de Zoologia, Instituto Biociências, Universidade de São Paulo, São Paulo, SP CEP 05508-090 Brazil.,4Centro de Biologia Marinha (CEBIMar), Universidade de São Paulo, São Sebastião, SP CEP 11612-109 Brazil
| | - Stefano Tiozzo
- 1Laboratoire de Biologie du Développement de Villefranche-sur-mer (LBDV), CNRS, Sorbonne Université, 06230 Villefranche sur Mer, France
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14
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Madgwick A, Magri MS, Dantec C, Gailly D, Fiuza UM, Guignard L, Hettinger S, Gomez-Skarmeta JL, Lemaire P. Evolution of embryonic cis-regulatory landscapes between divergent Phallusia and Ciona ascidians. Dev Biol 2019; 448:71-87. [PMID: 30661644 DOI: 10.1016/j.ydbio.2019.01.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 12/31/2018] [Accepted: 01/01/2019] [Indexed: 01/21/2023]
Abstract
Ascidian species of the Phallusia and Ciona genera are distantly related, their last common ancestor dating several hundred million years ago. Although their genome sequences have extensively diverged since this radiation, Phallusia and Ciona species share almost identical early morphogenesis and stereotyped cell lineages. Here, we explored the evolution of transcriptional control between P. mammillata and C. robusta. We combined genome-wide mapping of open chromatin regions in both species with a comparative analysis of the regulatory sequences of a test set of 10 pairs of orthologous early regulatory genes with conserved expression patterns. We find that ascidian chromatin accessibility landscapes obey similar rules as in other metazoa. Open-chromatin regions are short, highly conserved within each genus and cluster around regulatory genes. The dynamics of chromatin accessibility and closest-gene expression are strongly correlated during early embryogenesis. Open-chromatin regions are highly enriched in cis-regulatory elements: 73% of 49 open chromatin regions around our test genes behaved as either distal enhancers or proximal enhancer/promoters following electroporation in Phallusia eggs. Analysis of this datasets suggests a pervasive use in ascidians of "shadow" enhancers with partially overlapping activities. Cross-species electroporations point to a deep conservation of both the trans-regulatory logic between these distantly-related ascidians and the cis-regulatory activities of individual enhancers. Finally, we found that the relative order and approximate distance to the transcription start site of open chromatin regions can be conserved between Ciona and Phallusia species despite extensive sequence divergence, a property that can be used to identify orthologous enhancers, whose regulatory activity can partially diverge.
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Affiliation(s)
- Alicia Madgwick
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, Montpellier, France
| | - Marta Silvia Magri
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas/Universidad Pablo de Olavide/Junta de Andalucía, Sevilla, Spain
| | - Christelle Dantec
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, Montpellier, France
| | - Damien Gailly
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, Montpellier, France
| | - Ulla-Maj Fiuza
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, Montpellier, France
| | - Léo Guignard
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix drive, Ashburn, VA, USA
| | - Sabrina Hettinger
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, Montpellier, France
| | - Jose Luis Gomez-Skarmeta
- Centro Andaluz de Biología del Desarrollo (CABD), Consejo Superior de Investigaciones Científicas/Universidad Pablo de Olavide/Junta de Andalucía, Sevilla, Spain
| | - Patrick Lemaire
- Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, Montpellier, France.
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15
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Bernadskaya YY, Brahmbhatt S, Gline SE, Wang W, Christiaen L. Discoidin-domain receptor coordinates cell-matrix adhesion and collective polarity in migratory cardiopharyngeal progenitors. Nat Commun 2019; 10:57. [PMID: 30610187 PMCID: PMC6320373 DOI: 10.1038/s41467-018-07976-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 12/09/2018] [Indexed: 12/22/2022] Open
Abstract
Integrated analyses of regulated effector genes, cellular processes, and extrinsic signals are required to understand how transcriptional networks coordinate fate specification and cell behavior during embryogenesis. Ciona cardiopharyngeal progenitors, the trunk ventral cells (TVCs), polarize as leader and trailer cells that migrate between the ventral epidermis and trunk endoderm. We show that the TVC-specific collagen-binding Discoidin-domain receptor (Ddr) cooperates with Integrin-β1 to promote cell-matrix adhesion. We find that endodermal cells secrete a collagen, Col9-a1, that is deposited in the basal epidermal matrix and promotes Ddr activation at the ventral membrane of migrating TVCs. A functional antagonism between Ddr/Intβ1-mediated cell-matrix adhesion and Vegfr signaling appears to modulate the position of cardiopharyngeal progenitors between the endoderm and epidermis. We show that Ddr promotes leader-trailer-polarized BMP-Smad signaling independently of its role in cell-matrix adhesion. We propose that dual functions of Ddr integrate transcriptional inputs to coordinate subcellular processes underlying collective polarity and migration.
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Affiliation(s)
- Yelena Y Bernadskaya
- Center for Developmental Genetics, Department of Biology, New York University, New York, 10003, NY, USA
| | - Saahil Brahmbhatt
- Center for Developmental Genetics, Department of Biology, New York University, New York, 10003, NY, USA
| | - Stephanie E Gline
- Center for Developmental Genetics, Department of Biology, New York University, New York, 10003, NY, USA
| | - Wei Wang
- Center for Developmental Genetics, Department of Biology, New York University, New York, 10003, NY, USA
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, 10003, NY, USA.
