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Piekarz KM, Stolfi A. Development and circuitry of the tunicate larval Motor Ganglion, a putative hindbrain/spinal cord homolog. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART B, MOLECULAR AND DEVELOPMENTAL EVOLUTION 2024; 342:200-211. [PMID: 37675754 PMCID: PMC10918034 DOI: 10.1002/jez.b.23221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 07/13/2023] [Accepted: 08/22/2023] [Indexed: 09/08/2023]
Abstract
The Motor Ganglion (MG) is a small collection of neurons that control the swimming movements of the tunicate tadpole larva. Situated at the base of the tail, molecular and functional comparisons suggest that may be a homolog of the spinal cord and/or hindbrain ("rhombospinal" region) of vertebrates. Here we review the most current knowledge of the development, connectivity, functions, and unique identities of the neurons that comprise the MG, drawn mostly from studies in Ciona spp. The simple cell lineages, minimal cellular composition, and comprehensively mapped "connectome" of the Ciona MG all make this an excellent model for studying the development and physiology of motor control in aquatic larvae.
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Affiliation(s)
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology
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2
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Hoyer J, Kolar K, Athira A, van den Burgh M, Dondorp D, Liang Z, Chatzigeorgiou M. Polymodal sensory perception drives settlement and metamorphosis of Ciona larvae. Curr Biol 2024; 34:1168-1182.e7. [PMID: 38335959 DOI: 10.1016/j.cub.2024.01.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 12/04/2023] [Accepted: 01/16/2024] [Indexed: 02/12/2024]
Abstract
The Earth's oceans brim with an incredible diversity of microscopic lifeforms, including motile planktonic larvae, whose survival critically depends on effective dispersal in the water column and subsequent exploration of the seafloor to identify a suitable settlement site. How their nervous systems mediate sensing of diverse multimodal cues remains enigmatic. Here, we uncover that the tunicate Ciona intestinalis larvae employ ectodermal sensory cells to sense various mechanical and chemical cues. Combining whole-brain imaging and chemogenetics, we demonstrate that stimuli encoded at the periphery are sufficient to drive global brain-state changes to promote or impede both larval attachment and metamorphosis behaviors. The ability of C. intestinalis larvae to leverage polymodal sensory perception to support information coding and chemotactile behaviors may explain how marine larvae make complex decisions despite streamlined nervous systems.
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Affiliation(s)
- Jorgen Hoyer
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Kushal Kolar
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Athira Athira
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Meike van den Burgh
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Daniel Dondorp
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Zonglai Liang
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway
| | - Marios Chatzigeorgiou
- Michael Sars Centre, Faculty of Mathematics and Natural Sciences, University of Bergen, Bergen 5006, Norway.
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3
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Anselmi C, Fuller GK, Stolfi A, Groves AK, Manni L. Sensory cells in tunicates: insights into mechanoreceptor evolution. Front Cell Dev Biol 2024; 12:1359207. [PMID: 38550380 PMCID: PMC10973136 DOI: 10.3389/fcell.2024.1359207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Tunicates, the sister group of vertebrates, offer a unique perspective for evolutionary developmental studies (Evo-Devo) due to their simple anatomical organization. Moreover, the separation of tunicates from vertebrates predated the vertebrate-specific genome duplications. As adults, they include both sessile and pelagic species, with very limited mobility requirements related mainly to water filtration. In sessile species, larvae exhibit simple swimming behaviors that are required for the selection of a suitable substrate on which to metamorphose. Despite their apparent simplicity, tunicates display a variety of mechanoreceptor structures involving both primary and secondary sensory cells (i.e., coronal sensory cells). This review encapsulates two decades of research on tunicate mechanoreception focusing on the coronal organ's sensory cells as prime candidates for understanding the evolution of vertebrate hair cells of the inner ear and the lateral line organ. The review spans anatomical, cellular and molecular levels emphasizing both similarity and differences between tunicate and vertebrate mechanoreception strategies. The evolutionary significance of mechanoreception is discussed within the broader context of Evo-Devo studies, shedding light on the intricate pathways that have shaped the sensory system in chordates.
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Affiliation(s)
- Chiara Anselmi
- Hopkins Marine Station, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Pacific Grove, CA, United States
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, United States
| | - Gwynna K. Fuller
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Andrew K. Groves
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
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4
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Satake H, Sasakura Y. The neuroendocrine system of Ciona intestinalis Type A, a deuterostome invertebrate and the closest relative of vertebrates. Mol Cell Endocrinol 2024; 582:112122. [PMID: 38109989 DOI: 10.1016/j.mce.2023.112122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/20/2023]
Abstract
Deuterostome invertebrates, including echinoderms, hemichordates, cephalochordates, and urochordates, exhibit common and species-specific morphological, developmental, physiological, and behavioral characteristics that are regulated by neuroendocrine and nervous systems. Over the past 15 years, omics, genetic, and/or physiological studies on deuterostome invertebrates have identified low-molecular-weight transmitters, neuropeptides and their cognate receptors, and have clarified their various biological functions. In particular, there has been increasing interest on the neuroendocrine and nervous systems of Ciona intestinalis Type A, which belongs to the subphylum Urochordata and occupies the critical phylogenetic position as the closest relative of vertebrates. During the developmental stage, gamma-aminobutylic acid, D-serine, and gonadotropin-releasing hormones regulate metamorphosis of Ciona. In adults, the neuropeptidergic mechanisms underlying ovarian follicle growth, oocyte maturation, and ovulation have been elucidated. This review article provides the most recent and fundamental knowledge of the neuroendocrine and nervous systems of Ciona, and their evolutionary aspects.
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Affiliation(s)
- Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan.
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, Shizuoka, Japan
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5
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Chung J, Newman-Smith E, Kourakis MJ, Miao Y, Borba C, Medina J, Laurent T, Gallean B, Faure E, Smith WC. A single oscillating proto-hypothalamic neuron gates taxis behavior in the primitive chordate Ciona. Curr Biol 2023; 33:3360-3370.e4. [PMID: 37490920 PMCID: PMC10528541 DOI: 10.1016/j.cub.2023.06.080] [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: 04/21/2023] [Revised: 06/05/2023] [Accepted: 06/29/2023] [Indexed: 07/27/2023]
Abstract
Ciona larvae display a number of behaviors, including negative phototaxis. In negative phototaxis, the larvae first perform short spontaneous rhythmic casting swims. As larvae are cast in a light field, their photoreceptors are directionally shaded by an associated pigment cell, providing a phototactic cue. This then evokes an extended negative taxis swim. We report here that the larval forebrain of Ciona has a previously uncharacterized single slow-oscillating inhibitory neuron (neuron cor-assBVIN78) that projects to the midbrain, where it targets key interneurons of the phototaxis circuit known as the photoreceptor relay neurons. The anatomical location, gene expression, and oscillation of cor-assBVIN78 suggest homology to oscillating neurons of the vertebrate hypothalamus. Ablation of cor-assBVIN78 results in larvae showing extended phototaxis-like swims, even in the absence of phototactic cues. These results indicate that cor-assBVIN78 has a gating activity on phototaxis by projecting temporally oscillating inhibition to the photoreceptor relay neurons. However, in intact larvae, the frequency of cor-assBVIN78 oscillation does not match that of the rhythmic spontaneous swims, indicating that the troughs in oscillations do not themselves initiate swims but rather that cor-assBVIN78 may modulate the phototaxis circuit by filtering out low-level inputs while restricting them temporally to the troughs in inhibition.
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Affiliation(s)
- Janeva Chung
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Erin Newman-Smith
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Matthew J Kourakis
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Yishen Miao
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Cezar Borba
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Juan Medina
- College of Creative Studies, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Tao Laurent
- Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Benjamin Gallean
- Centre de Recherche de Biologie cellulaire de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Emmanuel Faure
- Laboratoire d'Informatique, de Robotique et de Microélectronique de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - William C Smith
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
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6
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Wijayawardene NN, Boonyuen N, Ranaweera CB, de Zoysa HKS, Padmathilake RE, Nifla F, Dai DQ, Liu Y, Suwannarach N, Kumla J, Bamunuarachchige TC, Chen HH. OMICS and Other Advanced Technologies in Mycological Applications. J Fungi (Basel) 2023; 9:688. [PMID: 37367624 DOI: 10.3390/jof9060688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/06/2023] [Accepted: 06/16/2023] [Indexed: 06/28/2023] Open
Abstract
Fungi play many roles in different ecosystems. The precise identification of fungi is important in different aspects. Historically, they were identified based on morphological characteristics, but technological advancements such as polymerase chain reaction (PCR) and DNA sequencing now enable more accurate identification and taxonomy, and higher-level classifications. However, some species, referred to as "dark taxa", lack distinct physical features that makes their identification challenging. High-throughput sequencing and metagenomics of environmental samples provide a solution to identifying new lineages of fungi. This paper discusses different approaches to taxonomy, including PCR amplification and sequencing of rDNA, multi-loci phylogenetic analyses, and the importance of various omics (large-scale molecular) techniques for understanding fungal applications. The use of proteomics, transcriptomics, metatranscriptomics, metabolomics, and interactomics provides a comprehensive understanding of fungi. These advanced technologies are critical for expanding the knowledge of the Kingdom of Fungi, including its impact on food safety and security, edible mushrooms foodomics, fungal secondary metabolites, mycotoxin-producing fungi, and biomedical and therapeutic applications, including antifungal drugs and drug resistance, and fungal omics data for novel drug development. The paper also highlights the importance of exploring fungi from extreme environments and understudied areas to identify novel lineages in the fungal dark taxa.
