1
|
Yáñez J, Eguiguren MH, Anadón R. Neural connections of the torus semicircularis in the adult Zebrafish. J Comp Neurol 2024; 532:e25586. [PMID: 38289191 DOI: 10.1002/cne.25586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 12/18/2023] [Accepted: 01/09/2024] [Indexed: 02/01/2024]
Abstract
The torus semicircularis (TS) of teleosts is a key midbrain center of the lateral line and acoustic sensory systems. To characterize the TS in adult zebrafish, we studied their connections using the carbocyanine tracers applied to the TS and to other related nuclei and tracts. Two main TS nuclei, central and ventrolateral, were differentiable by their afferent connections. From central TS, (TSc) numerous toropetal cells were labeled bilaterally in several primary octaval nuclei (anterior, magnocellular, descending, and posterior octaval nuclei), in the secondary octaval nucleus, in the caudal octavolateralis nucleus, and in the perilemniscular region. In the midbrain, numerous toropetal cells were labeled in the contralateral TSc. In the diencephalon, toropetal cells labeled from the TSc were observed ipsilaterally in the medial prethalamic nucleus and the periventricular posterior tubercle nucleus. TSc toropetal neurons were also labeled bilaterally in the hypothalamic anterior tuberal nucleus (ATN) and ipsilaterally in the parvicellular preoptic nucleus but not in the telencephalon. Tracer application to the medial octavolateralis nucleus revealed contralateral projections to the ventrolateral TS (TSvl), whereas tracer application to the secondary octaval nucleus labeled fibers bilaterally in TSc and neurons in rostral TSc. The TSc sends ascending fibers to the ipsilateral lateral preglomerular region that, in turn, projects to the pallium. Application of DiI to the optic tectum labeled cells and fibers in the TSvl, whereas application of DiI to the ATN labeled cells and fibers in the TSc. These results reveal that the TSvl and TSc are mainly related with the mechanosensory lateral line and acoustic centers, respectively, and that they show different higher order connections.
Collapse
Affiliation(s)
- Julián Yáñez
- Department of Biology, Faculty of Sciences, University of A Coruña, Coruña, Spain
- Interdisciplinary Center for Chemistry and Biology (CICA), University of A Coruña, Coruña, Spain
| | | | - Ramón Anadón
- Department of Functional Biology, Faculty of Biology, University of Santiago de Compostela, Santiago de Compostela, Spain
| |
Collapse
|
2
|
Mazzolini J, Le Clerc S, Morisse G, Coulonges C, Zagury J, Sieger D. Wasl is crucial to maintain microglial core activities during glioblastoma initiation stages. Glia 2022; 70:1027-1051. [PMID: 35194846 PMCID: PMC9306864 DOI: 10.1002/glia.24154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/28/2022]
Abstract
Microglia actively promotes the growth of high-grade gliomas. Within the glioma microenvironment an amoeboid microglial morphology has been observed, however the underlying causes and the related impact on microglia functions and their tumor promoting activities is unclear. Using the advantages of the larval zebrafish model, we identified the underlying mechanism and show that microglial morphology and functions are already impaired during glioma initiation stages. The presence of pre-neoplastic HRasV12 expressing cells induces an amoeboid morphology of microglia, increases microglial numbers and decreases their motility and phagocytic activity. RNA sequencing analysis revealed lower expression levels of the actin nucleation promoting factor wasla in microglia. Importantly, a microglia specific rescue of wasla expression restores microglial morphology and functions. This results in increased phagocytosis of pre-neoplastic cells and slows down tumor progression. In conclusion, we identified a mechanism that de-activates core microglial functions within the emerging glioma microenvironment. Restoration of this mechanism might provide a way to impair glioma growth.
