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Kourakis MJ, Ryan K, Newman-Smith ED, Meinertzhagen IA, Smith WC. Deep homologies in chordate caudal central nervous systems. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.03.597227. [PMID: 38895365 PMCID: PMC11185728 DOI: 10.1101/2024.06.03.597227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Invertebrate chordates, such as the tunicate Ciona, can offer insight into the evolution of the chordate phylum. Anatomical features that are shared between invertebrate chordates and vertebrates may be taken as evidence of their presence in a common chordate ancestor. The central nervous systems of Ciona larvae and vertebrates share a similar anatomy despite the Ciona CNS having ~180 neurons. However, the depth of conservation between the Ciona CNS and those in vertebrates is not resolved. The Ciona caudal CNS, while appearing spinal cord-like, has hitherto been thought to lack motor neurons, bringing into question its homology with the vertebrate spinal cord. We show here that the Ciona larval caudal CNS does, in fact, have functional motor neurons along its length, pointing to the presence of a spinal cord-like structure at the base of the chordates. We extend our analysis of shared CNS anatomy further to explore the Ciona "motor ganglion", which has been proposed to be a homolog of the vertebrate hindbrain, spinal cord, or both. We find that a cluster of neurons in the dorsal motor ganglion shares anatomical location, developmental pathway, neural circuit architecture, and gene expression with the vertebrate cerebellum. However, functionally, the Ciona cluster appears to have more in common with vertebrate cerebellum-like structures, insofar as it receives and processes direct sensory input. These findings are consistent with earlier speculation that the cerebellum evolved from a cerebellum-like structure, and suggest that the latter structure was present in the dorsal hindbrain of a common chordate ancestor.
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Affiliation(s)
- Matthew J Kourakis
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA 93106
| | - Kerrianne Ryan
- Life Sciences Centre, Dalhousie University, Halifax, NS, Canada B3H 1A5
| | - Erin D Newman-Smith
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA 93106
| | | | - William C Smith
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA 93106
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA 93106
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2
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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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3
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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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4
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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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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. 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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6
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Athira A, Dondorp D, Rudolf J, Peytral O, Chatzigeorgiou M. Comprehensive analysis of locomotion dynamics in the protochordate Ciona intestinalis reveals how neuromodulators flexibly shape its behavioral repertoire. PLoS Biol 2022; 20:e3001744. [PMID: 35925898 PMCID: PMC9352054 DOI: 10.1371/journal.pbio.3001744] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/06/2022] [Indexed: 11/19/2022] Open
Abstract
Vertebrate nervous systems can generate a remarkable diversity of behaviors. However, our understanding of how behaviors may have evolved in the chordate lineage is limited by the lack of neuroethological studies leveraging our closest invertebrate relatives. Here, we combine high-throughput video acquisition with pharmacological perturbations of bioamine signaling to systematically reveal the global structure of the motor behavioral repertoire in the Ciona intestinalis larvae. Most of Ciona’s postural variance can be captured by 6 basic shapes, which we term “eigencionas.” Motif analysis of postural time series revealed numerous stereotyped behavioral maneuvers including “startle-like” and “beat-and-glide.” Employing computational modeling of swimming dynamics and spatiotemporal embedding of postural features revealed that behavioral differences are generated at the levels of motor modules and the transitions between, which may in part be modulated by bioamines. Finally, we show that flexible motor module usage gives rise to diverse behaviors in response to different light stimuli. Vertebrate nervous systems can generate a remarkable diversity of behaviors, but how did these evolve in the chordate lineage? A study of the protochordate Ciona intestinalis reveals novel insights into how a simple chordate brain uses neuromodulators to control its behavioral repertoire.
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Affiliation(s)
- Athira Athira
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Daniel Dondorp
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Jerneja Rudolf
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Olivia Peytral
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Marios Chatzigeorgiou
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
- * E-mail:
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7
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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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8
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Ahmed W, Gupta S, Singh D, Singh R. Insight of genetic features prevalent in three Echinoderm species (Apostichopus japonicus, Heliocedaris erythrogramma and Asterias rubens) and their evolutionary association using comparative codon pattern analysis. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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McDonald M, Griffin NP, Howell E, Li D, Harnew-Spradley S, Rodriguez P, Lancaster A, Umutoni F, Besh J, Shelley C. Effects of neurotransmitter receptor antagonists on sea urchin righting behavior and tube foot motility. J Exp Biol 2022; 225:274563. [DOI: 10.1242/jeb.243076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 02/22/2022] [Indexed: 11/20/2022]
Abstract
Sea urchins, as echinoderms, occupy an interesting position in animal phylogeny in that they are genetically closer to vertebrates than the vast majority of all other invertebrates but have a nervous system that lacks a brain or brain-like structure. Despite this, very little is known about neurobiology of the adult sea urchin, and how the nervous system, is utilized to produced behavior. Here we investigate effects on the righting response of antagonists of ionotropic receptors for the neurotransmitters acetylcholine, GABA, and glycine, and antagonists of metabotropic receptors for the amines dopamine and norepinephrine. Antagonists slowed the righting response in a dose-dependent manner, with a rank order of potency of strychnine>haloperidol>propranolol>bicuculline>hexamethonium, with RT50s (concentrations that slowed righting time by 50%) ranging from 4.3 µM for strychnine to 7.8 mM for hexamethonium. It is also shown that both glycine and adrenergic receptors are needed for actual tube foot movement, and this may explain the slowed righting seen when these receptors are inhibited. Conversely, inhibition of dopamine receptors slowed the righting response but had no effect on tube foot motility, indicating that these receptors play roles more in the neural processing involved in the righting behavior, rather than the actual physical righting. Our results identity the first effects of inhibiting the glycinergic, dopaminergic, and adrenergic neurotransmitter systems in adult sea urchins and distinguish between the ability of sea urchins to right themselves, and the ability of sea urchins to move their tube feet.