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Affiliation(s)
- Nalin N Wijayawardene
- Centre for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing 655011, China
- Department of Bioprocess Technology, Faculty of Technology, Rajarata University of Sri Lanka, Mihintale 50300, Sri Lanka
- Section of Genetics, Institute for Research and Development in Health and Social Care, No: 393/3, Lily Avenue, Off Robert Gunawardane Mawatha, Battaramulla 10120, Sri Lanka
| | - Nattawut Boonyuen
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - Chathuranga B Ranaweera
- Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, General Sir John Kotelawala Defence University Sri Lanka, Kandawala Road, Rathmalana 10390, Sri Lanka
| | - Heethaka K S de Zoysa
- Department of Bioprocess Technology, Faculty of Technology, Rajarata University of Sri Lanka, Mihintale 50300, Sri Lanka
| | - Rasanie E Padmathilake
- Department of Plant Sciences, Faculty of Agriculture, Rajarata University of Sri Lanka, Pulliyankulama, Anuradhapura 50000, Sri Lanka
| | - Faarah Nifla
- Department of Bioprocess Technology, Faculty of Technology, Rajarata University of Sri Lanka, Mihintale 50300, Sri Lanka
| | - Dong-Qin Dai
- Centre for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing 655011, China
| | - Yanxia Liu
- Guizhou Academy of Tobacco Science, No.29, Longtanba Road, Guanshanhu District, Guiyang 550000, China
| | - Nakarin Suwannarach
- Research Center of Microbial Diversity and Sustainable Utilization, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Jaturong Kumla
- Research Center of Microbial Diversity and Sustainable Utilization, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Thushara C Bamunuarachchige
- Department of Bioprocess Technology, Faculty of Technology, Rajarata University of Sri Lanka, Mihintale 50300, Sri Lanka
| | - Huan-Huan Chen
- Centre for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing 655011, China
- Key Laboratory of Insect-Pollinator Biology of Ministry of Agriculture and Rural Affairs, Institute of Agricultural Research, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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7
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Chung J, Newman-Smith E, Kourakis MJ, Miao Y, Borba C, Medina J, Laurent T, Gallean B, Faure E, Smith WC. A single oscillating proto-hypothalamic neuron gates taxis behavior in the primitive chordate Ciona. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.538092. [PMID: 37162881 PMCID: PMC10168268 DOI: 10.1101/2023.04.24.538092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Ciona larvae display a number of behaviors, including negative phototaxis. In negative phototaxis, the larvae first perform short spontaneous rhythmic casting swims. As larvae cast in a light field, their photoreceptors are directionally shaded by an associated pigment cell, providing a phototactic cue. This then evokes an extended negative taxis swim. We report here that the larval forebrain of Ciona has a previously uncharacterized single slow-oscillating inhibitory neuron (neuron cor-assBVIN78 ) that projects to the midbrain, where it targets key interneurons of the phototaxis circuit known as the photoreceptor relay neurons . The anatomical location, gene expression and oscillation of cor-assBVIN78 suggest homology to oscillating neurons of the vertebrate hypothalamus. Ablation of cor-assBVIN78 results in larvae showing extended phototaxis-like swims, but which occur in the absence of phototactic cues. These results indicate that cor-assBVIN78 has a gating activity on phototaxis by projecting temporally-oscillating inhibition to the photoreceptor relay neurons. However, in intact larvae the frequency of cor-assBVIN78 oscillation does not match that of the rhythmic spontaneous swims, indicating that the troughs in oscillations do not themselves initiate swims, but rather that cor-assBVIN78 may modulate the phototaxis circuit by filtering out low level inputs while restricting them temporally to the troughs in inhibition.
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Affiliation(s)
- Janeva Chung
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA 93106
| | - Erin Newman-Smith
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA 93106
| | - Matthew J. Kourakis
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA 93106
| | - Yishen Miao
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA 93106
| | - Cezar Borba
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA 93106
| | - Juan Medina
- College of Creative Studies, University of California Santa Barbara, Santa Barbara, CA, USA 93106
| | - Tao Laurent
- Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier, Université de Montpellier,CNRS, Montpellier, France
| | - Benjamin Gallean
- Centre de Recherche de Biologie cellulaire de Montpellier, Université de Montpellier, CNRS, Montpellier, France
| | - Emmanuel Faure
- Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier, Université de Montpellier,CNRS, Montpellier, France
| | - William C Smith
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA 93106
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA 93106
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Utsumi MK, Oka K, Hotta K. Transitions of motor neuron activities during Ciona development. Front Cell Dev Biol 2023; 11:1100887. [PMID: 36711039 PMCID: PMC9880257 DOI: 10.3389/fcell.2023.1100887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/03/2023] [Indexed: 01/15/2023] Open
Abstract
Motor neurons (MNs) are one of the most important components of Central Pattern Generators (CPG) in vertebrates (Brown, Proceedings of The Royal Society B: Biological Sciences (The Royal Society), 1911, 84(572), 308-319). However, it is unclear how the neural activities of these components develop during their embryogenesis. Our previous study revealed that in Ciona robusta (Ciona intestinalis type A), a model organism with a simple neural circuit, a single pair of MNs (MN2L/MN2R) was determining the rhythm of its spontaneous early motor behavior (developmental stage St.22-24). MN2s are known to be one of the main components of Ciona CPG, though the neural activities of MN2s in the later larval period (St.25-) were not yet investigated. In this study, we investigated the neural activities of MN2s during their later stages and how they are related to Ciona's swimming CPG. Long-term simultaneous Ca2+ imaging of both MN2s with GCaMP6s/f (St.22-34) revealed that MN2s continued to determine the rhythm of motor behavior even in their later larval stages. Their activities were classified into seven phases (I-VII) depending on the interval and the synchronicity of MN2L and MN2R Ca2+ transients. Initially, each MN2 oscillates sporadically (I). As they develop into swimming larvae, they gradually oscillate at a constant interval (II-III), then start to synchronize (IV) and fully synchronize (V). Intervals become longer (VI) and sporadic again during the tail aggression period (VII). Interestingly, 76% of the embryos started to oscillate from MN2R. In addition, independent photostimulations on left and right MN2s were conducted. This is the first report of the live imaging of neural activities in Ciona's developing swimming CPG. These findings will help to understand the development of motor neuron circuits in chordate animals.
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Affiliation(s)
- Madoka K. Utsumi
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Kotaro Oka
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan,Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku, Japan,Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Kohji Hotta
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan,*Correspondence: Kohji Hotta,
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9
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Sakamoto A, Hozumi A, Shiraishi A, Satake H, Horie T, Sasakura Y. The
TRP
channel
PKD2
is involved in sensing the mechanical stimulus of adhesion for initiating metamorphosis in the chordate
Ciona. Dev Growth Differ 2022; 64:395-408. [DOI: 10.1111/dgd.12801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/07/2022] [Accepted: 07/10/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Aya Sakamoto
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
| | - Akiko Hozumi
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
| | - Akira Shiraishi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences Kyoto Japan
| | - Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences Kyoto Japan
| | - Takeo Horie
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
| | - Yasunori Sasakura
- Shimoda Marine Research Center University of Tsukuba, Shimoda Shizuoka Japan
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10
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Hara T, Hasegawa S, Iwatani Y, Nishino AS. The trunk-tail junctional region in Ciona larvae autonomously expresses tail-beating bursts at ∼20 second intervals. J Exp Biol 2022; 225:275646. [PMID: 35678124 DOI: 10.1242/jeb.243828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 06/03/2022] [Indexed: 11/20/2022]
Abstract
Swimming locomotion in aquatic vertebrates, such as fish and tadpoles, is expressed through neuron networks in the spinal cord. These networks are arranged in parallel, ubiquitously distributed and mutually coupled along the spinal cord to express undulation patterns accommodated to various inputs into the networks. While these systems have been widely studied in vertebrate swimmers, their evolutionary origin along the chordate phylogeny remains unclear. Ascidians, representing a sister group of vertebrates, give rise to tadpole larvae that swim freely in seawater. In the present study, we examined the locomotor ability of the anterior and posterior body fragments of larvae of the ascidian Ciona that had been cut at an arbitrary position. Examination of more than 200 fragments revealed a necessary and sufficient body region that spanned only ∼10% of the body length and included the trunk-tail junction. 'Mid-piece' body fragments, which included the trunk-tail junctional region, but excluded most of the anterior trunk and posterior tail, autonomously expressed periodic tail-beating bursts at ∼20 s intervals. We compared the durations and intervals of tail-beating bursts expressed by mid-piece fragments, and also by whole larvae under different sensory conditions. The results suggest that body parts outside the mid-piece effect shortening of swimming intervals, particularly in the dark, and vary the burst duration. We propose that Ciona larvae express swimming behaviors by modifying autonomous and periodic locomotor drives that operate locally in the trunk-tail junctional region.
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Affiliation(s)
- Takashi Hara
- Department of Biology, Graduate School of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan
| | - Shuya Hasegawa
- Department of Biology, Graduate School of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan
| | - Yasushi Iwatani
- Department of Science and Technology, Graduate School of Science and Technology, Hirosaki University, Hirosaki 036-8561, Japan
| | - Atsuo S Nishino
- Department of Biology, Graduate School of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan.,Department of Bioresources Science, United Graduate School of Agricultural Sciences, Iwate University, Hirosaki 036-8561, Japan
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11
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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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12
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Neuronal identities derived by misexpression of the POU IV sensory determinant in a protovertebrate. Proc Natl Acad Sci U S A 2022; 119:2118817119. [PMID: 35042818 PMCID: PMC8794889 DOI: 10.1073/pnas.2118817119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2021] [Indexed: 12/13/2022] Open
Abstract
The protovertebrate Ciona intestinalis is an ideal system to investigate both gene regulatory networks that underlie cell-type specification and how cell types have evolved. In this study, we use single-cell technology, experimental manipulations, and computational analyses to understand the role of the regulatory determinant POU IV—a homolog of Brn3 in vertebrates—in specifying various sensory cell types in Ciona. Surprisingly, the misexpression of POU IV throughout the epidermis led to the formation of hybrid sensory cell types, including those exhibiting properties of both palp sensory cells and bipolar tail neurons. These results demonstrate the interconnectedness of diverse sensory specification networks and give insights into the opportunities and challenges of reprogramming cell types through the targeted misexpression of cellular determinants. The protovertebrate Ciona intestinalis type A (sometimes called Ciona robusta) contains a series of sensory cell types distributed across the head–tail axis of swimming tadpoles. They arise from lateral regions of the neural plate that exhibit properties of vertebrate placodes and neural crest. The sensory determinant POU IV/Brn3 is known to work in concert with regional determinants, such as Foxg and Neurogenin, to produce palp sensory cells (PSCs) and bipolar tail neurons (BTNs), in head and tail regions, respectively. A combination of single-cell RNA-sequencing (scRNA-seq) assays, computational analysis, and experimental manipulations suggests that misexpression of POU IV results in variable transformations of epidermal cells into hybrid sensory cell types, including those exhibiting properties of both PSCs and BTNs. Hybrid properties are due to coexpression of Foxg and Neurogenin that is triggered by an unexpected POU IV feedback loop. Hybrid cells were also found to express a synthetic gene battery that is not coexpressed in any known cell type. We discuss these results with respect to the opportunities and challenges of reprogramming cell types through the targeted misexpression of cellular determinants.
