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Feng G, Sun Y. The Polycomb group gene rnf2 is essential for central and enteric neural system development in zebrafish. Front Neurosci 2022; 16:960149. [PMID: 36117635 PMCID: PMC9475114 DOI: 10.3389/fnins.2022.960149] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/03/2022] [Indexed: 11/13/2022] Open
Abstract
The development of central nervous system (CNS) and enteric nervous system (ENS) is under precise and strict control in vertebrates. Whether and how the Polycomb repressive complex 1 (PRC1) is involved in it remain unclear. To investigate the role of PRC1 in the nervous system development, using CRISPR/Cas9 technology, we have generated mutant zebrafish lines for the rnf2 gene which encodes Ring1b, the enzymatic component of the PRC1 complex. We show that rnf2 loss of function leads to abnormal migration and differentiation of neural crest and neural precursor cells. rnf2 mutant embryos exhibit aganglionosis, in which the hindgut is devoid of neurons. In particular, the formation of 5-HT serotonin neurons and myelinating glial cells is defective. Furthermore, ectopic expression of ENS marker genes is observed in forebrain of rnf2 mutant embryos. These findings suggest that the rnf2 gene plays an important role in the migration and differentiation of neural precursor cells, and its absence leads to abnormal development of ENS and CNS in zebrafish.
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Affiliation(s)
- Gang Feng
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Gang Feng,
| | - Yuhua Sun
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- Yuhua Sun,
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2
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Levraud JP, Rawls JF, Clatworthy AE. Using zebrafish to understand reciprocal interactions between the nervous and immune systems and the microbial world. J Neuroinflammation 2022; 19:170. [PMID: 35765004 PMCID: PMC9238045 DOI: 10.1186/s12974-022-02506-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 06/01/2022] [Indexed: 11/10/2022] Open
Abstract
Animals rely heavily on their nervous and immune systems to perceive and survive within their environment. Despite the traditional view of the brain as an immunologically privileged organ, these two systems interact with major consequences. Furthermore, microorganisms within their environment are major sources of stimuli and can establish relationships with animal hosts that range from pathogenic to mutualistic. Research from a variety of human and experimental animal systems are revealing that reciprocal interactions between microbiota and the nervous and immune systems contribute significantly to normal development, homeostasis, and disease. The zebrafish has emerged as an outstanding model within which to interrogate these interactions due to facile genetic and microbial manipulation and optical transparency facilitating in vivo imaging. This review summarizes recent studies that have used the zebrafish for analysis of bidirectional control between the immune and nervous systems, the nervous system and the microbiota, and the microbiota and immune system in zebrafish during development that promotes homeostasis between these systems. We also describe how the zebrafish have contributed to our understanding of the interconnections between these systems during infection in fish and how perturbations may result in pathology.
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Affiliation(s)
- Jean-Pierre Levraud
- Université Paris-Saclay, CNRS, Institut Pasteur, Université Paris-Cité, Institut des Neurosciences Paris-Saclay, 91400, Saclay, France.
| | - John F. Rawls
- grid.26009.3d0000 0004 1936 7961Department of Molecular Genetics and Microbiology, Duke Microbiome Center, Duke University School of Medicine, 213 Research Drive, Durham, NC 27710 USA
| | - Anne E. Clatworthy
- grid.66859.340000 0004 0546 1623Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA 02142 USA ,grid.32224.350000 0004 0386 9924Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114 USA
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3
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Raj B, Farrell JA, Liu J, El Kholtei J, Carte AN, Navajas Acedo J, Du LY, McKenna A, Relić Đ, Leslie JM, Schier AF. Emergence of Neuronal Diversity during Vertebrate Brain Development. Neuron 2020; 108:1058-1074.e6. [PMID: 33068532 PMCID: PMC8286448 DOI: 10.1016/j.neuron.2020.09.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/05/2020] [Accepted: 09/17/2020] [Indexed: 01/03/2023]
Abstract
Neurogenesis comprises many highly regulated processes including proliferation, differentiation, and maturation. However, the transcriptional landscapes underlying brain development are poorly characterized. We describe a developmental single-cell catalog of ∼220,000 zebrafish brain cells encompassing 12 stages from embryo to larva. We characterize known and novel gene markers for ∼800 clusters and provide an overview of the diversification of neurons and progenitors across these time points. We also introduce an optimized GESTALT lineage recorder that enables higher expression and recovery of Cas9-edited barcodes to query lineage segregation. Cell type characterization indicates that most embryonic neural progenitor states are transitory and transcriptionally distinct from neural progenitors of post-embryonic stages. Reconstruction of cell specification trajectories reveals that late-stage retinal neural progenitors transcriptionally overlap cell states observed in the embryo. The zebrafish brain development atlas provides a resource to define and manipulate specific subsets of neurons and to uncover the molecular mechanisms underlying vertebrate neurogenesis.
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Affiliation(s)
- Bushra Raj
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA.
| | - Jeffrey A Farrell
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Unit on Cell Specification and Differentiation, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20814, USA
| | - Jialin Liu
- Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA; Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Jakob El Kholtei
- Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA; Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Adam N Carte
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Biozentrum, University of Basel, 4056 Basel, Switzerland; Systems, Synthetic, and Quantitative Biology Program, Harvard University, Cambridge, MA 02138, USA
| | - Joaquin Navajas Acedo
- Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA; Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Lucia Y Du
- Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA; Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Aaron McKenna
- Department of Molecular and Systems Biology, Dartmouth Geisel School of Medicine, Lebanon, NH 03756, USA
| | - Đorđe Relić
- Biozentrum, University of Basel, 4056 Basel, Switzerland; Swiss Institute of Bioinformatics (SIB), 4056 Basel, Switzerland
| | - Jessica M Leslie
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Alexander F Schier
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Allen Discovery Center for Cell Lineage Tracing, Seattle, WA, USA; Biozentrum, University of Basel, 4056 Basel, Switzerland; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Harvard Stem Cell Institute, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
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4
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Lawal TA, Wires ES, Terry NL, Dowling JJ, Todd JJ. Preclinical model systems of ryanodine receptor 1-related myopathies and malignant hyperthermia: a comprehensive scoping review of works published 1990-2019. Orphanet J Rare Dis 2020; 15:113. [PMID: 32381029 PMCID: PMC7204063 DOI: 10.1186/s13023-020-01384-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/14/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Pathogenic variations in the gene encoding the skeletal muscle ryanodine receptor (RyR1) are associated with malignant hyperthermia (MH) susceptibility, a life-threatening hypermetabolic condition and RYR1-related myopathies (RYR1-RM), a spectrum of rare neuromuscular disorders. In RYR1-RM, intracellular calcium dysregulation, post-translational modifications, and decreased protein expression lead to a heterogenous clinical presentation including proximal muscle weakness, contractures, scoliosis, respiratory insufficiency, and ophthalmoplegia. Preclinical model systems of RYR1-RM and MH have been developed to better understand underlying pathomechanisms and test potential therapeutics. METHODS We conducted a comprehensive scoping review of scientific literature pertaining to RYR1-RM and MH preclinical model systems in accordance with the PRISMA Scoping Reviews Checklist and the framework proposed by Arksey and O'Malley. Two major electronic databases (PubMed and EMBASE) were searched without language restriction for articles and abstracts published between January 1, 1990 and July 3, 2019. RESULTS Our search yielded 5049 publications from which 262 were included in this review. A majority of variants tested in RYR1 preclinical models were localized to established MH/central core disease (MH/CCD) hot spots. A total of 250 unique RYR1 variations were reported in human/rodent/porcine models with 95% being missense substitutions. The most frequently reported RYR1 variant was R614C/R615C (human/porcine total n = 39), followed by Y523S/Y524S (rabbit/mouse total n = 30), I4898T/I4897T/I4895T (human/rabbit/mouse total n = 20), and R163C/R165C (human/mouse total n = 18). The dyspedic mouse was utilized by 47% of publications in the rodent category and its RyR1-null (1B5) myotubes were transfected in 23% of publications in the cellular model category. In studies of transfected HEK-293 cells, 57% of RYR1 variations affected the RyR1 channel and activation core domain. A total of 15 RYR1 mutant mouse strains were identified of which ten were heterozygous, three were compound heterozygous, and a further two were knockout. Porcine, avian, zebrafish, C. elegans, canine, equine, and drosophila model systems were also reported. CONCLUSIONS Over the past 30 years, there were 262 publications on MH and RYR1-RM preclinical model systems featuring more than 200 unique RYR1 variations tested in a broad range of species. Findings from these studies have set the foundation for therapeutic development for MH and RYR1-RM.
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Affiliation(s)
- Tokunbor A Lawal
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Emily S Wires
- National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA
| | - Nancy L Terry
- National Institutes of Health Library, National Institutes of Health, Bethesda, MD, USA
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Joshua J Todd
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, 20892, USA.