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16
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Zhang X, Liu X, Liu C, Wei J, Yu H, Dong B. Identification and characterization of microRNAs involved in ascidian larval metamorphosis. BMC Genomics 2018; 19:168. [PMID: 29490613 PMCID: PMC5831862 DOI: 10.1186/s12864-018-4566-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 02/22/2018] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Metamorphosis takes place within the life cycle of most marine invertebrates. The marine ascidian is a classical model to study complex cellular processes and underlying molecular mechanisms involved in its larval metamorphosis. The detailed molecular signaling pathways remain elusive, though extracellular signal-regulated kinases (ERKs) and c-Jun N-terminal kinase (JNK) have been revealed to regulate cell migration, differentiation, and apoptosis in ascidian larval organ regression and juvenile organ development. MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression at the post-transcriptional level. Large numbers of miRNAs have been demonstrated to be involved in many developmental and metamorphic processes. However, the identification of miRNAs in ascidian larval metamorphosis has not yet been investigated. RESULTS Totally, 106 known and 59 novel miRNAs were screened out through RNA-sequencing of three small RNA libraries from 18 to 21-h post-fertilization (hpf) tailbud embryos as well as from 42 hpf larvae (after tail regression) in Ciona savignyi. Expression profiling of miRNAs was confirmed by quantitative real-time PCR, showing that the expression levels of csa-miR-4040, csa-miR-4086, csa-miR-4055, csa-miR-4060, csa-miR-216a, csa-miR-216b, csa-miR-217, csa-miR-183, and csa-miR-92c were significantly higher in 42 hpf larvae, whereas those of csa-miR-4018a, csa-miR-4018b, and csa-miR-4000f were higher in 18 and 21 hpf embryos; then, their expression in 42 hpf larvae became significantly low. For these 12 miRNAs, whose expression levels significantly changed, we predicted their target genes through the combination of miRanda and TargetScan. This prediction analysis revealed 332 miRNA-target gene pairs that were associated with the ERK, JNK, and transforming growth factor beta signaling pathways, suggesting that the identified miRNAs are involved in the regulation of C. savignyi larval metamorphosis via controlling the expression of their target genes. Furthermore, we validated the expression of five selected miRNAs by northern blotting. Among the selected miRNAs, the expression patterns of csa-miR-4018a, csa-miR-4018b, and csa-miR-4000f were further examined by whole-mount in situ hybridization. The results showed that all three miRNAs were specifically expressed in a cell population resembling mesenchymal cells at the head and trunk part in swimming larvae but not in metamorphic larvae. Utilizing the luciferase assay, we also confirmed that miR-4000f targeted Mapk1, suggesting that the csa-miR-4018a/csa-miR-4018b/csa-miR-4000f cluster regulates larval metamorphosis through the Mapk1-mediated signaling pathway. CONCLUSIONS Totally, 165 miRNAs, including 59 novel ones, were identified from the embryos and larvae of C. savignyi. Twelve of them showed significant changes in expression before and during metamorphosis. In situ hybridization and northern blotting results revealed that three miRNAs are potentially involved in the signaling regulatory network for the migration and differentiation of mesenchymal cells in larval metamorphosis. Furthermore, the luciferase reporter assay revealed that Mapk1 is a target of csa-miR-4000f. Our results not only present a list and profile of miRNAs involved in Ciona metamorphosis but also provide informative cues to further understand their function in ascidian larval metamorphosis.
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Affiliation(s)
- Xiaoming Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Xiaozhuo Liu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
| | - Chengzhang Liu
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071 China
| | - Jiankai Wei
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
| | - Haiyan Yu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
| | - Bo Dong
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, No. 5 Yushan Road, Qingdao, 266003 People’s Republic of China
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17
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Razy-Krajka F, Gravez B, Kaplan N, Racioppi C, Wang W, Christiaen L. An FGF-driven feed-forward circuit patterns the cardiopharyngeal mesoderm in space and time. eLife 2018; 7:e29656. [PMID: 29431097 PMCID: PMC5809146 DOI: 10.7554/elife.29656] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 01/26/2018] [Indexed: 12/16/2022] Open
Abstract
In embryos, multipotent progenitors divide to produce distinct progeny and express their full potential. In vertebrates, multipotent cardiopharyngeal progenitors produce second-heart-field-derived cardiomyocytes, and branchiomeric skeletal head muscles. However, the mechanisms underlying these early fate choices remain largely elusive. The tunicate Ciona emerged as an attractive model to study early cardiopharyngeal development at high resolution: through two asymmetric and oriented divisions, defined cardiopharyngeal progenitors produce distinct first and second heart precursors, and pharyngeal muscle (aka atrial siphon muscle, ASM) precursors. Here, we demonstrate that differential FGF-MAPK signaling distinguishes between heart and ASM precursors. We characterize a feed-forward circuit that promotes the successive activations of essential ASM determinants, Hand-related, Tbx1/10 and Ebf. Finally, we show that coupling FGF-MAPK restriction and cardiopharyngeal network deployment with cell divisions defines the timing of gene expression and permits the emergence of diverse cell types from multipotent progenitors.
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Affiliation(s)
- Florian Razy-Krajka
- Center for Developmental Genetics, Department of BiologyCollege of Arts and Science, New York UniversityNew YorkUnited States
| | - Basile Gravez
- Center for Developmental Genetics, Department of BiologyCollege of Arts and Science, New York UniversityNew YorkUnited States
| | - Nicole Kaplan
- Center for Developmental Genetics, Department of BiologyCollege of Arts and Science, New York UniversityNew YorkUnited States
| | - Claudia Racioppi
- Center for Developmental Genetics, Department of BiologyCollege of Arts and Science, New York UniversityNew YorkUnited States
| | - Wei Wang
- Center for Developmental Genetics, Department of BiologyCollege of Arts and Science, New York UniversityNew YorkUnited States
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of BiologyCollege of Arts and Science, New York UniversityNew YorkUnited States
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18
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Wei J, Wang G, Li X, Ren P, Yu H, Dong B. Architectural delineation and molecular identification of extracellular matrix in ascidian embryos and larvae. Biol Open 2017; 6:1383-1390. [PMID: 28916708 PMCID: PMC5612238 DOI: 10.1242/bio.026336] [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] [Indexed: 11/20/2022] Open
Abstract
The extracellular matrix (ECM) not only provides essential physical scaffolding for cellular constituents but also initiates crucial biochemical and biomechanical cues that are required for tissue morphogenesis. In this study, we utilized wheat germ agglutinin (WGA) staining to characterize the ECM architecture in ascidian embryos and larvae. The results showed three distinct populations of ECM presenting in Ciona embryogenesis: the outer layer localized at the surface of embryo, an inner layer of notochord sheath and the apical ECM secreted by the notochord. To further elucidate the precise structure of Ciona embryonic ECM, we employed scanning and transmission electron microscopy, and found that the outer membrane was relatively thick with short fibres, whereas the ECM layer in notochord sheath was not as thick as the outer membrane but more regular arranged; the lumen between notochord cells was hydrostatic and sticky. Then, we used the RNA sequencing data from the embryos and larvae of Ciona savignyi to identify ECM genes and acquire their expression patterns. We identified 115 unigenes as 67 ECM genes, and 77 unigenes showed dynamic expression changes between different stages. Our results reveal the architecture, molecular composition and dynamic expression profile of ECM in ascidian embryogenesis, and may increase understanding of the function of the ECM in chordate development. Summary: This study reveals the architecture, molecular composition and dynamic expression profile of the extracellular matrix in ascidian embryos and larvae, providing clues for its function in chordate development.