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Morphological Study and 3D Reconstruction of the Larva of the Ascidian Halocynthia roretzi. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2021. [DOI: 10.3390/jmse10010011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The swimming larva represents the dispersal phase of ascidians, marine invertebrates belonging to tunicates. Due to its adhesive papillae, the larva searches the substrate, adheres to it, and undergoes metamorphosis, thereby becoming a sessile filter feeding animal. The larva anatomy has been described in detail in a few species, revealing a different degree of adult structure differentiation, called adultation. In the solitary ascidian Halocynthia roretzi, a species reared for commercial purposes, embryogenesis has been described in detail, but information on the larval anatomy is still lacking. Here, we describe it using a comparative approach, utilizing 3D reconstruction, as well as histological/TEM observations, with attention to its papillae. The larva is comparable to those of other solitary ascidians, such as Ciona intestinalis. However, it displays a higher level of adultation for the presence of the atrium, opened outside by means of the atrial siphon, and the peribranchial chambers. It does not reach the level of complexity of the larva of Botryllus schlosseri, a phylogenetically close colonial ascidian. Our study reveals that the papillae of H. roretzi, previously described as simple and conform, exhibit dynamic changes during settlement. This opens up new considerations on papillae morphology and evolution and deserves to be further investigated.
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Kolar K, Dondorp D, Zwiggelaar JC, Høyer J, Chatzigeorgiou M. Mesmerize is a dynamically adaptable user-friendly analysis platform for 2D and 3D calcium imaging data. Nat Commun 2021; 12:6569. [PMID: 34772921 PMCID: PMC8589933 DOI: 10.1038/s41467-021-26550-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 10/13/2021] [Indexed: 01/09/2023] Open
Abstract
Calcium imaging is an increasingly valuable technique for understanding neural circuits, neuroethology, and cellular mechanisms. The analysis of calcium imaging data presents challenges in image processing, data organization, analysis, and accessibility. Tools have been created to address these problems independently, however a comprehensive user-friendly package does not exist. Here we present Mesmerize, an efficient, expandable and user-friendly analysis platform, which uses a Findable, Accessible, Interoperable and Reproducible (FAIR) system to encapsulate the entire analysis process, from raw data to interactive visualizations for publication. Mesmerize provides a user-friendly graphical interface to state-of-the-art analysis methods for signal extraction & downstream analysis. We demonstrate the broad scientific scope of Mesmerize's applications by analyzing neuronal datasets from mouse and a volumetric zebrafish dataset. We also applied contemporary time-series analysis techniques to analyze a novel dataset comprising neuronal, epidermal, and migratory mesenchymal cells of the protochordate Ciona intestinalis.
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Affiliation(s)
- Kushal Kolar
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5006, Bergen, Norway.
| | - Daniel Dondorp
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5006, Bergen, Norway
| | | | - Jørgen Høyer
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5006, Bergen, Norway
| | - Marios Chatzigeorgiou
- Sars International Centre for Marine Molecular Biology, University of Bergen, 5006, Bergen, Norway.
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15
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Kourakis MJ, Bostwick M, Zabriskie A, Smith WC. Disruption of left-right axis specification in Ciona induces molecular, cellular, and functional defects in asymmetric brain structures. BMC Biol 2021; 19:141. [PMID: 34256748 PMCID: PMC8276506 DOI: 10.1186/s12915-021-01075-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/17/2021] [Indexed: 11/28/2022] Open
Abstract
Background Left-right asymmetries are a common feature of metazoans and can be found in a number of organs including the nervous system. These asymmetries are particularly pronounced in the simple central nervous system (CNS) of the swimming tadpole larva of the tunicate Ciona, which displays a chordate ground plan. While common pathway elements for specifying the left/right axis are found among chordates, particularly a requirement for Nodal signaling, Ciona differs temporally from its vertebrate cousins by specifying its axis at the neurula stage, rather than at gastrula. Additionally, Ciona and other ascidians require an intact chorionic membrane for proper left-right specification. Whether such differences underlie distinct specification mechanisms between tunicates and vertebrates will require broad understanding of their influence on CNS formation. Here, we explore the consequences of disrupting left-right axis specification on Ciona larval CNS cellular anatomy, gene expression, synaptic connectivity, and behavior. Results We show that left-right asymmetry disruptions caused by removal of the chorion (dechorionation) are highly variable and present throughout the Ciona larval nervous system. While previous studies have documented disruptions to the conspicuously asymmetric sensory systems in the anterior brain vesicle, we document asymmetries in seemingly symmetric structures such as the posterior brain vesicle and motor ganglion. Moreover, defects caused by dechorionation include misplaced or absent neuron classes, loss of asymmetric gene expression, aberrant synaptic projections, and abnormal behaviors. In the motor ganglion, a brain structure that has been equated with the vertebrate hindbrain, we find that despite the apparent left-right symmetric distribution of interneurons and motor neurons, AMPA receptors are expressed exclusively on the left side, which equates with asymmetric swimming behaviors. We also find that within a population of dechorionated larvae, there is a small percentage with apparently normal left-right specification and approximately equal population with inverted (mirror-image) asymmetry. We present a method based on a behavioral assay for isolating these larvae. When these two classes of larvae (normal and inverted) are assessed in a light dimming assay, they display mirror-image behaviors, with normal larvae responding with counterclockwise swims, while inverted larvae respond with clockwise swims. Conclusions Our findings highlight the importance of left-right specification pathways not only for proper CNS anatomy, but also for correct synaptic connectivity and behavior. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01075-4.
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Affiliation(s)
- Matthew J Kourakis
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA
| | - Michaela Bostwick
- College of Creative Studies, University of California, Santa Barbara, CA, 93106, USA
| | - Amanda Zabriskie
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - William C Smith
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA. .,Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA.
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16
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Sun X, Tu K, Li L, Wu B, Wu L, Liu Z, Zhou L, Tian J, Yang A. Integrated transcriptome and metabolome analysis reveals molecular responses of the clams to acute hypoxia. MARINE ENVIRONMENTAL RESEARCH 2021; 168:105317. [PMID: 33819872 DOI: 10.1016/j.marenvres.2021.105317] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 03/13/2021] [Accepted: 03/18/2021] [Indexed: 06/12/2023]
Abstract
Mudflat shellfish have evolved well-adapted strategies for coping with dynamic environmental fluxes and stressful conditions, including oxygen availability. The Manila clams Ruditapes philippinarum are worldwide cultured shellfish in marine intertidal zone, which usually encounter great risk of acute hypoxia exposure in coastal habitats. To reveal the effects of acute hypoxia on metabolic changes of the clams, we performed the integrated analysis of transcriptomics and metabolomics to investigate the global changes of genes and metabolites during acute hypoxia stress at the whole-organism level. The comparative transcriptome analysis reveals that the clams show the remarkable depression in a variety of biological performance, such as metabolic rates, neuronal activity, biomineralization activity, and cell proliferation and differentiation at the hypoxic condition. The metabolomic analysis reveals that amino acid metabolism plays a critical role in the metabolic changes of the clams in response to acute hypoxia. A variety of free amino acids may not only be served as the potential osmolytes for osmotic regulation, but also may contribute to energy production during the acute hypoxia exposure. The metabolite analysis also reveals several important biomarkers for metabolic changes, and provides new insights into how clams deal with acute hypoxia. These findings suggest that clams may get through acute hypoxia stress by the adaptive metabolic strategy to survive short-period of acute hypoxia which is likely to occur in their typical habitat. The present findings will not only shed lights on the molecular and metabolic mechanisms of adaptive strategies under stressful conditions, but also provide the signaling metabolites to assess the physiological states of clams in aquaculture.
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Affiliation(s)
- Xiujun Sun
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Kang Tu
- Putian Institute of Aquaculture Science of Fujian Province, Putian, 351100, China
| | - Li Li
- Marine Biology Institute of Shandong Province, Qingdao, 266104, China
| | - Biao Wu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Lei Wu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China; Jiangsu Ocean University, Lianyungang, 222005, China
| | - Zhihong Liu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Liqing Zhou
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Jiteng Tian
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China
| | - Aiguo Yang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
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Lemaire LA, Cao C, Yoon PH, Long J, Levine M. The hypothalamus predates the origin of vertebrates. SCIENCE ADVANCES 2021; 7:7/18/eabf7452. [PMID: 33910896 PMCID: PMC8081355 DOI: 10.1126/sciadv.abf7452] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 03/09/2021] [Indexed: 05/02/2023]
Abstract
The hypothalamus coordinates neuroendocrine functions in vertebrates. To explore its evolutionary origin, we describe integrated transcriptome/connectome brain maps for swimming tadpoles of Ciona, which serves as an approximation of the ancestral proto-vertebrate. This map features several cell types related to different regions of the vertebrate hypothalamus, including the mammillary nucleus, the arcuate nucleus, and magnocellular neurons. Coronet cells express melanopsin and share additional properties with the saccus vasculosus, a specialized region of the hypothalamus that mediates photoperiodism in nontropical fishes. Comparative transcriptome analyses identified orthologous cell types for mechanosensory switch neurons, and VP+ and VPR+ relay neurons in different regions of the mouse hypothalamus. These observations provide evidence that the hypothalamus predates the evolution of the vertebrate brain. We discuss the possibility that switch neurons, coronet cells, and FoxP+ /VPR+ relay neurons comprise a behavioral circuit that helps trigger metamorphosis of Ciona larvae in response to twilight.