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Chhabria K, Plant K, Bandmann O, Wilkinson RN, Martin C, Kugler E, Armitage PA, Santoscoy PL, Cunliffe VT, Huisken J, McGown A, Ramesh T, Chico TJ, Howarth C. The effect of hyperglycemia on neurovascular coupling and cerebrovascular patterning in zebrafish. J Cereb Blood Flow Metab 2020; 40:298-313. [PMID: 30398083 PMCID: PMC6985997 DOI: 10.1177/0271678x18810615] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Neurovascular coupling (through which local cerebral blood flow changes in response to neural activation are mediated) is impaired in many diseases including diabetes. Current preclinical rodent models of neurovascular coupling rely on invasive surgery and instrumentation, but transgenic zebrafish coupled with advances in imaging techniques allow non-invasive quantification of cerebrovascular anatomy, neural activation, and cerebral vessel haemodynamics. We therefore established a novel non-invasive, non-anaesthetised zebrafish larval model of neurovascular coupling, in which visual stimulus evokes neuronal activation in the optic tectum that is associated with a specific increase in red blood cell speed in tectal blood vessels. We applied this model to the examination of the effect of glucose exposure on cerebrovascular patterning and neurovascular coupling. We found that chronic exposure of zebrafish to glucose impaired tectal blood vessel patterning and neurovascular coupling. The nitric oxide donor sodium nitroprusside rescued all these adverse effects of glucose exposure on cerebrovascular patterning and function. Our results establish the first non-mammalian model of neurovascular coupling, offering the potential to perform more rapid genetic modifications and high-throughput screening than is currently possible using rodents. Furthermore, using this zebrafish model, we reveal a potential strategy to ameliorate the effects of hyperglycemia on cerebrovascular function.
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Affiliation(s)
- Karishma Chhabria
- Neuroimaging in Cardiovascular Disease (NICAD) Network, University of Sheffield, Sheffield, UK.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK.,The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Karen Plant
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK.,The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Oliver Bandmann
- The Bateson Centre, University of Sheffield, Sheffield, UK.,Department of Neuroscience, University of Sheffield Medical School, Sheffield, UK
| | - Robert N Wilkinson
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK.,The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Chris Martin
- Neuroimaging in Cardiovascular Disease (NICAD) Network, University of Sheffield, Sheffield, UK.,Department of Psychology, University of Sheffield, Sheffield, UK
| | - Elisabeth Kugler
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK.,The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Paul A Armitage
- Neuroimaging in Cardiovascular Disease (NICAD) Network, University of Sheffield, Sheffield, UK.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK
| | - Paola Lm Santoscoy
- The Bateson Centre, University of Sheffield, Sheffield, UK.,Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Vincent T Cunliffe
- The Bateson Centre, University of Sheffield, Sheffield, UK.,Department of Biomedical Science, University of Sheffield, Sheffield, UK
| | - Jan Huisken
- Morgridge Institute for Research, Madison, WI, USA
| | - Alexander McGown
- The Bateson Centre, University of Sheffield, Sheffield, UK.,Department of Neuroscience, University of Sheffield Medical School, Sheffield, UK
| | - Tennore Ramesh
- The Bateson Centre, University of Sheffield, Sheffield, UK.,Department of Neuroscience, University of Sheffield Medical School, Sheffield, UK
| | - Tim Ja Chico
- Neuroimaging in Cardiovascular Disease (NICAD) Network, University of Sheffield, Sheffield, UK.,Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK.,The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Clare Howarth
- Neuroimaging in Cardiovascular Disease (NICAD) Network, University of Sheffield, Sheffield, UK.,Department of Psychology, University of Sheffield, Sheffield, UK
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Thyme SB, Pieper LM, Li EH, Pandey S, Wang Y, Morris NS, Sha C, Choi JW, Herrera KJ, Soucy ER, Zimmerman S, Randlett O, Greenwood J, McCarroll SA, Schier AF. Phenotypic Landscape of Schizophrenia-Associated Genes Defines Candidates and Their Shared Functions. Cell 2019; 177:478-491.e20. [PMID: 30929901 PMCID: PMC6494450 DOI: 10.1016/j.cell.2019.01.048] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 10/15/2018] [Accepted: 01/27/2019] [Indexed: 01/25/2023]
Abstract
Genomic studies have identified hundreds of candidate genes near loci associated with risk for schizophrenia. To define candidates and their functions, we mutated zebrafish orthologs of 132 human schizophrenia-associated genes. We created a phenotype atlas consisting of whole-brain activity maps, brain structural differences, and profiles of behavioral abnormalities. Phenotypes were diverse but specific, including altered forebrain development and decreased prepulse inhibition. Exploration of these datasets identified promising candidates in more than 10 gene-rich regions, including the magnesium transporter cnnm2 and the translational repressor gigyf2, and revealed shared anatomical sites of activity differences, including the pallium, hypothalamus, and tectum. Single-cell RNA sequencing uncovered an essential role for the understudied transcription factor znf536 in the development of forebrain neurons implicated in social behavior and stress. This phenotypic landscape of schizophrenia-associated genes prioritizes more than 30 candidates for further study and provides hypotheses to bridge the divide between genetic association and biological mechanism.
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Affiliation(s)
- Summer B Thyme
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
| | - Lindsey M Pieper
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Eric H Li
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Shristi Pandey
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Yiqun Wang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Nathan S Morris
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Carrie Sha
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Joo Won Choi
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Kristian J Herrera
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Edward R Soucy
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Steve Zimmerman
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Owen Randlett
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Joel Greenwood
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Steven A McCarroll
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Stanley Center for Psychiatric Research, Cambridge, MA 02142, USA
| | - Alexander F Schier
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Biozentrum, University of Basel, CH-4056 Basel, Switzerland; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; FAS Center for Systems Biology, Harvard University, MA 02138, USA; Allen Discovery Center for Cell Lineage Tracing, Seattle, WA 98104, USA.
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Simultaneous single-cell profiling of lineages and cell types in the vertebrate brain. Nat Biotechnol 2018; 36:442-450. [PMID: 29608178 PMCID: PMC5938111 DOI: 10.1038/nbt.4103] [Citation(s) in RCA: 374] [Impact Index Per Article: 62.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 02/15/2018] [Indexed: 12/25/2022]
Abstract
The lineage relationships among the hundreds of cell types generated during development are difficult to reconstruct. A recent method, GESTALT, used CRISPR-Cas9 barcode editing for large-scale lineage tracing, but was restricted to early development and did not identify cell types. Here we present scGESTALT, which combines the lineage recording capabilities of GESTALT with cell-type identification by single-cell RNA sequencing. The method relies on an inducible system that enables barcodes to be edited at multiple time points, capturing lineage information from later stages of development. Sequencing of ~60,000 transcriptomes from the juvenile zebrafish brain identifies >100 cell types and marker genes. Using these data, we generate lineage trees with hundreds of branches that help uncover restrictions at the level of cell types, brain regions, and gene expression cascades during differentiation. scGESTALT can be applied to other multicellular organisms to simultaneously characterize molecular identities and lineage histories of thousands of cells during development and disease.
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8
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Kelu JJ, Webb SE, Galione A, Miller AL. TPC2-mediated Ca 2+ signaling is required for the establishment of synchronized activity in developing zebrafish primary motor neurons. Dev Biol 2018; 438:57-68. [PMID: 29577882 DOI: 10.1016/j.ydbio.2018.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 10/17/2022]
Abstract
During the development of the early spinal circuitry in zebrafish, spontaneous Ca2+ transients in the primary motor neurons (PMNs) are reported to transform from being slow and uncorrelated, to being rapid, synchronized and patterned. In this study, we demonstrated that in intact zebrafish, Ca2+ release via two-pore channel type 2 (TPC2) from acidic stores/endolysosomes is required for the establishment of synchronized activity in the PMNs. Using the SAIGFF213A;UAS:GCaMP7a double-transgenic zebrafish line, Ca2+ transients were visualized in the caudal PMNs (CaPs). TPC2 inhibition via molecular, genetic or pharmacological means attenuated the CaP Ca2+ transients, and decreased the normal ipsilateral correlation and contralateral anti-correlation, indicating a disruption in normal spinal circuitry maturation. Furthermore, treatment with MS-222 resulted in a complete (but reversible) inhibition of the CaP Ca2+ transients, as well as a significant decrease in the concentration of the Ca2+ mobilizing messenger, nicotinic acid adenine diphosphate (NAADP) in whole embryo extract. Together, our new data suggest a novel function for NAADP/TPC2-mediated Ca2+ signaling in the development, coordination, and maturation of the spinal network in zebrafish embryos.
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Affiliation(s)
- Jeffrey J Kelu
- Division of Life Science&State Key Laboratory of Molecular Neuroscience, HKUST, Hong Kong
| | - Sarah E Webb
- Division of Life Science&State Key Laboratory of Molecular Neuroscience, HKUST, Hong Kong
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Andrew L Miller
- Division of Life Science&State Key Laboratory of Molecular Neuroscience, HKUST, Hong Kong.