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Affiliation(s)
- Morgan McDonald
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
| | | | - Emma Howell
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
| | - Dingchen Li
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
| | | | - Patrick Rodriguez
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
| | - Abigail Lancaster
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
| | - Feza Umutoni
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
| | - Jordan Besh
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
| | - Chris Shelley
- Biology Department, The University of the South, Sewanee, TN, 37383, USA
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10
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Matsuo K, Tamura R, Hotta K, Okada M, Takeuchi A, Wu Y, Hashimoto K, Takano H, Momose A, Nishino A. Bilaterally Asymmetric Helical Myofibrils in Ascidian Tadpole Larvae. Front Cell Dev Biol 2021; 9:800455. [PMID: 34950666 PMCID: PMC8688927 DOI: 10.3389/fcell.2021.800455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 11/18/2021] [Indexed: 11/13/2022] Open
Abstract
The locomotor system is highly bilateral at the macroscopic level. Homochirality of biological molecules is fully compatible with the bilateral body. However, whether and how single-handed cells contribute to the bilateral locomotor system is obscure. Here, exploiting the small number of cells in the swimming tadpole larva of the ascidian Ciona, we analyzed morphology of the tail at cellular and subcellular scales. Quantitative phase-contrast X-ray tomographic microscopy revealed a high-density midline structure ventral to the notochord in the tail. Muscle cell nuclei on each side of the notochord were roughly bilaterally aligned. However, fluorescence microscopy detected left-right asymmetry of myofibril inclination relative to the longitudinal axis of the tail. Zernike phase-contrast X-ray tomographic microscopy revealed the presence of left-handed helices of myofibrils in muscle cells on both sides. Therefore, the locomotor system of ascidian larvae harbors symmetry-breaking left-handed helical cells, while maintaining bilaterally symmetrical cell alignment. These results suggest that bilateral animals can override cellular homochirality to generate the bilateral locomotor systems at the supracellular scale.
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Affiliation(s)
- Koichi Matsuo
- Laboratory of Cell and Tissue Biology, Keio University School of Medicine, Tokyo, Japan
| | - Ryota Tamura
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan
| | - Kohji Hotta
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Mayu Okada
- Laboratory of Cell and Tissue Biology, Keio University School of Medicine, Tokyo, Japan
| | - Akihisa Takeuchi
- Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Japan
| | - Yanlin Wu
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
| | - Koh Hashimoto
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
| | - Hidekazu Takano
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
| | - Atsushi Momose
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Japan
| | - Atsuo Nishino
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
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11
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Bozzo M, Costa S, Obino V, Bachetti T, Marcenaro E, Pestarino M, Schubert M, Candiani S. Functional Conservation and Genetic Divergence of Chordate Glycinergic Neurotransmission: Insights from Amphioxus Glycine Transporters. Cells 2021; 10:cells10123392. [PMID: 34943900 PMCID: PMC8699752 DOI: 10.3390/cells10123392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 11/24/2022] Open
Abstract
Glycine is an important neurotransmitter in vertebrates, performing both excitatory and inhibitory actions. Synaptic levels of glycine are tightly controlled by the action of two glycine transporters, GlyT1 and GlyT2, located on the surface of glial cells and neurons, respectively. Only limited information is available on glycinergic neurotransmission in invertebrates, and the evolution of glycinergic neurotransmission is poorly understood. Here, by combining phylogenetic and gene expression analyses, we characterized the glycine transporter complement of amphioxus, an important invertebrate model for studying the evolution of chordates. We show that amphioxus possess three glycine transporter genes. Two of these (GlyT2.1 and GlyT2.2) are closely related to GlyT2 of vertebrates, whereas the third (GlyT) is a member of an ancestral clade of deuterostome glycine transporters. GlyT2.2 expression is predominantly non-neural, whereas GlyT and GlyT2.1 are widely expressed in the amphioxus nervous system and are differentially expressed, respectively, in neurons and glia. Vertebrate glycinergic neurons express GlyT2 and glia GlyT1, suggesting that the evolution of the chordate glycinergic system was accompanied by a paralog-specific inversion of gene expression. Despite this genetic divergence between amphioxus and vertebrates, we found strong evidence for conservation in the role glycinergic neurotransmission plays during larval swimming, the implication being that the neural networks controlling the rhythmic movement of chordate bodies may be homologous.
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Affiliation(s)
- Matteo Bozzo
- Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università degli Studi di Genova, 16132 Genoa, Italy; (S.C.); (T.B.); (M.P.)
- Dipartimento di Medicina Sperimentale (DIMES), Università degli Studi di Genova, 16132 Genoa, Italy; (V.O.); (E.M.)
- Correspondence: (M.B.); (S.C.); Tel.: +39-010-335-8043 (M.B.); +39-010-335-8051 (S.C.)
| | - Simone Costa
- Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università degli Studi di Genova, 16132 Genoa, Italy; (S.C.); (T.B.); (M.P.)
| | - Valentina Obino
- Dipartimento di Medicina Sperimentale (DIMES), Università degli Studi di Genova, 16132 Genoa, Italy; (V.O.); (E.M.)
| | - Tiziana Bachetti
- Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università degli Studi di Genova, 16132 Genoa, Italy; (S.C.); (T.B.); (M.P.)
| | - Emanuela Marcenaro
- Dipartimento di Medicina Sperimentale (DIMES), Università degli Studi di Genova, 16132 Genoa, Italy; (V.O.); (E.M.)
| | - Mario Pestarino
- Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università degli Studi di Genova, 16132 Genoa, Italy; (S.C.); (T.B.); (M.P.)
| | - Michael Schubert
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer (LBDV), Institut de la Mer de Villefranche, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France;
| | - Simona Candiani
- Dipartimento di Scienze della Terra, dell’Ambiente e della Vita (DISTAV), Università degli Studi di Genova, 16132 Genoa, Italy; (S.C.); (T.B.); (M.P.)
- Correspondence: (M.B.); (S.C.); Tel.: +39-010-335-8043 (M.B.); +39-010-335-8051 (S.C.)