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Affiliation(s)
- Laurence A Lemaire
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Chen Cao
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Peter H Yoon
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Juanjuan Long
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Michael Levine
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
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18
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Wakai MK, Nakamura MJ, Sawai S, Hotta K, Oka K. Two-Round Ca 2+ transient in papillae by mechanical stimulation induces metamorphosis in the ascidian Ciona intestinalis type A. Proc Biol Sci 2021; 288:20203207. [PMID: 33593191 DOI: 10.1098/rspb.2020.3207] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Marine invertebrate larvae are known to begin metamorphosis in response to environmentally derived cues. However, little is known about the relationships between the perception of such cues and internal signalling for metamorphosis. To elucidate the mechanism underlying the initiation of metamorphosis in the ascidian, Ciona intestinalis type A (Ciona robusta), we artificially induced ascidian metamorphosis and investigated Ca2+ dynamics from pre- to post-metamorphosis. Ca2+ transients were observed and consisted of two temporally distinct phases with different durations before tail regression which is the early event of metamorphosis. In the first phase, Phase I, the Ca2+ transient in the papillae (adhesive organ of the anterior trunk) was coupled with the Ca2+ transient in dorsally localized cells and endoderm cells just after mechanical stimulation. The Ca2+ transients in Phase I were also observed when applying only short stimulation. In the second phase, Phase II, the Ca2+ transient in papillae was observed again and lasted for approximately 5-11 min just after the Ca2+ transient in Phase I continued for a few minutes. The impaired papillae by Foxg-knockdown failed to induce the second Ca2+ transient in Phase II and tail regression. In Phase II, a wave-like Ca2+ propagation was also observed across the entire epidermis. Our results indicate that the papillae sense a mechanical cue and two-round Ca2+ transients in papillae transmits the internal metamorphic signals to different tissues, which subsequently induces tail regression. Our study will help elucidate the internal mechanism of metamorphosis in marine invertebrate larvae in response to environmental cues.
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Affiliation(s)
- Maiki K Wakai
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Mitsuru J Nakamura
- Graduate School of Arts and Sciences, University of Tokyo, Komaba, 153-8902 Tokyo, Japan
| | - Satoshi Sawai
- Graduate School of Arts and Sciences, University of Tokyo, Komaba, 153-8902 Tokyo, Japan
| | - Kohji Hotta
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kouhoku-ku, Yokohama 223-8522, Japan
| | - Kotaro Oka
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Kouhoku-ku, Yokohama 223-8522, Japan.,Waseda Research Institute for Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan.,Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan
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19
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Coulcher JF, Roure A, Chowdhury R, Robert M, Lescat L, Bouin A, Carvajal Cadavid J, Nishida H, Darras S. Conservation of peripheral nervous system formation mechanisms in divergent ascidian embryos. eLife 2020; 9:e59157. [PMID: 33191918 PMCID: PMC7710358 DOI: 10.7554/elife.59157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 11/13/2020] [Indexed: 01/23/2023] Open
Abstract
Ascidians with very similar embryos but highly divergent genomes are thought to have undergone extensive developmental system drift. We compared, in four species (Ciona and Phallusia for Phlebobranchia, Molgula and Halocynthia for Stolidobranchia), gene expression and gene regulation for a network of six transcription factors regulating peripheral nervous system (PNS) formation in Ciona. All genes, but one in Molgula, were expressed in the PNS with some differences correlating with phylogenetic distance. Cross-species transgenesis indicated strong levels of conservation, except in Molgula, in gene regulation despite lack of sequence conservation of the enhancers. Developmental system drift in ascidians is thus higher for gene regulation than for gene expression and is impacted not only by phylogenetic distance, but also in a clade-specific manner and unevenly within a network. Finally, considering that Molgula is divergent in our analyses, this suggests deep conservation of developmental mechanisms in ascidians after 390 My of separate evolution.
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Affiliation(s)
- Joshua F Coulcher
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Agnès Roure
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Rafath Chowdhury
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Méryl Robert
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Laury Lescat
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Aurélie Bouin
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Juliana Carvajal Cadavid
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
| | - Hiroki Nishida
- Department of Biological Sciences, Graduate School of Science, Osaka UniversityToyonakaJapan
| | - Sébastien Darras
- Sorbonne Université, CNRS, Biologie Intégrative des Organismes Marins (BIOM)Banyuls-sur-MerFrance
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20
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Cellular identity and Ca 2+ signaling activity of the non-reproductive GnRH system in the Ciona intestinalis type A (Ciona robusta) larva. Sci Rep 2020; 10:18590. [PMID: 33122709 PMCID: PMC7596717 DOI: 10.1038/s41598-020-75344-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 10/12/2020] [Indexed: 12/14/2022] Open
Abstract
Tunicate larvae have a non-reproductive gonadotropin-releasing hormone (GnRH) system with multiple ligands and receptor heterodimerization enabling complex regulation. In Ciona intestinalis type A larvae, one of the gnrh genes, gnrh2, is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord, respectively, of vertebrates. The gnrh2 gene is also expressed in the proto-placodal sensory neurons, which are the proposed homologue of vertebrate olfactory neurons. Tunicate larvae occupy a non-reproductive dispersal stage, yet the role of their GnRH system remains elusive. In this study, we investigated neuronal types of gnrh2-expressing cells in Ciona larvae and visualized the activity of these cells by fluorescence imaging using a calcium sensor protein. Some cholinergic neurons and dopaminergic cells express gnrh2, suggesting that GnRH plays a role in controlling swimming behavior. However, none of the gnrh2-expressing cells overlap with glycinergic or GABAergic neurons. A role in motor control is also suggested by a relationship between the activity of gnrh2-expressing cells and tail movements. Interestingly, gnrh2-positive ependymal cells in the nerve cord, known as a kind of glia cells, actively produced Ca2+ transients, suggesting that active intercellular signaling occurs in the glia cells of the nerve cord.
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21
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Yamaji S, Hozumi A, Matsunobu S, Sasakura Y. Orchestration of the distinct morphogenetic movements in different tissues drives tail regression during ascidian metamorphosis. Dev Biol 2020; 465:66-78. [PMID: 32697971 DOI: 10.1016/j.ydbio.2020.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/10/2020] [Accepted: 07/11/2020] [Indexed: 11/26/2022]
Abstract
Metamorphosis is the dramatic conversion of an animal body from larva to adult. In ascidians, tadpole-shaped, swimming larvae become sessile juveniles by losing their tail during metamorphosis. This study investigated the cellular and molecular mechanisms underlying this metamorphic event called tail regression, in the model ascidian Ciona. The ascidian tail consists of internal organs such as muscle, notochord, nerve cord, and the outer epidermal layer surrounding them. We found that the epidermis and internal organs show different regression strategies. Epidermal cells are shortened along the anterior-posterior axis and gather at the posterior region. The epidermal mass is then invaginated into the trunk by apical constriction. The internal tissues, by contrast, enter into the trunk by forming coils. During coiling, notches are introduced into the muscle cells, which likely reduces their rigidness to promote coiling. Actin filament is the major component necessary for the regression events in both the epidermis and internal tissues. The shortening and invagination of the epidermis depend on the phosphorylation of the myosin regulatory light chain (mrlc) regulated by rho-kinase (ROCK). The coiling of internal tissues does not require ROCK-dependent phosphorylation of mrlc, and they can complete coiling without epidermis, although epidermis can facilitate the coiling of internal tissues. We conclude that tail regression in ascidians consists of active morphogenetic movements in which each tissue's independent mechanism is orchestrated with the others to complete this event within the available time window.
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Affiliation(s)
- Sota Yamaji
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, 415-0025, Japan
| | - Akiko Hozumi
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, 415-0025, Japan
| | - Shohei Matsunobu
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, 415-0025, Japan
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, 415-0025, Japan.
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22
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Mercurio S, Cauteruccio S, Manenti R, Candiani S, Scarì G, Licandro E, Pennati R. Exploring miR-9 Involvement in Ciona intestinalis Neural Development Using Peptide Nucleic Acids. Int J Mol Sci 2020; 21:ijms21062001. [PMID: 32183450 PMCID: PMC7139483 DOI: 10.3390/ijms21062001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/12/2020] [Accepted: 03/13/2020] [Indexed: 12/16/2022] Open
Abstract
The microRNAs are small RNAs that regulate gene expression at the post-transcriptional level and can be involved in the onset of neurodegenerative diseases and cancer. They are emerging as possible targets for antisense-based therapy, even though the in vivo stability of miRNA analogues is still questioned. We tested the ability of peptide nucleic acids, a novel class of nucleic acid mimics, to downregulate miR-9 in vivo in an invertebrate model organism, the ascidian Ciona intestinalis, by microinjection of antisense molecules in the eggs. It is known that miR-9 is a well-conserved microRNA in bilaterians and we found that it is expressed in epidermal sensory neurons of the tail in the larva of C. intestinalis. Larvae developed from injected eggs showed a reduced differentiation of tail neurons, confirming the possibility to use peptide nucleic acid PNA to downregulate miRNA in a whole organism. By identifying putative targets of miR-9, we discuss the role of this miRNA in the development of the peripheral nervous system of ascidians.
