1
|
Kozmik Z, Kozmikova I. Ancestral role of Pax6 in chordate brain regionalization. Front Cell Dev Biol 2024; 12:1431337. [PMID: 39119036 PMCID: PMC11306081 DOI: 10.3389/fcell.2024.1431337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Accepted: 07/10/2024] [Indexed: 08/10/2024] Open
Abstract
The Pax6 gene is essential for eye and brain development across various animal species. Here, we investigate the function of Pax6 in the development of the anterior central nervous system (CNS) of the invertebrate chordate amphioxus using CRISPR/Cas9-induced genome editing. Specifically, we examined Pax6 mutants featuring a 6 bp deletion encompassing two invariant amino acids in the conserved paired domain, hypothesized to impair Pax6 DNA-binding capacity and gene regulatory functions. Although this mutation did not result in gross morphological changes in amphioxus larvae, it demonstrated a reduced ability to activate Pax6-responsive reporter gene, suggesting a hypomorphic effect. Expression analysis in mutant larvae revealed changes in gene expression within the anterior CNS, supporting the conserved role of Pax6 gene in brain regionalization across chordates. Additionally, our findings lend support to the hypothesis of a zona limitans intrathalamica (ZLI)-like region in amphioxus, suggesting evolutionary continuity in brain patterning mechanisms. ZLI region, found in both hemichordates and vertebrates, functions as a key signaling center and serves as a restrictive boundary between major thalamic regions.
Collapse
Affiliation(s)
| | - Iryna Kozmikova
- Laboratory of Transcriptional Regulation, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| |
Collapse
|
2
|
Altbürger C, Rath M, Armbruster D, Driever W. Neurog1 and Olig2 integrate patterning and neurogenesis signals in development of zebrafish dopaminergic and glutamatergic dual transmitter neurons. Dev Biol 2024; 505:85-98. [PMID: 37944224 DOI: 10.1016/j.ydbio.2023.10.005] [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: 03/23/2023] [Revised: 10/02/2023] [Accepted: 10/20/2023] [Indexed: 11/12/2023]
Abstract
Dopaminergic neurons develop in distinct neural domains by integrating local patterning and neurogenesis signals. While the proneural proteins Neurog1 and Olig2 have been previously linked to development of dopaminergic neurons, their dependence on local prepatterning and specific contributions to dopaminergic neurogenesis are not well understood. Here, we show that both transcription factors are differentially required for the development of defined dopaminergic glutamatergic subpopulations in the zebrafish posterior tuberculum, which are homologous to A11 dopaminergic neurons in mammals. Both Olig2 and Neurog1 are expressed in otpa expressing progenitor cells and appear to act upstream of Otpa during dopaminergic neurogenesis. Our epistasis analysis confirmed that Neurog1 acts downstream of Notch signaling, while Olig2 acts downstream of Shh, but upstream and/or in parallel to Notch signaling during neurogenesis of A11-type dopaminergic clusters. Furthermore, we identified Olig2 to be an upstream regulator of neurog1 in dopaminergic neurogenesis. This regulation occurs through Olig2-dependent repression of the proneural repressor and Notch target gene her2. Our study reveals how Neurog1 and Olig2 integrate local patterning signals, including Shh, with Notch neurogenic selection signaling, to specify the progenitor population and initiate neurogenesis and differentiation of A11-type dopaminergic neurons.
Collapse
Affiliation(s)
- Christian Altbürger
- Department of Developmental Biology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Meta Rath
- Department of Developmental Biology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany
| | - Daniel Armbruster
- Department of Developmental Biology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany; MeInBio Research Training Group, University of Freiburg, 79104 Freiburg, Germany
| | - Wolfgang Driever
- Department of Developmental Biology, Faculty of Biology, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany.
| |
Collapse
|
3
|
Hildebrandt K, Klöppel C, Gogel J, Hartenstein V, Walldorf U. Orthopedia expression during Drosophila melanogaster nervous system development and its regulation by microRNA-252. Dev Biol 2022; 492:87-100. [PMID: 36179878 DOI: 10.1016/j.ydbio.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/05/2022] [Accepted: 09/19/2022] [Indexed: 11/03/2022]
Abstract
During brain development of Drosophila melanogaster many transcription factors are involved in regulating neural fate and morphogenesis. In our study we show that the transcription factor Orthopedia (Otp), a member of the 57B homeobox gene cluster, plays an important role in this process. Otp is expressed in a stable pattern in defined lineages from mid-embryonic stages into the adult brain and therefore a very stable marker for these lineages. We determined the abundance of the two different otp transcripts in the brain and hindgut during development using qPCR. CRISPR/Cas9 generated otp mutants of the longer protein form significantly affect the expression of Otp in specific areas. We generated an otp enhancer trap strain by gene targeting and reintegration of Gal4, which mimics the complete expression of otp during development except the embryonic hindgut expression. Since in the embryo, the expression of Otp is posttranscriptionally regulated, we looked for putative miRNAs interacting with the otp 3'UTR, and identified microRNA-252 as a candidate. Further analyses with mutated and deleted forms of the microRNA-252 interacting sequence in the otp 3'UTR demonstrate an in vivo interaction of microRNA-252 with the otp 3'UTR. An effect of this interaction is seen in the adult brain, where Otp expression is partially abolished in a knockout strain of microRNA-252. Our results show that Otp is another important factor for brain development in Drosophila melanogaster.
Collapse
Affiliation(s)
- Kirsten Hildebrandt
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany
| | - Christine Klöppel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany
| | - Jasmin Gogel
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany
| | - Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, CA, 90095, USA
| | - Uwe Walldorf
- Developmental Biology, Saarland University, Building 61, 66421, Homburg, Saar, Germany.
| |
Collapse
|
4
|
Santos-Durán GN, Ferreiro-Galve S, Mazan S, Anadón R, Rodríguez-Moldes I, Candal E. Developmental genoarchitectonics as a key tool to interpret the mature anatomy of the chondrichthyan hypothalamus according to the prosomeric model. Front Neuroanat 2022; 16:901451. [PMID: 35991967 PMCID: PMC9385951 DOI: 10.3389/fnana.2022.901451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/30/2022] [Indexed: 11/29/2022] Open
Abstract
The hypothalamus is a key vertebrate brain region involved in survival and physiological functions. Understanding hypothalamic organization and evolution is important to deciphering many aspects of vertebrate biology. Recent comparative studies based on gene expression patterns have proposed the existence of hypothalamic histogenetic domains (paraventricular, TPa/PPa; subparaventricular, TSPa/PSPa; tuberal, Tu/RTu; perimamillary, PM/PRM; and mamillary, MM/RM), revealing conserved evolutionary trends. To shed light on the functional relevance of these histogenetic domains, this work aims to interpret the location of developed cell groups according to the prosomeric model in the hypothalamus of the catshark Scyliorhinus canicula, a representative of Chondrichthyans (the sister group of Osteichthyes, at the base of the gnathostome lineage). To this end, we review in detail the expression patterns of ScOtp, ScDlx2, and ScPitx2, as well as Pax6-immunoreactivity in embryos at stage 32, when the morphology of the adult catshark hypothalamus is already organized. We also propose homologies with mammals when possible. This study provides a comprehensive tool to better understand previous and novel data on hypothalamic development and evolution.