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Affiliation(s)
- Jiankai Wei
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Guilin Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Xiang Li
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Ping Ren
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Haiyan Yu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Bo Dong
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China .,Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
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19
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Racioppi C, Valoroso MC, Coppola U, Lowe EK, Brown CT, Swalla BJ, Christiaen L, Stolfi A, Ristoratore F. Evolutionary loss of melanogenesis in the tunicate Molgula occulta. EvoDevo 2017; 8:11. [PMID: 28729899 PMCID: PMC5516394 DOI: 10.1186/s13227-017-0074-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 07/08/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Analyzing close species with diverse developmental modes is instrumental for investigating the evolutionary significance of physiological, anatomical and behavioral features at a molecular level. Many examples of trait loss are known in metazoan populations living in dark environments. Tunicates are the closest living relatives of vertebrates and typically present a lifecycle with distinct motile larval and sessile adult stages. The nervous system of the motile larva contains melanized cells associated with geotactic and light-sensing organs. It has been suggested that these are homologous to vertebrate neural crest-derived melanocytes. Probably due to ecological adaptation to distinct habitats, several species of tunicates in the Molgulidae family have tailless (anural) larvae that fail to develop sensory organ-associated melanocytes. Here we studied the evolution of Tyrosinase family genes, indispensible for melanogenesis, in the anural, unpigmented Molgula occulta and in the tailed, pigmented Molgula oculata by using phylogenetic, developmental and molecular approaches. RESULTS We performed an evolutionary reconstruction of the tunicate Tyrosinase gene family: in particular, we found that M. oculata possesses genes predicted to encode one Tyrosinase (Tyr) and three Tyrosinase-related proteins (Tyrps) while M. occulta has only Tyr and Tyrp.a pseudogenes that are not likely to encode functional proteins. Analysis of Tyr sequences from various M. occulta individuals indicates that different alleles independently acquired frameshifting short indels and/or larger mobile genetic element insertions, resulting in pseudogenization of the Tyr locus. In M. oculata, Tyr is expressed in presumptive pigment cell precursors as in the model tunicate Ciona robusta. Furthermore, a M. oculata Tyr reporter gene construct was active in the pigment cell precursors of C. robusta embryos, hinting at conservation of the regulatory network underlying Tyr expression in tunicates. In contrast, we did not observe any expression of the Tyr pseudogene in M. occulta embryos. Similarly, M. occulta Tyr allele expression was not rescued in pigmented interspecific M. occulta × M. oculata hybrid embryos, suggesting deleterious mutations also to its cis-regulatory sequences. However, in situ hybridization for transcripts from the M. occulta Tyrp.a pseudogene revealed its expression in vestigial pigment cell precursors in this species. CONCLUSIONS We reveal a complex evolutionary history of the melanogenesis pathway in tunicates, characterized by distinct gene duplication and loss events. Our expression and molecular data support a tight correlation between pseudogenization of Tyrosinase family members and the absence of pigmentation in the immotile larvae of M. occulta. These results suggest that relaxation of purifying selection has resulted in the loss of sensory organ-associated melanocytes and core genes in the melanogenesis biosynthetic pathway in M. occulta.
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Affiliation(s)
- Claudia Racioppi
- Biology and Evolution of Marine organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY USA
- Station Biologique de Roscoff, Roscoff, France
| | - Maria Carmen Valoroso
- Biology and Evolution of Marine organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Ugo Coppola
- Biology and Evolution of Marine organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Elijah K. Lowe
- Biology and Evolution of Marine organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
- Station Biologique de Roscoff, Roscoff, France
- Department of Biology, University of Washington, Seattle, WA USA
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA USA
| | - C. Titus Brown
- Station Biologique de Roscoff, Roscoff, France
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA USA
- Population Health and Reproduction, UC Davis School of Veterinary Medicine, Davis, CA USA
| | - Billie J. Swalla
- Station Biologique de Roscoff, Roscoff, France
- Department of Biology, University of Washington, Seattle, WA USA
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA USA
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY USA
- Station Biologique de Roscoff, Roscoff, France
| | - Alberto Stolfi
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY USA
- Station Biologique de Roscoff, Roscoff, France
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA USA
| | - Filomena Ristoratore
- Biology and Evolution of Marine organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy
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20
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Karakostis K, Ponnuswamy A, Fusée LTS, Bailly X, Laguerre L, Worall E, Vojtesek B, Nylander K, Fåhraeus R. p53 mRNA and p53 Protein Structures Have Evolved Independently to Interact with MDM2. Mol Biol Evol 2016; 33:1280-92. [PMID: 26823446 DOI: 10.1093/molbev/msw012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The p53 tumor suppressor and its key regulator MDM2 play essential roles in development, ageing, cancer, and cellular stress responses in mammals. Following DNA damage, MDM2 interacts with p53 mRNA in an ATM kinase-dependent fashion and stimulates p53 synthesis, whereas under normal conditions, MDM2 targets the p53 protein for degradation. The peptide- and RNA motifs that interact with MDM2 are encoded by the same conserved BOX-I sequence, but how these interactions have evolved is unknown. Here, we show that a temperature-sensitive structure in the invertebrate Ciona intestinalis (Ci) p53 mRNA controls its interaction with MDM2. We also show that a nonconserved flanking region of Ci-BOX-I domain prevents the p53-MDM2 protein-protein interaction. These results indicate that the temperature-regulated p53 mRNA-MDM2 interaction evolved to become kinase regulated in the mammalian DNA damage response. The data also suggest that the negative regulation of p53 by MDM2 via protein-protein interaction evolved in vertebrates following changes in the BOX-I flanking sequence.