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Affiliation(s)
- Silvia Mercurio
- Department of Environmental Science and Policy, Università degli Studi di Milano, 20133 Milano, Italy; (S.M.); (R.M.); (R.P.)
| | - Silvia Cauteruccio
- Department of Chemistry, Università degli Studi di Milano, 20133 Milano, Italy;
- Correspondence: (S.C.); (S.C.); Tel.: +39-0250314147 (S.C.); +39-0103538051 (S.C.)
| | - Raoul Manenti
- Department of Environmental Science and Policy, Università degli Studi di Milano, 20133 Milano, Italy; (S.M.); (R.M.); (R.P.)
| | - Simona Candiani
- Department of Earth Science, Environment and Life, Università degli Studi di Genova, 16132 Genova, Italy
- Correspondence: (S.C.); (S.C.); Tel.: +39-0250314147 (S.C.); +39-0103538051 (S.C.)
| | - Giorgio Scarì
- Department of Biosciences, Università degli Studi di Milano, 20133 Milano, Italy;
| | - Emanuela Licandro
- Department of Chemistry, Università degli Studi di Milano, 20133 Milano, Italy;
| | - Roberta Pennati
- Department of Environmental Science and Policy, Università degli Studi di Milano, 20133 Milano, Italy; (S.M.); (R.M.); (R.P.)
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Bostwick M, Smith EL, Borba C, Newman-Smith E, Guleria I, Kourakis MJ, Smith WC. Antagonistic Inhibitory Circuits Integrate Visual and Gravitactic Behaviors. Curr Biol 2020; 30:600-609.e2. [PMID: 32008899 PMCID: PMC7066595 DOI: 10.1016/j.cub.2019.12.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/03/2019] [Accepted: 12/05/2019] [Indexed: 01/01/2023]
Abstract
Larvae of the tunicate Ciona intestinalis possess a central nervous system of 177 neurons. This simplicity has facilitated the generation of a complete synaptic connectome. As chordates and the closest relatives of vertebrates, tunicates promise insight into the organization and evolution of vertebrate nervous systems. Ciona larvae have several sensory systems, including the ocellus and otolith, which are sensitive to light and gravity, respectively. Here, we describe circuitry by which these two are integrated into a complex behavior: the rapid reorientation of the body followed by upward swimming in response to dimming. Significantly, the gravity response causes an orienting behavior consisting of curved swims in downward-facing larvae but only when triggered by dimming. In contrast, the majority of larvae facing upward do not respond to dimming with orientation swims-but instead swim directly upward. Under constant light conditions, the gravity circuit appears to be inoperable, and both upward and downward swims were observed. Using connectomic and neurotransmitter data, we propose a circuit model that can account for these behaviors. The otolith consists of a statocyst cell and projecting excitatory sensory neurons (antenna cells). Postsynaptic to the antenna cells are a group of inhibitory primary interneurons, the antenna relay neurons (antRNs), which then project asymmetrically to the right and left motor units, thereby mediating curved orientation swims. Also projecting to the antRNs are inhibitory photoreceptor relay interneurons. These interneurons appear to antagonize the otolith circuit until they themselves are inhibited by photoreceptors in response to dimming, thus providing a triggering circuit.
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Affiliation(s)
- Michaela Bostwick
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Eleanor L Smith
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616, USA
| | - Cezar Borba
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Erin Newman-Smith
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Iraa Guleria
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Matthew J Kourakis
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - William C Smith
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA; Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
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24
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Bezares-Calderón LA, Berger J, Jékely G. Diversity of cilia-based mechanosensory systems and their functions in marine animal behaviour. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190376. [PMID: 31884914 PMCID: PMC7017336 DOI: 10.1098/rstb.2019.0376] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2019] [Indexed: 12/12/2022] Open
Abstract
Sensory cells that detect mechanical forces usually have one or more specialized cilia. These mechanosensory cells underlie hearing, proprioception or gravity sensation. To date, it is unclear how cilia contribute to detecting mechanical forces and what is the relationship between mechanosensory ciliated cells in different animal groups and sensory systems. Here, we review examples of ciliated sensory cells with a focus on marine invertebrate animals. We discuss how various ciliated cells mediate mechanosensory responses during feeding, tactic responses or predator-prey interactions. We also highlight some of these systems as interesting and accessible models for future in-depth behavioural, functional and molecular studies. We envisage that embracing a broader diversity of organisms could lead to a more complete view of cilia-based mechanosensation. This article is part of the Theo Murphy meeting issue 'Unity and diversity of cilia in locomotion and transport'.
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Affiliation(s)
| | - Jürgen Berger
- Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Gáspár Jékely
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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25
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Gibboney S, Orvis J, Kim K, Johnson CJ, Martinez-Feduchi P, Lowe EK, Sharma S, Stolfi A. Effector gene expression underlying neuron subtype-specific traits in the Motor Ganglion of Ciona. Dev Biol 2020; 458:52-63. [PMID: 31639337 PMCID: PMC6987015 DOI: 10.1016/j.ydbio.2019.10.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/11/2019] [Accepted: 10/16/2019] [Indexed: 12/31/2022]
Abstract
The central nervous system of the Ciona larva contains only 177 neurons. The precise regulation of neuron subtype-specific morphogenesis and differentiation observed during the formation of this minimal connectome offers a unique opportunity to dissect gene regulatory networks underlying chordate neurodevelopment. Here we compare the transcriptomes of two very distinct neuron types in the hindbrain/spinal cord homolog of Ciona, the Motor Ganglion (MG): the Descending decussating neuron (ddN, proposed homolog of Mauthner Cells in vertebrates) and the MG Interneuron 2 (MGIN2). Both types are invariantly represented by a single bilaterally symmetric left/right pair of cells in every larva. Supernumerary ddNs and MGIN2s were generated in synchronized embryos and isolated by fluorescence-activated cell sorting for transcriptome profiling. Differential gene expression analysis revealed ddN- and MGIN2-specific enrichment of a wide range of genes, including many encoding potential "effectors" of subtype-specific morphological and functional traits. More specifically, we identified the upregulation of centrosome-associated, microtubule-stabilizing/bundling proteins and extracellular guidance cues part of a single intrinsic regulatory program that might underlie the unique polarization of the ddNs, the only descending MG neurons that cross the midline. Consistent with our predictions, CRISPR/Cas9-mediated, tissue-specific elimination of two such candidate effectors, Efcab6-related and Netrin1, impaired ddN polarized axon outgrowth across the midline.
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Affiliation(s)
- Susanne Gibboney
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Jameson Orvis
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Kwantae Kim
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Christopher J Johnson
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | | | - Elijah K Lowe
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Sarthak Sharma
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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26
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Serrano-Saiz E, Vogt MC, Levy S, Wang Y, Kaczmarczyk KK, Mei X, Bai G, Singson A, Grant BD, Hobert O. SLC17A6/7/8 Vesicular Glutamate Transporter Homologs in Nematodes. Genetics 2020; 214:163-178. [PMID: 31776169 PMCID: PMC6944403 DOI: 10.1534/genetics.119.302855] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 11/24/2019] [Indexed: 01/04/2023] Open
Abstract
Members of the superfamily of solute carrier (SLC) transmembrane proteins transport diverse substrates across distinct cellular membranes. Three SLC protein families transport distinct neurotransmitters into synaptic vesicles to enable synaptic transmission in the nervous system. Among them is the SLC17A6/7/8 family of vesicular glutamate transporters, which endows specific neuronal cell types with the ability to use glutamate as a neurotransmitter. The genome of the nematode Caenorhabditis elegans encodes three SLC17A6/7/8 family members, one of which, eat-4/VGLUT, has been shown to be involved in glutamatergic neurotransmission. Here, we describe our analysis of the two remaining, previously uncharacterized SLC17A6/7/8 family members, vglu-2 and vglu-3 These two genes directly neighbor one another and are the result of a recent gene duplication event in C. elegans, but not in other Caenorhabditis species. Compared to EAT-4, the VGLU-2 and VGLU-3 protein sequences display a more distant similarity to canonical, vertebrate VGLUT proteins. We tagged both genomic loci with gfp and detected no expression of vglu-3 at any stage of development in any cell type of both C. elegans sexes. In contrast, vglu-2::gfp is dynamically expressed in a restricted set of distinct cell types. Within the nervous system, vglu-2::gfp is exclusively expressed in a single interneuron class, AIA, where it localizes to vesicular structures in the soma, but not along the axon, suggesting that VGLU-2 may not be involved in synaptic transport of glutamate. Nevertheless, vglu-2 mutants are partly defective in the function of the AIA neuron in olfactory behavior. Outside the nervous system, VGLU-2 is expressed in collagen secreting skin cells where VGLU-2 most prominently localizes to early endosomes, and to a lesser degree to apical clathrin-coated pits, the trans-Golgi network, and late endosomes. On early endosomes, VGLU-2 colocalizes most strongly with the recycling promoting factor SNX-1, a retromer component. Loss of vglu-2 affects the permeability of the collagen-containing cuticle of the worm, and based on the function of a vertebrate VGLUT1 protein in osteoclasts, we speculate that vglu-2 may have a role in collagen trafficking in the skin. We conclude that C. elegans SLC17A6/7/8 family members have diverse functions within and outside the nervous system.
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Affiliation(s)
- Esther Serrano-Saiz
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, New York 10027
- Centro de Biologia Molecular Severo Ochoa/Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Merly C Vogt
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, New York 10027
| | - Sagi Levy
- Rockefeller University, New York, New York 10065
| | - Yu Wang
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08854
| | - Karolina K Kaczmarczyk
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, New York 10027
| | - Xue Mei
- Waksman Institute, Rutgers University, Piscataway, New Jersey 08854
| | - Ge Bai
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08854
| | - Andrew Singson
- Waksman Institute, Rutgers University, Piscataway, New Jersey 08854
- Department of Genetics, Rutgers University, Piscataway, New Jersey 08854
| | - Barth D Grant
- Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, New Jersey 08854
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, New York 10027
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27
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Ryan K, Meinertzhagen IA. Neuronal identity: the neuron types of a simple chordate sibling, the tadpole larva of Ciona intestinalis. Curr Opin Neurobiol 2019; 56:47-60. [PMID: 30530111 PMCID: PMC6551260 DOI: 10.1016/j.conb.2018.10.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 10/30/2018] [Indexed: 11/19/2022]
Abstract
Neurons of the sparsely populated nervous system of the tadpole larva in the tunicate Ciona intestinalis, a chordate sibling, are known from sporadic previous studies but especially two recent reports that document the connectome of both the central and peripheral nervous systems at EM level. About 330 CNS cells comprise mostly ciliated ependymal cells, with ∼180 neurons that constitute about 50 morphologically distinguishable types. The neurons reveal various chordate characters amid many features that are idiosyncratic. Most neurons are ciliated and lack dendrites, some even lack an axon. Synapses mostly form en passant between axons, and resemble those in basal invertebrates; some are dyads and all have heterogenous synaptic vesicle populations. Each neuron has on average 49 synapses with other cells; these constitute a synaptic network of unpredicted complexity.