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12
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Borba C, Kourakis MJ, Schwennicke S, Brasnic L, Smith WC. Fold Change Detection in Visual Processing. Front Neural Circuits 2021; 15:705161. [PMID: 34497492 PMCID: PMC8419522 DOI: 10.3389/fncir.2021.705161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/30/2021] [Indexed: 11/13/2022] Open
Abstract
Visual processing transforms the complexities of the visual world into useful information. Ciona, an invertebrate chordate and close relative of the vertebrates, has one of the simplest nervous systems known, yet has a range of visuomotor behaviors. This simplicity has facilitated studies linking behavior and neural circuitry. Ciona larvae have two distinct visuomotor behaviors - a looming shadow response and negative phototaxis. These are mediated by separate neural circuits that initiate from different clusters of photoreceptors, with both projecting to a CNS structure called the posterior brain vesicle (pBV). We report here that inputs from both circuits are processed to generate fold change detection (FCD) outputs. In FCD, the behavioral response scales with the relative fold change in input, but is invariant to the overall magnitude of the stimulus. Moreover, the two visuomotor behaviors have fundamentally different stimulus/response relationships - indicative of differing circuit strategies, with the looming shadow response showing a power relationship to fold change, while the navigation behavior responds linearly. Pharmacological modulation of the FCD response points to the FCD circuits lying outside of the visual organ (the ocellus), with the pBV being the most likely location. Consistent with these observations, the connectivity and properties of pBV interneurons conform to known FCD circuit motifs, but with different circuit architectures for the two circuits. The negative phototaxis circuit forms a putative incoherent feedforward loop that involves interconnecting cholinergic and GABAergic interneurons. The looming shadow circuit uses the same cholinergic and GABAergic interneurons, but with different synaptic inputs to create a putative non-linear integral feedback loop. These differing circuit architectures are consistent with the behavioral outputs of the two circuits. Finally, while some reports have highlighted parallels between the pBV and the vertebrate midbrain, suggesting a common origin for the two, others reports have disputed this, suggesting that invertebrate chordates lack a midbrain homolog. The convergence of visual inputs at the pBV, and its putative role in visual processing reported here and in previous publications, lends further support to the proposed common origin of the pBV and the vertebrate midbrain.
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Affiliation(s)
- Cezar Borba
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Matthew J Kourakis
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Shea Schwennicke
- College of Creative Studies, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Lorena Brasnic
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States.,Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - William C Smith
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States.,College of Creative Studies, University of California, Santa Barbara, Santa Barbara, CA, United States
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13
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Hudson C, Yasuo H. Neuromesodermal Lineage Contribution to CNS Development in Invertebrate and Vertebrate Chordates. Genes (Basel) 2021; 12:genes12040592. [PMID: 33920662 PMCID: PMC8073528 DOI: 10.3390/genes12040592] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 12/12/2022] Open
Abstract
Ascidians are invertebrate chordates and the closest living relative to vertebrates. In ascidian embryos a large part of the central nervous system arises from cells associated with mesoderm rather than ectoderm lineages. This seems at odds with the traditional view of vertebrate nervous system development which was thought to be induced from ectoderm cells, initially with anterior character and later transformed by posteriorizing signals, to generate the entire anterior-posterior axis of the central nervous system. Recent advances in vertebrate developmental biology, however, show that much of the posterior central nervous system, or spinal cord, in fact arises from cells that share a common origin with mesoderm. This indicates a conserved role for bi-potential neuromesoderm precursors in chordate CNS formation. However, the boundary between neural tissue arising from these distinct neural lineages does not appear to be fixed, which leads to the notion that anterior-posterior patterning and neural fate formation can evolve independently.
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14
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Yaguchi J, Yaguchi S. Sea urchin larvae utilize light for regulating the pyloric opening. BMC Biol 2021; 19:64. [PMID: 33820528 PMCID: PMC8022552 DOI: 10.1186/s12915-021-00999-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 03/05/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Light is essential for various biological activities. In particular, visual information through eyes or eyespots is very important for most of animals, and thus, the functions and developmental mechanisms of visual systems have been well studied to date. In addition, light-dependent non-visual systems expressing photoreceptor Opsins have been used to study the effects of light on diverse animal behaviors. However, it remains unclear how light-dependent systems were acquired and diversified during deuterostome evolution due to an almost complete lack of knowledge on the light-response signaling pathway in Ambulacraria, one of the major groups of deuterostomes and a sister group of chordates. RESULTS Here, we show that sea urchin larvae utilize light for digestive tract activity. We found that photoirradiation of larvae induces pyloric opening even without addition of food stimuli. Micro-surgical and knockdown experiments revealed that this stimulating light is received and mediated by Go(/RGR)-Opsin (Opsin3.2 in sea urchin genomes) cells around the anterior neuroectoderm. Furthermore, we found that the anterior neuroectodermal serotoninergic neurons near Go-Opsin-expressing cells are essential for mediating light stimuli-induced nitric oxide (NO) release at the pylorus. Our results demonstrate that the light>Go-Opsin>serotonin>NO pathway functions in pyloric opening during larval stages. CONCLUSIONS The results shown here will lead us to understand how light-dependent systems of pyloric opening functioning via neurotransmitters were acquired and established during animal evolution. Based on the similarity of nervous system patterns and the gut proportions among Ambulacraria, we suggest the light>pyloric opening pathway may be conserved in the clade, although the light signaling pathway has so far not been reported in other members of the group. In light of brain-gut interactions previously found in vertebrates, we speculate that one primitive function of anterior neuroectodermal neurons (brain neurons) may have been to regulate the function of the digestive tract in the common ancestor of deuterostomes. Given that food consumption and nutrient absorption are essential for animals, the acquirement and development of brain-based sophisticated gut regulatory system might have been important for deuterostome evolution.
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Affiliation(s)
- Junko Yaguchi
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan
| | - Shunsuke Yaguchi
- Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka, 415-0025, Japan.
- PRESTO, JST, 4-1-8 Honcho, Kawaguchi, 332-0012, Japan.