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Knockdown of epigenetic transcriptional co-regulator Brd2a disrupts apoptosis and proper formation of hindbrain and midbrain-hindbrain boundary (MHB) region in zebrafish. Mech Dev 2017; 146:10-30. [PMID: 28549975 DOI: 10.1016/j.mod.2017.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 05/17/2017] [Accepted: 05/22/2017] [Indexed: 01/03/2023]
Abstract
Brd2 is a member of the bromodomain-extraterminal domain (BET) family of proteins and functions as an acetyl-histone-directed transcriptional co-regulator and recruitment scaffold in chromatin modification complexes affecting signal-dependent transcription. While Brd2 acts as a protooncogene in mammalian blood, developmental studies link it to regulation of neuronal apoptosis and epilepsy, and complete knockout of the gene is invariably embryonic lethal. In Drosophila, the Brd2 homolog acts as a maternal effect factor necessary for segment formation and identity and proper expression of homeotic loci, including Ultrabithorax and engrailed. To test the various roles attributed to Brd2 in a single developmental system representing a non-mammalian vertebrate, we conducted a phenotypic characterization of Brd2a deficient zebrafish embryos produced by morpholino knockdown and corroborated by Crispr-Cas9 disruption and small molecule inhibitor treatments. brd2aMO morphants exhibit reduced hindbrain with an ill-defined midbrain-hindbrain boundary (MHB) region; irregular notochord, neural tube, and somites; and abnormalities in ventral trunk and ventral nerve cord interneuron positioning. Using whole mount TUNEL and confocal microscopy, we uncover a significant decrease, then a dramatic increase, of p53-independent cell death at the start and end of segmentation, respectively. In contrast, using qualitative and quantitative analyses of BrdU incorporation, phosphohistone H3-tagging, and flow cytometry, we detect little effect of Brd2a knockdown on overall proliferation levels in embryos. RNA in situ hybridization shows reduced or absent expression of homeobox gene eng2a and paired box gene pax2a, in the hindbrain domain of the MHB region, and an overabundance of pax2a-positive kidney progenitors, in knockdowns. Together, these results suggest an evolutionarily conserved role for Brd2 in the proper formation and/or patterning of segmented tissues, including the vertebrate CNS, where it acts as a bi-modal regulator of apoptosis, and is necessary, directly or indirectly, for proper expression of genes that pattern the MHB and/or regulate differentiation in the anterior hindbrain.
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10
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Karoubi N, Segev R, Wullimann MF. The Brain of the Archerfish Toxotes chatareus: A Nissl-Based Neuroanatomical Atlas and Catecholaminergic/Cholinergic Systems. Front Neuroanat 2016; 10:106. [PMID: 27891081 PMCID: PMC5104738 DOI: 10.3389/fnana.2016.00106] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 10/13/2016] [Indexed: 01/30/2023] Open
Abstract
Over recent years, the seven-spot archerfish (Toxotes chatareus) has emerged as a new model for studies in visual and behavioral neuroscience thanks to its unique hunting strategy. Its natural ability to spit at insects outside of water can be used in the laboratory for well controlled behavioral experiments where the fish is trained to aim at targets on a screen. The need for a documentation of the neuroanatomy of this animal became critical as more research groups use it as a model. Here we present an atlas of adult T. chatareus specimens caught in the wild in South East Asia. The atlas shows representative sections of the brain and specific structures revealed by a classic Nissl staining as well as corresponding schematic drawings. Additional immunostainings for catecholaminergic and cholinergic systems were conducted to corroborate the identification of certain nuclei and the data of a whole brain scanner is available online. We describe the general features of the archerfish brain as well as its specificities, especially for the visual system and compare the neuroanatomy of the archerfish with other teleosts. This atlas of the archerfish brain shows all levels of the neuraxis and intends to provide a solid basis for further neuroscientific research on T. chatareus, in particular electrophysiological studies.
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Affiliation(s)
- Naomi Karoubi
- Life Sciences Department and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beersheba, Israel
| | - Ronen Segev
- Life Sciences Department and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev Beersheba, Israel
| | - Mario F Wullimann
- Graduate School of Systemic Neurosciences and Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University of Munich Munich, Germany
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11
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Kazokaitė J, Aspatwar A, Kairys V, Parkkila S, Matulis D. Fluorinated benzenesulfonamide anticancer inhibitors of carbonic anhydrase IX exhibit lower toxic effects on zebrafish embryonic development than ethoxzolamide. Drug Chem Toxicol 2016; 40:309-319. [PMID: 27600313 DOI: 10.1080/01480545.2016.1223095] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The toxic effects of two recently discovered inhibitors (VD12-09 and VD11-4-2) that selectively and with extraordinary strong, picomolar binding affinity to human carbonic anhydrase (CA) isoform IX were investigated on zebrafish embryonic development. CA IX has been recently introduced as an anticancer target since it is highly overexpressed in numerous human cancers but nearly absent in normal tissues. Morphological changes in zebrafish treated by the compounds were studied by light-field microscopy and histological analysis. Homology models of zebrafish CA II and CA IX were built to identify the conserved amino acid residues in the active site of zebrafish CAs. The toxicity studies here showed that the LC50 values at 120 hours post-fertilization (hpf) were 13 μM for VD12-09, 120 μM for VD11-4-2, and 9 μM for ethoxzolamide (EZA), a non-selective CA inhibitor commonly used as a drug in clinics. Thus, EZA was the most toxic of the three compounds. The zebrafish embryos exposed to LC50 doses of VD12-09 and VD11-4-2 showed fewer phenotypic abnormalities compared with the embryos exposed to the corresponding dose of EZA. Histochemical studies did not show any gross morphological changes in the embryos treated with VD12-09 and VD11-4-2 unlike EZA. The results of our study indicate that the compounds exhibited 10-fold lower toxicity and induced fewer side effects in zebrafish than EZA. Therefore, the exposure to VD11-4-2 and VD12-09 at concentrations below LC50 did not lead to deleterious effects on the zebrafish embryonic development and thus both inhibitors may be further developed as drugs.
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Affiliation(s)
- Justina Kazokaitė
- a Department of Biothermodynamics and Drug Design , Institute of Biotechnology, Vilnius University , Vilnius , Lithuania
| | - Ashok Aspatwar
- b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland.,c Fimlab Ltd, Tampere University Hospital , Tampere , Finland , and
| | - Visvaldas Kairys
- d Department of Bioinformatics , Institute of Biotechnology, Vilnius University , Vilnius , Lithuania
| | - Seppo Parkkila
- b Faculty of Medicine and Life Sciences , University of Tampere , Tampere , Finland.,c Fimlab Ltd, Tampere University Hospital , Tampere , Finland , and
| | - Daumantas Matulis
- a Department of Biothermodynamics and Drug Design , Institute of Biotechnology, Vilnius University , Vilnius , Lithuania
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12
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Ma Y, Zhang C, Gao XB, Luo HY, Chen Y, Li HH, Ma X, Lu CL. Folic acid protects against arsenic-mediated embryo toxicity by up-regulating the expression of Dvr1. Sci Rep 2015; 5:16093. [PMID: 26537450 PMCID: PMC4633590 DOI: 10.1038/srep16093] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/08/2015] [Indexed: 12/15/2022] Open
Abstract
As a nutritional factor, folic acid can prevent cardiac and neural defects during embryo development. Our previous study showed that arsenic impairs embryo development by down-regulating Dvr1/GDF1 expression in zebrafish. Here, we investigated whether folic acid could protect against arsenic-mediated embryo toxicity. We found that folic acid supplementation increases hatching and survival rates, decreases malformation rate and ameliorates abnormal cardiac and neural development of zebrafish embryos exposed to arsenite. Both real-time PCR analysis and whole in-mount hybridization showed that folic acid significantly rescued the decrease in Dvr1 expression caused by arsenite. Subsequently, our data demonstrated that arsenite significantly decreased cell viability and GDF1 mRNA and protein levels in HEK293ET cells, while folic acid reversed these effects. Folic acid attenuated the increase in subcellular reactive oxygen species (ROS) levels and oxidative adaptor p66Shc protein expression in parallel with the changes in GDF1 expression and cell viability. P66Shc knockdown significantly inhibited the production of ROS and the down-regulation of GDF1 induced by arsenite. Our data demonstrated that folic acid supplementation protected against arsenic-mediated embryo toxicity by up-regulating the expression of Dvr1/GDF1, and folic acid enhanced the expression of GDF1 by decreasing p66Shc expression and subcellular ROS levels.