Collapse
Affiliation(s)
- Gabriel N. Santos-Durán
- Grupo NEURODEVO, Departamento de Bioloxía Funcional, Universidade de Santiago de Compostela, Santiago, Spain
| | - Susana Ferreiro-Galve
- Grupo NEURODEVO, Departamento de Bioloxía Funcional, Universidade de Santiago de Compostela, Santiago, Spain
| | - Sylvie Mazan
- CNRS-UMR 7232, Sorbonne Universités, UPMC Univ Paris 06, Observatoire Océanologique, Paris, France
| | - Ramón Anadón
- Grupo NEURODEVO, Departamento de Bioloxía Funcional, Universidade de Santiago de Compostela, Santiago, Spain
| | - Isabel Rodríguez-Moldes
- Grupo NEURODEVO, Departamento de Bioloxía Funcional, Universidade de Santiago de Compostela, Santiago, Spain
| | - Eva Candal
- Grupo NEURODEVO, Departamento de Bioloxía Funcional, Universidade de Santiago de Compostela, Santiago, Spain
- *Correspondence: Eva Candal,
| |
Collapse
|
5
|
Eugenin von Bernhardi J, Biechl D, Miek L, Herget U, Ryu S, Wullimann MF. A versatile transcription factor: Multiple roles of orthopedia a (otpa) beyond its restricted localization in dopaminergic systems of developing and adult zebrafish (Danio rerio) brains. J Comp Neurol 2022; 530:2537-2561. [PMID: 35708548 DOI: 10.1002/cne.25351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/09/2022] [Accepted: 05/11/2022] [Indexed: 11/06/2022]
Abstract
Many transcription factors boost neural development and differentiation in specific directions and serve for identifying similar or homologous structures across species. The expression of Orthopedia (Otp) is critical for the development of certain cell groups along the vertebrate neuraxis, for example, the medial amygdala or hypothalamic neurosecretory neurons. Therefore, the primary focus of the present study is the distribution of Orthopedia a (Otpa) in the larval and adult zebrafish (Danio rerio) brain. Since Otpa is also critical for the development of zebrafish basal diencephalic dopaminergic cells, colocalization of Otpa with the catecholamine synthesizing enzyme tyrosine hydroxylase (TH) is studied. Cellular colocalization of Otpa and dopamine is only seen in magnocellular neurons of the periventricular posterior tubercular nucleus and in the posterior tuberal nucleus. Otpa-positive cells occur in many additional structures along the zebrafish neuraxis, from the secondary prosencephalon down to the hindbrain. Furthermore, Otpa expression is studied in shh-GFP and islet1-GFP transgenic zebrafish. Otpa-positive cells only express shh in dopaminergic magnocellular periventricular posterior tubercular cells, and only colocalize with islet1-GFP in the ventral zone and prerecess caudal periventricular hypothalamic zone and the perilemniscal nucleus. The scarcity of cellular colocalization of Otpa in islet1-GFP cells indicates that the Shh-islet1 neurogenetic pathway is not active in most Otpa-expressing domains. Our analysis reveals detailed correspondences between mouse and zebrafish forebrain territories including the zebrafish intermediate nucleus of the ventral telencephalon and the mouse medial amygdala. The zebrafish preoptic Otpa-positive domain represents the neuropeptidergic supraopto-paraventricular region of all tetrapods. Otpa domains in the zebrafish basal plate hypothalamus suggest that the ventral periventricular hypothalamic zone corresponds to the otp-expressing basal hypothalamic tuberal field in the mouse. Furthermore, the mouse otp domain in the mammillary hypothalamus compares partly to our Otpa-positive domain in the prerecess caudal periventricular hypothalamic zone (Hc-a).
Collapse
Affiliation(s)
- Jaime Eugenin von Bernhardi
- Faculty of Biology, Division of Neurobiology, Ludwig-Maximilians-Universität Munich, München, Bavaria, Germany.,The Solomon Snyder Department of Neuroscience, Johns Hopkins Univeristy, Baltimore, Maryland, USA
| | - Daniela Biechl
- Faculty of Biology, Division of Neurobiology, Ludwig-Maximilians-Universität Munich, München, Bavaria, Germany
| | - Laura Miek
- Faculty of Biology, Division of Neurobiology, Ludwig-Maximilians-Universität Munich, München, Bavaria, Germany
| | - Ulrich Herget
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Soojin Ryu
- Living Systems Institute University of Exeter, Exeter, Devon, UK.,College of Medicine and Health, University of Exeter, Exeter, Devon, UK
| | - Mario F Wullimann
- Faculty of Biology, Division of Neurobiology, Ludwig-Maximilians-Universität Munich, München, Bavaria, Germany.,Max-Planck-Institute of Neurobiology, Planegg-Martinsried, Germany
| |
Collapse
|
6
|
Westphal M, Panza P, Kastenhuber E, Wehrle J, Driever W. Wnt/β-catenin signaling promotes neurogenesis in the diencephalospinal dopaminergic system of embryonic zebrafish. Sci Rep 2022; 12:1030. [PMID: 35046434 PMCID: PMC8770493 DOI: 10.1038/s41598-022-04833-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/28/2021] [Indexed: 12/21/2022] Open
Abstract
Wnt/β-catenin signaling contributes to patterning, proliferation, and differentiation throughout vertebrate neural development. Wnt/β-catenin signaling is important for mammalian midbrain dopaminergic neurogenesis, while little is known about its role in ventral forebrain dopaminergic development. Here, we focus on the A11-like, Otp-dependent diencephalospinal dopaminergic system in zebrafish. We show that Wnt ligands, receptors and extracellular antagonist genes are expressed in the vicinity of developing Otp-dependent dopaminergic neurons. Using transgenic Wnt/β-catenin-reporters, we found that Wnt/β-catenin signaling activity is absent from these dopaminergic neurons, but detected Wnt/β-catenin activity in cells adjacent to the caudal DC5/6 clusters of Otp-dependent dopaminergic neurons. Pharmacological manipulations of Wnt/β-catenin signaling activity, as well as heat-shock driven overexpression of Wnt agonists and antagonists, interfere with the development of DC5/6 dopaminergic neurons, such that Wnt/β-catenin activity positively correlates with their number. Wnt/β-catenin activity promoted dopaminergic development specifically at stages when DC5/6 dopaminergic progenitors are in a proliferative state. Our data suggest that Wnt/β-catenin signaling acts in a spatially and temporally restricted manner on proliferative dopaminergic progenitors in the hypothalamus to positively regulate the size of the dopaminergic neuron groups DC5 and DC6.
Collapse
Affiliation(s)
- Markus Westphal
- Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany.,CIBSS and BIOSS-Centres for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Paolo Panza
- Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany.,Department of Developmental Genetics, Max-Planck-Institute for Heart and Lung Research, Ludwigstraße 43, 61231, Bad Nauheim, Germany
| | - Edda Kastenhuber
- Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany.,Institute of Anatomy, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Johanna Wehrle
- Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany.,CIBSS and BIOSS-Centres for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Wolfgang Driever
- Developmental Biology, Faculty of Biology, Institute Biology 1, Albert Ludwigs University Freiburg, Hauptstrasse 1, 79104, Freiburg, Germany. .,CIBSS and BIOSS-Centres for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany.
| |
Collapse
|
7
|
Fasano G, Godoy RS, Angiulli E, Consalvo A, Franco C, Mancini M, Santucci D, Alleva E, Ciavardelli D, Toni M, Biffali E, Ekker M, Canzoniero LMT, Sordino P. Effects of low-dose methylcyclopentadienyl manganese tricarbonyl-derived manganese on the development of diencephalic dopaminergic neurons in zebrafish. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 287:117151. [PMID: 34020261 DOI: 10.1016/j.envpol.2021.117151] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 04/02/2021] [Accepted: 04/11/2021] [Indexed: 06/12/2023]
Abstract
Fuel additive methylcyclopentadienyl manganese tricarbonyl (MMT) is counted as an organic manganese (Mn)-derived compound. The toxic effects of Mn (alone and complexed) on dopaminergic (DA) neurotransmission have been investigated in both cellular and animal models. However, the impact of environmentally relevant Mn exposure on DA neurodevelopment is rather poorly understood. In the present study, the MMT dose of 100 μM (about 5 mg Mn/L) caused up-regulation of DA-related genes in association with cell body swelling and increase in the number of DA neurons of the ventral diencephalon subpopulation DC2. Furthermore, our analysis identified significant brain Mn bioaccumulation and enhancement of total dopamine levels in association with locomotor hyperactivity. Although DA levels were restored at adulthood, we observed a deficit in the acquisition and consolidation of memory. Collectively, these findings suggest that developmental exposure to low-level MMT-derived Mn is responsible for the selective alteration of diencephalic DA neurons and with long-lasting effects on fish explorative behaviour in adulthood.