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Affiliation(s)
- Konstantinos Karakostis
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, Paris, France
| | - Anand Ponnuswamy
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, Paris, France
| | - Leïla T S Fusée
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, Paris, France
| | - Xavier Bailly
- UPMC-CNRS, FR2424, Station Biologique de Roscoff, Roscoff, France
| | - Laurent Laguerre
- UPMC-CNRS, FR2424, Station Biologique de Roscoff, Roscoff, France
| | - Erin Worall
- Edinburgh Cancer Research UK Centre, the University of Edinburgh, Edinburgh, United Kingdom
| | - Borek Vojtesek
- Regional Centre for Applied Molecular Oncology, RECAMO and Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Karin Nylander
- Department of Medical Biosciences, Umeå University, Umeå, Sweden
| | - Robin Fåhraeus
- Équipe Labellisée Ligue Contre le Cancer, Université Paris 7, INSERM UMR 1162, Paris, France Regional Centre for Applied Molecular Oncology, RECAMO and Masaryk Memorial Cancer Institute, Brno, Czech Republic Department of Medical Biosciences, Umeå University, Umeå, Sweden
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21
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Diverse ETS transcription factors mediate FGF signaling in the Ciona anterior neural plate. Dev Biol 2015; 399:218-25. [PMID: 25576927 DOI: 10.1016/j.ydbio.2014.12.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 12/23/2014] [Accepted: 12/24/2014] [Indexed: 11/24/2022]
Abstract
The ascidian Ciona intestinalis is a marine invertebrate belonging to the sister group of the vertebrates, the tunicates. Its compact genome and simple, experimentally tractable embryos make Ciona well-suited for the study of cell-fate specification in chordates. Tunicate larvae possess a characteristic chordate body plan, and many developmental pathways are conserved between tunicates and vertebrates. Previous studies have shown that FGF signals are essential for neural induction and patterning at sequential steps of Ciona embryogenesis. Here we show that two different ETS family transcription factors, Ets1/2 and Elk1/3/4, have partially redundant activities in the anterior neural plate of gastrulating embryos. Whereas Ets1/2 promotes pigment cell formation in lateral lineages, both Ets1/2 and Elk1/3/4 are involved in the activation of Myt1L in medial lineages and the restriction of Six3/6 expression to the anterior-most regions of the neural tube. We also provide evidence that photoreceptor cells arise from posterior regions of the presumptive sensory vesicle, and do not depend on FGF signaling. Cells previously identified as photoreceptor progenitors instead form ependymal cells and neurons of the larval brain. Our results extend recent findings on FGF-dependent patterning of anterior-posterior compartments in the Ciona central nervous system.
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22
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Stolfi A, Gandhi S, Salek F, Christiaen L. Tissue-specific genome editing in Ciona embryos by CRISPR/Cas9. Development 2014; 141:4115-20. [PMID: 25336740 DOI: 10.1242/dev.114488] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The CRISPR/Cas9 system has ushered in a new era of targeted genetic manipulations. Here, we report the use of CRISPR/Cas9 to induce double-stranded breaks in the genome of the sea squirt Ciona intestinalis. We use electroporation to deliver CRISPR/Cas9 components for tissue-specific disruption of the Ebf (Collier/Olf/EBF) gene in hundreds of synchronized Ciona embryos. Phenotyping of transfected embryos in the 'F0' generation revealed that endogenous Ebf function is required for specification of Islet-expressing motor ganglion neurons and atrial siphon muscles. We demonstrate that CRISPR/Cas9 is sufficiently effective and specific to generate large numbers of embryos carrying mutations in a targeted gene of interest, which should allow for rapid screening of gene function in Ciona.
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Affiliation(s)
- Alberto Stolfi
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
| | - Shashank Gandhi
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
| | - Farhana Salek
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
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23
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Belyaeva OV, Chang C, Berlett MC, Kedishvili NY. Evolutionary origins of retinoid active short-chain dehydrogenases/reductases of SDR16C family. Chem Biol Interact 2014; 234:135-43. [PMID: 25451586 DOI: 10.1016/j.cbi.2014.10.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 10/09/2014] [Accepted: 10/17/2014] [Indexed: 12/11/2022]
Abstract
Vertebrate enzymes that belong to the 16C family of short-chain dehydrogenases/reductases (SDR16C) were shown to play an essential role in the control of retinoic acid (RA) levels during development. To trace the evolution of enzymatic function of SDR16C family, and to examine the origins of the pathway for RA biosynthesis from vitamin A, we identified putative SDR16C enzymes through the extensive search of available genome sequencing data in a subset of species representing major metazoan phyla. The phylogenetic analysis revealed that enzymes from protostome, non-chordate deuterostome and invertebrate chordate species are found in three clades of SDR16C family containing retinoid active enzymes, which are retinol dehydrogenase 10 (RDH10), retinol dehydrogenases E2 (RDHE2) and RDHE2-similar, and dehydrogenase reductase (SDR family) member 3 (DHRS3). For the initial functional analysis, we cloned RDH10- and RDHE2-related enzymes from the early developmental stages of a non-chordate deuterostome, green sea urchin Lytechinus variegatus, and an invertebrate chordate, sea squirt Ciona intestinalis. In situ hybridization revealed that these proteins are expressed in a pattern relevant to development, while assays performed on proteins expressed in mammalian cell culture showed that they possess retinol-oxidizing activity as their vertebrate homologs. The existence of invertebrate homologs of DHRS3 was inferred from the analysis of phylogeny and cofactor-binding residues characteristic of preference for NADP(H). The presence of invertebrate homologs in the DHRS3 group of SDR16C is interesting in light of the complex mutually activating interaction, which we have recently described for human RDH10 and DHRS3 enzymes. Further functional analysis of these homologs will establish whether this interaction evolved to control retinoid homeostasis only in vertebrates, or is also conserved in pre-vertebrates.