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Affiliation(s)
- Kerrianne Ryan
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
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28
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Kourakis MJ, Borba C, Zhang A, Newman-Smith E, Salas P, Manjunath B, Smith WC. Parallel visual circuitry in a basal chordate. eLife 2019; 8:44753. [PMID: 30998184 PMCID: PMC6499539 DOI: 10.7554/elife.44753] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 04/11/2019] [Indexed: 12/28/2022] Open
Abstract
A common CNS architecture is observed in all chordates, from vertebrates to basal chordates like the ascidian Ciona. Ciona stands apart among chordates in having a complete larval connectome. Starting with visuomotor circuits predicted by the Ciona connectome, we used expression maps of neurotransmitter use with behavioral assays to identify two parallel visuomotor circuits that are responsive to different components of visual stimuli. The first circuit is characterized by glutamatergic photoreceptors and responds to the direction of light. These photoreceptors project to cholinergic motor neurons, via two tiers of cholinergic interneurons. The second circuit responds to changes in ambient light and mediates an escape response. This circuit uses GABAergic photoreceptors which project to GABAergic interneurons, and then to cholinergic interneurons. Our observations on the behavior of larvae either treated with a GABA receptor antagonist or carrying a mutation that eliminates photoreceptors indicate the second circuit is disinhibitory.
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Affiliation(s)
- Matthew J Kourakis
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, United States
| | - Cezar Borba
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
| | - Angela Zhang
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Erin Newman-Smith
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, United States.,Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
| | - Priscilla Salas
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
| | - B Manjunath
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, United States
| | - William C Smith
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, United States.,Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
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29
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Sharma S, Wang W, Stolfi A. Single-cell transcriptome profiling of the Ciona larval brain. Dev Biol 2019; 448:226-236. [PMID: 30392840 PMCID: PMC6487232 DOI: 10.1016/j.ydbio.2018.09.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/10/2018] [Accepted: 09/10/2018] [Indexed: 11/27/2022]
Abstract
The tadpole-type larva of Ciona has emerged as an intriguing model system for the study of neurodevelopment. The Ciona intestinalis connectome has been recently mapped, revealing the smallest central nervous system (CNS) known in any chordate, with only 177 neurons. This minimal CNS is highly reminiscent of larger CNS of vertebrates, sharing many conserved developmental processes, anatomical compartments, neuron subtypes, and even specific neural circuits. Thus, the Ciona tadpole offers a unique opportunity to understand the development and wiring of a chordate CNS at single-cell resolution. Here we report the use of single-cell RNAseq to profile the transcriptomes of single cells isolated by fluorescence-activated cell sorting (FACS) from the whole brain of Ciona robusta (formerly intestinalis Type A) larvae. We have also compared these profiles to bulk RNAseq data from specific subsets of brain cells isolated by FACS using cell type-specific reporter plasmid expression. Taken together, these datasets have begun to reveal the compartment- and cell-specific gene expression patterns that define the organization of the Ciona larval brain.
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Affiliation(s)
- Sarthak Sharma
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, United States
| | - Wei Wang
- New York University, Department of Biology, New York, NY, United States
| | - Alberto Stolfi
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, United States.
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30
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Zeng F, Wunderer J, Salvenmoser W, Hess MW, Ladurner P, Rothbächer U. Papillae revisited and the nature of the adhesive secreting collocytes. Dev Biol 2019; 448:183-198. [DOI: 10.1016/j.ydbio.2018.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 11/17/2018] [Accepted: 11/20/2018] [Indexed: 11/26/2022]
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31
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Shared evolutionary origin of vertebrate neural crest and cranial placodes. Nature 2018; 560:228-232. [PMID: 30069052 PMCID: PMC6390964 DOI: 10.1038/s41586-018-0385-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 06/13/2018] [Indexed: 12/21/2022]
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32
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Hirai S, Hotta K, Okado H. Developmental Roles and Evolutionary Significance of AMPA-Type Glutamate Receptors. Bioessays 2018; 40:e1800028. [PMID: 30058076 DOI: 10.1002/bies.201800028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 07/02/2018] [Indexed: 11/07/2022]
Abstract
Organogenesis and metamorphosis require the intricate orchestration of multiple types of cellular interactions and signaling pathways. Glutamate (Glu) is an excitatory extracellular signaling molecule in the nervous system, while Ca2+ is a major intracellular signaling molecule. The first Glu receptors to be cloned are Ca2+ -permeable receptors in mammalian brains. Although recent studies have focused on Glu signaling in synaptic mechanisms of the mammalian central nervous system, it is unclear how this signaling functions in development. Our recent article demonstrated that Ca2+ -permeable AMPA-type Glu receptors (GluAs) are essential for formation of a photosensitive organ, development of some neurons, and metamorphosis, including tail absorption and body axis rotation, in ascidian embryos. Based on findings in these embryos and mammalian brains, we formed several hypotheses regarding the evolution of GluAs, the non-synaptic function of Glu, the origin of GluA-positive neurons, and the neuronal network that controls metamorphosis in ascidians.
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Affiliation(s)
- Shinobu Hirai
- Department of Brain Development and Neural Regeneration, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-0057, Japan
| | - Kohji Hotta
- Faculty of Science and Technology, Department of Biosciences and Informatics, Keio University, Kohoku, Yokohama, 223-8522, Japan
| | - Haruo Okado
- Department of Brain Development and Neural Regeneration, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo 156-0057, Japan
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33
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Sasakura Y. Cellulose production and the evolution of the sessile lifestyle in ascidians. ACTA ACUST UNITED AC 2018. [DOI: 10.4282/sosj.35.21] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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34
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Salas P, Vinaithirthan V, Newman-Smith E, Kourakis MJ, Smith WC. Photoreceptor specialization and the visuomotor repertoire of the primitive chordate Ciona. J Exp Biol 2018; 221:jeb177972. [PMID: 29511068 PMCID: PMC5963834 DOI: 10.1242/jeb.177972] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 02/22/2018] [Indexed: 01/06/2023]
Abstract
The swimming tadpole larva of Ciona has one of the simplest central nervous systems (CNSs) known, with only 177 neurons. Despite its simplicity, the Ciona CNS has a common structure with the CNS of its close chordate relatives, the vertebrates. The recent completion of a larval Ciona CNS connectome creates enormous potential for detailed understanding of chordate CNS function, yet our understanding of Ciona larval behavior is incomplete. We show here that Ciona larvae have a surprisingly rich and dynamic set of visual responses, including a looming-object escape behavior characterized by erratic circular swims, as well as negative phototaxis characterized by sustained directional swims. Making use of mutant lines, we show that these two behaviors are mediated by distinct groups of photoreceptors. The Ciona connectome predicts that these two behavioral responses should act through distinct, but overlapping, visuomotor pathways, and that the escape behavior is likely to be integrated into a broader startle behavior.
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Affiliation(s)
- Priscilla Salas
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Vall Vinaithirthan
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Erin Newman-Smith
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Matthew J Kourakis
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - William C Smith
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
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35
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Rigon F, Gasparini F, Shimeld SM, Candiani S, Manni L. Developmental signature, synaptic connectivity and neurotransmission are conserved between vertebrate hair cells and tunicate coronal cells. J Comp Neurol 2018; 526:957-971. [PMID: 29277977 DOI: 10.1002/cne.24382] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 12/15/2017] [Accepted: 12/18/2017] [Indexed: 11/08/2022]
Abstract
In tunicates, the coronal organ represents a sentinel checking particle entrance into the pharynx. The organ differentiates from an anterior embryonic area considered a proto-placode. For their embryonic origin, morphological features and function, coronal sensory cells have been hypothesized to be homologues to vertebrate hair cells. However, vertebrate hair cells derive from a posterior placode. This contradicts one of the principle historical criteria for homology, similarity of position, which could be taken as evidence against coronal cells/hair cells homology. In the tunicates Ciona intestinalis and C. robusta, we found that the coronal organ expresses genes (Atoh, Notch, Delta-like, Hairy-b, and Musashi) characterizing vertebrate neural and hair cell development. Moreover, coronal cells exhibit a complex synaptic connectivity pattern, and express neurotransmitters (Glu, ACh, GABA, 5-HT, and catecholamines), or enzymes for their synthetic machinery, involved in hair cell activity. Lastly, coronal cells express the Trpa gene, which encodes an ion channel expressed in hair cells. These data lead us to hypothesize a model in which competence to make secondary mechanoreceptors was initially broadly distributed through placode territories, but has become confined to different placodes during the evolution of the vertebrate and tunicate lineages.
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Affiliation(s)
- Francesca Rigon
- Dipartimento di Biologia, Università di Padova, Padova, Italy
| | - Fabio Gasparini
- Dipartimento di Biologia, Università di Padova, Padova, Italy
| | | | - Simona Candiani
- Dipartimento di Scienze della Terra dell'Ambiente e della Vita, Università di Genova, Genova, Italy
| | - Lucia Manni
- Dipartimento di Biologia, Università di Padova, Padova, Italy
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36
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Shimai K, Kusakabe TG. The Use of cis-Regulatory DNAs as Molecular Tools. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018. [DOI: 10.1007/978-981-10-7545-2_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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37
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Nishino A. Morphology and Physiology of the Ascidian Nervous Systems and the Effectors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018. [PMID: 29542090 DOI: 10.1007/978-981-10-7545-2_16] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurobiology in ascidians has made many advances. Ascidians have offered natural advantages to researchers, including fecundity, structural simplicity, invariant morphology, and fast and stereotyped developmental processes. The researchers have also accumulated on this animal a great deal of knowledge, genomic resources, and modern genetic techniques. A recent connectomic analysis has shown an ultimately resolved image of the larval nervous system, whereas recent applications of live imaging and optogenetics have clarified the functional organization of the juvenile nervous system. Progress in resources and techniques have provided convincing ways to deepen what we have wanted to know about the nervous systems of ascidians. Here, the research history and the current views regarding ascidian nervous systems are summarized.