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15
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Lowe EK, Racioppi C, Peyriéras N, Ristoratore F, Christiaen L, Swalla BJ, Stolfi A. A cis-regulatory change underlying the motor neuron-specific loss of Ebf expression in immotile tunicate larvae. Evol Dev 2021; 23:72-85. [PMID: 33355999 PMCID: PMC7920938 DOI: 10.1111/ede.12364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 10/23/2020] [Accepted: 12/06/2020] [Indexed: 11/26/2022]
Abstract
Many species in the tunicate family Molgulidae have independently lost their swimming larval form and instead develop as tailless, immotile larvae. These larvae do not develop structures that are essential for swimming such as the notochord, otolith, and tail muscles. However, little is known about neural development in these nonswimming larvae. Here, we studied the patterning of the Motor Ganglion (MG) of Molgula occulta, a nonswimming species. We found that spatial patterns of MG neuron regulators in this species are conserved, compared with species with swimming larvae, suggesting that the gene networks regulating their expression are intact despite the loss of swimming. However, expression of the key motor neuron regulatory gene Ebf (Collier/Olf/EBF) was reduced in the developing MG of M. occulta when compared with molgulid species with swimming larvae. This was corroborated by measuring allele-specific expression of Ebf in hybrid embryos from crosses of M. occulta with the swimming species M. oculata. Heterologous reporter construct assays in the model tunicate species Ciona robusta revealed a specific cis-regulatory sequence change that reduces expression of Ebf in the MG, but not in other cells. Taken together, these data suggest that MG neurons are still specified in M. occulta larvae, but their differentiation might be impaired due to reduction of Ebf expression levels.
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Affiliation(s)
- Elijah K. Lowe
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Station Biologique de Roscoff, Roscoff, France
| | - Claudia Racioppi
- Station Biologique de Roscoff, Roscoff, France
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY, USA
| | - Nadine Peyriéras
- Station Biologique de Roscoff, Roscoff, France
- UPS3611 Complex Systems Institute Paris Ile-de-France (ISC-PIF), CNRS, Paris, France
- USR3695 BioEmergences, CNRS, Paris-Saclay University, Gif-sur-Yvette, France
| | - Filomena Ristoratore
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Lionel Christiaen
- Station Biologique de Roscoff, Roscoff, France
- Center for Developmental Genetics, Department of Biology, New York University, New York, NY, USA
| | - Billie J. Swalla
- Station Biologique de Roscoff, Roscoff, France
- Department of Biology, University of Washington, Seattle, WA, USA
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA, USA
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Station Biologique de Roscoff, Roscoff, France
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16
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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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17
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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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18
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Grillner S, El Manira A. Current Principles of Motor Control, with Special Reference to Vertebrate Locomotion. Physiol Rev 2019; 100:271-320. [PMID: 31512990 DOI: 10.1152/physrev.00015.2019] [Citation(s) in RCA: 220] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The vertebrate control of locomotion involves all levels of the nervous system from cortex to the spinal cord. Here, we aim to cover all main aspects of this complex behavior, from the operation of the microcircuits in the spinal cord to the systems and behavioral levels and extend from mammalian locomotion to the basic undulatory movements of lamprey and fish. The cellular basis of propulsion represents the core of the control system, and it involves the spinal central pattern generator networks (CPGs) controlling the timing of different muscles, the sensory compensation for perturbations, and the brain stem command systems controlling the level of activity of the CPGs and the speed of locomotion. The forebrain and in particular the basal ganglia are involved in determining which motor programs should be recruited at a given point of time and can both initiate and stop locomotor activity. The propulsive control system needs to be integrated with the postural control system to maintain body orientation. Moreover, the locomotor movements need to be steered so that the subject approaches the goal of the locomotor episode, or avoids colliding with elements in the environment or simply escapes at high speed. These different aspects will all be covered in the review.
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Affiliation(s)
- Sten Grillner
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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19
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Razy-Krajka F, Stolfi A. Regulation and evolution of muscle development in tunicates. EvoDevo 2019; 10:13. [PMID: 31249657 PMCID: PMC6589888 DOI: 10.1186/s13227-019-0125-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 06/08/2019] [Indexed: 12/16/2022] Open
Abstract
For more than a century, studies on tunicate muscle formation have revealed many principles of cell fate specification, gene regulation, morphogenesis, and evolution. Here, we review the key studies that have probed the development of all the various muscle cell types in a wide variety of tunicate species. We seize this occasion to explore the implications and questions raised by these findings in the broader context of muscle evolution in chordates.
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Affiliation(s)
- Florian Razy-Krajka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, USA
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, USA
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20
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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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21
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Lowe EK, Stolfi A. Developmental system drift in motor ganglion patterning between distantly related tunicates. EvoDevo 2018; 9:18. [PMID: 30062003 PMCID: PMC6057086 DOI: 10.1186/s13227-018-0107-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/18/2018] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The larval nervous system of the solitary tunicate Ciona is a simple model for the study of chordate neurodevelopment. The development and connectivity of the Ciona motor ganglion have been studied in fine detail, but how this important structure develops in other tunicates is not well known. METHODS AND RESULTS By comparing gene expression patterns in the developing MG of the distantly related tunicate Molgula occidentalis, we found that its patterning is highly conserved compared to the Ciona MG. MG neuronal subtypes in Molgula were specified in the exact same positions as in Ciona, though the timing of subtype-specific gene expression onset was slightly shifted to begin earlier, relative to mitotic exit and differentiation. In transgenic Molgula embryos electroporated with Dmbx reporter plasmids, we were also able to characterize the morphology of the lone pair of descending decussating neurons (ddNs) in Molgula, revealing the same unique contralateral projection seen in Ciona ddNs and their putative vertebrate homologs the Mauthner cells. Although Dmbx expression labels the ddNs in both species, cross-species transgenic assays revealed significant changes to the regulatory logic underlying Dmbx transcription. We found that Dmbx cis-regulatory DNAs from Ciona can drive highly specific reporter gene expression in Molgula ddNs, but Molgula sequences are not active in Ciona ddNs. CONCLUSIONS This acute divergence in the molecular mechanisms that underlie otherwise functionally conserved cis-regulatory DNAs supports the recently proposed idea that the extreme genetic plasticity observed in tunicates may be attributed to the extreme rigidity of the spatial organization of their embryonic cell lineages.