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Affiliation(s)
- Yan Ma
- Graduate School of Peking Union Medical College, Beijing, China.,Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Chen Zhang
- Graduate School of Peking Union Medical College, Beijing, China.,Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Xiao-Bo Gao
- Graduate School of Peking Union Medical College, Beijing, China.,Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Hai-Yan Luo
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Yang Chen
- MOE Key Laboratory of Bioinformatics, TNLIST Bioinformatics Division &Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China
| | - Hui-hua Li
- Department of Nutrition and Food Hygiene, School of Public Health, Dalian Medical University, Dalian, China.,Department of Cardiology, Institute of Cardiovascular Disease, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Xu Ma
- Graduate School of Peking Union Medical College, Beijing, China.,Department of Genetics, National Research Institute for Family Planning, Beijing, China
| | - Cai-Ling Lu
- Graduate School of Peking Union Medical College, Beijing, China.,Department of Genetics, National Research Institute for Family Planning, Beijing, China
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13
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Oosterhof N, Boddeke E, van Ham TJ. Immune cell dynamics in the CNS: Learning from the zebrafish. Glia 2014; 63:719-35. [PMID: 25557007 DOI: 10.1002/glia.22780] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/10/2014] [Indexed: 12/22/2022]
Abstract
A major question in research on immune responses in the brain is how the timing and nature of these responses influence physiology, pathogenesis or recovery from pathogenic processes. Proper understanding of the immune regulation of the human brain requires a detailed description of the function and activities of the immune cells in the brain. Zebrafish larvae allow long-term, noninvasive imaging inside the brain at high-spatiotemporal resolution using fluorescent transgenic reporters labeling specific cell populations. Together with recent additional technical advances this allows an unprecedented versatility and scope of future studies. Modeling of human physiology and pathology in zebrafish has already yielded relevant insights into cellular dynamics and function that can be translated to the human clinical situation. For instance, in vivo studies in the zebrafish have provided new insight into immune cell dynamics in granuloma formation in tuberculosis and the mechanisms involving treatment resistance. In this review, we highlight recent findings and novel tools paving the way for basic neuroimmunology research in the zebrafish. GLIA 2015;63:719-735.
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Affiliation(s)
- Nynke Oosterhof
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands
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14
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Herrero-Turrión MJ, Rodríguez-Martín I, López-Bellido R, Rodríguez RE. Whole-genome expression profile in zebrafish embryos after chronic exposure to morphine: identification of new genes associated with neuronal function and mu opioid receptor expression. BMC Genomics 2014; 15:874. [PMID: 25294025 PMCID: PMC4201762 DOI: 10.1186/1471-2164-15-874] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 09/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A great number of studies have investigated changes induced by morphine exposure in gene expression using several experimental models. In this study, we examined gene expression changes during chronic exposure to morphine during maturation and differentiation of zebrafish CNS. RESULTS Microarray analysis showed 254 genes whose expression was identified as different by at least 1.3 fold change following chronic morphine exposure as compared to controls. Of these, several novel genes (grb2, copb2, otpb, magi1b, grik-l, bnip4 and sox19b) have been detected for the first time in an experimental animal model treated with morphine. We have also identified a subset of genes (dao.1, wls, bnip4 and camk1γb) differentially expressed by chronic morphine exposure whose expression is related to mu opioid receptor gene expression. Altered expression of copb2, bnip4, sox19b, otpb, dao.1, grik-l and wls is indicative of modified neuronal development, CNS patterning processes, differentiation and dopaminergic neurotransmission, serotonergic signaling pathway, and glutamatergic neurotransmission. The deregulation of camk1γb signaling genes suggests an activation of axonogenesis and dendritogenesis. CONCLUSIONS Our study identified different functional classes of genes and individual candidates involved in the mechanisms underlying susceptibility to morphine actions related to CNS development. These results open new lines to study the treatment of pain and the molecular mechanisms involved in addiction. We also found a set of zebrafish-specific morphine-induced genes, which may be putative targets in human models for addiction and pain processes.
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Affiliation(s)
| | | | | | - Raquel E Rodríguez
- Instituto de Neurociencias de Castilla y León, University of Salamanca, Salamanca 37007, Spain.
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15
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Evidence for the coevolution of axon guidance molecule Netrin and its receptor Frazzled. Gene 2014; 544:25-31. [DOI: 10.1016/j.gene.2014.04.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 04/14/2014] [Accepted: 04/16/2014] [Indexed: 11/24/2022]
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16
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Chen X, Xu B, Han X, Mao Z, Chen M, Du G, Talbot P, Wang X, Xia Y. The effects of triclosan on pluripotency factors and development of mouse embryonic stem cells and zebrafish. Arch Toxicol 2014; 89:635-46. [PMID: 24879426 DOI: 10.1007/s00204-014-1270-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 05/13/2014] [Indexed: 01/27/2023]
Abstract
Triclosan (TCS) poses potential risks to reproduction and development due to its endocrine-disrupting properties. However, the mechanism of TCS's effects on early embryonic development is little known. Embryonic stem cells (ESC) and zebrafish embryos provide valuable models for testing the toxic effects of environmental chemicals on early embryogenesis. In this study, mouse embryonic stem cells (mESC) were acutely exposed to TCS for 24 h, and general cytotoxicity and the effect of TCS on pluripotency were then evaluated. In addition, zebrafish embryos were exposed to TCS from 2- to 24-h post-fertilization (hpf), and their morphology was evaluated. In mESC, alkaline phosphatase staining was significantly decreased after treatment with the highest concentration of TCS (50 μM). Although the expression levels of Sox2 mRNA were not changed, the mRNA levels of Oct4 and Nanog in TCS-treated groups were significantly decreased compared to controls. In addition, the protein levels of Oct4, Sox2 and Nanog were significantly reduced in response to TCS treatment. MicroRNA (miR)-134, an expression inhibitor of pluripotency markers, was significantly increased in TCS-treated mESC. In zebrafish experiments, after 24 hpf of treatment, the controls had developed to the late stage of somitogenesis, while embryos exposed to 300 μg/L of TCS were still at the early stage of somitogenesis, and three genes (Oct4, Sox2 and Nanog) were upregulated in treated groups when compared with the controls. The two models demonstrated that TCS may affect early embryonic development by disturbing the expression of the pluripotency markers (Oct4, Sox2 and Nanog).
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Affiliation(s)
- Xiaojiao Chen
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, 210029, China
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17
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Zenki KC, Mussulini BHM, Rico EP, de Oliveira DL, Rosemberg DB. Effects of ethanol and acetaldehyde in zebrafish brain structures: an in vitro approach on glutamate uptake and on toxicity-related parameters. Toxicol In Vitro 2014; 28:822-8. [PMID: 24681127 DOI: 10.1016/j.tiv.2014.03.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/14/2014] [Accepted: 03/18/2014] [Indexed: 01/30/2023]
Abstract
Ethanol (EtOH) and its metabolite, acetaldehyde (ALD), induce deleterious effects on central nervous system (CNS). Here we investigate the in vitro toxicity of EtOH and ALD (concentrations of 0.25%, 0.5%, and 1%) in zebrafish brain structures [telencephalon (TE), opticum tectum (OT), and cerebellum (CE)] by measuring the functionality of glutamate transporters, MTT reduction, and extracellular LDH activity. Both molecules decreased the activity of the Na(+)-dependent glutamate transporters in all brain structures. The strongest glutamate uptake inhibition after EtOH exposure was 58% (TE-1%), and after ALD, 91% (CE-1%). The results of MTT assay and LDH released demonstrated that the actions of EtOH and its metabolite are concentration and structure-dependent, in which ALD was more toxic than EtOH. In summary, our findings demonstrate a differential toxicity in vitro of EtOH and ALD in zebrafish brain structures, which can involve changes on glutamatergic parameters. We suggest that this species may be an interesting model for assessing the toxicological actions of alcohol and its metabolite in CNS.
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Affiliation(s)
- Kamila Cagliari Zenki
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. Rua Ramiro Barcelos, 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil.
| | - Ben Hur Marins Mussulini
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. Rua Ramiro Barcelos, 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil
| | - Eduardo Pacheco Rico
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. Rua Ramiro Barcelos, 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil; Instituto Nacional de Ciência e Tecnologia em Excitotoxicidade e Neuroproteção (INCT-EN) 90035-003, Porto Alegre, RS, Brazil
| | - Diogo Lösch de Oliveira
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. Rua Ramiro Barcelos, 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil; Zebrafish Neuroscience Research Consortium (ZNRC), USA
| | - Denis Broock Rosemberg
- Instituto Nacional de Ciência e Tecnologia em Excitotoxicidade e Neuroproteção (INCT-EN) 90035-003, Porto Alegre, RS, Brazil; Zebrafish Neuroscience Research Consortium (ZNRC), USA; Programa de Pós-graduação em Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria. Avenida Roraima, 1000, 97105-900 Santa Maria, RS, Brazil.
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18
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Zebrafish models for assessing developmental and reproductive toxicity. Neurotoxicol Teratol 2014; 42:35-42. [PMID: 24503215 DOI: 10.1016/j.ntt.2014.01.006] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 01/22/2014] [Accepted: 01/26/2014] [Indexed: 11/20/2022]
Abstract
The zebrafish is increasingly used as a vertebrate animal model for in vivo drug discovery and for assessing chemical toxicity and safety. Numerous studies have confirmed that zebrafish and mammals are similar in their physiology, development, metabolism and pathways, and that zebrafish responses to toxic substances are highly predictive of mammalian responses. Developmental and reproductive toxicity assessments are an important part of new drug safety profiling. A significant number of drug candidates have failed in preclinical tests due to their adverse effect on development and reproductivity. Compared to conventional mammal testing, zebrafish testing for assessing developmental and reproductive toxicity offers several compelling experimental advantages, including transparency of embryo and larva, higher throughput, shorter test period, lower cost, smaller amount of compound required, easier manipulation and direct compound delivery. Toxicity and safety assessments using zebrafish have also been accepted by the FDA and EMEA for investigative new drug (IND) approval.