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Affiliation(s)
- Olga V Belyaeva
- Department of Biochemistry and Molecular Genetics, University of Alabama - Birmingham, Birmingham, AL 35294, USA.
| | - Chenbei Chang
- Department of Cell, Developmental and Integrative Biology, University of Alabama - Birmingham, Birmingham, AL 35294, USA
| | - Michael C Berlett
- Department of Biochemistry and Molecular Genetics, University of Alabama - Birmingham, Birmingham, AL 35294, USA
| | - Natalia Y Kedishvili
- Department of Biochemistry and Molecular Genetics, University of Alabama - Birmingham, Birmingham, AL 35294, USA
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24
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Stolfi A, Lowe EK, Racioppi C, Ristoratore F, Brown CT, Swalla BJ, Christiaen L. Divergent mechanisms regulate conserved cardiopharyngeal development and gene expression in distantly related ascidians. eLife 2014; 3:e03728. [PMID: 25209999 PMCID: PMC4356046 DOI: 10.7554/elife.03728] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 09/05/2014] [Indexed: 12/13/2022] Open
Abstract
Ascidians present a striking dichotomy between conserved phenotypes and divergent genomes: embryonic cell lineages and gene expression patterns are conserved between distantly related species. Much research has focused on Ciona or Halocynthia spp. but development in other ascidians remains poorly characterized. In this study, we surveyed the multipotent myogenic B7.5 lineage in Molgula spp. Comparisons to the homologous lineage in Ciona revealed identical cell division and fate specification events that result in segregation of larval, cardiac, and pharyngeal muscle progenitors. Moreover, the expression patterns of key regulators are conserved, but cross-species transgenic assays uncovered incompatibility, or ‘unintelligibility’, of orthologous cis-regulatory sequences between Molgula and Ciona. These sequences drive identical expression patterns that are not recapitulated in cross-species assays. We show that this unintelligibility is likely due to changes in both cis- and trans-acting elements, hinting at widespread and frequent turnover of regulatory mechanisms underlying otherwise conserved aspects of ascidian embryogenesis. DOI:http://dx.doi.org/10.7554/eLife.03728.001 When two species have features that look similar, this may be because the features arise by the same processes during development. Other features may look similar yet develop by different mechanisms. ‘Developmental system drift’ refers to the process where a physical feature remains unaltered during evolution, but the underlying pathway that controls its development is changed. However, to date, there have been only a few experimental studies that support this idea. Ascidians—also commonly known as sea squirts—are vase-like marine creatures, which start off as tadpole-like larvae that swim around until they find a place to settle down and attach themselves. Once attached, the sea squirts lose the ability to swim and start feeding, typically by filtering material out of the seawater. Sea squirts and their close relatives are the invertebrates (animals without backbones) that are most closely related to all vertebrates (animals with backbones), including humans. Furthermore, although different species of sea squirt have almost identical embryos, their genomes are very different. Stolfi et al. have now studied whether developmental system drift may have occurred during the evolution of ascidians, by analyzing different species of sea squirt named Molgula and Ciona. Stolfi et al. compared the genomes of Molgula and Ciona and studied the expression of genes in the cells that give rise to the heart and the muscles of the head. As an embryo develops, specific genes are switched on or off, and these patterns of gene activation were broadly identical in the two species of sea squirt examined. Enhancers are sequences of DNA that control when and how a gene is switched on. Given the similarities between the development of heart and head muscle cells in the different sea squirts, Stolfi et al. looked to see if the mechanisms of gene expression, and therefore the enhancers, were also conserved. Unexpectedly, this was not the case. When enhancers from Molgula were introduced into Ciona (and vice versa), these sequences were unable to switch on gene expression—thus enhancers from one sea squirt species could not function in the other. Stolfi et al. conclude that the developmental systems may have drifted considerably during evolution of the sea squirts, in spite of their nearly identical embryos. This reinforces the view that different paths can lead to the formation of similar physical features. DOI:http://dx.doi.org/10.7554/eLife.03728.002
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Affiliation(s)
- Alberto Stolfi
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
| | - Elijah K Lowe
- Department of Computer Science and Engineering, Michigan State University, East Lansing, United States
| | - Claudia Racioppi
- Cellular and Developmental Biology Laboratory, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Filomena Ristoratore
- Cellular and Developmental Biology Laboratory, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - C Titus Brown
- Department of Computer Science and Engineering, Michigan State University, East Lansing, United States
| | - Billie J Swalla
- Department of Biology, University of Washington, Seattle, United States
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, United States
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25
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Fibroblast growth factor signalling controls nervous system patterning and pigment cell formation in Ciona intestinalis. Nat Commun 2014; 5:4830. [PMID: 25189217 DOI: 10.1038/ncomms5830] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 07/25/2014] [Indexed: 11/09/2022] Open
Abstract
During the development of the central nervous system (CNS), combinations of transcription factors and signalling molecules orchestrate patterning, specification and differentiation of neural cell types. In vertebrates, three types of melanin-containing pigment cells, exert a variety of functional roles including visual perception. Here we analysed the mechanisms underlying pigment cell specification within the CNS of a simple chordate, the ascidian Ciona intestinalis. Ciona tadpole larvae exhibit a basic chordate body plan characterized by a small number of neural cells. We employed lineage-specific transcription profiling to characterize the expression of genes downstream of fibroblast growth factor signalling, which govern pigment cell formation. We demonstrate that FGF signalling sequentially imposes a pigment cell identity at the expense of anterior neural fates. We identify FGF-dependent and pigment cell-specific factors, including the small GTPase, Rab32/38 and demonstrated its requirement for the pigmentation of larval sensory organs.