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Affiliation(s)
- Atsuo Nishino
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Aomori, Japan.
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38
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Ryan K, Lu Z, Meinertzhagen IA. The peripheral nervous system of the ascidian tadpole larva: Types of neurons and their synaptic networks. J Comp Neurol 2017; 526:583-608. [PMID: 29124768 DOI: 10.1002/cne.24353] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 01/01/2023]
Abstract
Physical and chemical cues from the environment are used to direct animal behavior through a complex network of connections originating in exteroceptors. In chordates, mechanosensory and chemosensory neurons of the peripheral nervous system (PNS) must signal to the motor circuits of the central nervous system (CNS) through a series of pathways that integrate and regulate the output to motor neurons (MN); ultimately these drive contraction of the tail and limb muscles. We used serial-section electron microscopy to reconstruct PNS neurons and their hitherto unknown synaptic networks in the tadpole larva of a sibling chordate, the ascidian, Ciona intestinalis. The larva has groups of neurons in its apical papillae, epidermal neurons in the rostral and apical trunk, caudal neurons in the dorsal and ventral epidermis, and a single tail tip neuron. The connectome reveals that the PNS input arises from scattered groups of these epidermal neurons, 54 in total, and has three main centers of integration in the CNS: in the anterior brain vesicle (which additionally receives input from photoreceptors of the ocellus), the motor ganglion (which contains five pairs of MN), and the tail, all of which in turn are themselves interconnected through important functional relay neurons. Some neurons have long collaterals that form autapses. Our study reveals interconnections with other sensory systems, and the exact inputs to the motor system required to regulate contractions in the tail that underlie larval swimming, or to the CNS to regulate substrate preference prior to the induction of larval settlement and metamorphosis.
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Affiliation(s)
- Kerrianne Ryan
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Zhiyuan Lu
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada
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Sasakura Y, Hozumi A. Formation of adult organs through metamorphosis in ascidians. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2017; 7. [PMID: 29105358 DOI: 10.1002/wdev.304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/28/2017] [Accepted: 09/11/2017] [Indexed: 02/05/2023]
Abstract
The representative characteristic of ascidians is their vertebrate-like, tadpole shape at the larval stage. Ascidians lose the tadpole shape through metamorphosis to become adults with a nonmotile, sessile body and a shape generally considered distinct from that of vertebrates. Solitary ascidians including Ciona species are extensively studied to understand the developmental mechanisms of ascidians, and to compare these mechanisms with their counterparts in vertebrates. In these ascidian species, the digestive and circulatory systems are not well developed in the larval trunk and the larvae do not take food. This is in contrast with the inner conditions of vertebrate tadpoles, which have functional organs comparable to those of adults. The adult organs and tissues of these ascidians become functional during metamorphosis that is completed quickly, suggesting that the ascidian larvae of solitary species are a transient stage of development. We here discuss how the cells and tissues in the ascidian larval body are converted into those of adults. The hearts of ascidians and vertebrates use closely related cellular and molecular mechanisms that suggest their shared origin. Hox genes of ascidians are essential for forming adult endodermal structures. To fully understand the development and evolution of chordates, a complete elucidation of the mechanisms underlying the adult tissue/organ formation of ascidians will be needed. WIREs Dev Biol 2018, 7:e304. doi: 10.1002/wdev.304 This article is categorized under: Comparative Development and Evolution > Body Plan Evolution Early Embryonic Development > Development to the Basic Body Plan.
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Affiliation(s)
- Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Akiko Hozumi
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
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Ryan K, Lu Z, Meinertzhagen IA. Circuit Homology between Decussating Pathways in the Ciona Larval CNS and the Vertebrate Startle-Response Pathway. Curr Biol 2017; 27:721-728. [PMID: 28216318 DOI: 10.1016/j.cub.2017.01.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 12/22/2016] [Accepted: 01/13/2017] [Indexed: 10/20/2022]
Abstract
Comparing synaptic circuits and networks between brains of different animal groups helps us derive an understanding of how nervous systems might have evolved. The circuits of the startle response pathway in the brains of tailed vertebrates are known from electrophysiological studies on the giant reticulospinal Mauthner cells (M-cells). To identify morphological counterparts in chordate tunicates, a sister group of vertebrates [1, 2], we have compiled a densely reconstructed connectome (defined in [3]) for the CNS in the tadpole larva of Ciona intestinalis (L.), using ssEM [4]. The dorsal, tubular CNS of the ∼1-mm tadpole larva is built on a similar plan to vertebrates, its neurons distributed rostrocaudally in three centers, a brain vesicle, motor ganglion, and caudal nerve cord [5]. A single pair of descending decussating neurons, ddNs, found in the motor ganglion, have similarities to reticulospinal neurons descending from the vertebrate hindbrain to the spinal cord. The pre- and postsynaptic connections and circuits of these ddNs support their homology with decussating vertebrate M-cells. Network analysis reveals that, like M-cells, ddNs receive mechanosensory input from the peripheral nervous system and provide input to motoneurons, premotor interneurons, and ascending commissural inhibitory neurons (ACINs). These circuits uncover a putative homologous startle network in the Ciona tadpole. However, differences in circuits, including a lack of bilateral symmetry in their network, and convergence of inputs from left and right sides, raise questions about the relationship between form and function, and are a possible outcome of the tiny number of neurons in ascidian larvae.
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Affiliation(s)
- Kerrianne Ryan
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, NS B3H 4R2, Canada.
| | - Zhiyuan Lu
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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Kusakabe TG. Identifying Vertebrate Brain Prototypes in Deuterostomes. DIVERSITY AND COMMONALITY IN ANIMALS 2017. [DOI: 10.1007/978-4-431-56469-0_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Hagimoto K, Takami S, Murakami F, Tanabe Y. Distinct migratory behaviors of striosome and matrix cells underlying the mosaic formation in the developing striatum. J Comp Neurol 2016; 525:794-817. [PMID: 27532901 DOI: 10.1002/cne.24096] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 08/07/2016] [Accepted: 08/08/2016] [Indexed: 01/19/2023]
Abstract
The striatum, the largest nucleus of the basal ganglia controlling motor and cognitive functions, can be characterized by a labyrinthine mosaic organization of striosome/matrix compartments. It is unclear how striosome/matrix mosaic formation is spatially and temporally controlled at the cellular level during striatal development. Here, by combining in vivo electroporation and brain slice cultures, we set up a prospective experimental system in which we differentially labeled striosome and matrix cells from the time of birth and followed their distributions and migratory behaviors. Our results showed that, at an initial stage of striosome/matrix mosaic formation, striosome cells were mostly stationary, whereas matrix cells actively migrated in multiple directions regardless of the presence of striosome cells. The mostly stationary striosome cells were still able to associate to form patchy clusters via attractive interactions. Our results suggest that the restricted migratory capability of striosome cells may allow them to cluster together only when they happen to be located in close proximity to each other and are not separated by actively migrating matrix cells. The way in which the mutidirectionally migrating matrix cells intermingle with the mostly stationary striosome cells may therefore determine the topographic features of striosomes. At later stages, the actively migrating matrix cells began to repulse the patchy clusters of striosomes, presumably enhancing the striosome cluster formation and the segregation and eventual formation of dichotomous homogeneous striosome/matrix compartments. Overall, our study reveals temporally distinct migratory behaviors of striosome/matrix cells, which may underlie the sequential steps of mosaic formation in the developing striatum. J. Comp. Neurol. 525:794-817, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Kazuya Hagimoto
- Department of Developmental Neuroscience, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Saki Takami
- Department of Developmental Neuroscience, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Fujio Murakami
- Department of Developmental Neuroscience, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yasuto Tanabe
- Department of Developmental Neuroscience, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, 565-0871, Japan
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The central nervous system of ascidian larvae. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:538-61. [DOI: 10.1002/wdev.239] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/05/2016] [Accepted: 04/09/2016] [Indexed: 11/07/2022]
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Stolfi A, Ryan K, Meinertzhagen IA, Christiaen L. Migratory neuronal progenitors arise from the neural plate borders in tunicates. Nature 2015; 527:371-4. [PMID: 26524532 PMCID: PMC4654654 DOI: 10.1038/nature15758] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 09/30/2015] [Indexed: 12/22/2022]
Abstract
The neural crest is an evolutionary novelty that fostered the emergence of vertebrate anatomical innovations such as the cranium and jaws. During embryonic development, multipotent neural crest cells are specified at the lateral borders of the neural plate before delaminating, migrating and differentiating into various cell types. In invertebrate chordates (cephalochordates and tunicates), neural plate border cells express conserved factors such as Msx, Snail and Pax3/7 and generate melanin-containing pigment cells, a derivative of the neural crest in vertebrates. However, invertebrate neural plate border cells have not been shown to generate homologues of other neural crest derivatives. Thus, proposed models of neural crest evolution postulate vertebrate-specific elaborations on an ancestral neural plate border program, through acquisition of migratory capabilities and the potential to generate several cell types. Here we show that a particular neuronal cell type in the tadpole larva of the tunicate Ciona intestinalis, the bipolar tail neuron, shares a set of features with neural-crest-derived spinal ganglia neurons in vertebrates. Bipolar tail neuron precursors derive from caudal neural plate border cells, delaminate and migrate along the paraxial mesoderm on either side of the neural tube, eventually differentiating into afferent neurons that form synaptic contacts with both epidermal sensory cells and motor neurons. We propose that the neural plate borders of the chordate ancestor already produced migratory peripheral neurons and pigment cells, and that the neural crest evolved through the acquisition of a multipotent progenitor regulatory state upstream of multiple, pre-existing neural plate border cell differentiation programs.