Collapse
Affiliation(s)
- Julie Mazzolini
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Sigrid Le Clerc
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Gregoire Morisse
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| | - Cédric Coulonges
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Jean‐François Zagury
- Laboratoire GBCM, EA7528, Conservatoire National des Arts et MétiersHESAM UniversitéParisFrance
| | - Dirk Sieger
- Centre for Discovery Brain SciencesUniversity of EdinburghEdinburghUK
| |
Collapse
|
3
|
Valera G, Markov DA, Bijari K, Randlett O, Asgharsharghi A, Baudoin JP, Ascoli GA, Portugues R, López-Schier H. A neuronal blueprint for directional mechanosensation in larval zebrafish. Curr Biol 2021; 31:1463-1475.e6. [PMID: 33545047 DOI: 10.1016/j.cub.2021.01.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/30/2020] [Accepted: 01/13/2021] [Indexed: 01/02/2023]
Abstract
Animals have a remarkable ability to use local cues to orient in space in the absence of a panoramic fixed reference frame. Here we use the mechanosensory lateral line in larval zebrafish to understand rheotaxis, an innate oriented swimming evoked by water currents. We generated a comprehensive light-microscopy cell-resolution projectome of lateralis afferent neurons (LANs) and used clustering techniques for morphological classification. We find surprising structural constancy among LANs. Laser-mediated microlesions indicate that precise topographic mapping of lateral-line receptors is not essential for rheotaxis. Recording neuronal-activity during controlled mechanical stimulation of neuromasts reveals unequal representation of water-flow direction in the hindbrain. We explored potential circuit architectures constrained by anatomical and functional data to suggest a parsimonious model under which the integration of lateralized signals transmitted by direction-selective LANs underlies the encoding of water-flow direction in the brain. These data provide a new framework to understand how animals use local mechanical cues to orient in space.
Collapse
Affiliation(s)
- Gema Valera
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, Germany
| | | | - Kayvan Bijari
- Krasnow Institute for Advanced Study, George Mason University, VA, USA
| | - Owen Randlett
- Department of Molecular and Cellular Biology, Harvard University, MA, USA
| | | | | | - Giorgio A Ascoli
- Krasnow Institute for Advanced Study, George Mason University, VA, USA
| | | | - Hernán López-Schier
- Sensory Biology and Organogenesis, Helmholtz Zentrum Munich, Germany; Centre for Genomic Regulation, Barcelona, Spain.
| |
Collapse
|
4
|
Deep Transcriptomic Analysis Reveals the Dynamic Developmental Progression during Early Development of Channel Catfish ( Ictalurus punctatus). Int J Mol Sci 2020; 21:ijms21155535. [PMID: 32748829 PMCID: PMC7432863 DOI: 10.3390/ijms21155535] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/21/2020] [Accepted: 07/29/2020] [Indexed: 12/20/2022] Open
Abstract
The transition from fertilized egg to larva in fish is accompanied with various biological processes. We selected seven early developmental stages in channel catfish, Ictalurus punctatus, for transcriptome analysis, and covered 22,635 genes with 590 million high-quality RNA-sequencing (seq) reads. Differential expression analysis between neighboring developmental timepoints revealed significantly enriched biological categories associated with growth, development and morphogenesis, which was most evident at 2 vs. 5 days post fertilization (dpf) and 5 vs. 6 dpf. A gene co-expression network was constructed using the Weighted Gene Co-expression Network Analysis (WGCNA) approach and four critical modules were identified. Among candidate hub genes, GDF10, FOXA2, HCEA and SYCE3 were involved in head formation, egg development and the transverse central element of synaptonemal complexes. CK1, OAZ2, DARS1 and UBE2V2 were mainly associated with regulation of cell cycle, growth, brain development, differentiation and proliferation of enterocytes. IFI44L and ZIP10 were critical for the regulation of immune activity and ion transport. Additionally, TCK1 and TGFB1 were related to phosphate transport and regulating cell proliferation. All these genes play vital roles in embryogenesis and regulation of early development. These results serve as a rich dataset for functional genomic studies. Our work reveals new insights of the underlying mechanisms in channel catfish early development.