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Affiliation(s)
- Elijah K. Lowe
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA USA
| | - Alberto Stolfi
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA USA
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22
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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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23
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Behrendt L, Raina JB, Lutz A, Kot W, Albertsen M, Halkjær-Nielsen P, Sørensen SJ, Larkum AW, Kühl M. In situ metabolomic- and transcriptomic-profiling of the host-associated cyanobacteria Prochloron and Acaryochloris marina. THE ISME JOURNAL 2018; 12:556-567. [PMID: 29087375 PMCID: PMC5776471 DOI: 10.1038/ismej.2017.192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 01/20/2023]
Abstract
The tropical ascidian Lissoclinum patella hosts two enigmatic cyanobacteria: (1) the photoendosymbiont Prochloron spp., a producer of valuable bioactive compounds and (2) the chlorophyll-d containing Acaryochloris spp., residing in the near-infrared enriched underside of the animal. Despite numerous efforts, Prochloron remains uncultivable, restricting the investigation of its biochemical potential to cultivation-independent techniques. Likewise, in both cyanobacteria, universally important parameters on light-niche adaptation and in situ photosynthetic regulation are unknown. Here we used genome sequencing, transcriptomics and metabolomics to investigate the symbiotic linkage between host and photoendosymbiont and simultaneously probed the transcriptional response of Acaryochloris in situ. During high light, both cyanobacteria downregulate CO2 fixing pathways, likely a result of O2 photorespiration on the functioning of RuBisCO, and employ a variety of stress-quenching mechanisms, even under less stressful far-red light (Acaryochloris). Metabolomics reveals a distinct biochemical modulation between Prochloron and L. patella, including noon/midnight-dependent signatures of amino acids, nitrogenous waste products and primary photosynthates. Surprisingly, Prochloron constitutively expressed genes coding for patellamides, that is, cyclic peptides of great pharmaceutical value, with yet unknown ecological significance. Together these findings shed further light on far-red-driven photosynthesis in natural consortia, the interplay of Prochloron and its ascidian partner in a model chordate photosymbiosis and the uncultivability of Prochloron.
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Affiliation(s)
- Lars Behrendt
- Department of Civil, Environmental and Geomatic Engineering, Swiss Federal Institute of Technology, Zürich, Switzerland.
- Department of Biology, Marine Biological Section, University of Copenhagen, Helsingør, Denmark.
- Department of Biology, Microbiology Section, University of Copenhagen, Copenhagen, Denmark.
| | - Jean-Baptiste Raina
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology, Sydney, New South Wales, Australia
| | - Adrian Lutz
- Metabolomics Australia, School of BioSciences, University of Melbourne, Parkville, Victoria, Australia
| | - Witold Kot
- Department of Environmental Science-Enviromental Microbiology and Biotechnology, Aarhus University, Roskilde, Denmark
| | - Mads Albertsen
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Per Halkjær-Nielsen
- Department of Chemistry and Bioscience, Center for Microbial Communities, Aalborg University, Aalborg, Denmark
| | - Søren J Sørensen
- Department of Biology, Microbiology Section, University of Copenhagen, Copenhagen, Denmark
| | - Anthony Wd Larkum
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology, Sydney, New South Wales, Australia
| | - Michael Kühl
- Department of Biology, Marine Biological Section, University of Copenhagen, Helsingør, Denmark
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology, Sydney, New South Wales, Australia
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24
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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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25
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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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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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Ryan K, Lu Z, Meinertzhagen IA. The CNS connectome of a tadpole larva of Ciona intestinalis (L.) highlights sidedness in the brain of a chordate sibling. eLife 2016; 5. [PMID: 27921996 PMCID: PMC5140270 DOI: 10.7554/elife.16962] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/17/2016] [Indexed: 12/12/2022] Open
Abstract
Left-right asymmetries in brains are usually minor or cryptic. We report brain asymmetries in the tiny, dorsal tubular nervous system of the ascidian tadpole larva, Ciona intestinalis. Chordate in body plan and development, the larva provides an outstanding example of brain asymmetry. Although early neural development is well studied, detailed cellular organization of the swimming larva's CNS remains unreported. Using serial-section EM we document the synaptic connectome of the larva's 177 CNS neurons. These formed 6618 synapses including 1772 neuromuscular junctions, augmented by 1206 gap junctions. Neurons are unipolar with at most a single dendrite, and few synapses. Some synapses are unpolarised, others form reciprocal or serial motifs; 922 were polyadic. Axo-axonal synapses predominate. Most neurons have ciliary organelles, and many features lack structural specialization. Despite equal cell numbers on both sides, neuron identities and pathways differ left/right. Brain vesicle asymmetries include a right ocellus and left coronet cells.
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Affiliation(s)
- Kerrianne Ryan
- Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, Canada.,Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Canada
| | - Zhiyuan Lu
- Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, Canada.,Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Canada
| | - Ian A Meinertzhagen
- Department of Biology, Life Sciences Centre, Dalhousie University, Halifax, Canada.,Department of Psychology and Neuroscience, Life Sciences Centre, Dalhousie University, Halifax, Canada
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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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Wijckmans E, Nys M, Debaveye S, Brams M, Pardon E, Willegems K, Bertrand D, Steyaert J, Efremov R, Ulens C. Functional and Biochemical Characterization of Alvinella pompejana Cys-Loop Receptor Homologues. PLoS One 2016; 11:e0151183. [PMID: 26999666 PMCID: PMC4801368 DOI: 10.1371/journal.pone.0151183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/24/2016] [Indexed: 11/22/2022] Open
Abstract
Cys-loop receptors are membrane spanning ligand-gated ion channels involved in fast excitatory and inhibitory neurotransmission. Three-dimensional structures of these ion channels, determined by X-ray crystallography or electron microscopy, have revealed valuable information regarding the molecular mechanisms underlying ligand recognition, channel gating and ion conductance. To extend and validate the current insights, we here present promising candidates for further structural studies. We report the biochemical and functional characterization of Cys-loop receptor homologues identified in the proteome of Alvinella pompejana, an extremophilic, polychaete annelid found in hydrothermal vents at the bottom of the Pacific Ocean. Seven homologues were selected, named Alpo1-7. Five of them, Alpo2-6, were unidentified prior to this study. Two-electrode voltage clamp experiments revealed that wild type Alpo5 and Alpo6, both sharing remarkably high sequence identity with human glycine receptor α subunits, are anion-selective channels that can be activated by glycine, GABA and taurine. Furthermore, upon expression in insect cells fluorescence size-exclusion chromatography experiments indicated that four homologues, Alpo1, Alpo4, Alpo6 and Alpo7, can be extracted out of the membrane by a wide variety of detergents while maintaining their oligomeric state. Finally, large-scale purification efforts of Alpo1, Alpo4 and Alpo6 resulted in milligram amounts of biochemically stable and monodisperse protein. Overall, our results establish the evolutionary conservation of glycine receptors in annelids and pave the way for future structural studies.