Collapse
Affiliation(s)
- Giulia Fasano
- Department of Sciences and Technologies, University of Sannio, Via Francesco de Sanctis, 82100, Benevento, Italy; Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
| | - Rafael Soares Godoy
- Department of Biology, University of Ottawa, Marie-Curie Private, Ottawa, ON K1N 9A7, Canada
| | - Elisa Angiulli
- Department of Biology and Biotechnology ''Charles Darwin", Sapienza University, Via Borelli 50, 00161, Rome, Italy
| | - Ada Consalvo
- Centro Scienze Dell'Invecchiamento e Medicina Traslazionale - CeSI-MeT, Via Polacchi 11, 66100, Chieti, Italy; Department of Medical, Oral and Biotechnological Sciences, "G. D'Annunzio" University of Chieti-Pescara, Via Dei Vestini, 66100, Chieti, Italy
| | - Cristina Franco
- Department of Sciences and Technologies, University of Sannio, Via Francesco de Sanctis, 82100, Benevento, Italy
| | - Maria Mancini
- Department of Neuroscience and Physiology, New York University School of Medicine, 435 East 30th Street, New York, NY, 10016, USA; NYU Marlene and Paolo Fresco Institute for Parkinson's Disease and Movement Disorders, New York University School of Medicine, 222 East 41st Street, New York, NY, 10017, USA
| | - Daniela Santucci
- Centro di Riferimento per le Scienze Comportamentali e La Salute Mentale, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Enrico Alleva
- Centro di Riferimento per le Scienze Comportamentali e La Salute Mentale, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161, Rome, Italy
| | - Domenico Ciavardelli
- Centro Scienze Dell'Invecchiamento e Medicina Traslazionale - CeSI-MeT, Via Polacchi 11, 66100, Chieti, Italy; School of Human and Social Science, "Kore" University of Enna, Cittadella Universitaria, 94100, Enna, Italy
| | - Mattia Toni
- Department of Biology and Biotechnology ''Charles Darwin", Sapienza University, Via Borelli 50, 00161, Rome, Italy
| | - Elio Biffali
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
| | - Marc Ekker
- Department of Biology, University of Ottawa, Marie-Curie Private, Ottawa, ON K1N 9A7, Canada
| | | | - Paolo Sordino
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy.
| |
Collapse
|
8
|
Diaz C, Puelles L. Developmental Genes and Malformations in the Hypothalamus. Front Neuroanat 2020; 14:607111. [PMID: 33324176 PMCID: PMC7726113 DOI: 10.3389/fnana.2020.607111] [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] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 10/26/2020] [Indexed: 12/15/2022] Open
Abstract
The hypothalamus is a heterogeneous rostral forebrain region that regulates physiological processes essential for survival, energy metabolism, and reproduction, mainly mediated by the pituitary gland. In the updated prosomeric model, the hypothalamus represents the rostralmost forebrain, composed of two segmental regions (terminal and peduncular hypothalamus), which extend respectively into the non-evaginated preoptic telencephalon and the evaginated pallio-subpallial telencephalon. Complex genetic cascades of transcription factors and signaling molecules rule their development. Alterations of some of these molecular mechanisms acting during forebrain development are associated with more or less severe hypothalamic and pituitary dysfunctions, which may be associated with brain malformations such as holoprosencephaly or septo-optic dysplasia. Studies on transgenic mice with mutated genes encoding critical transcription factors implicated in hypothalamic-pituitary development are contributing to understanding the high clinical complexity of these pathologies. In this review article, we will analyze first the complex molecular genoarchitecture of the hypothalamus resulting from the activity of previous morphogenetic signaling centers and secondly some malformations related to alterations in genes implicated in the development of the hypothalamus.
Collapse
Affiliation(s)
- Carmen Diaz
- Department of Medical Sciences, School of Medicine and Institute for Research in Neurological Disabilities, University of Castilla-La Mancha, Albacete, Spain
| | - Luis Puelles
- Department of Human Anatomy and Psychobiology and IMIB-Arrixaca Institute, University of Murcia, Murcia, Spain
| |
Collapse
|
9
|
Hildebrandt K, Bach N, Kolb D, Walldorf U. The homeodomain transcription factor Orthopedia is involved in development of the Drosophila hindgut. Hereditas 2020; 157:46. [PMID: 33213520 PMCID: PMC7678101 DOI: 10.1186/s41065-020-00160-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/11/2020] [Indexed: 12/20/2022] Open
Abstract
Background The Drosophila hindgut is commonly used model for studying various aspects of organogenesis like primordium establishment, further specification, patterning, and morphogenesis. During embryonic development of Drosophila, many transcriptional activators are involved in the formation of the hindgut. The transcription factor Orthopedia (Otp), a member of the 57B homeobox gene cluster, is expressed in the hindgut and nervous system of developing Drosophila embryos, but due to the lack of mutants no functional analysis has been conducted yet. Results We show that two different otp transcripts, a hindgut-specific and a nervous system-specific form, are present in the Drosophila embryo. Using an Otp antibody, a detailed expression analysis during hindgut development was carried out. Otp was not only expressed in the embryonic hindgut, but also in the larval and adult hindgut. To analyse the function of otp, we generated the mutant otp allele otpGT by ends-out gene targeting. In addition, we isolated two EMS-induced otp alleles in a genetic screen for mutants of the 57B region. All three otp alleles showed embryonic lethality with a severe hindgut phenotype. Anal pads were reduced and the large intestine was completely missing. This phenotype is due to apoptosis in the hindgut primordium and the developing hindgut. Conclusion Our data suggest that Otp is another important factor for hindgut development of Drosophila. As a downstream factor of byn Otp is most likely present only in differentiated hindgut cells during all stages of development rather than in stem cells.
Collapse
Affiliation(s)
- Kirsten Hildebrandt
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Saarland, Germany
| | - Nicole Bach
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Saarland, Germany
| | - Dieter Kolb
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Saarland, Germany
| | - Uwe Walldorf
- Developmental Biology, Saarland University, Building 61, 66421, Homburg/Saar, Saarland, Germany.
| |
Collapse
|
10
|
Wasel O, Freeman JL. Chemical and Genetic Zebrafish Models to Define Mechanisms of and Treatments for Dopaminergic Neurodegeneration. Int J Mol Sci 2020; 21:ijms21175981. [PMID: 32825242 PMCID: PMC7503535 DOI: 10.3390/ijms21175981] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 08/14/2020] [Accepted: 08/16/2020] [Indexed: 01/08/2023] Open
Abstract
The zebrafish (Danio rerio) is routinely used in biological studies as a vertebrate model system that provides unique strengths allowing applications in studies of neurodevelopmental and neurodegenerative diseases. One specific advantage is that the neurotransmitter systems are highly conserved throughout vertebrate evolution, including between zebrafish and humans. Disruption of the dopaminergic signaling pathway is linked to multiple neurological disorders. One of the most common is Parkinson’s disease, a neurodegenerative disease associated with the loss of dopaminergic neurons, among other neuropathological characteristics. In this review, the development of the zebrafish’s dopaminergic system, focusing on genetic control of the dopaminergic system, is detailed. Second, neurotoxicant models used to study dopaminergic neuronal loss, including 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), the pesticides paraquat and rotenone, and 6-hydroxydopamine (6-OHDA), are described. Next, zebrafish genetic knockdown models of dj1, pink1, and prkn established for investigating mechanisms of Parkinson’s disease are discussed. Chemical modulators of the dopaminergic system are also highlighted to showcase the applicability of the zebrafish to identify mechanisms and treatments for neurodegenerative diseases such as Parkinson’s disease associated with the dopaminergic system.
Collapse
|
11
|
Wong CED, Hua K, Monis S, Saxena V, Norazit A, Noor SM, Ekker M. gdnf affects early diencephalic dopaminergic neuron development through regulation of differentiation-associated transcription factors in zebrafish. J Neurochem 2020; 156:481-498. [PMID: 32583440 DOI: 10.1111/jnc.15108] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 05/31/2020] [Accepted: 06/16/2020] [Indexed: 01/21/2023]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) has been reported to enhance dopaminergic neuron survival and differentiation in vitro and in vivo, although those results are still being debated. Glial cell line-derived neurotrophic factor (gdnf) is highly conserved in zebrafish and plays a role in enteric nervous system function. However, little is known about gdnf function in the teleost brain. Here, we employed clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 to impede gdnf function in the maintenance of dopaminergic neuron development. Genotyping of gdnf crispants revealed successful deletions of the coding region with various mutant band sizes and down-regulation of gdnf transcripts at 1, 3 and 7 day(s) post fertilization. Notably, ~20% reduction in ventral diencephalic dopaminergic neuron numbers in clusters 8 and 13 was observed in the gdnf-deficient crispants. In addition, gdnf depletion caused a modest reduction in dopaminergic neurogenesis as determined by 5-ethynyl-2'-deoxyuridine pulse chase assay. These deleterious effects could be partly attributed to deregulation of dopaminergic neuron fate specification-related transcription factors (otp,lmx1b,shha,and ngn1) in both crispants and established homozygous mutants with whole mount in-situ hybridization (WISH) on gdnf mutants showing reduced otpb and lmx1b.1 expression in the ventral diencephalon. Interestingly, locomotor function of crispants was only impacted at 7 dpf, but not earlier. Lastly, as expected, gdnf deficiency heightened crispants vulnerability to 1-methyl-4-phenylpyridinium toxic insult. Our results suggest conservation of teleost gdnf brain function with mammals and revealed the interactions between gdnf and transcription factors in dopaminergic neuron differentiation.