Collapse
|
5
|
Lipovsek M, Wingate RJ. Conserved and divergent development of brainstem vestibular and auditory nuclei. eLife 2018; 7:40232. [PMID: 30566077 PMCID: PMC6317910 DOI: 10.7554/elife.40232] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/18/2018] [Indexed: 12/20/2022] Open
Abstract
Vestibular function was established early in vertebrates and has remained, for the most part, unchanged. In contrast, each group of tetrapods underwent independent evolutionary processes to solve the problem of hearing on land, resulting in a remarkable mixture of conserved, divergent and convergent features that define extant auditory systems. The vestibuloacoustic nuclei of the hindbrain develop from a highly conserved ground plan and provide an ideal framework on which to address the participation of developmental processes to the evolution of neuronal circuits. We employed an electroporation strategy to unravel the contribution of two dorsoventral and four axial lineages to the development of the chick hindbrain vestibular and auditory nuclei. We compare the chick developmental map with recently established genetic fate-maps of the developing mouse hindbrain. Overall, we find considerable conservation of developmental origin for the vestibular nuclei. In contrast, a comparative analysis of the developmental origin of hindbrain auditory structures echoes the complex evolutionary history of the auditory system. In particular, we find that the developmental origin of the chick auditory interaural time difference circuit supports its emergence from an ancient vestibular network, unrelated to the analogous mammalian counterpart.
Collapse
Affiliation(s)
- Marcela Lipovsek
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Richard Jt Wingate
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.,MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| |
Collapse
|
6
|
Ono M, Ito T. Inhibitory Neural Circuits in the Mammalian Auditory Midbrain. J Exp Neurosci 2018; 12:1179069518818230. [PMID: 30559596 PMCID: PMC6291857 DOI: 10.1177/1179069518818230] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 11/15/2018] [Indexed: 01/12/2023] Open
Abstract
The auditory midbrain is the critical integration center in the auditory pathway of vertebrates. Synaptic inhibition plays a key role during information processing in the auditory midbrain, and these inhibitory neural circuits are seen in all vertebrates and are likely essential for hearing. Here, we review the structure and function of the inhibitory neural circuits of the auditory midbrain. First, we provide an overview on how these inhibitory circuits are organized within different clades of vertebrates. Next, we focus on recent findings in the mammalian auditory midbrain, the most studied of the vertebrates, and discuss how the mammalian auditory midbrain is functionally coordinated.
Collapse
Affiliation(s)
- Munenori Ono
- Department of Physiology, School of Medicine, Kanazawa Medical University, Uchinada, Japan
| | - Tetsufumi Ito
- Department of Anatomy, School of Medicine, Kanazawa Medical University, Uchinada, Japan
| |
Collapse
|
7
|
An Evolutionarily Conserved Mesodermal Enhancer in Vertebrate Zic3. Sci Rep 2018; 8:14954. [PMID: 30297839 PMCID: PMC6175831 DOI: 10.1038/s41598-018-33235-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 09/25/2018] [Indexed: 11/08/2022] Open
Abstract
Zic3 encodes a zinc finger protein essential for the development of meso-ectodermal tissues. In mammals, Zic3 has important roles in the development of neural tube, axial skeletons, left-right body axis, and in maintaining pluripotency of ES cells. Here we characterized cis-regulatory elements required for Zic3 expression. Enhancer activities of human-chicken-conserved noncoding sequences around Zic1 and Zic3 were screened using chick whole-embryo electroporation. We identified enhancers for meso-ectodermal tissues. Among them, a mesodermal enhancer (Zic3-ME) in distant 3' flanking showed robust enhancement of reporter gene expression in the mesodermal tissue of chicken and mouse embryos, and was required for mesodermal Zic3 expression in mice. Zic3-ME minimal core region is included in the DNase hypersensitive region of ES cells, mesoderm, and neural progenitors, and was bound by T (Brachyury), Eomes, Lef1, Nanog, Oct4, and Zic2. Zic3-ME is derived from an ancestral sequence shared with a sequence encoding a mitochondrial enzyme. These results indicate that Zic3-ME is an integrated cis-regulatory element essential for the proper expression of Zic3 in vertebrates, serving as a hub for a gene regulatory network including Zic3.