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26
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Razy-Krajka F, Lam K, Wang W, Stolfi A, Joly M, Bonneau R, Christiaen L. Collier/OLF/EBF-dependent transcriptional dynamics control pharyngeal muscle specification from primed cardiopharyngeal progenitors. Dev Cell 2014; 29:263-76. [PMID: 24794633 DOI: 10.1016/j.devcel.2014.04.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 01/26/2014] [Accepted: 04/01/2014] [Indexed: 01/09/2023]
Abstract
In vertebrates, pluripotent pharyngeal mesoderm progenitors produce the cardiac precursors of the second heart field as well as the branchiomeric head muscles and associated stem cells. However, the mechanisms underlying the transition from multipotent progenitors to distinct muscle precursors remain obscured by the complexity of vertebrate embryos. Using Ciona intestinalis as a simple chordate model, we show that bipotent cardiopharyngeal progenitors are primed to activate both heart and pharyngeal muscle transcriptional programs, which progressively become restricted to corresponding precursors. The transcription factor COE (Collier/OLF/EBF) orchestrates the transition to pharyngeal muscle fate both by promoting an MRF-associated myogenic program in myoblasts and by maintaining an undifferentiated state in their sister cells through Notch-mediated lateral inhibition. The latter are stem cell-like muscle precursors that form most of the juvenile pharyngeal muscles. We discuss the implications of our findings for the development and evolution of the chordate cardiopharyngeal mesoderm.
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Affiliation(s)
- Florian Razy-Krajka
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
| | - Karen Lam
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA; Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003, USA; Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
| | - Wei Wang
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
| | - Alberto Stolfi
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
| | - Marine Joly
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA
| | - Richard Bonneau
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003, USA; Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY 10003, USA.
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27
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Russo MT, Racioppi C, Zanetti L, Ristoratore F. Expression of a single prominin homolog in the embryo of the model chordate Ciona intestinalis. Gene Expr Patterns 2014; 15:38-45. [PMID: 24755348 DOI: 10.1016/j.gep.2014.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/07/2014] [Accepted: 04/10/2014] [Indexed: 12/21/2022]
Abstract
Prominins are a family of pentaspan transmembrane glycoproteins, expressed in various types of cells, including stem and cancer stem cells in mammals. Prominin-1 is critical in generating and maintaining the structure of the photoreceptors in the eye since mutations in the PROM1 gene are associated with retinal and macular degeneration in human. In this study, we identified a single prominin homolog, Ci-prom1/2, in the model chordate the ascidian Ciona intestinalis and characterized Ci-prom1/2 expression profile in relation to photoreceptor differentiation during Ciona embryonic development. In situ hybridization experiments show Ci-prom1/2 transcripts localized in the developing central nervous system, predominantly in photoreceptor cell precursors as early as neurula stage and expression is maintained through larva stage in photoreceptor cells around the simple eye. We also isolated the regulatory region responsible for the specific spatio-temporal expression of the Ci-prom1/2 in photoreceptor cell lineage. Collectively, we report that Ci-prom1/2 is a novel molecular marker for ascidian photoreceptor cells and might represent a potential source to enlarge the knowledge about the function of prominin family in photoreceptor cell evolution and development.
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Affiliation(s)
- Monia T Russo
- Cellular and Developmental Biology Laboratory, Stazione Zoologica Anton Dorhn, Villa Comunale, 80121 Napoli, Italy
| | - Claudia Racioppi
- Cellular and Developmental Biology Laboratory, Stazione Zoologica Anton Dorhn, Villa Comunale, 80121 Napoli, Italy
| | - Laura Zanetti
- Cellular and Developmental Biology Laboratory, Stazione Zoologica Anton Dorhn, Villa Comunale, 80121 Napoli, Italy
| | - Filomena Ristoratore
- Cellular and Developmental Biology Laboratory, Stazione Zoologica Anton Dorhn, Villa Comunale, 80121 Napoli, Italy.
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28
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Pezzotti MR, Locascio A, Racioppi C, Fucci L, Branno M. Auto and cross regulatory elements control Onecut expression in the ascidian nervous system. Dev Biol 2014; 390:273-87. [PMID: 24680893 DOI: 10.1016/j.ydbio.2014.03.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 02/28/2014] [Accepted: 03/19/2014] [Indexed: 10/25/2022]
Abstract
The expression pattern of Onecut genes in the central and peripheral nervous systems is highly conserved in invertebrates and vertebrates but the regulatory networks in which they are involved are still largely unknown. The presence of three gene copies in vertebrates has revealed the functional roles of the Onecut genes in liver, pancreas and some populations of motor neurons. Urochordates have only one Onecut gene and are the closest living relatives of vertebrates and thus represent a good model system to understand its regulatory network and involvement in nervous system formation. In order to define the Onecut genetic cascade, we extensively characterized the Onecut upstream cis-regulatory DNA in the ascidian Ciona intestinalis. Electroporation experiments using a 2.5kb genomic fragment and of a series of deletion constructs identified a small region of 262bp able to reproduce most of the Onecut expression profile during embryonic development. Further analyses, both bioinformatic and in vivo using transient transgenes, permitted the identification of transcription factors responsible for Onecut endogenous expression. We provide evidence that Neurogenin is a direct activator of Onecut and that an autoregulatory loop is responsible for the maintenance of its expression. Furthermore, for the first time we propose the existence of a direct connection among Neurogenin, Onecut and Rx transcription factors in photoreceptor cell formation.