Collapse
Affiliation(s)
- Chee Ern David Wong
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| | - Khang Hua
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| | - Simon Monis
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| | - Vishal Saxena
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| | - Anwar Norazit
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Suzita Mohd Noor
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Marc Ekker
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON, Canada
| |
Collapse
|
12
|
Nagpal J, Herget U, Choi MK, Ryu S. Anatomy, development, and plasticity of the neurosecretory hypothalamus in zebrafish. Cell Tissue Res 2018; 375:5-22. [PMID: 30109407 DOI: 10.1007/s00441-018-2900-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 07/20/2018] [Indexed: 01/08/2023]
Abstract
The paraventricular nucleus (PVN) of the hypothalamus harbors diverse neurosecretory cells with critical physiological roles for the homeostasis. Decades of research in rodents have provided a large amount of information on the anatomy, development, and function of this important hypothalamic nucleus. However, since the hypothalamus lies deep within the brain in mammals and is difficult to access, many questions regarding development and plasticity of this nucleus still remain. In particular, how different environmental conditions, including stress exposure, shape the development of this important nucleus has been difficult to address in animals that develop in utero. To address these open questions, the transparent larval zebrafish with its rapid external development and excellent genetic toolbox offers exciting opportunities. In this review, we summarize recent information on the anatomy and development of the neurosecretory preoptic area (NPO), which represents a similar structure to the mammalian PVN in zebrafish. We will then review recent studies on the development of different cell types in the neurosecretory hypothalamus both in mouse and in fish. Lastly, we discuss stress-induced plasticity of the PVN mainly discussing the data obtained in rodents, but pointing out tools and approaches available in zebrafish for future studies. This review serves as a primer for the currently available information relevant for studying the development and plasticity of this important brain region using zebrafish.
Collapse
Affiliation(s)
- Jatin Nagpal
- German Resilience Center, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Ulrich Herget
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Blvd. Mail Code 156-29, Pasadena, CA, 91125, USA
| | - Min K Choi
- German Resilience Center, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany
| | - Soojin Ryu
- German Resilience Center, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, 55128, Mainz, Germany.
| |
Collapse
|
13
|
Abstract
Transcriptional control of oxytocinergic cell development influences social, sexual, and appetite related behaviors and is implicated in disorders such as autism and Prader-Willi syndrome. Mediator 12 (Med12) is a transcriptional coactivator required for multiple facets of brain development including subsets of serotonergic and dopaminergic neurons. We surveyed hormone gene expression within the hypothalamo-pituitary axis of med12 mutant zebrafish embryos with a focus on oxytocin (oxt) expression. Some transcripts, such as oxt, vasopressin (avp) and corticotrophin releasing hormone (crh) are undetectable in the med12 mutant, while others are upregulated or downregulated to varying degrees. In med12 mutants, the expression patterns of upstream transcriptional regulators of oxytocinergic cell development remain largely intact in the pre-optic area, suggesting a more direct influence of Med12 on oxt expression. We show that Med12 is required for Wnt signaling in zebrafish. However, oxt expression is unaffected in Wnt-inhibited embryos indicating independence of Wnt signaling. In fact, overactive Wnt signaling inhibits oxt expression, and we identify a Wnt-sensitive period starting at 24 h post fertilization (hpf). Thus, Med12 and repression of Wnt signaling display critical but unrelated roles in regulating oxt expression. Summary: Mediator 12, a transcriptional coactivator, greatly enhances Wnt signaling in the developing embryo. Separate from its role in Wnt signaling, Mediator 12 is required for oxytocin expression.
Collapse
Affiliation(s)
- Emma D Spikol
- Department of Oncology, Georgetown University, 4000 Reservoir Rd., Washington, DC 20057, USA
| | - Eric Glasgow
- Department of Oncology, Georgetown University, 4000 Reservoir Rd., Washington, DC 20057, USA
| |
Collapse
|
14
|
Identification of accessory olfactory system and medial amygdala in the zebrafish. Sci Rep 2017; 7:44295. [PMID: 28290515 PMCID: PMC5349599 DOI: 10.1038/srep44295] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 02/06/2017] [Indexed: 01/02/2023] Open
Abstract
Zebrafish larvae imprint on visual and olfactory cues of their kin on day 5 and 6 postfertilization, respectively. Only imprinted (but not non-imprinted) larvae show strongly activated crypt (and some microvillous) cells demonstrated by pERK levels after subsequent exposure to kin odor. Here, we investigate the olfactory bulb of zebrafish larvae for activated neurons located at the sole glomerulus mdG2 which receives crypt cell input. Imprinted larvae show a significantly increased activation of olfactory bulb cells compared to non-imprinted larvae after exposure to kin odor. Surprisingly, pERK activated Orthopedia-positive cell numbers in the intermediate ventral telencephalic nucleus were higher in non-imprinted, kin odor stimulated larvae compared to control and to kin-odor stimulated imprinted larvae and control. Moreover, DiI tracing experiments in adult zebrafish show a neuronal circuit from crypt/microvillous olfactory sensory neurons via dorsomedial olfactory bulb and intermediate ventral telencephalic nucleus (thus, arguably the teleostean medial amygdala) to tuberal hypothalamus, demonstrating for the first time an accessory olfactory system in teleosts.
Collapse
|
15
|
Du Y, Guo Q, Shan M, Wu Y, Huang S, Zhao H, Hong H, Yang M, Yang X, Ren L, Peng J, Sun J, Zhou H, Li S, Su B. Spatial and Temporal Distribution of Dopaminergic Neurons during Development in Zebrafish. Front Neuroanat 2016; 10:115. [PMID: 27965546 PMCID: PMC5124710 DOI: 10.3389/fnana.2016.00115] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/15/2016] [Indexed: 11/13/2022] Open
Abstract
As one of the model organisms of Parkinson’s disease (PD) research, the zebrafish has its advantages, such as the 87% homology with human genome and transparent embryos which make it possible to observe the development of dopaminergic neurons in real time. However, there is no midbrain dopaminergic system in zebrafish when compared with mammals, and the location and projection of the dopaminergic neurons are seldom reported. In this study, Vmat2:GFP transgenic zebrafish was used to observe the development and distribution of dopaminergic neurons in real time. We found that diencephalons (DC) 2 and DC4 neuronal populations were detected at 24 h post fertilization (hpf). All DC neuronal populations as well as those in locus coeruleus (LC), raphe nuclei (Ra) and telencephalon were detected at 48 hpf. Axons were detected at 72 hpf. At 96 hpf, all the neuronal populations were detected. For the first time we reported axons from the posterior tubercle (PT) of ventral DC projected to subpallium in vivo. However, when compared with results from whole mount tyrosine hydroxylase (TH) immunofluorescence staining in wild type (WT) zebrafish, we found that DC2 and DC4 neuronal populations were mainly dopaminergic, while DC1, DC3, DC5 and DC6 might not. Neurons in pretectum (Pr) and telencephalon were mainly dopaminergic, while neurons in LC and Ra might be noradrenergic. Our study makes some corrections and modifications on the development, localization and distribution of zebrafish dopaminergic neurons, and provides some experimental evidences for the construction of the zebrafish PD model.