Collapse
|
8
|
Abstract
Zic family genes encode five C2H2-type zinc finger domain-containing proteins that have many roles in animal development and maintenance. Recent phylogenetic analyses showed that Zic family genes are distributed in metazoans (multicellular animals), except Porifera (sponges) and Ctenophora (comb jellies). The sequence comparisons revealed that the zinc finger domains were absolutely conserved among the Zic family genes. Zic zinc finger domains are similar to, but distinct from those of the Gli, Glis, and Nkl gene family, and these zinc finger protein families are proposed to have been derived from a common ancestor gene. The Gli-Glis-Nkl-Zic superfamily and some other eukaryotic zinc finger proteins share a tandem CWCH2 (tCWCH2) motif, a hallmark for inter-zinc finger interaction between two adjacent C2H2 zinc fingers. In Zic family proteins, there exist additional evolutionally conserved domains known as ZOC and ZFNC, both of which may have appeared before cnidarian-bilaterian divergence. Comparison of the exon-intron boundaries in the Zic zinc finger domains revealed an intron (A-intron) that was absolutely conserved in bilaterians (metazoans with bilateral symmetry) and a placozoan (a simple nonparasitic metazoan). In vertebrates, there are five to seven Zic paralogs among which Zic1, Zic2, and Zic3 are generated through a tandem gene duplication and carboxy-terminal truncation in a vertebrate common ancestor, sharing a conserved carboxy-terminal sequence. Several hypotheses have been proposed to explain the Zic family phylogeny, including their origin, unique features in the first and second zinc finger motif, evolution of the nuclear localization signal, significance of the animal taxa-selective degeneration, gene multiplication in the vertebrate lineage, and involvement in the evolutionary alteration of the animal body plan.
Collapse
|
9
|
Naumann EA, Fitzgerald JE, Dunn TW, Rihel J, Sompolinsky H, Engert F. From Whole-Brain Data to Functional Circuit Models: The Zebrafish Optomotor Response. Cell 2017; 167:947-960.e20. [PMID: 27814522 DOI: 10.1016/j.cell.2016.10.019] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 05/24/2016] [Accepted: 10/11/2016] [Indexed: 02/06/2023]
Abstract
Detailed descriptions of brain-scale sensorimotor circuits underlying vertebrate behavior remain elusive. Recent advances in zebrafish neuroscience offer new opportunities to dissect such circuits via whole-brain imaging, behavioral analysis, functional perturbations, and network modeling. Here, we harness these tools to generate a brain-scale circuit model of the optomotor response, an orienting behavior evoked by visual motion. We show that such motion is processed by diverse neural response types distributed across multiple brain regions. To transform sensory input into action, these regions sequentially integrate eye- and direction-specific sensory streams, refine representations via interhemispheric inhibition, and demix locomotor instructions to independently drive turning and forward swimming. While experiments revealed many neural response types throughout the brain, modeling identified the dimensions of functional connectivity most critical for the behavior. We thus reveal how distributed neurons collaborate to generate behavior and illustrate a paradigm for distilling functional circuit models from whole-brain data.