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Affiliation(s)
- Eveline Wijckmans
- Department of Cellular and Molecular Medicine, Laboratory of Structural Neurobiology, University of Leuven, Leuven, Belgium
| | - Mieke Nys
- Department of Cellular and Molecular Medicine, Laboratory of Structural Neurobiology, University of Leuven, Leuven, Belgium
- * E-mail:
| | - Sarah Debaveye
- Department of Cellular and Molecular Medicine, Laboratory of Structural Neurobiology, University of Leuven, Leuven, Belgium
| | - Marijke Brams
- Department of Cellular and Molecular Medicine, Laboratory of Structural Neurobiology, University of Leuven, Leuven, Belgium
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Structural Biology Research Center, VIB, Brussels, Belgium
| | - Katrien Willegems
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Structural Biology Research Center, VIB, Brussels, Belgium
| | | | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Structural Biology Research Center, VIB, Brussels, Belgium
| | - Rouslan Efremov
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
- Structural Biology Research Center, VIB, Brussels, Belgium
| | - Chris Ulens
- Department of Cellular and Molecular Medicine, Laboratory of Structural Neurobiology, University of Leuven, Leuven, Belgium
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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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Flores-Fernández JM, Gutiérrez-Ortega A, Padilla-Camberos E, Rosario-Cruz R, Hernández-Gutiérrez R, Martínez-Velázquez M. Molecular cloning and characterization of a glycine-like receptor gene from the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). Parasite 2014; 21:43. [PMID: 25174962 PMCID: PMC4150426 DOI: 10.1051/parasite/2014047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/15/2014] [Indexed: 11/18/2022] Open
Abstract
The cattle tick Rhipicephalus (Boophilus) microplus is the most economically important ectoparasite affecting the cattle industry in tropical and subtropical areas around the world. The principal method of tick control has relied mainly on the use of chemical acaricides, including ivermectin; however, cattle tick populations resistant to ivermectin have recently been reported in Brazil, Mexico, and Uruguay. Currently, the molecular basis for ivermectin susceptibility and resistance are not well understood in R. microplus. This prompted us to search for potential molecular targets for ivermectin. Here, we report the cloning and molecular characterization of a R. microplus glycine-like receptor (RmGlyR) gene. The characterized mRNA encodes for a 464-amino acid polypeptide, which contains features common to ligand-gated ion channels, such as a large N-terminal extracellular domain, four transmembrane domains, a large intracellular loop and a short C-terminal extracellular domain. The deduced amino acid sequence showed around 30% identity to GlyRs from some invertebrate and vertebrate organisms. The polypeptide also contains the PAR motif, which is important for forming anion channels, and a conserved glycine residue at the third transmembrane domain, which is essential for high ivermectin sensitivity. PCR analyses showed that RmGlyR is expressed at egg, larval and adult developmental stages. Our findings suggest that the deduced receptor is an additional molecular target to ivermectin and it might be involved in ivermectin resistance in R. microplus.
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Affiliation(s)
- José Miguel Flores-Fernández
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, AC, Av. Normalistas 800, Col. Colinas de la Normal, 44270 Guadalajara, Jalisco, México
| | - Abel Gutiérrez-Ortega
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, AC, Av. Normalistas 800, Col. Colinas de la Normal, 44270 Guadalajara, Jalisco, México
| | - Eduardo Padilla-Camberos
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, AC, Av. Normalistas 800, Col. Colinas de la Normal, 44270 Guadalajara, Jalisco, México
| | - Rodrigo Rosario-Cruz
- Centro Nacional de Investigaciones en Parasitología Veterinaria-INIFAP, Carretera Federal Cuernavaca Cuautla No. 8534, Colonia Progreso, 62550 Jiutepec, Morelos, México
| | - Rodolfo Hernández-Gutiérrez
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, AC, Av. Normalistas 800, Col. Colinas de la Normal, 44270 Guadalajara, Jalisco, México
| | - Moisés Martínez-Velázquez
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, AC, Av. Normalistas 800, Col. Colinas de la Normal, 44270 Guadalajara, Jalisco, México
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Matsushima A, Ryan K, Shimohigashi Y, Meinertzhagen IA. An endocrine disruptor, bisphenol A, affects development in the protochordate Ciona intestinalis: hatching rates and swimming behavior alter in a dose-dependent manner. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2013; 173:257-263. [PMID: 23207495 DOI: 10.1016/j.envpol.2012.10.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2012] [Revised: 10/04/2012] [Accepted: 10/10/2012] [Indexed: 05/20/2023]
Abstract
Bisphenol A (BPA) is widely used industrially to produce polycarbonate plastics and epoxy resins. Numerous studies document the harmful effects caused by low-dose BPA exposure especially on nervous systems and behavior in experimental animals such as mice and rats. Here, we exposed embryos of a model chordate, Ciona intestinalis, to seawater containing BPA to evaluate adverse effects on embryonic development and on the swimming behavior of subsequent larvae. Ciona is ideal because its larva develops rapidly and has few cells. The rate of larval hatching decreased in a dose-dependent manner with exposures to BPA above 3 μM; swimming behavior was also affected in larvae emerging from embryos exposed to 1 μM BPA. Adverse effects were most severe on fertilized eggs exposed to BPA within 7 h post-fertilization. Ciona shares twelve nuclear receptors with mammals, and BPA is proposed to disturb the physiological functions of one or more of these.