Collapse
Affiliation(s)
- Yuchen Du
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Qiang Guo
- Chongqing Key Laboratory of Neurobiology, Department of Neurobiology, Third Military Medical University Chongqing, China
| | - Minghui Shan
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Yongmei Wu
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Sizhou Huang
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Haixia Zhao
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Huarong Hong
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Ming Yang
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Xi Yang
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Liyi Ren
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Jiali Peng
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Jing Sun
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Hongli Zhou
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical College Chengdu, China
| | - Shurong Li
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical CollegeChengdu, China; Chengdu Medical College Infertility HospitalChengdu, China
| | - Bingyin Su
- Development and Regeneration Key Lab of Sichuan Province, Department of Anatomy and Histology and Embryology, Department of Pathology, Chengdu Medical CollegeChengdu, China; Chengdu Medical College Infertility HospitalChengdu, China
| |
Collapse
|
16
|
Santos-Durán GN, Ferreiro-Galve S, Menuet A, Quintana-Urzainqui I, Mazan S, Rodríguez-Moldes I, Candal E. The Shark Alar Hypothalamus: Molecular Characterization of Prosomeric Subdivisions and Evolutionary Trends. Front Neuroanat 2016; 10:113. [PMID: 27932958 PMCID: PMC5121248 DOI: 10.3389/fnana.2016.00113] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 11/08/2016] [Indexed: 12/31/2022] Open
Abstract
The hypothalamus is an important physiologic center of the vertebrate brain involved in the elaboration of individual and species survival responses. To better understand the ancestral organization of the alar hypothalamus we revisit previous data on ScOtp, ScDlx2/5, ScTbr1, ScNkx2.1 expression and Pax6 immunoreactivity jointly with new data on ScNeurog2, ScLhx9, ScLhx5, and ScNkx2.8 expression, in addition to immunoreactivity to serotonin (5-HT) and doublecortin (DCX) in the catshark Scyliorhinus canicula, a key species for this purpose since cartilaginous fishes are basal representatives of gnathostomes (jawed vertebrates). Our study revealed a complex genoarchitecture for the chondrichthyan alar hypothalamus. We identified terminal (rostral) and peduncular (caudal) subdivisions in the prosomeric paraventricular and subparaventricular areas (TPa/PPa and TSPa/PSPa, respectively) evidenced by the expression pattern of developmental genes like ScLhx5 (TPa) and immunoreactivity against Pax6 (PSPa) and 5-HT (PPa and PSPa). Dorso-ventral subdivisions were only evidenced in the SPa (SPaD, SPaV; respectively) by means of Pax6 and ScNkx2.8 (respectively). Interestingly, ScNkx2.8 expression overlaps over the alar-basal boundary, as Nkx2.2 does in other vertebrates. Our results reveal evidences for the existence of different groups of tangentially migrated cells expressing ScOtp, Pax6, and ScDlx2. The genoarchitectonic comparative analysis suggests alternative interpretations of the rostral-most alar plate in prosomeric terms and reveals a conserved molecular background for the vertebrate alar hypothalamus likely acquired before/during the agnathan-gnathostome transition, on which Otp, Pax6, Lhx5, and Neurog2 are expressed in the Pa while Dlx and Nkx2.2/Nkx2.8 are expressed in the SPa.
Collapse
Affiliation(s)
- Gabriel N Santos-Durán
- Grupo BRAINSHARK, Departamento de Biología Funcional, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - Susana Ferreiro-Galve
- Grupo BRAINSHARK, Departamento de Biología Funcional, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - Arnaud Menuet
- CNRS, UMR 7355, University of Orleans Orleans, France
| | - Idoia Quintana-Urzainqui
- Grupo BRAINSHARK, Departamento de Biología Funcional, Universidade de Santiago de CompostelaSantiago de Compostela, Spain; Centre for Integrative Physiology, University of EdinburghEdinburgh, UK
| | - Sylvie Mazan
- Sorbonne Universités, UPMC, CNRS UMR7232 Biologie Intégrative des Organismes Marins, Observatoire Océanologique Banyuls sur Mer, France
| | - Isabel Rodríguez-Moldes
- Grupo BRAINSHARK, Departamento de Biología Funcional, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - Eva Candal
- Grupo BRAINSHARK, Departamento de Biología Funcional, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| |
Collapse
|
17
|
Gao Y, Sun T. Molecular regulation of hypothalamic development and physiological functions. Mol Neurobiol 2016; 53:4275-85. [PMID: 26223804 PMCID: PMC4733441 DOI: 10.1007/s12035-015-9367-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 07/17/2015] [Indexed: 01/08/2023]
Abstract
The hypothalamus is composed of many heterogeneous nuclei that control distinct physiological functions. Investigating molecular mechanisms that regulate the specification of these nuclei and specific neuronal subtypes, and their contribution to diverse hypothalamic functions, is an exciting research focus. Here, we begin by summarizing the hypothalamic functions of feeding regulation, sleep-wake cycles, stress responses, and circadian rhythm, and describing their anatomical bases. Next, we review the molecular regulation of formation of hypothalamic territories, specification of nuclei and subnuclei, and generation of specific neurons. Finally, we highlight physiological and behavioral consequences of altered hypothalamic development. Identifying molecules that regulate hypothalamic development and function will increase our understanding of hypothalamus-related disorders, such as obesity and diabetes, and aid in the development of therapies aimed specifically at their etiologies.
Collapse
Affiliation(s)
- Yanxia Gao
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Tao Sun
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, Box 60, New York, NY, 10065, USA.
| |
Collapse
|
18
|
Domínguez L, González A, Moreno N. Patterns of hypothalamic regionalization in amphibians and reptiles: common traits revealed by a genoarchitectonic approach. Front Neuroanat 2015; 9:3. [PMID: 25691860 PMCID: PMC4315040 DOI: 10.3389/fnana.2015.00003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/09/2015] [Indexed: 01/05/2023] Open
Abstract
Most studies in mammals and birds have demonstrated common patterns of hypothalamic development highlighted by the combination of developmental regulatory genes (genoarchitecture), supporting the notion of the hypothalamus as a component of the secondary prosencephalon, topologically rostral to the diencephalon. In our comparative analysis we have summarized the data on the expression patterns of different transcription factors and neuroactive substances, used as anatomical markers, in the developing hypothalamus of the amphibian Xenopus laevis and the juvenile turtle Pseudemys scripta. This analysis served to highlight the organization of the hypothalamus in the anamniote/amniotic transition. We have identified supraoptoparaventricular and the suprachiasmatic regions (SCs) in the alar part of the hypothalamus, and tuberal and mammillary regions in the basal hypothalamus. Shared features in the two species are: (1) The supraoptoparaventricular region (SPV) is defined by the expression of Otp and the lack of Nkx2.1/Isl1. It is subdivided into rostral, rich in Otp and Nkx2.2, and caudal, only Otp-positive, portions. (2) The suprachiasmatic area contains catecholaminergic cell groups and lacks Otp, and can be further divided into rostral (rich in Nkx2.1 and Nkx2.2) and a caudal (rich in Isl1 and devoid of Nkx2.1) portions. (3) Expression of Nkx2.1 and Isl1 define the tuberal hypothalamus and only the rostral portion expresses Otp. (4) Its caudal boundary is evident by the lack of Isl1 in the adjacent mammillary region, which expresses Nkx2.1 and Otp. Differences in the anamnio-amniote transition were noted since in the turtle, like in other amniotes, the boundary between the alar hypothalamus and the telencephalic preoptic area shows distinct Nkx2.2 and Otp expressions but not in the amphibian (anamniote), and the alar SPV is defined by the expression of Otp/Pax6, whereas in Xenopus only Otp is expressed.
Collapse
Affiliation(s)
- Laura Domínguez
- Faculty of Biology, Department of Cell Biology, University Complutense of Madrid Madrid, Spain
| | - Agustín González
- Faculty of Biology, Department of Cell Biology, University Complutense of Madrid Madrid, Spain
| | - Nerea Moreno
- Faculty of Biology, Department of Cell Biology, University Complutense of Madrid Madrid, Spain
| |
Collapse
|
19
|
Manoli M, Driever W. nkx2.1 and nkx2.4 genes function partially redundant during development of the zebrafish hypothalamus, preoptic region, and pallidum. Front Neuroanat 2014; 8:145. [PMID: 25520628 PMCID: PMC4251446 DOI: 10.3389/fnana.2014.00145] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 11/14/2014] [Indexed: 01/27/2023] Open
Abstract
During ventral forebrain development, orthologs of the homeodomain transcription factor Nkx2.1 control patterning of hypothalamus, preoptic region, and ventral telencephalon. However, the relative contributions of Nkx2.1 and Nkx2.4 to prosencephalon development are poorly understood. Therefore, we analyzed functions of the previously uncharacterized nkx2.4-like zgc:171531 as well as of the presumed nkx2.1 orthologs nkx2.1a and nkx2.1b in zebrafish forebrain development. Our results show that zgc:171531 and nkx2.1a display overlapping expression patterns and a high sequence similarity. Together with a high degree of synteny conservation, these findings indicate that both these genes indeed are paralogs of nkx2.4. As a result, we name zgc:171531 now nkx2.4a, and changed the name of nkx2.1a to nkx2.4b, and of nkx2.1b to nkx2.1. In nkx2.1, nkx2.4a, and nkx2.4b triple morpholino knockdown (nkx2TKD) embryos we observed a loss of the rostral part of prosomere 3 and its derivative posterior tubercular and hypothalamic structures. Furthermore, there was a loss of rostral and intermediate hypothalamus, while a residual preoptic region still develops. The reduction of the ventral diencephalon was accompanied by a ventral expansion of the dorsally expressed pax6, revealing a dorsalization of the basal hypothalamus. Within the telencephalon we observed a loss of pallidal markers, while striatum and pallium are forming. At the neuronal level, nkx2TKD morphants lacked several neurosecretory neuron types, including avp, crh, and pomc expressing cells in the hypothalamus, but still form oxt neurons in the preoptic region. Our data reveals that, while nkx2.1, nkx2.4a, and nkx2.4b genes act partially redundant in hypothalamic development, nkx2.1 is specifically involved in the development of rostral ventral forebrain including the pallidum and preoptic regions, whereas nkx2.4a and nkx2.4b control the intermediate and caudal hypothalamus.