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19
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Miyake A, Itoh N. Fgf22 regulated by Fgf3/Fgf8 signaling is required for zebrafish midbrain development. Biol Open 2013; 2:515-24. [PMID: 23789101 PMCID: PMC3654271 DOI: 10.1242/bio.20134226] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 03/01/2013] [Indexed: 12/24/2022] Open
Abstract
Fibroblast growth factor (Fgf) signaling plays important roles in various developmental processes including brain development. Here, we identified zebrafish fgf22 predominantly expressed in the posterior midbrain and anterior midbrain-hindbrain boundary (MHB) primordia during early embryonic brain development. To examine roles of Fgf22 in midbrain development, we analyzed fgf22 knockdown embryos. The fgf22 morphants were defective in proper formation of the MHB constriction and the midbrain. The knockdown of fgf22 caused decreased cell proliferation in the midbrain, expanded expression of roof plate and tegmental marker genes, and decreased expression of tectal marker genes, indicating that Fgf22 is required for cell proliferation, roof plate formation, and tectum specification in the midbrain. Fgf receptor 2b (Fgfr2b), a potential receptor for Fgf22, was also required, indicating that Fgf22 signaling is mediated through Fgfr2b. The floor plate and the MHB are crucial for the dorsoventral patterning of the midbrain through Hedgehog (Hh) and Fgf signaling, respectively. The fgf3/fgf8 double morphant phenotype was essentially similar to that of fgf22 morphants, whereas the phenotype caused by inhibition of Hh signaling was not. fgf3 and fgf8 were expressed earlier than fgf22 in the MHB primordium and Fgf3/Fgf8 signaling was required for fgf22 expression in the posterior midbrain. Furthermore, fgf22 partially rescued the fgf3/fgf8 double morphant phenotype. The present results indicate Fgf22 to be involved in midbrain development downstream of Fgf3 and Fgf8 in the MHB but not of Hh in the floor plate.
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Affiliation(s)
- Ayumi Miyake
- Department of Genetic Biochemistry, Kyoto University Graduate School of Pharmaceutical Sciences , Sakyo, Kyoto 606-8501 , Japan
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20
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Schmidt R, Strähle U, Scholpp S. Neurogenesis in zebrafish - from embryo to adult. Neural Dev 2013; 8:3. [PMID: 23433260 PMCID: PMC3598338 DOI: 10.1186/1749-8104-8-3] [Citation(s) in RCA: 216] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 01/17/2013] [Indexed: 01/19/2023] Open
Abstract
Neurogenesis in the developing central nervous system consists of the induction and proliferation of neural progenitor cells and their subsequent differentiation into mature neurons. External as well as internal cues orchestrate neurogenesis in a precise temporal and spatial way. In the last 20 years, the zebrafish has proven to be an excellent model organism to study neurogenesis in the embryo. Recently, this vertebrate has also become a model for the investigation of adult neurogenesis and neural regeneration. Here, we summarize the contributions of zebrafish in neural development and adult neurogenesis.
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Affiliation(s)
- Rebecca Schmidt
- Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, 76021, Karlsruhe, Germany
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21
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de Esch C, Slieker R, Wolterbeek A, Woutersen R, de Groot D. Zebrafish as potential model for developmental neurotoxicity testing. Neurotoxicol Teratol 2012; 34:545-53. [DOI: 10.1016/j.ntt.2012.08.006] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 08/24/2012] [Accepted: 08/28/2012] [Indexed: 11/26/2022]
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22
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Abstract
The cerebellum controls smooth and skillful movements and it is also involved in higher cognitive and emotional functions. The cerebellum is derived from the dorsal part of the anterior hindbrain and contains two groups of cerebellar neurons: glutamatergic and gamma-aminobutyric acid (GABA)ergic neurons. Purkinje cells are GABAergic and granule cells are glutamatergic. Granule and Purkinje cells receive input from outside of the cerebellum from mossy and climbing fibers. Genetic analysis of mice and zebrafish has revealed genetic cascades that control the development of the cerebellum and cerebellar neural circuits. During early neurogenesis, rostrocaudal patterning by intrinsic and extrinsic factors, such as Otx2, Gbx2 and Fgf8, plays an important role in the positioning and formation of the cerebellar primordium. The cerebellar glutamatergic neurons are derived from progenitors in the cerebellar rhombic lip, which express the proneural gene Atoh1. The GABAergic neurons are derived from progenitors in the ventricular zone, which express the proneural gene Ptf1a. The mossy and climbing fiber neurons originate from progenitors in the hindbrain rhombic lip that express Atoh1 or Ptf1a. Purkinje cells exhibit mediolateral compartmentalization determined on the birthdate of Purkinje cells, and linked to the precise neural circuitry formation. Recent studies have shown that anatomy and development of the cerebellum is conserved between mammals and bony fish (teleost species). In this review, we describe the development of cerebellar neurons and neural circuitry, and discuss their evolution by comparing developmental processes of mammalian and teleost cerebellum.
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Affiliation(s)
- Mitsuhiro Hashimoto
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa, Nagoya, Aichi, 466-8550, Japan.
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23
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Ma Y, Wu M, Li D, Li XQ, Li P, Zhao J, Luo MN, Guo CL, Gao XB, Lu CL, Ma X. Embryonic developmental toxicity of selenite in zebrafish (Danio rerio) and prevention with folic acid. Food Chem Toxicol 2012; 50:2854-63. [DOI: 10.1016/j.fct.2012.04.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 04/06/2012] [Accepted: 04/24/2012] [Indexed: 01/28/2023]
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24
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He C, Wang C, Zhou Y, Li J, Zuo Z. Embryonic exposure to benzo(a)pyrene influences neural development and function in rockfish (Sebastiscus marmoratus). Neurotoxicology 2012; 33:758-62. [DOI: 10.1016/j.neuro.2012.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 11/20/2011] [Accepted: 01/06/2012] [Indexed: 12/27/2022]
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25
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He C, Wang C, Li B, Wu M, Geng H, Chen Y, Zuo Z. Exposure of Sebastiscus marmoratus embryos to pyrene results in neurodevelopmental defects and disturbs related mechanisms. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2012; 116-117:109-115. [PMID: 22487263 DOI: 10.1016/j.aquatox.2012.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 03/13/2012] [Accepted: 03/13/2012] [Indexed: 05/31/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants, which are known to be carcinogenic and teratogenic. These compounds cause a range of macroscopic malformations, particularly to the craniofacial apparatus and cardiovascular system during vertebrate development. However, little is known concerning microscopic effects, especially on the sensitive early life stages or on the molecular basis of developmental neurotoxicity. Using the rockfish (Sebastiscus marmoratus), we explored the neurodevelopmental defects caused by early-life exposure to environmentally relevant concentrations of pyrene, a 4-ring PAH. The results showed that pyrene substantially disrupted the cranial innervation pattern and caused deficiency of motor nerves. The expression of a protein associated with axon growth, growth associated protein 43, was decreased in the central nervous system after treatment with pyrene. N-methyl-D-aspartate receptor (NMDAR) plays a vital role in a variety of processes, including neuronal development, synaptic plasticity, and neuronal survival and death. Our results showed that the expression of Ca²⁺/calmodulin dependent kinase II and cAMP-response element-binding, which belong to the NMDAR pathway, were increased in a dose-dependent manner after exposure to pyrene. Acetylcholine, an important neurotransmitter which is known to suppress retinal cells neurite outgrowth, was increased by pyrene exposure. Nitric oxide (NO) acts as an activity-dependent retrograde signal that can coordinate axonal targeting and synaptogenesis during development. The level of NO was decreased in a dose-dependent manner following exposure to pyrene. Taken together, the defects in neurodevelopment and the damage to related mechanisms provided the basis for a better understanding of the neurotoxic effects of pyrene.