Collapse
Affiliation(s)
- Eva A Naumann
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | | | - Timothy W Dunn
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Jason Rihel
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK
| | - Haim Sompolinsky
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Racah Institute of Physics and the Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Florian Engert
- Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
| |
Collapse
|
10
|
Evolution of mammalian sound localization circuits: A developmental perspective. Prog Neurobiol 2016; 141:1-24. [PMID: 27032475 DOI: 10.1016/j.pneurobio.2016.02.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 02/27/2016] [Accepted: 02/27/2016] [Indexed: 01/06/2023]
Abstract
Localization of sound sources is a central aspect of auditory processing. A unique feature of mammals is the smooth, tonotopically organized extension of the hearing range to high frequencies (HF) above 10kHz, which likely induced positive selection for novel mechanisms of sound localization. How this change in the auditory periphery is accompanied by changes in the central auditory system is unresolved. I will argue that the major VGlut2(+) excitatory projection neurons of sound localization circuits (dorsal cochlear nucleus (DCN), lateral and medial superior olive (LSO and MSO)) represent serial homologs with modifications, thus being paramorphs. This assumption is based on common embryonic origin from an Atoh1(+)/Wnt1(+) cell lineage in the rhombic lip of r5, same cell birth, a fusiform cell morphology, shared genetic components such as Lhx2 and Lhx9 transcription factors, and similar projection patterns. Such a parsimonious evolutionary mechanism likely accelerated the emergence of neurons for sound localization in all three dimensions. Genetic analyses indicate that auditory nuclei in fish, birds, and mammals receive contributions from the same progenitor lineages. Anatomical and physiological differences and the independent evolution of tympanic ears in vertebrate groups, however, argue for convergent evolution of sound localization circuits in tetrapods (amphibians, reptiles, birds, and mammals). These disparate findings are discussed in the context of the genetic architecture of the developing hindbrain, which facilitates convergent evolution. Yet, it will be critical to decipher the gene regulatory networks underlying development of auditory neurons across vertebrates to explore the possibility of homologous neuronal populations.
Collapse
|
11
|
Akash G, Kaniganti T, Tiwari NK, Subhedar NK, Ghose A. Differential distribution and energy status-dependent regulation of the four CART neuropeptide genes in the zebrafish brain. J Comp Neurol 2014; 522:2266-85. [DOI: 10.1002/cne.23532] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 11/08/2013] [Accepted: 12/20/2013] [Indexed: 11/10/2022]
Affiliation(s)
- G. Akash
- Indian Institute of Science Education and Research (IISER) Pune; Pune 411 008 India
| | - Tarun Kaniganti
- Indian Institute of Science Education and Research (IISER) Pune; Pune 411 008 India
| | - Neeraj Kumar Tiwari
- Indian Institute of Science Education and Research (IISER) Pune; Pune 411 008 India
| | | | - Aurnab Ghose
- Indian Institute of Science Education and Research (IISER) Pune; Pune 411 008 India
| |
Collapse
|
12
|
Barreiro-Iglesias A, Mysiak KS, Adrio F, Rodicio MC, Becker CG, Becker T, Anadón R. Distribution of glycinergic neurons in the brain of glycine transporter-2 transgenic Tg(glyt2:Gfp) adult zebrafish: Relationship to brain-spinal descending systems. J Comp Neurol 2012; 521:389-425. [DOI: 10.1002/cne.23179] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 01/25/2012] [Accepted: 06/21/2012] [Indexed: 12/19/2022]
|
13
|
Abstract
Spatially distributed sensory information is topographically mapped in the brain by point-to-point correspondence of connections between peripheral receptors and central target neurons. In fishes, for example, the axonal projections from the mechanosensory lateral line organize a somatotopic neural map. The lateral line provides hydrodynamic information for intricate behaviors such as navigation and prey detection. It also mediates fast startle reactions triggered by the Mauthner cell. However, it is not known how the lateralis neural map is built to subserve these contrasting behaviors. Here we reveal that birth order diversifies lateralis afferent neurons in the zebrafish. We demonstrate that early- and late-born lateralis afferents diverge along the main axes of the hindbrain to synapse with hundreds of second-order targets. However, early-born afferents projecting from primary neuromasts also assemble a separate map by converging on the lateral dendrite of the Mauthner cell, whereas projections from secondary neuromasts never make physical contact with the Mauthner cell. We also show that neuronal diversity and map topology occur normally in animals permanently deprived of mechanosensory activity. We conclude that neuronal birth order correlates with the assembly of neural submaps, whose combination is likely to govern appropriate behavioral reactions to the sensory context.