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Affiliation(s)
- Maria Rosa Pezzotti
- Cellular and Developmental Biology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
| | - Annamaria Locascio
- Cellular and Developmental Biology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - Claudia Racioppi
- Cellular and Developmental Biology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - Laura Fucci
- Biology Department, University of Naples Federico II, Via Cinthia, 80126 Napoli, Italy
| | - Margherita Branno
- Cellular and Developmental Biology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
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Monro K, Marshall DJ. Two sexes, one body: intra- and intersex covariation of gamete phenotypes in simultaneous hermaphrodites. Ecol Evol 2014; 4:1340-6. [PMID: 24834330 PMCID: PMC4020693 DOI: 10.1002/ece3.1035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 02/20/2014] [Accepted: 02/20/2014] [Indexed: 11/24/2022] Open
Abstract
By harboring male and female functions in the same genome and expressing them in every individual, simultaneous hermaphrodites may incur sexual conflict unless both sex functions can evolve phenotypic optima independently of each other. The first step toward understanding their capacity to do so lies in understanding whether sex functions are phenotypically correlated within individuals, but remarkably few data address this issue. We tested the potential for intra- and intersex covariation of gamete phenotypes to mediate sexual conflict in broadcast-spawning hermaphrodites (the ascidians Ciona intestinalis and Pyura praeputialis), for which sex-specific selection acts predominantly on sperm–egg interactions in the water column. In both species, gamete phenotypes covaried within and across sex functions, implying that selection may be unable to target them independently because its direct effects on male gametes translate into correlated effects on female gametes and vice versa. This alone does not preclude the evolution of a different phenotypic optimum for each sex function, but imposes the more restrictive requirement that selection – which ultimately sorts among whole individuals, not sex functions – aligns with the direction in which gamete phenotypes covary at this level.
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Affiliation(s)
- Keyne Monro
- School of Biological Sciences, Monash University Melbourne, Victoria, 3800, Australia
| | - Dustin J Marshall
- School of Biological Sciences, Monash University Melbourne, Victoria, 3800, Australia
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30
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Reeves W, Thayer R, Veeman M. Anterior-posterior regionalized gene expression in the Ciona notochord. Dev Dyn 2013; 243:612-620. [PMID: 24288133 DOI: 10.1002/dvdy.24101] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 11/19/2013] [Accepted: 11/20/2013] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND In the simple ascidian chordate Ciona, the signaling pathways and gene regulatory networks giving rise to initial notochord induction are largely understood and the mechanisms of notochord morphogenesis are being systematically elucidated. The notochord has generally been thought of as a non-compartmentalized or regionalized organ that is not finely patterned at the level of gene expression. Quantitative imaging methods have recently shown, however, that notochord cell size, shape, and behavior vary consistently along the anterior-posterior (AP) axis. RESULTS Here we screen candidate genes by whole mount in situ hybridization for potential AP asymmetry. We identify 4 genes that show non-uniform expression in the notochord. Ezrin/radixin/moesin (ERM) is expressed more strongly in the secondary notochord lineage than the primary. CTGF is expressed stochastically in a subset of notochord cells. A novel calmodulin-like gene (BCamL) is expressed more strongly at both the anterior and posterior tips of the notochord. A TGF-β ortholog is expressed in a gradient from posterior to anterior. The asymmetries in ERM, BCamL, and TGF-β expression are evident even before the notochord cells have intercalated into a single-file column. CONCLUSIONS We conclude that the Ciona notochord is not a homogeneous tissue but instead shows distinct patterns of regionalized gene expression.
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Affiliation(s)
- Wendy Reeves
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Rachel Thayer
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Michael Veeman
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
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31
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Wang W, Razy-Krajka F, Siu E, Ketcham A, Christiaen L. NK4 antagonizes Tbx1/10 to promote cardiac versus pharyngeal muscle fate in the ascidian second heart field. PLoS Biol 2013; 11:e1001725. [PMID: 24311985 PMCID: PMC3849182 DOI: 10.1371/journal.pbio.1001725] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 10/23/2013] [Indexed: 12/27/2022] Open
Abstract
Cross inhibition between NK4 and TBX1 transcription factors specifies heart versus pharyngeal muscle fates by promoting the activation of tissue-specific regulators in distinct precursors within the cardiopharyngeal lineage of the ascidian, Ciona intestinalis. The heart and head muscles share common developmental origins and genetic underpinnings in vertebrates, including humans. Parts of the heart and cranio-facial musculature derive from common mesodermal progenitors that express NKX2-5, ISL1, and TBX1. This ontogenetic kinship is dramatically reflected in the DiGeorge/Cardio-Velo-Facial syndrome (DGS/CVFS), where mutations of TBX1 cause malformations in the pharyngeal apparatus and cardiac outflow tract. Cardiac progenitors of the first heart field (FHF) do not require TBX1 and segregate precociously from common progenitors of the second heart field (SHF) and pharyngeal muscles. However, the cellular and molecular mechanisms that govern heart versus pharyngeal muscle specification within this lineage remain elusive. Here, we harness the simplicity of the ascidian larva to show that, following asymmetric cell division of common progenitors, NK4/NKX2-5 promotes GATAa/GATA4/5/6 expression and cardiac specification in the second heart precursors by antagonizing Tbx1/10-mediated inhibition of GATAa and activation of Collier/Olf/EBF (COE), the determinant of atrial siphon muscle (ASM) specification. Our results uncover essential regulatory connections between the conserved cardio-pharyngeal factor Tbx1/10 and muscle determinant COE, as well as a mutual antagonism between NK4 and Tbx1/10 activities upstream of GATAa and COE. The latter cross-antagonism underlies a fundamental heart versus pharyngeal muscle fate choice that occurs in a conserved lineage of cardio-pharyngeal progenitors. We propose that this basic ontogenetic motif underlies cardiac and pharyngeal muscle development and evolution in chordates. Mutations in the regulatory genes encoding the transcription factors NKX2-5 and TBX1, which govern heart and head muscle development, cause prevalent congenital defects. Recent studies using vertebrate models have shown that the heart and pharyngeal head muscle cells derive from common progenitors in the early embryo. To better understand the genetic mechanisms by which these progenitors select one of the two developmental trajectories, we studied the activity of these transcription factors in a simple invertebrate chordate model, the sea squirt Ciona intestinalis. We show that the sea squirt homolog of NKX2-5 promotes early heart specification by inhibiting the formation of pharyngeal muscles. Conversely, the TBX1 homolog determines pharyngeal muscle fate by inhibiting GATAa and thereby the heart program it instructs, as well as promoting the pharyngeal muscle program through activation of COE (Collier/Olf-1/EBF), a recently identified regulator of skeletal muscle differentiation. Finally, we show that the NKX2-5 homolog protein directly binds to the COE gene to repress its activity. Notably, these antagonistic interactions occur in heart and pharyngeal precursors immediately following the division of their pluripotent mother cells, thus contributing to their respective fate choice. These mechanistic insights into the process of early heart versus head muscle specification in this simple chordate provide the grounds for establishing the etiology of human congenital cardio-craniofacial defects.