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Affiliation(s)
- Ayami Matsushima
- Laboratory of Structure-Function Biochemistry, Department of Chemistry, Faculty and Graduate School of Sciences, Kyushu University, Fukuoka 812-8581, Japan.
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Kusakabe TG, Sakai T, Aoyama M, Kitajima Y, Miyamoto Y, Takigawa T, Daido Y, Fujiwara K, Terashima Y, Sugiuchi Y, Matassi G, Yagisawa H, Park MK, Satake H, Tsuda M. A conserved non-reproductive GnRH system in chordates. PLoS One 2012; 7:e41955. [PMID: 22848672 PMCID: PMC3407064 DOI: 10.1371/journal.pone.0041955] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 06/27/2012] [Indexed: 01/28/2023] Open
Abstract
Gonadotropin-releasing hormone (GnRH) is a neuroendocrine peptide that plays a central role in the vertebrate hypothalamo-pituitary axis. The roles of GnRH in the control of vertebrate reproductive functions have been established, while its non-reproductive function has been suggested but less well understood. Here we show that the tunicate Ciona intestinalis has in its non-reproductive larval stage a prominent GnRH system spanning the entire length of the nervous system. Tunicate GnRH receptors are phylogenetically closest to vertebrate GnRH receptors, yet functional analysis of the receptors revealed that these simple chordates have evolved a unique GnRH system with multiple ligands and receptor heterodimerization enabling complex regulation. One of the gnrh genes is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord of vertebrates. Correspondingly, GnRH receptor genes were found to be expressed in the tail muscle and notochord of embryos, both of which are phylotypic axial structures along the nerve cord. Our findings suggest a novel non-reproductive role of GnRH in tunicates. Furthermore, we present evidence that GnRH-producing cells are present in the hindbrain and spinal cord of the medaka, Oryzias latipes, thereby suggesting the deep evolutionary origin of a non-reproductive GnRH system in chordates.
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Affiliation(s)
- Takehiro G. Kusakabe
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo, Japan
| | - Tsubasa Sakai
- Division of Biomolecular Research, Suntory Institute for Bioorganic Research, Shimamoto, Osaka, Japan
| | - Masato Aoyama
- Division of Biomolecular Research, Suntory Institute for Bioorganic Research, Shimamoto, Osaka, Japan
| | - Yuka Kitajima
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo, Japan
| | - Yuki Miyamoto
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo, Japan
| | - Toru Takigawa
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Yutaka Daido
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Kentaro Fujiwara
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Yasuko Terashima
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo, Japan
| | - Yoko Sugiuchi
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Giorgio Matassi
- Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Japan
- Department of Agriculture and Environmental Sciences, University of Udine, Udine, Italy
| | - Hitoshi Yagisawa
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo, Japan
| | - Min Kyun Park
- Department of Biological Sciences, Graduate School of Science, the University of Tokyo, Tokyo, Japan
| | - Honoo Satake
- Division of Biomolecular Research, Suntory Institute for Bioorganic Research, Shimamoto, Osaka, Japan
| | - Motoyuki Tsuda
- Graduate School of Life Science, University of Hyogo, Kamigori, Hyogo, Japan
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa, Japan
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Razy-Krajka F, Brown ER, Horie T, Callebert J, Sasakura Y, Joly JS, Kusakabe TG, Vernier P. Monoaminergic modulation of photoreception in ascidian: evidence for a proto-hypothalamo-retinal territory. BMC Biol 2012; 10:45. [PMID: 22642675 PMCID: PMC3414799 DOI: 10.1186/1741-7007-10-45] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 05/29/2012] [Indexed: 12/12/2022] Open
Abstract
Background The retina of craniates/vertebrates has been proposed to derive from a photoreceptor prosencephalic territory in ancestral chordates, but the evolutionary origin of the different cell types making the retina is disputed. Except for photoreceptors, the existence of homologs of retinal cells remains uncertain outside vertebrates. Methods The expression of genes expressed in the sensory vesicle of the ascidian Ciona intestinalis including those encoding components of the monoaminergic neurotransmission systems, was analyzed by in situ hybridization or in vivo transfection of the corresponding regulatory elements driving fluorescent reporters. Modulation of photic responses by monoamines was studied by electrophysiology combined with pharmacological treatments. Results We show that many molecular characteristics of dopamine-synthesizing cells located in the vicinity of photoreceptors in the sensory vesicle of the ascidian Ciona intestinalis are similar to those of amacrine dopamine cells of the vertebrate retina. The ascidian dopamine cells share with vertebrate amacrine cells the expression of the key-transcription factor Ptf1a, as well as that of dopamine-synthesizing enzymes. Surprisingly, the ascidian dopamine cells accumulate serotonin via a functional serotonin transporter, as some amacrine cells also do. Moreover, dopamine cells located in the vicinity of the photoreceptors modulate the light-off induced swimming behavior of ascidian larvae by acting on alpha2-like receptors, instead of dopamine receptors, supporting a role in the modulation of the photic response. These cells are located in a territory of the ascidian sensory vesicle expressing genes found both in the retina and the hypothalamus of vertebrates (six3/6, Rx, meis, pax6, visual cycle proteins). Conclusion We propose that the dopamine cells of the ascidian larva derive from an ancestral multifunctional cell population located in the periventricular, photoreceptive field of the anterior neural tube of chordates, which also gives rise to both anterior hypothalamus and the retina in craniates/vertebrates. It also shows that the existence of multiple cell types associated with photic responses predates the formation of the vertebrate retina.