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Affiliation(s)
- Chengyong He
- Key Laboratory of Ministry of Education for Subtropical Wetland Ecosystem Research, School of Life Sciences, Xiamen University, Xiamen, China
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26
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de Esch C, van der Linde H, Slieker R, Willemsen R, Wolterbeek A, Woutersen R, De Groot D. Locomotor activity assay in zebrafish larvae: Influence of age, strain and ethanol. Neurotoxicol Teratol 2012; 34:425-33. [DOI: 10.1016/j.ntt.2012.03.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 02/16/2012] [Accepted: 03/19/2012] [Indexed: 10/28/2022]
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27
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Hibi M, Shimizu T. Development of the cerebellum and cerebellar neural circuits. Dev Neurobiol 2012; 72:282-301. [DOI: 10.1002/dneu.20875] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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28
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Singh SK, Saxena S, Meena Lakshmi MG, Saxena P, Idris MM. Proteome Profile of Zebrafish Danio rerio Olfactory Bulb Based on Two-Dimensional Gel Electrophoresis Matrix-Assisted Laser Desorption/Ionization MS/MS Analysis. Zebrafish 2011; 8:183-9. [DOI: 10.1089/zeb.2011.0711] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Sachin K. Singh
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Sandeep Saxena
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Priyanka Saxena
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
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29
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Zhang L, Li YY, Chen T, Xia W, Zhou Y, Wan YJ, Lv ZQ, Li GQ, Xu SQ. Abnormal development of motor neurons in perfluorooctane sulphonate exposed zebrafish embryos. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:643-652. [PMID: 21298338 DOI: 10.1007/s10646-011-0604-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/27/2011] [Indexed: 05/30/2023]
Abstract
Perfluorooctane sulfonate (PFOS) is an environmental organic pollutant, the potential neurotoxicity of which is causing great concern in fish. In the present study, we examined the effects of PFOS on motor neurons, and investigated the potential toxicological mechanisms oxidative stress in zebrafish embryos. Six-hour post-fertilization (hpf) zebrafish embryos were exposed to 1.0 mg/L PFOS, then we examined the expression of alpha-tubulin, proliferating cell nuclear antigen (PCNA), cyclin-dependent kinase 5 (CDK5), and peroxiredoxin 2 (PRX2) after PFOS exposure until 120 hpf. The results showed that PFOS increased alpha-tubulin in the coccygeal spinal cord (CSC) at 96 hpf, whereas decreased alpha-tubulin in the brain and spinal cord at 120 hpf. PCNA expression was highly increased in CSC and abdomen compared with control at 96 and 120 hpf after PFOS exposure. In addition, PFOS exposure caused CDK5 expression to be highly increased in brain region following by down-regulation of PRX2 expression at 96 hpf. These results indicated that, at least in part, the effect on motor neurons induced by PFOS was mediated by dynamically interfering with the expression of alpha-tubulin and PCNA. Furthermore, PFOS-induced toxicity was associated with oxidative stress by deregulating CDK5 and PRX2.
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Affiliation(s)
- Ling Zhang
- Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
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30
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Hui SP, Dutta A, Ghosh S. Cellular response after crush injury in adult zebrafish spinal cord. Dev Dyn 2010; 239:2962-79. [DOI: 10.1002/dvdy.22438] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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31
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Guo S. Using zebrafish to assess the impact of drugs on neural development and function. Expert Opin Drug Discov 2009; 4:715-726. [PMID: 19774094 DOI: 10.1517/17460440902988464] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND: Zebrafish is becoming an increasingly attractive model organism for understanding biology and developing therapeutics, because as a vertebrate, it shares considerable similarity with mammals in both genetic compositions and tissue/organ structures, and yet remains accessible to high throughput phenotype-based genetic and small molecule compound screening. OBJECTIVE/METHOD: The focus of this review is on the nervous system, which is arguably the most complex organ and known to be afflicted by more than six hundred disorders in humans. I discuss the past, present, and future of using zebrafish to assess the impact of small molecule drugs on neural development and function, in light of understanding and treating neurodevelopmental disorders such as autism, neurodegenerative disorders including Alzheimer's, Parkinson's, and Hungtington's disease, and neural system dysfunctions such as anxiety/depression and addiction. CONCLUSION: These studies hold promise to reveal fundamental mechanisms governing nervous system development and function, and to facilitate small molecule drug discovery for the many types of neurological disorders.
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Affiliation(s)
- Su Guo
- Department of Biopharmaceutical Sciences, Programs in Biological Sciences and Human Genetics, Institute for Regenerative Medicine, University of California San Francisco, CA 94143-2811
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Li D, Lu C, Wang J, Hu W, Cao Z, Sun D, Xia H, Ma X. Developmental mechanisms of arsenite toxicity in zebrafish (Danio rerio) embryos. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2009; 91:229-37. [PMID: 19110324 DOI: 10.1016/j.aquatox.2008.11.007] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 11/08/2008] [Accepted: 11/10/2008] [Indexed: 05/06/2023]
Abstract
Arsenic usually accumulates in soil, water and airborne particles, from which it is taken up by various organisms. Exposure to arsenic through food and drinking water is a major public health problem affecting some countries. At present there are limited laboratory data on the effects of arsenic exposure on early embryonic development and the mechanisms behind its toxicity. In this study, we used zebrafish as a model system to investigate the effects of arsenite on early development. Zebrafish embryos were exposed to a range of sodium arsenite concentrations (0-10.0mM) between 4 and 120h post-fertilization (hpf). Survival and early development of the embryos were not obviously influenced by arsenite concentrations below 0.5mM. However, embryos exposed to higher concentrations (0.5-10.0mM) displayed reduced survival and abnormal development including delayed hatching, retarded growth and changed morphology. Alterations in neural development included weak tactile responses to light (2.0-5.0mM, 30hpf), malformation of the spinal cord and disordered motor axon projections (2.0mM, 48hpf). Abnormal cardiac function was observed as bradycardia (0.5-2.0mM, 60hpf) and altered ventricular shape (2.0mM, 48hpf). Furthermore, altered cell proliferation (2.0mM, 24hpf) and apoptosis status (2.0mM, 24 and 48hpf), as well as abnormal genomic DNA methylation patterning (2.0mM, 24 and 48hpf) were detected in the arsenite-treated embryos. All of these indicate a possible relationship between arsenic exposure and developmental failure in early embryogenesis. Our studies suggest that the negative effects of arsenic on vertebrate embryogenesis are substantial.
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Affiliation(s)
- Dan Li
- Department of Genetics, National Research Institute for Family Planning, Beijing, China
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Hoppmann V, Wu JJ, Søviknes AM, Helvik JV, Becker TS. Expression of the eight AMPA receptor subunit genes in the developing central nervous system and sensory organs of zebrafish. Dev Dyn 2008; 237:788-99. [PMID: 18224707 DOI: 10.1002/dvdy.21447] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The AMPA type glutamate receptors mediate the majority of fast synaptic transmission in the vertebrate nervous system. Whereas mammals have four subunit genes, Gria1-4, zebrafish has retained a duplicated set of eight genes named gria1-4a and b. We give here a detailed overview of the expression patterns of all eight zebrafish subunits within the developing central nervous system and sensory organs at 24, 48, and 72 hr after fertilization. Expression domains include distinct neuronal subsets in the developing forebrain, midbrain, hindbrain, and spinal cord, as well as in the ganglion- and inner nuclear layers of the retina. As a general rule, each pair of duplicated gria genes is differentially expressed, indicating subfunctionalization of AMPA receptor subunit expression in the teleost lineage. Our findings suggest that zebrafish can serve as a useful model system to investigate the role of AMPA receptors and their differential expression in the vertebrate nervous system.
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Affiliation(s)
- Verena Hoppmann
- Sars International Centre for Molecular Marine Biology, University Bergen, Thormøhlensgate, Bergen, Norway
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Tessmar-Raible K, Raible F, Christodoulou F, Guy K, Rembold M, Hausen H, Arendt D. Conserved sensory-neurosecretory cell types in annelid and fish forebrain: insights into hypothalamus evolution. Cell 2007; 129:1389-400. [PMID: 17604726 DOI: 10.1016/j.cell.2007.04.041] [Citation(s) in RCA: 249] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Revised: 01/12/2007] [Accepted: 04/26/2007] [Indexed: 10/23/2022]
Abstract
Neurosecretory control centers form part of the forebrain in many animal phyla, including vertebrates, insects, and annelids. The evolutionary origin of these centers is largely unknown. To identify conserved, and thus phylogenetically ancient, components of neurosecretory brain centers, we characterize and compare neurons that express the prohormone vasotocin (vasopressin/oxytocin)-neurophysin in the developing forebrain of the annelid Platynereis dumerilii and of the zebrafish. These neurons express the same tissue-restricted microRNA, miR-7, and conserved, cell-type-specific combinations of transcription factors (nk2.1, rx, and otp) that specify their identity, as evidenced by the specific requirement of zebrafish rx3 for vasotocin-neurophysin expression. MiR-7 also labels another shared population of neurons containing RFamides. Since the vasotocinergic and RFamidergic neurons appear to be directly sensory in annelid and fish, we propose that cell types with dual sensory-neurosecretory properties were the starting point for the evolution of neurosecretory brain centers in Bilateria.
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Affiliation(s)
- Kristin Tessmar-Raible
- Developmental Biology Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69012 Heidelberg, Germany.