Collapse
|
14
|
The transcriptional mediator component Med12 is required for hindbrain boundary formation. PLoS One 2011; 6:e19076. [PMID: 21533047 PMCID: PMC3080914 DOI: 10.1371/journal.pone.0019076] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 03/23/2011] [Indexed: 11/30/2022] Open
Abstract
Background Rhombomere boundaries form during hindbrain segmentation and are critical for maintaining segmental integrity and regulating migration in the hindbrain. Some genetic models affecting hindbrain boundary formation have been described, but involvement of components of the transcriptional mediator complex in boundary formation has not reported so far. Principal Findings The kto/med12 mutant zebrafish, which affects the Mediator component Med12, causes specific loss of rhombomere boundary cells even though segmentation of the hindbrain takes place at least in part. In kto mutant embryos, cells forming rhombomere boundaries were largely absent as indicated by the use of several marker genes. While no obvious increase in cell death was observed, we found a notable reduction of cell proliferation in the hindbrain of kto mutant zebrafish. Conclusions The kto/med12 mutation results in specific defects of boundary cell formation in the zebrafish hindbrain.
Collapse
|
15
|
Pujol-Martí J, Baudoin JP, Faucherre A, Kawakami K, López-Schier H. Progressive neurogenesis defines lateralis somatotopy. Dev Dyn 2010; 239:1919-30. [PMID: 20549716 DOI: 10.1002/dvdy.22320] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Fishes and amphibians localize hydromechanical variations along their bodies using the lateral-line sensory system. This is possible because the spatial distribution of neuromasts is represented in the hindbrain by a somatotopic organization of the lateralis afferent neurons' central projections. The mechanisms that establish lateralis somatotopy are not known. Using BAPTI and neuronal tracing in the zebrafish, we demonstrate growth anisotropy of the posterior lateralis ganglion. We characterized a new transgenic line for in vivo imaging to show that although peripheral growth-cone structure adumbrates somatotopy, the order of neurogenesis represents a more accurate predictor of the position of a neuron's central axon along the somatotopic axis in the hindbrain. We conclude that progressive neurogenesis defines lateralis somatotopy.
Collapse
Affiliation(s)
- Jesús Pujol-Martí
- Laboratory of Sensory Cell Biology and Organogenesis, Centre de Regulació Genòmica, Barcelona, Spain
| | | | | | | | | |
Collapse
|
16
|
Abstract
For more than a decade, the zebrafish has proven to be an excellent model organism to investigate the mechanisms of neurogenesis during development. The often cited advantages, namely external development, genetic, and optical accessibility, have permitted direct examination and experimental manipulations of neurogenesis during development. Recent studies have begun to investigate adult neurogenesis, taking advantage of its widespread occurrence in the mature zebrafish brain to investigate the mechanisms underlying neural stem cell maintenance and recruitment. Here we provide a comprehensive overview of the tools and techniques available to study neurogenesis in zebrafish both during development and in adulthood. As useful resources, we provide tables of available molecular markers, transgenic, and mutant lines. We further provide optimized protocols for studying neurogenesis in the adult zebrafish brain, including in situ hybridization, immunohistochemistry, in vivo lipofection and electroporation methods to deliver expression constructs, administration of bromodeoxyuridine (BrdU), and finally slice cultures. These currently available tools have put zebrafish on par with other model organisms used to investigate neurogenesis.
Collapse
Affiliation(s)
- Prisca Chapouton
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | | |
Collapse
|
17
|
Ogura E, Okuda Y, Kondoh H, Kamachi Y. Adaptation of GAL4 activators for GAL4 enhancer trapping in zebrafish. Dev Dyn 2009; 238:641-55. [PMID: 19191223 DOI: 10.1002/dvdy.21863] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
An enhancer trap-based GAL4-UAS system in zebrafish requires strong GAL4 activators with minimal adverse effects. However, the activity of yeast GAL4 is too low in zebrafish, while a fusion protein of the GAL4 DNA-binding domain and the VP16 activation domain is toxic to embryonic development, even when expressed at low levels. To alleviate this toxicity, we developed variant GAL4 activators by fusing either multimeric forms of the VP16 minimal activation domain or the NF-kappaB activation domain to the GAL4 DNA-binding domain. These variant GAL4 activators are sufficiently innocuous and yet highly effective transactivators in developing zebrafish. Enhancer-trap vectors containing these GAL4 activators downstream of an appropriate weak promoter were randomly inserted into the zebrafish genome using the Sleeping Beauty transposon system. By the combination of these genetic elements, we have successfully developed enhancer trap lines that activate UAS-dependent reporter genes in a tissue-specific fashion that reflects trapped enhancer activities.