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Affiliation(s)
- Florian Razy-Krajka
- Neurobiology and Development, UPR, Institut de Neurobiologie Alfred Fessard, Centre National de la Recherche Scientifique, Gif-sur-Yvette, France
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Sasakura Y, Mita K, Ogura Y, Horie T. Ascidians as excellent chordate models for studying the development of the nervous system during embryogenesis and metamorphosis. Dev Growth Differ 2012; 54:420-37. [DOI: 10.1111/j.1440-169x.2012.01343.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Yasunori Sasakura
- Shimoda Marine Research Center; University of Tsukuba; Shimoda; Shizuoka; 415-0025; Japan
| | - Kaoru Mita
- Shimoda Marine Research Center; University of Tsukuba; Shimoda; Shizuoka; 415-0025; Japan
| | - Yosuke Ogura
- Shimoda Marine Research Center; University of Tsukuba; Shimoda; Shizuoka; 415-0025; Japan
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Stolfi A, Wagner E, Taliaferro JM, Chou S, Levine M. Neural tube patterning by Ephrin, FGF and Notch signaling relays. Development 2012; 138:5429-39. [PMID: 22110057 DOI: 10.1242/dev.072108] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The motor ganglion (MG) controls the rhythmic swimming behavior of the Ciona intestinalis tadpole. Despite its cellular simplicity (five pairs of neurons), the MG exhibits conservation of transcription factor expression with the spinal cord of vertebrates. Evidence is presented that the developing MG is patterned by sequential Ephrin/FGF/MAPK and Delta/Notch signaling events. FGF/MAPK attenuation by a localized EphrinAb signal specifies posterior neuronal subtypes, which in turn relay a Delta2/Notch signal that specifies anterior fates. This short-range relay is distinct from the patterning of the vertebrate spinal cord, which is a result of opposing BMP and Shh morphogen gradients. Nonetheless, both mechanisms lead to localized expression of related homeodomain codes for the specification of distinct neuronal subtypes. This MG regulatory network provides a foundation for elucidating the genetic and cellular basis of a model chordate central pattern generator.
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Affiliation(s)
- Alberto Stolfi
- Department of Molecular and Cell Biology, Division of Genetics, Genomics and Development, Center for Integrative Genomics, University of California, Berkeley, CA 94720, USA.
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Nishitsuji K, Horie T, Ichinose A, Sasakura Y, Yasuo H, Kusakabe TG. Cell lineage and cis-regulation for a unique GABAergic/glycinergic neuron type in the larval nerve cord of the ascidian Ciona intestinalis. Dev Growth Differ 2012; 54:177-86. [DOI: 10.1111/j.1440-169x.2011.01319.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Ion channels in key marine invertebrates; their diversity and potential for applications in biotechnology. Biotechnol Adv 2011; 29:457-67. [PMID: 21620946 DOI: 10.1016/j.biotechadv.2011.05.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 05/10/2011] [Accepted: 05/10/2011] [Indexed: 12/31/2022]
Abstract
Of the intra-membrane proteins, the class that comprises voltage and ligand-gated ion channels represents the major substrate whereby signals pass between and within cells in all organisms. It has been presumed that vertebrate and particularly mammalian ion channels represent the apex of evolutionary complexity and diversity and much effort has been focused on understanding their function. However, the recent availability of cheap high throughput genome sequencing has massively broadened and deepened the quality of information across phylogeny and is radically changing this view. Here we review current knowledge on such channels in key marine invertebrates where physiological evidence is backed up by molecular sequences and expression/functional studies. As marine invertebrates represent a much greater range of phyla than terrestrial vertebrates and invertebrates together, we argue that these animals represent a highly divergent, though relatively underused source of channel novelty. As ion channels are exquisitely selective sensors for voltage and ligands, their potential and actual applications in biotechnology are manifold.
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Jordan LM, Sławińska U. Chapter 12--modulation of rhythmic movement: control of coordination. PROGRESS IN BRAIN RESEARCH 2011; 188:181-95. [PMID: 21333810 DOI: 10.1016/b978-0-444-53825-3.00017-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Three rhythmic movements, breathing, walking, and chewing, are considered from the perspective of the emerging factors that control their coordination. This takes us beyond the concept of a core excitatory kernel and into the common principles that govern the interaction between components of the neural networks that must be orchestrated properly to produce meaningful movement beyond the production of the basic rhythm. We focus on the role of neuromodulators, especially 5-hydroxytryptamine (5-HT), in the production of coordinated breathing, walking, and chewing, and we review the evidence that at least in the case of breathing and walking, 5-HT input to the CPGs acts through the selection of inhibitory interneurons that are essential for coordination. We review data from recently developed mouse models that offer insight into the contributions of inhibitory coordinating neurons, including the development of a new model that has allowed the revelation that there are glycinergic pacemaker neurons that likely contribute to the production of the respiratory rhythm. Perhaps walking and chewing will not be far behind.
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Affiliation(s)
- Larry M Jordan
- Department of Physiology, Spinal Cord Research Centre, University of Manitoba, Winnipeg MB, Canada
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Ogasawara M, Sasaki M, Nakazawa N, Nishino A, Okamura Y. Gene expression profile of Ci-VSP in juveniles and adult blood cells of ascidian. Gene Expr Patterns 2010; 11:233-8. [PMID: 21172457 DOI: 10.1016/j.gep.2010.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 12/11/2010] [Accepted: 12/15/2010] [Indexed: 10/18/2022]
Abstract
VSP is a transmembrane protein whose cytoplasmic region shows significant similarity to phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Notably, VSP exhibits a unique ability to transduce electrical signals into phosphoinositide turnover by coupling a transmembrane voltage sensor domain to the PTEN-like phosphoinositide phosphatase domain. Moreover, VSP gene is known to be widely conserved among deuterostome genomes, though the function of VSP in vivo remains largely unknown. In the present study, the expression pattern of ascidian VSP(Ci-VSP) was examined in embryos and juveniles of a marine invertebrate chordate, Ciona intestinalis. RT-PCR showed that Ci-VSP is expressed at the larval stage and that expression persists in juveniles. Whole mount in situ hybridization showed that Ci-VSP is expressed in cells of the stomach, intestine and blood cells of 2- to 3-week-old juveniles. Moreover, double staining blood cells from 2-month-old adults with Ci-VSP and Ci-PTEN probes showed that Ci-VSP-positive cells are a distinct population, separate from cells expressing Ci-PTEN. These findings suggest that in addition to its previously suggested roles in testis or sperm, Ci-VSP plays a key role in voltage-induced signal transduction in cells of the digestive system and blood.
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Affiliation(s)
- Michio Ogasawara
- Department of Nanobiology, Graduate School of Advanced Integration Science, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263-8522, Japan
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