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Hirata H, Watanabe T, Hatakeyama J, Sprague SM, Saint-Amant L, Nagashima A, Cui WW, Zhou W, Kuwada JY. Zebrafish relatively relaxed mutants have a ryanodine receptor defect, show slow swimming and provide a model of multi-minicore disease. Development 2007; 134:2771-81. [PMID: 17596281 DOI: 10.1242/dev.004531] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Wild-type zebrafish embryos swim away in response to tactile stimulation. By contrast, relatively relaxed mutants swim slowly due to weak contractions of trunk muscles. Electrophysiological recordings from muscle showed that output from the CNS was normal in mutants, suggesting a defect in the muscle. Calcium imaging revealed that Ca2+ transients were reduced in mutant fast muscle. Immunostaining demonstrated that ryanodine and dihydropyridine receptors, which are responsible for Ca2+ release following membrane depolarization, were severely reduced at transverse-tubule/sarcoplasmic reticulum junctions in mutant fast muscle. Thus, slow swimming is caused by weak muscle contractions due to impaired excitation-contraction coupling. Indeed, most of the ryanodine receptor 1b(ryr1b) mRNA in mutants carried a nonsense mutation that was generated by aberrant splicing due to a DNA insertion in an intron of the ryr1b gene, leading to a hypomorphic condition in relatively relaxed mutants. RYR1 mutations in humans lead to a congenital myopathy,multi-minicore disease (MmD), which is defined by amorphous cores in muscle. Electron micrographs showed minicore structures in mutant fast muscles. Furthermore, following the introduction of antisense morpholino oligonucleotides that restored the normal splicing of ryr1b, swimming was recovered in mutants. These findings suggest that zebrafish relatively relaxed mutants may be useful for understanding the development and physiology of MmD.
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Affiliation(s)
- Hiromi Hirata
- Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
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Gulati-Leekha A, Goldman D. A reporter-assisted mutagenesis screen using α1-tubulin-GFP transgenic zebrafish uncovers missteps during neuronal development and axonogenesis. Dev Biol 2006; 296:29-47. [PMID: 16784739 DOI: 10.1016/j.ydbio.2006.03.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 03/07/2006] [Accepted: 03/20/2006] [Indexed: 12/30/2022]
Abstract
Alpha1-tubulin expression occurs in a neural-specific, temporally regulated, and regeneration-inducible fashion in zebrafish. A GFP reporter driven by the alpha1-tubulin promoter in transgenic zebrafish acts as a stable, in vivo molecular tag that follows neuronal development from birth/specification through postmitotic differentiation to axonal outgrowth and synaptogenesis. We exploited this transgenic system in a reporter expression-dependent (morphology-independent) mutagenesis screen to identify disruptions in genetic loci essential for neuronogenesis and axon elaboration, which would manifest as visually appreciable perturbations in GFP fluorescence. Thirty-two such recessive mutations were obtained, a subset of which was screened through a secondary RNA quantification-based assay to eliminate housekeeping gene defects. Three representative loci, when characterized in detail, were found to exhibit missteps in discrete, sequential stages of embryonic neuronal development. Mutation in sookshma panneurally diminishes the neural precursor pool by affecting cell proliferation in the developing embryo while patterning along the neuraxis remains unperturbed. Disruption of drishti on the other hand ameliorates the mitotic neural population by affecting cell cycle exit of progenitors and stalling their progression to the postmitotic neuronal stage, without impairing subsequent cell fate determination or differentiation. Finally, dhruva is required during neuronal differentiation for axonal branching and terminal innervation in spinal motoaxons and the retinotectal projection. Molecular identification of these loci and analysis of the remaining mutational repertoire will offer unique insights into the genetic inputs that go on to make a mature, differentiated neuron.
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Affiliation(s)
- Abhilasha Gulati-Leekha
- Molecular and Behavioral Neuroscience Institute, Department of Biological Chemistry, University of Michigan, 205 Zina Pitcher Place, Ann Arbor, MI 48109-070, USA
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Abstract
Zebrafish are vertebrate organisms that are of growing interest for preclinical drug discovery applications. Zebrafish embryos develop most of the major organ systems present in mammals, including the cardiovascular, nervous and digestive systems, in < 1 week. Additional characteristics that make them advantageous for compound screening are their small size, transparency and ability to absorb compounds through the water. Furthermore, gene function analysis with antisense technology is now routine procedure. Thus, it is relatively simple to assess whether compounds or gene knockdowns cause toxic effects in zebrafish. Assays are being developed to exploit the unique characteristics of zebrafish for pharmacological toxicology. This review discusses assays that may be used to assess in vivo toxicity and provides examples of compounds known to be toxic to humans that have been demonstrated to function similarly in zebrafish.
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Affiliation(s)
- Amy L Rubinstein
- Zygogen LLC, 520 Kell Hall, 24 Peachtree Center Avenue, Atlanta, GA 30303, USA.
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Ton C, Lin Y, Willett C. Zebrafish as a model for developmental neurotoxicity testing. ACTA ACUST UNITED AC 2006; 76:553-67. [PMID: 16933308 DOI: 10.1002/bdra.20281] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND To establish zebrafish as a developmental toxicity model, we used 7 well-characterized compounds to examine several parameters of neurotoxicity during development. METHODS Embryos were exposed by semistatic immersion from 6 hrs postfertilization (hpf). Teratogenicity was assessed using a modified method previously developed by Phylonix. Dying cells in the brain were assessed by acridine orange staining (these cells are likely to be apoptotic). Motor neurons were assessed by antiacetylated tubulin staining and catecholaminergic neurons were visualized by antityrosine hydroxylase staining. RESULTS Atrazine, dichlorodiphenyltrichloroethane (DDT), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were primarily teratogenic and not specifically neurotoxic. 2,4-dichlorophenoxyacetic acid (2,4-D), dieldrin, and nonylphenol showed specific neurotoxicity; dieldrin and nonylphenol were specifically toxic to catecholaminergic neurons. Malathion, although not teratogenic, showed some nonspecific toxicity. CONCLUSIONS Teratogenicity measured in 96-hpf zebrafish is predictive of mammalian teratogenicity and is useful in determining whether a compound causes specific neurotoxicity or general developmental toxicity. Induction of apoptosis or necrosis is an indicator of neurotoxicity. An effect on motor neurons in the caudal third of the embryo correlates with expected defects in motility. Overall, our results showed a strong correlation with mammalian data and suggest that zebrafish is a predictive animal model for neurotoxicity screening.
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Affiliation(s)
- Christopher Ton
- Phylonix Pharmaceuticals, Inc., Cambridge, Massachusetts 02142, USA
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Ashworth R. Approaches to measuring calcium in zebrafish: focus on neuronal development. Cell Calcium 2004; 35:393-402. [PMID: 15003849 DOI: 10.1016/j.ceca.2004.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 12/20/2003] [Accepted: 01/06/2004] [Indexed: 02/03/2023]
Abstract
Calcium ions are known to act as important cellular signals during nervous system development. In vitro studies have provided significant information on the role of calcium signals during neuronal development; however, the function of this messenger in nervous system maturation in vivo remains to be established. The zebrafish has emerged as a valuable model for the study of vertebrate embryogenesis. Fertilisation is external and the rapid growth of the transparent embryo, including development of internal organs, can be observed easily making it well suited for imaging studies. The developing nervous system is relatively simple and has been well characterised, allowing individual neurons to be identified. Using the zebrafish model, both intracellular and intercellular calcium signals throughout embryonic development have been characterised. This review summarises technical approaches to measure calcium signals in developing embryonic and larval zebrafish, and includes recent developments that will facilitate the study of calcium signalling in vivo. The application of calcium imaging techniques to investigate the action of this messenger during embryogenesis in intact zebrafish is illustrated by discussion of their contribution to our understanding of neuronal development in vivo.
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Affiliation(s)
- Rachel Ashworth
- Department of Physiology, University College London, Rockefeller Building, University Street, London WC1E 6JJ, UK.
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Teraoka H, Russell C, Regan J, Chandrasekhar A, Concha ML, Yokoyama R, Higashi K, Take-Uchi M, Dong W, Hiraga T, Holder N, Wilson SW. Hedgehog and Fgf signaling pathways regulate the development of tphR-expressing serotonergic raphe neurons in zebrafish embryos. ACTA ACUST UNITED AC 2004; 60:275-88. [PMID: 15281067 PMCID: PMC2789256 DOI: 10.1002/neu.20023] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Serotonin (5HT) plays major roles in the physiological regulation of many behavioral processes, including sleep, feeding, and mood, but the genetic mechanisms by which serotonergic neurons arise during development are poorly understood. In the present study, we have investigated the development of serotonergic neurons in the zebrafish. Neurons exhibiting 5HT-immunoreactivity (5HT-IR) are detected from 45 h postfertilization (hpf) in the ventral hindbrain raphe, the hypothalamus, pineal organ, and pretectal area. Tryptophan hydroxylases encode rate-limiting enzymes that function in the synthesis of 5HT. As part of this study, we cloned and analyzed a novel zebrafish tph gene named tphR. Unlike two other zebrafish tph genes (tphD1 and tphD2), tphR is expressed in serotonergic raphe neurons, similar to tph genes in mammalian species. tphR is also expressed in the pineal organ where it is likely to be involved in the pathway leading to synthesis of melatonin. To better understand the signaling pathways involved in the induction of the serotonergic phenotype, we analyzed tphR expression and 5HT-IR in embryos in which either Hh or Fgf signals are abrogated. Hindbrain 5HT neurons are severely reduced in mutants lacking activity of either Ace/Fgf8 or the transcription factor Noi/Pax2.1, which regulates expression of ace/fgf8, and probably other genes encoding signaling proteins. Similarly, serotonergic raphe neurons are absent in embryos lacking Hh activity confirming a conserved role for Hh signals in the induction of these cells. Conversely, over-activation of the Hh pathway increases the number of serotonergic neurons. As in mammals, our results are consistent with the transcription factors Nk2.2 and Gata3 acting downstream of Hh activity in the development of serotonergic raphe neurons. Our results show that the pathways involved in induction of hindbrain serotonergic neurons are likely to be conserved in all vertebrates and help establish the zebrafish as a model system to study this important neuronal class.