Collapse
Affiliation(s)
- Martha Manoli
- Developmental Biology, Faculty of Biology, Institute Biology I, University of Freiburg Freiburg, Germany
| | - Wolfgang Driever
- Developmental Biology, Faculty of Biology, Institute Biology I, University of Freiburg Freiburg, Germany ; Centre for Biological Signaling Studies (BIOSS), University of Freiburg Freiburg, Germany
| |
Collapse
|
20
|
Herget U, Wolf A, Wullimann MF, Ryu S. Molecular neuroanatomy and chemoarchitecture of the neurosecretory preoptic-hypothalamic area in zebrafish larvae. J Comp Neurol 2014; 522:1542-64. [PMID: 24127437 DOI: 10.1002/cne.23480] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 07/31/2013] [Accepted: 09/30/2013] [Indexed: 12/16/2022]
Abstract
The paraventricular nucleus (PVN) in mammals is the main hypothalamic nucleus controlling hormone release in the pituitary and plays pivotal roles in homeostasis. While the location of a PVN-homologous region has been described in adult fish as the neurosecretory preoptic area (NPO), this region has not been clearly defined in larval zebrafish due to the difficulty in defining cytoarchitectonic nuclear boundaries in the larval brain. Here we identify the precise location of the larval zebrafish NPO using conserved transcription factor and neuropeptide gene expressions. Our results identify the dorsal half of the preoptic-hypothalamic orthopedia a (otpa) domain as the larval NPO and the homologous region to the mammalian PVN. Further, by reconstructing the locations of cells producing zebrafish neuropeptides found in the mammalian PVN (CCK, CRH, ENK, NTS, SS, VIP, OXT, AVP), we provide the first 3D arrangement map of NPO neuropeptides in the larval zebrafish brain. Our results show striking conservation of transcription factor expression (otp, arx, dlx5a, isl1) in and around the NPO/PVN together with neuropeptide expression within it. Finally, we describe the exact anatomical location of cells producing Oxt and Avp in the adult zebrafish. Thus, our results identify the definitive borders and extent of the PVN homologous region in larval zebrafish and serve as an important basis for cross-species comparisons of PVN/NPO structure and function.
Collapse
Affiliation(s)
- Ulrich Herget
- Max Planck Institute for Medical Research, Developmental Genetics of the Nervous System, 69120, Heidelberg, Germany; The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology, University of Heidelberg, Germany
| | | | | | | |
Collapse
|
21
|
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.
Collapse
Affiliation(s)
| | | | | | - Raquel E Rodríguez
- Instituto de Neurociencias de Castilla y León, University of Salamanca, Salamanca 37007, Spain.
| |
Collapse
|
22
|
Domínguez L, González A, Moreno N. Characterization of the hypothalamus of Xenopus laevis during development. II. The basal regions. J Comp Neurol 2014; 522:1102-31. [PMID: 24122702 DOI: 10.1002/cne.23471] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/25/2013] [Accepted: 09/13/2013] [Indexed: 01/10/2023]
Abstract
The expression patterns of conserved developmental regulatory transcription factors and neuronal markers were analyzed in the basal hypothalamus of Xenopus laevis throughout development by means of combined immunohistochemical and in situ hybridization techniques. The connectivity of the main subdivisions was investigated by in vitro tracing techniques with dextran amines. The basal hypothalamic region is topologically rostral to the basal diencephalon and is composed of the tuberal (rostral) and mammillary (caudal) subdivisions, according to the prosomeric model. It is dorsally bounded by the optic chiasm and the alar hypothalamus, and caudally by the diencephalic prosomere p3. The tuberal hypothalamus is defined by the expression of Nkx2.1, xShh, and Isl1, and rostral and caudal portions can be distinguished by the distinct expression of Otp rostrally and Nkx2.2 caudally. In the mammillary region the xShh/Nkx2.1 combination defined the rostral mammillary area, expressing Nkx2.1, and the caudal retromammillary area, expressing xShh. The expression of xLhx1, xDll4, and Otp in the mammillary area and Isl1 in the tuberal region highlights the boundary between the two basal hypothalamic territories. Both regions are strongly connected with subpallial regions, especially those conveying olfactory/vomeronasal information, and also possess abundant intrahypothalamic connections. They show reciprocal connections with the diencephalon (mainly the thalamus), project to the midbrain tectum, and are bidirectionally related to the rhombencephalon. These results illustrate that the basal hypothalamus of anurans shares many features of specification, regionalization, and hodology with amniotes, reinforcing the idea of a basic bauplan in the organization of this prosencephalic region in all tetrapods.
Collapse
Affiliation(s)
- Laura Domínguez
- Faculty of Biology, Department of Cell Biology, University Complutense of Madrid, Madrid, Spain
| | | | | |
Collapse
|
23
|
Flinn LJ, Keatinge M, Bretaud S, Mortiboys H, Matsui H, De Felice E, Woodroof HI, Brown L, McTighe A, Soellner R, Allen CE, Heath PR, Milo M, Muqit MMK, Reichert AS, Köster RW, Ingham PW, Bandmann O. TigarB causes mitochondrial dysfunction and neuronal loss in PINK1 deficiency. Ann Neurol 2014; 74:837-47. [PMID: 24027110 PMCID: PMC4154126 DOI: 10.1002/ana.23999] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 07/30/2013] [Accepted: 08/03/2013] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Loss of function mutations in PINK1 typically lead to early onset Parkinson disease (PD). Zebrafish (Danio rerio) are emerging as a powerful new vertebrate model to study neurodegenerative diseases. We used a pink1 mutant (pink(-/-) ) zebrafish line with a premature stop mutation (Y431*) in the PINK1 kinase domain to identify molecular mechanisms leading to mitochondrial dysfunction and loss of dopaminergic neurons in PINK1 deficiency. METHODS The effect of PINK1 deficiency on the number of dopaminergic neurons, mitochondrial function, and morphology was assessed in both zebrafish embryos and adults. Genome-wide gene expression studies were undertaken to identify novel pathogenic mechanisms. Functional experiments were carried out to further investigate the effect of PINK1 deficiency on early neurodevelopmental mechanisms and microglial activation. RESULTS PINK1 deficiency results in loss of dopaminergic neurons as well as early impairment of mitochondrial function and morphology in Danio rerio. Expression of TigarB, the zebrafish orthologue of the human, TP53-induced glycolysis and apoptosis regulator TIGAR, was markedly increased in pink(-/-) larvae. Antisense-mediated inactivation of TigarB gave rise to complete normalization of mitochondrial function, with resulting rescue of dopaminergic neurons in pink(-/-) larvae. There was also marked microglial activation in pink(-/-) larvae, but depletion of microglia failed to rescue the dopaminergic neuron loss, arguing against microglial activation being a key factor in the pathogenesis. INTERPRETATION Pink1(-/-) zebrafish are the first vertebrate model of PINK1 deficiency with loss of dopaminergic neurons. Our study also identifies TIGAR as a promising novel target for disease-modifying therapy in PINK1-related PD.
Collapse
Affiliation(s)
- Laura J Flinn
- Medical Research Council Centre for Developmental and Biomedical Genetics, University of Sheffield, Sheffield, United Kingdom; Sheffield Institute for Translational Neuroscience, Department of Neuroscience, University of Sheffield, Sheffield, United Kingdom
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
De Felice E, Porreca I, Alleva E, De Girolamo P, Ambrosino C, Ciriaco E, Germanà A, Sordino P. Localization of BDNF expression in the developing brain of zebrafish. J Anat 2014; 224:564-74. [PMID: 24588510 DOI: 10.1111/joa.12168] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2014] [Indexed: 12/14/2022] Open
Abstract
The brain-derived neurotrophic factor (BDNF) gene is expressed in differentiating and post-mitotic neurons of the zebrafish embryo, where it has been implicated in Huntington's disease. Little is known, however, about the full complement of neuronal cell types that express BDNF in this important vertebrate model. Here, we further explored the transcriptional profiles during the first week of development using real-time quantitative polymerase chain reaction (RT-qPCR) and whole-mount in situ hybridization (WISH). RT-qPCR results revealed a high level of maternal contribution followed by a steady increase of zygotic transcription, consistent with the notion of a prominent role of BDNF in neuronal maturation and maintenance. Based on WISH, we demonstrate for the first time that BDNF expression in the developing brain of zebrafish is structure specific. Anatomical criteria and co-staining with genetic markers (shh, pax2a, emx1, krox20, lhx2b and lhx9) visualized major topological domains of BDNF-positive cells in the pallium, hypothalamus, posterior tuberculum and optic tectum. Moreover, the relative timing of BDNF transcription in the eye and tectum may illustrate a mechanism for coordinated development of the retinotectal system. Taken together, our results are compatible with a local delivery and early role of BDNF in the developing brain of zebrafish, adding basic knowledge to the study of neurotrophin functions in neural development and disease.