Collapse
Affiliation(s)
- Eri Ogura
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | | | | | | |
Collapse
|
18
|
Ohata S, Kinoshita S, Aoki R, Tanaka H, Wada H, Tsuruoka-Kinoshita S, Tsuboi T, Watabe S, Okamoto H. Neuroepithelial cells require fucosylated glycans to guide the migration of vagus motor neuron progenitors in the developing zebrafish hindbrain. Development 2009; 136:1653-63. [PMID: 19369395 DOI: 10.1242/dev.033290] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The molecular mechanisms by which neurons migrate and accumulate to form the neural layers and nuclei remain unclear. The formation of vagus motor nuclei in zebrafish embryos is an ideal model system in which to address this issue because of the transparency of the embryos and the availability of established genetic and molecular biological techniques. To determine the genes required for the formation of the vagus motor nuclei, we performed N-ethyl-N-nitrosourea-based mutant screening using a zebrafish line that expresses green fluorescent protein in the motor neurons. In wild-type embryos, the vagus motor neuron progenitors are born in the ventral ventricular zone, then migrate tangentially in the dorsolateral direction, forming the nuclei. However, in towhead (twd(rw685)) mutant embryos, the vagus motor neuron progenitors stray medially away from the normal migratory pathway and fail to stop in the right location. The twd(rw685) mutant has a defect in the GDP-mannose 4,6 dehydratase (gmds) gene, which encodes a key enzyme in the fucosylation pathway. Levels of fucosylated glycans were markedly and specifically reduced in twd(rw685) mutant embryos. Cell transplantation analysis revealed that GMDS is not essential in the vagus motor neuron progenitors for correct formation of the vagus motor nuclei, but is required in the neuroepithelial cells that surround the progenitors. Together, these findings suggest that fucosylated glycans expressed in neuroepithelial cells are required to guide the migration of vagus motor neuron progenitors.
Collapse
Affiliation(s)
- Shinya Ohata
- Laboratory for Developmental Gene Regulation, RIKEN Brain Science Institute, Saitama, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Cadherin-7 function in zebrafish development. Cell Tissue Res 2008; 334:37-45. [PMID: 18665394 DOI: 10.1007/s00441-008-0664-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Accepted: 06/10/2008] [Indexed: 12/19/2022]
Abstract
Cadherin cell adhesion molecules play crucial roles in vertebrate development. Most studies have focused on examining the functions of classical type I cadherins (e.g., cadherin-2) in the development of vertebrates. Little information is available concerning the function of classical type II cadherins (e.g., cadherin-7) in vertebrate development. We have previously shown that cadherin-7 mRNA exhibits a dynamic expression pattern in the central nervous system and notochord in embryonic zebrafish. To gain insight into the role of cadherin-7 in the formation of these structures, we analyzed their formation in zebrafish embryos injected with cadherin-7-specific antisense morpholino oligonucleotides (MO). Notochord development was severely disrupted in MO-injected embryos, whereas gross defects in the development of the central nervous system were not detected in MO-injected embryos. Our results thus demonstrate that cadherin-7 plays an important role in the normal development of the zebrafish notochord.
Collapse
|
20
|
Okamoto H, Sato T, Aizawa H. Transgenic technology for visualization and manipulation of the neural circuits controlling behavior in zebrafish. Dev Growth Differ 2008; 50 Suppl 1:S167-75. [DOI: 10.1111/j.1440-169x.2008.01003.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|