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Affiliation(s)
- H Teraoka
- Department of Anatomy & Developmental Biology, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
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Jászai J, Reifers F, Picker A, Langenberg T, Brand M. Isthmus-to-midbrain transformation in the absence of midbrain-hindbrain organizer activity. Development 2003; 130:6611-23. [PMID: 14660549 DOI: 10.1242/dev.00899] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In zebrafish acerebellar (ace) embryos, because of a point mutation in fgf8, the isthmic constriction containing the midbrain-hindbrain boundary (MHB) organizer fails to form. The mutants lack cerebellar development by morphological criteria, and they appear to have an enlarged tectum, showing no obvious reduction in the tissue mass at the dorsal mesencephalic/metencephalic alar plate. To reveal the molecular identity of the tissues located at equivalent rostrocaudal positions along the neuraxis as the isthmic and cerebellar primordia in wild-types, we undertook a detailed analysis of ace embryos. In ace mutants, the appearance of forebrain and midbrain specific marker genes (otx2, dmbx1, wnt4) in the caudal tectal enlargement reveals a marked rostralized gene expression profile during early somitogenesis, followed by the lack of early and late cerebellar-specific gene expression (zath1/atoh1, gap43,tag1/cntn2, neurod, zebrin II). The Locus coeruleus(LC) derived from rostral rhombomere 1 is also absent in the mutants. A new interface between otx2 and epha4a suggests that the rostralization stops at the caudal part of rhombomere 1. The mesencephalic basal plate is also affected in the mutant embryos, as indicated by the caudal expansion of the diencephalic expression domains of epha4a,zash1b/ashb, gap43 and tag1/cntn2, and by the dramatic reduction of twhh expression. No marked differences are seen in cell proliferation and apoptotic patterns around the time the rostralization of gene expression becomes evident in the mutants. Therefore,locally distinct cell proliferation and cell death is unlikely to be the cause of the fate alteration of the isthmic and cerebellar primordia in the mutants. Dil cell-lineage labeling of isthmic primordial cells reveals that cells, at the location equivalent of the wild-type MHB, give rise to caudal tectum in ace embryos. This suggests that a caudalto-rostral transformation leads to the tectal expansion in the mutants. Fgf8-coated beads are able to rescue morphological MHB formation, and elicit the normal molecular identity of the isthmic and cerebellar primordium in ace embryos. Taken together, our analysis reveals that cells of the isthmic and cerebellar primordia acquire a more rostral, tectal identity in the absence of the functional MHB organizer signal Fgf8.
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Affiliation(s)
- József Jászai
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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Scholpp S, Brand M. Integrity of the midbrain region is required to maintain the diencephalic-mesencephalic boundary in zebrafishno isthmus/pax2.1 mutants. Dev Dyn 2003; 228:313-22. [PMID: 14579372 DOI: 10.1002/dvdy.10384] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Initial anterior-posterior patterning of the neural tube into forebrain, midbrain, and hindbrain primordia occurs already during gastrulation, in response to signals patterning the gastrula embryo. After the initial establishment, further development within each brain part is thought to proceed largely independently of the others. However, mechanisms should exist that ensure proper delineation of brain subdivisions also at later stages; such mechanisms are, however, poorly understood. In zebrafish no isthmus mutant embryos, inactivation of the pax2.1 gene leads to a failure of the midbrain and isthmus primordium to develop normally from the gastrula stage onward (Lun and Brand [1998] Development 125:3049-3062). Here, we report that, after the initially correct establishment during gastrulation stages, the neighbouring forebrain primordium and, partially, the hindbrain primordium expand into the misspecified midbrain territory in no isthmus mutant embryos. The expansion is particularly evident for the posterior part of the diencephalon and less so for the first rhombomeric segment, the territories immediately abutting the midbrain/isthmus primordium. The nucleus of the posterior commissure is expanded in size, and marker genes of the forebrain and rhombomere 1 expand progressively into the misspecified midbrain primordium, eventually resulting in respecification of the midbrain primordium. We therefore suggest that the genetic program controlled by Pax2.1 is not only involved in initiating but also in maintaining the identity of midbrain and isthmus cells to prevent them from assuming a forebrain or hindbrain fate.
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Affiliation(s)
- Steffen Scholpp
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), Dresden, Germany
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Scholpp S, Lohs C, Brand M. Engrailed and Fgf8 act synergistically to maintain the boundary between diencephalon and mesencephalon. Development 2003; 130:4881-93. [PMID: 12917294 DOI: 10.1242/dev.00683] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Specification of the forebrain, midbrain and hindbrain primordia occurs during gastrulation in response to signals that pattern the gastrula embryo. Following establishment of the primordia, each brain part is thought to develop largely independently from the others under the influence of local organizing centers like the midbrain-hindbrain boundary (MHB, or isthmic) organizer. Mechanisms that maintain the integrity of brain subdivisions at later stages are not yet known. To examine such mechanisms in the anterior neural tube, we have studied the establishment and maintenance of the diencephalic-mesencephalic boundary (DMB). We show that maintenance of the DMB requires both the presence of a specified midbrain and a functional MHB organizer. Expression of pax6.1, a key regulator of forebrain development, is posteriorly suppressed by the Engrailed proteins, Eng2 and Eng3. Mis-expression of eng3 in the forebrain primordium causes downregulation of pax6.1, and forebrain cells correspondingly change their fate and acquire midbrain identity. Conversely, in embryos lacking both eng2 and eng3, the DMB shifts caudally into the midbrain territory. However, a patch of midbrain tissue remains between the forebrain and the hindbrain primordia in such embryos. This suggests that an additional factor maintains midbrain cell fate. We find that Fgf8 is a candidate for this signal, as it is both necessary and sufficient to repress pax6.1 and hence to shift the DMB anteriorly independently of the expression status of eng2/eng3. By examining small cell clones that are unable to receive an Fgf signal, we show that cells in the presumptive midbrain neural plate require an Fgf signal to keep them from following a forebrain fate. Combined loss of both Eng2/Eng3 and Fgf8 leads to complete loss of midbrain identity, resulting in fusion of the forebrain and the hindbrain primordia. Thus, Eng2/Eng3 and Fgf8 are necessary to maintain midbrain identity in the neural plate and thereby position the DMB. This provides an example of a mechanism needed to maintain the subdivision of the anterior neural plate into forebrain and midbrain.
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Affiliation(s)
- Steffen Scholpp
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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McCaffery PJ, Adams J, Maden M, Rosa-Molinar E. Too much of a good thing: retinoic acid as an endogenous regulator of neural differentiation and exogenous teratogen. Eur J Neurosci 2003; 18:457-72. [PMID: 12911743 DOI: 10.1046/j.1460-9568.2003.02765.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Retinoic acid (RA) is essential for both embryonic and adult growth, activating gene transcription via specific nuclear receptors. It is generated, via a retinaldehyde intermediate, from retinol (vitamin A). RA levels require precise regulation by controlled synthesis and catabolism, and when RA concentrations deviate from normal, in either direction, abnormal growth and development occurs. This review describes: (i) how the pattern of RA metabolic enzymes controls the actions of RA; and (ii) the type of abnormalities that result when this pattern breaks down. Examples are given of RA control of the anterior/posterior axis of the hindbrain, the dorsal/ventral axis of the spinal cord, as well as certain sex-specific segments of the spinal cord, using varied animal models including mouse, quail and mosquitofish. These functions are highly sensitive to abnormal changes in RA concentration. In rodents, the control of neural patterning and differentiation are disrupted when RA concentrations are lowered, whereas inappropriately high concentrations of RA result in abnormal development of cerebellum and hindbrain nuclei. The latter parallels the malformations seen in the human embryo exposed to RA due to treatment of the mother with the acne drug Accutane (13-cis RA) and, in cases where the child survives beyond birth, a particular set of behavioural anomalies can be described. Even the adult brain may be susceptible to an imbalance of RA, particularly the hippocampus. This report shows how the properties of RA as a neural induction agent and organizer of segmentation can explain the consequences of RA depletion and overexpression.
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