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Affiliation(s)
- Wei Wang
- Department of Biology, New York University, New York, New York, United States of America
| | - Florian Razy-Krajka
- Department of Biology, New York University, New York, New York, United States of America
| | - Eric Siu
- Department of Biology, New York University, New York, New York, United States of America
| | - Alexandra Ketcham
- Department of Biology, New York University, New York, New York, United States of America
| | - Lionel Christiaen
- Department of Biology, New York University, New York, New York, United States of America
- * E-mail:
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32
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Bacterial diversity associated with the tunic of the model chordate Ciona intestinalis. ISME JOURNAL 2013; 8:309-20. [PMID: 24048225 DOI: 10.1038/ismej.2013.156] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 05/07/2013] [Accepted: 07/29/2013] [Indexed: 01/09/2023]
Abstract
The sea squirt Ciona intestinalis is a well-studied model organism in developmental biology, yet little is known about its associated bacterial community. In this study, a combination of 454 pyrosequencing of 16S ribosomal RNA genes, catalyzed reporter deposition-fluorescence in situ hybridization and bacterial culture were used to characterize the bacteria living inside and on the exterior coating, or tunic, of C. intestinalis adults. The 454 sequencing data set demonstrated that the tunic bacterial community structure is different from that of the surrounding seawater. The observed tunic bacterial consortium contained a shared community of <10 abundant bacterial phylotypes across three individuals. Culture experiments yielded four bacterial strains that were also dominant groups in the 454 sequencing data set, including novel representatives of the classes Alphaproteobacteria and Flavobacteria. The relatively simple bacterial community and availability of dominant community members in culture make C. intestinalis a promising system in which to investigate functional interactions between host-associated microbiota and the development of host innate immunity.
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33
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Hackley C, Mulholland E, Kim GJ, Newman-Smith E, Smith WC. A transiently expressed connexin is essential for anterior neural plate development in Ciona intestinalis. Development 2012; 140:147-55. [PMID: 23175630 DOI: 10.1242/dev.084681] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A forward genetic screen in the ascidian Ciona intestinalis identified a mutant line (frimousse) with a profound disruption in neural plate development. In embryos with the frimousse mutation, the anteriormost neural plate cells, which are products of an FGF induction at the blastula and gastrula stages, initially express neural plate-specific genes but fail to maintain the induced state and ultimately default to epidermis. The genetic lesion in the frimousse mutant lies within a connexin gene (cx-11) that is transiently expressed in the developing neural plate in a temporal window corresponding to the period of a-lineage neural induction. Using a genetically encoded calcium indicator we observed multiple calcium transients throughout the developing neural plate in wild-type embryos, but not in mutant embryos. A series of treatments at the gastrula and neurula stages that block the calcium transients, including gap junction inhibition and calcium depletion, were also found to disrupt the development of the anterior neural plate in a similar way to the frimousse mutation. The requirement for cx-11 for anterior neural fate points to a crucial role for intercellular communication via gap junctions, probably through mediation of Ca(2+) transients, in Ciona intestinalis neural induction.
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Affiliation(s)
- Christopher Hackley
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
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Wagner E, Levine M. FGF signaling establishes the anterior border of the Ciona neural tube. Development 2012; 139:2351-9. [PMID: 22627287 DOI: 10.1242/dev.078485] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The Ciona tadpole is constructed from simple, well-defined cell lineages governed by provisional gene networks that have been defined via extensive gene disruption assays. Here, we examine the patterning of the anterior neural plate, which produces placodal derivatives such as the adhesive palps and stomodeum, as well as the sensory vesicle (simple brain) of the Ciona tadpole. Evidence is presented that the doublesex-related gene DMRT is expressed throughout the anterior neural plate of neurulating embryos. It leads to the activation of FoxC and ZicL in the palp placode and anterior neural tube, respectively. This differential expression depends on FGF signaling, which inhibits FoxC expression in the anterior neural tube. Inhibition of FGF signaling leads to expanded expression of FoxC, the loss of ZicL, and truncation of the anterior neural tube.
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Affiliation(s)
- Eileen Wagner
- Center for Integrative Genomics, Division of Genetics, Genomics, and Development, Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA.
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Christiaen L, Wagner E, Shi W, Levine M. The sea squirt Ciona intestinalis. Cold Spring Harb Protoc 2009; 2009:pdb.emo138. [PMID: 20150076 DOI: 10.1101/pdb.emo138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
INTRODUCTIONSea squirts (Ciona intestinalis) are tunicates (or urochordates), the closest living relatives of the vertebrates. Although the adults are simple, sessile filter feeders, the embryos and larvae possess clear chordate features including a prominent notochord and dorsal, hollow neural tube. Tail-bud-stage embryos and mature swimming tadpoles are composed of approximately 1000 and 2600 cells, respectively, with complete lineage information. This cellular simplicity is coupled with a streamlined genome that has not undergone the duplications seen in vertebrates. A variety of molecular tools have been applied to understanding Ciona embryogenesis. Comparisons of the C. intestinalis genome and the related but divergent Ciona savignyi genome have facilitated the identification of conserved non-coding DNAs, including regulatory DNAs such as tissue-specific enhancers. Systematic in situ hybridization assays and gene-disruption experiments using specific morpholino antisense oligonucleotides have led to the elaboration of provisional gene regulatory networks underlying the specification of key chordate tissues, including the notochord, neural tube, and beating heart. These networks provide a foundation for understanding the mechanistic basis of more complex cell-specification processes in vertebrates, and for understanding the evolutionary origins of distinctive vertebrate characteristics such as the neural crest. Because tunicates and vertebrates are sister groups, there is every indication that the developmental mechanisms revealed in the simple Ciona model will be applicable to comparable processes in vertebrates.
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Affiliation(s)
- Lionel Christiaen
- Molecular and Cell Biology Department, University of California, Berkeley, California 94720, USA.
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