Collapse
Affiliation(s)
- E De Felice
- Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Naples, Italy; Department of Morphology, Biochemistry, Physiology and Animal Productions, Section of Morphology, University of Messina, Messina, Italy
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Panula P, Sundvik M, Karlstedt K. Developmental roles of brain histamine. Trends Neurosci 2014; 37:159-68. [PMID: 24486025 DOI: 10.1016/j.tins.2014.01.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/31/2013] [Accepted: 01/02/2014] [Indexed: 12/17/2022]
Abstract
Histamine appears early during brain development, has been shown to regulate fetal and adult brain-derived stem cells in a receptor type-dependent manner, and has widespread actions on systems involved in arousal and movement. Developmental studies in both rodents and zebrafish have elucidated the spatiotemporal patterning of the histaminergic system and, in zebrafish, have revealed the mechanisms whereby histamine regulates the number of hypocretin/orexin (hcrt) neurons, which in turn may regulate the number of histaminergic cells. Recent demonstrations of increased numbers of histaminergic neurons in patients with narcolepsy highlight the importance, for our understanding of both normal and pathological brain function, of understanding these interactions. Here, we review recent research into the developmental roles of histamine and suggest key areas for future research.
Collapse
Affiliation(s)
- Pertti Panula
- Neuroscience Center, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland; Institute of Biomedicine, Anatomy, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland.
| | - Maria Sundvik
- Neuroscience Center, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland; Institute of Biomedicine, Anatomy, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Kaj Karlstedt
- Institute of Biomedicine, Physiology, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| |
Collapse
|
26
|
Fernandes AM, Beddows E, Filippi A, Driever W. Orthopedia transcription factor otpa and otpb paralogous genes function during dopaminergic and neuroendocrine cell specification in larval zebrafish. PLoS One 2013; 8:e75002. [PMID: 24073233 PMCID: PMC3779234 DOI: 10.1371/journal.pone.0075002] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 08/08/2013] [Indexed: 11/29/2022] Open
Abstract
The homeodomain transcription factor Orthopedia (Otp) is an important regulator for specification of defined subsets of neuroendocrine cells and dopaminergic neurons in vertebrates. In zebrafish, two paralogous otp genes, otpa and otpb, are present in the genome. Neither complete loss of Otp activity nor differential contributions of Otpa and Otpb to specification of defined neuronal populations have been analyzed in detail. We characterized zebrafish embryos and early larvae mutant for null alleles of otpa, otpb, or both genes to determine their individual contributions to the specification of th expressing dopaminergic neuronal populations as well as of crh, oxt, avp, trh or sst1.1 expressing neuroendocrine cells. otpa mutant larvae show an almost complete reduction of ventral diencephalic dopaminergic neurons, as reported previously. A small reduction in the number of trh cells in the preoptic region is detectable in otpa mutants, but no significant loss of crh, oxt and avp preoptic neuroendocrine cells. otpb single mutant larvae do not display a reduction in dopaminergic neurons or neuroendocrine cells in the otp expressing regions. In contrast, in otpa and otpb double mutant larvae specific groups of dopaminergic neurons as well as of crh, oxt, avp, trh and sst1.1-expressing neuroendocrine cells are completely lost. These observations suggest that the requirement for otpa and otpb function during development of the larval diencephalon is partially redundant. During evolutionary diversification of the paralogous otp genes, otpa maintained the prominent role in ventral diencephalic dopaminergic and neuroendocrine cell specification and is capable of partially compensating otpb loss of function. In addition, we identified a role of Otp in the development of a domain of somatostatin1-expressing cells in the rostral hindbrain, a region with strong otp expression but so far uncharacterized Otp function. Otp may thus be crucial for defined neuronal cell types also in the hindbrain.
Collapse
Affiliation(s)
- António M. Fernandes
- Developmental Biology Unit, Faculty of Biology, and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Erin Beddows
- Developmental Biology Unit, Faculty of Biology, and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Alida Filippi
- Developmental Biology Unit, Faculty of Biology, and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Wolfgang Driever
- Developmental Biology Unit, Faculty of Biology, and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- * E-mail:
| |
Collapse
|
27
|
Domínguez L, Morona R, González A, Moreno N. Characterization of the hypothalamus of Xenopus laevis during development. I. The alar regions. J Comp Neurol 2013; 521:725-59. [PMID: 22965483 DOI: 10.1002/cne.23222] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 06/19/2012] [Accepted: 08/21/2012] [Indexed: 12/19/2022]
Abstract
The patterns of expression of a set of conserved developmental regulatory transcription factors and neuronal markers were analyzed in the alar hypothalamus of Xenopus laevis throughout development. Combined immunohistochemical and in situ hybridization techniques were used for the identification of subdivisions and their boundaries. The alar hypothalamus was located rostral to the diencephalon in the secondary prosencephalon and represents the rostral continuation of the alar territories of the diencephalon and brainstem, according to the prosomeric model. It is composed of the supraoptoparaventricular (dorsal) and the suprachiasmatic (ventral) regions, and limits dorsally with the preoptic region, caudally with the prethalamic eminence and the prethalamus, and ventrally with the basal hypothalamus. The supraoptoparaventricular area is defined by the orthopedia (Otp) expression and is subdivided into rostral and caudal portions, on the basis of the Nkx2.2 expression only in the rostral portion. This region is the source of many neuroendocrine cells, primarily located in the rostral subdivision. The suprachiasmatic region is characterized by Dll4/Isl1 expression, and was also subdivided into rostral and caudal portions, based on the expression of Nkx2.1/Nkx2.2 and Lhx1/7 exclusively in the rostral portion. Both alar regions are mainly connected with subpallial areas strongly implicated in the limbic system and show robust intrahypothalamic connections. Caudally, both regions project to brainstem centers and spinal cord. All these data support that in terms of topology, molecular specification, and connectivity the subdivisions of the anuran alar hypothalamus possess many features shared with their counterparts in amniotes, likely controlling similar reflexes, responses, and behaviors.
Collapse
Affiliation(s)
- Laura Domínguez
- Faculty of Biology, Department of Cell Biology, University Complutense of Madrid, Madrid, Spain
| | | | | | | |
Collapse
|
28
|
Ren G, Li S, Zhong H, Lin S. Zebrafish tyrosine hydroxylase 2 gene encodes tryptophan hydroxylase. J Biol Chem 2013; 288:22451-9. [PMID: 23754283 DOI: 10.1074/jbc.m113.485227] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The primary pathological hallmark of Parkinson disease (PD) is the profound loss of dopaminergic neurons in the substantia nigra pars compacta. To facilitate the understanding of the underling mechanism of PD, several zebrafish PD models have been generated to recapitulate the characteristics of dopaminergic (DA) neuron loss. In zebrafish studies, tyrosine hydroxylase 1 (th1) has been frequently used as a molecular marker of DA neurons. However, th1 also labels norepinephrine and epinephrine neurons. Recently, a homologue of th1, named tyrosine hydroxylase 2 (th2), was identified based on the sequence homology and subsequently used as a novel marker of DA neurons. In this study, we present evidence that th2 co-localizes with serotonin in the ventral diencephalon and caudal hypothalamus in zebrafish embryos. In addition, knockdown of th2 reduces the level of serotonin in the corresponding th2-positive neurons. This phenotype can be rescued by both zebrafish th2 and mouse tryptophan hydroxylase 1 (Tph1) mRNA as well as by 5-hydroxytryptophan, the product of tryptophan hydroxylase. Moreover, the purified Th2 protein has tryptophan hydroxylase activity comparable with that of the mouse TPH1 protein in vitro. Based on these in vivo and in vitro results, we conclude that th2 is a gene encoding for tryptophan hydroxylase and should be used as a marker gene of serotonergic neurons.