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Affiliation(s)
- Alberto Stolfi
- Center for Developmental Genetics, Department of Biology, New York University, New York, New York 10003, USA
| | - Kerrianne Ryan
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Lionel Christiaen
- Center for Developmental Genetics, Department of Biology, New York University, New York, New York 10003, USA
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Hozumi A, Horie T, Sasakura Y. Neuronal map reveals the highly regionalized pattern of the juvenile central nervous system of the ascidian Ciona intestinalis. Dev Dyn 2015; 244:1375-93. [PMID: 26250096 DOI: 10.1002/dvdy.24317] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/28/2015] [Accepted: 08/02/2015] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The dorsally located central nervous system (CNS) is an important hallmark of chordates. Among chordates, tunicate ascidians change their CNS remarkably by means of a metamorphosis from a highly regionalized larval CNS to an oval-shaped juvenile CNS without prominent morphological features. The neuronal organization of the CNS of ascidian tadpole larvae has been well described, but that in the CNS of postmetamorphosis juveniles has not been characterized well. RESULTS We investigated the number of neural cells, the number and position of differentiated neurons, and their axonal trajectories in the juvenile CNS of the ascidian Ciona intestinalis. The cell bodies of cholinergic, glutamatergic, and GABAergic/glycinergic neurons exhibited different localization patterns along the anterior-posterior axis in the juvenile CNS. Cholinergic neurons extended their axons toward the oral, atrial and body wall muscles and pharyngeal gill to regulate muscle contraction and ciliary movement. CONCLUSIONS Unlike its featureless shape, the juvenile CNS is highly patterned along the anterior-posterior axis. This patterning may be necessary for exerting multiple roles in the regulation of adult tissues distributed throughout the body. This basic information of the juvenile CNS of Ciona will allow in-depth studies of molecular mechanisms underlying the reconstruction of the CNS during ascidian metamorphosis.
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Affiliation(s)
- Akiko Hozumi
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
| | - Takeo Horie
- Japan Science and Technology Agency, PRESTO, Honcho, Kawaguchi, Saitama, Japan
| | - Yasunori Sasakura
- Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka, Japan
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Pennati R, Ficetola GF, Brunetti R, Caicci F, Gasparini F, Griggio F, Sato A, Stach T, Kaul-Strehlow S, Gissi C, Manni L. Morphological Differences between Larvae of the Ciona intestinalis Species Complex: Hints for a Valid Taxonomic Definition of Distinct Species. PLoS One 2015; 10:e0122879. [PMID: 25955391 PMCID: PMC4425531 DOI: 10.1371/journal.pone.0122879] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 02/24/2015] [Indexed: 11/18/2022] Open
Abstract
The cosmopolitan ascidian Ciona intestinalis is the most common model species of Tunicata, the sister-group of Vertebrata, and widely used in developmental biology, genomics and evolutionary studies. Recently, molecular studies suggested the presence of cryptic species hidden within the C. intestinalis species, namely C. intestinalis type A and type B. So far, no substantial morphological differences have been identified between individuals belonging to the two types. Here we present morphometric, immunohistochemical, and histological analyses, as well as 3-D reconstructions, of late larvae obtained by cross-fertilization experiments of molecularly determined type A and type B adults, sampled in different seasons and in four different localities. Our data point to quantitative and qualitative differences in the trunk shape of larvae belonging to the two types. In particular, type B larvae exhibit a longer pre-oral lobe, longer and relatively narrower total body length, and a shorter ocellus-tail distance than type A larvae. All these differences were found to be statistically significant in a Discriminant Analysis. Depending on the number of analyzed parameters, the obtained discriminant function was able to correctly classify > 93% of the larvae, with the remaining misclassified larvae attributable to the existence of intra-type seasonal variability. No larval differences were observed at the level of histology and immunohistochemical localization of peripheral sensory neurons. We conclude that type A and type B are two distinct species that can be distinguished on the basis of larval morphology and molecular data. Since the identified larval differences appear to be valid diagnostic characters, we suggest to raise both types to the rank of species and to assign them distinct names.
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Affiliation(s)
- Roberta Pennati
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Gentile Francesco Ficetola
- Dipartimento di Scienze dell’Ambiente e del Territorio e di Scienze della Terra, Università di Milano Bicocca, Milano, Italy
- Laboratoire d’Ecologie Alpine (LECA), Université Grenoble-Alpes, Grenoble, France
| | | | - Federico Caicci
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
| | - Fabio Gasparini
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
| | - Francesca Griggio
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
| | - Atsuko Sato
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Thomas Stach
- Humboldt-Universität zu Berlin, Institut fur Lebenswissenschaften, Vergleichende Zoologie, Berlin, Germany
| | | | - Carmela Gissi
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy
- * E-mail: (CG); (LM)
| | - Lucia Manni
- Dipartimento di Biologia, Università degli Studi di Padova, Padova, Italy
- * E-mail: (CG); (LM)
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Yokoyama TD, Hotta K, Oka K. Comprehensive morphological analysis of individual peripheral neuron dendritic arbors in ascidian larvae using the photoconvertible protein kaede. Dev Dyn 2014; 243:1362-73. [DOI: 10.1002/dvdy.24169] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 07/23/2014] [Accepted: 07/23/2014] [Indexed: 12/15/2022] Open
Affiliation(s)
- Takatoshi D. Yokoyama
- Department of Bioscience and Informatics; Faculty of Science and Technology; Keio University; Yokohama Japan
| | - Kohji Hotta
- Department of Bioscience and Informatics; Faculty of Science and Technology; Keio University; Yokohama Japan
| | - Kotaro Oka
- Department of Bioscience and Informatics; Faculty of Science and Technology; Keio University; Yokohama Japan
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High-throughput SNP discovery and transcriptome expression profiles from the salmon louse Caligus rogercresseyi (Copepoda: Caligidae). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2014; 10:9-21. [DOI: 10.1016/j.cbd.2014.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/29/2014] [Accepted: 01/31/2014] [Indexed: 01/01/2023]
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Yoshida K, Ueno M, Niwano T, Saiga H. Transcription regulatory mechanism of Pitx in the papilla-forming region in the ascidian, Halocynthia roretzi, implies conserved involvement of Otx as the upstream gene in the adhesive organ development of chordates. Dev Growth Differ 2012; 54:649-59. [PMID: 22889275 DOI: 10.1111/j.1440-169x.2012.01366.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Pitx genes play important roles in a variety of developmental processes in vertebrates. In an ascidian species, Halocynthia roretzi, Hr-Pitx, the only Pitx gene of this species, has been reported to be expressed in the left epidermis at the tailbud stage. In the present study, first, we have shown that Hr-Pitx is also expressed in the papilla-forming region at the neurula to tailbud stages, and then we addressed transcription regulatory mechanisms for the expression of Hr-Pitx in the papilla-forming region. We have identified the genomic region ranging from 850 to 1211 bp upstream from the translation start site of the Hr-Pitx gene as an enhancer region that drives the transcription of Hr-Pitx in the papilla-forming region. Within the enhancer region, putative transcriptional factor binding sites for Otx as well as Fox were shown to be required for its activity. Finally, we carried out knocking down experiments of Hr-Otx function using an antisense morpholino oligonucleotide, in which the knocking down of Hr-Otx function resulted in reduction of the enhancer activity and loss of the expression of Hr-Pitx in the papilla-forming region. In Xenopus laevis, it has been reported that Pitx genes are expressed downstream of Otx function during development of the cement gland, an adhesive organ of its larva. Taken together, it is suggested that the expression regulatory mechanism of Pitx, involving Otx as the upstream gene, in the developing adhesive organ is conserved between ascidians and vertebrates.
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Affiliation(s)
- Keita Yoshida
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minamiohsawa, Hachiohji, Tokyo, 192-0397, Japan
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Pasini A, Manenti R, Rothbächer U, Lemaire P. Antagonizing retinoic acid and FGF/MAPK pathways control posterior body patterning in the invertebrate chordate Ciona intestinalis. PLoS One 2012; 7:e46193. [PMID: 23049976 PMCID: PMC3458022 DOI: 10.1371/journal.pone.0046193] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 08/28/2012] [Indexed: 11/18/2022] Open
Abstract
Vertebrate embryos exploit the mutual inhibition between the RA and FGF signalling pathways to coordinate the proliferative elongation of the main body axis with the progressive patterning and differentiation of its neuroectodermal and paraxial mesodermal structures. The evolutionary history of this patterning system is still poorly understood. Here, we investigate the role played by the RA and FGF/MAPK signals during the development of the tail structures in the tunicate Ciona intestinalis, an invertebrate chordate belonging to the sister clade of vertebrates, in which the prototypical chordate body plan is established through very derived morphogenetic processes. Ciona embryos are constituted of few cells and develop according to a fixed lineage; elongation of the tail occurs largely by rearrangement of postmitotic cells; mesoderm segmentation and somitogenesis are absent. We show that in the Ciona embryo, the antagonism of the RA and FGF/MAPK signals is required to control the anteroposterior patterning of the tail epidermis. We also demonstrate that the RA, FGF/MAPK and canonical Wnt pathways control the anteroposterior patterning of the tail peripheral nervous system, and reveal the existence of distinct subpopulations of caudal epidermal neurons with different responsiveness to the RA, FGF/MAPK and canonical Wnt signals. Our data provide the first demonstration that the use of the antagonism between the RA and FGF signals to pattern the main body axis predates the emergence of vertebrates and highlight the evolutionary plasticity of this patterning strategy, showing that in different chordates it can be used to pattern different tissues within the same homologous body region.
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Affiliation(s)
- Andrea Pasini
- Institut de Biologie du Développement de Marseille-Luminy (IBDML), UMR7288, CNRS/Université Aix-Marseille, Marseille, France.
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