Collapse
Affiliation(s)
- Guiqi Ren
- Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | | | | | | |
Collapse
|
29
|
Wolf A, Ryu S. Specification of posterior hypothalamic neurons requires coordinated activities of Fezf2, Otp, Sim1a and Foxb1.2. Development 2013; 140:1762-73. [PMID: 23533176 DOI: 10.1242/dev.085357] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The hypothalamus is a key integrative center in the brain that consists of diverse cell types required for a variety of functions including homeostasis, reproduction, stress response, social and cognitive behavior. Despite our knowledge of several transcription factors crucial for hypothalamic development, it is not known how the wide diversity of neuron types in the hypothalamus is produced. In particular, almost nothing is known about the mechanisms that specify neurons in the posteriormost part of the hypothalamus, the mammillary area. Here, we investigated the specification of two distinct neuron types in the mammillary area that produce the hypothalamic hormones Vasoactive intestinal peptide (Vip) and Urotensin 1 (Uts1). We show that Vip- and Uts1-positive neurons develop in distinct domains in the mammillary area defined by the differential expression of the transcription factors Fezf2, Otp, Sim1a and Foxb1.2. Coordinated activities of these factors are crucial for the establishment of the mammillary area subdomains and the specification of Vip- and Uts1-positive neurons. In addition, Fezf2 is important for early development of the posterior hypothalamus. Thus, our study provides the first molecular anatomical map of the posterior hypothalamus in zebrafish and identifies, for the first time, molecular requirements underlying the specification of distinct posterior hypothalamic neuron types.
Collapse
Affiliation(s)
- Andrea Wolf
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Heidelberg, Germany
| | | |
Collapse
|
30
|
Maximino C, Lima MG, Oliveira KRM, Batista EDJO, Herculano AM. “Limbic associative” and “autonomic” amygdala in teleosts: A review of the evidence. J Chem Neuroanat 2013; 48-49:1-13. [DOI: 10.1016/j.jchemneu.2012.10.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 10/04/2012] [Accepted: 10/05/2012] [Indexed: 12/31/2022]
|
31
|
Cocaine modulates the expression of transcription factors related to the dopaminergic system in zebrafish. Neuroscience 2013; 231:258-71. [DOI: 10.1016/j.neuroscience.2012.11.052] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/13/2012] [Accepted: 11/28/2012] [Indexed: 11/17/2022]
|
32
|
Schweitzer J, Löhr H, Bonkowsky JL, Hübscher K, Driever W. Sim1a and Arnt2 contribute to hypothalamo-spinal axon guidance by regulating Robo2 activity via a Robo3-dependent mechanism. Development 2013; 140:93-106. [PMID: 23222439 DOI: 10.1242/dev.087825] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Precise spatiotemporal control of axon guidance factor expression is a prerequisite for formation of functional neuronal connections. Although Netrin/Dcc- and Robo/Slit-mediated attractive and repulsive guidance of commissural axons have been extensively studied, little is known about mechanisms controlling mediolateral positioning of longitudinal axons in vertebrates. Here, we use a genetic approach in zebrafish embryos to study pathfinding mechanisms of dopaminergic and neuroendocrine longitudinal axons projecting from the hypothalamus into hindbrain and spinal cord. The transcription factors Sim1a and Arnt2 contribute to differentiation of a defined population of dopaminergic and neuroendocrine neurons. We show that both factors also control aspects of axon guidance: Sim1a or Arnt2 depletion results in displacement of hypothalamo-spinal longitudinal axons towards the midline. This phenotype is suppressed in robo3 guidance receptor mutant embryos. In the absence of Sim1a and Arnt2, expression of the robo3 splice isoform robo3a.1 is increased in the hypothalamus, indicating negative control of robo3a.1 transcription by these factors. We further provide evidence that increased Robo3a.1 levels interfere with Robo2-mediated repulsive axon guidance. Finally, we show that the N-terminal domain unique to Robo3a.1 mediates the block of Robo2 repulsive activity. Therefore, Sim1a and Arnt2 contribute to control of lateral positioning of longitudinal hypothalamic-spinal axons by negative regulation of robo3a.1 expression, which in turn attenuates the repulsive activity of Robo2.
Collapse
Affiliation(s)
- Jörn Schweitzer
- Developmental Biology, Institute Biology 1, Faculty of Biology, University of Freiburg, Hauptstrasse 1, D-79104 Freiburg, Germany.
| | | | | | | | | |
Collapse
|
33
|
Nesan D, Vijayan MM. Role of glucocorticoid in developmental programming: evidence from zebrafish. Gen Comp Endocrinol 2013; 181:35-44. [PMID: 23103788 DOI: 10.1016/j.ygcen.2012.10.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 10/13/2012] [Indexed: 10/27/2022]
Abstract
The vertebrate corticosteroid stress response is highly conserved and a key function is to restore homeostasis by mobilizing and reallocating energy stores. This process is primarily initiated by activation of the hypothalamus-pituitary-adrenal axis, leading to the release of corticosteroids into the circulation. In teleosts, cortisol is the primary corticosteroid that is released into the circulation in response to stress. This steroid activates corticosteroid receptors that are ligand-bound transcription factors, modulating downstream gene expression in target tissues. Recent research in zebrafish (Danio rerio) has identified novel roles for cortisol in early developmental processes, including organogenesis and mesoderm formation. As cortisol biosynthesis commences only around the time of hatch in teleosts, the early developmental events are orchestrated by cortisol that is maternally deposited prior to fertilization. This review will highlight the molecular events leading to the development of the corticosteroid stress axis, and the possible role of cortisol in the developmental programming of stress axis function. Use of zebrafish as a model may lead to significant insights into the conserved role of glucocorticoids during early development with potential implications in biomedical research, including fetal stress syndromes in humans.
Collapse
Affiliation(s)
- Dinushan Nesan
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | | |
Collapse
|
34
|
Schweitzer J, Lohr H, Filippi A, Driever W. Dopaminergic and noradrenergic circuit development in zebrafish. Dev Neurobiol 2012; 72:256-68. [PMID: 21567980 DOI: 10.1002/dneu.20911] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Dopaminergic and noradrenergic neurons constitute some of the major far projecting systems in the vertebrate brain and spinal cord that modulate the activity of circuits controlling a broad range of behaviors. Degeneration or dysfunction of dopaminergic neurons has also been linked to a number of neurological and psychiatric disorders, including Parkinson's disease.Zebrafish (Danio rerio) have emerged over the past two decades into a major genetic vertebrate model system,and thus contributed to a better understanding of developmental mechanisms controlling dopaminergic neuron specification and axonogenesis. In this review, we want to focus on conserved and dynamic aspects of the different catecholaminergic systems, which may help to evaluate the zebrafish as a model for dopaminergic and noradrenergic cellular specification and circuit function as well as biomedical aspects of catecholamine systems.
Collapse
|
35
|
Moreno N, Domínguez L, Morona R, González A. Subdivisions of the turtle Pseudemys scripta hypothalamus based on the expression of regulatory genes and neuronal markers. J Comp Neurol 2012; 520:453-78. [PMID: 21935937 DOI: 10.1002/cne.22762] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The patterns of distribution of a set of conserved brain developmental regulatory transcription factors and neuronal markers were analyzed in the hypothalamus of the juvenile turtle, Pseudemys scripta. Combined immunohistochemical techniques were used for the identification of the main boundaries and subdivisions in the optic, paraventricular, tuberal, and mammillary hypothalamic regions. The combination of Tbr1 and Pax6 with Nkx2.1 allowed identification of the boundary between the telencephalic preoptic area, rich in Nkx2.1 expression, and the prethalamic eminence, rich in Tbr1 expression. In addition, at this level Nkx2.2 expression defined the boundary between the telencephalon and the hypothalamus. The dorsalmost hypothalamic domain was the supraoptoparaventricular region that was defined by the expression of Otp/Pax6 and the lack of Nkx2.1/Isl1. It is subdivided into rostral, rich in Otp and Nkx2.2, and caudal, only Otp-positive, portions. Ventrally, the suprachiasmatic area was identified by its catecholaminergic groups and the lack of Otp, and could be further divided into a rostral portion, rich in Nkx2.1 and Nkx2.2, and a caudal portion, rich in Isl1 and devoid of Nkx2.1 expression. The expressions of Nkx2.1 and Isl1 defined the tuberal hypothalamus, whereas only the rostral portion expressed Otp. Its caudal boundary was evident by the lack of Isl1 in the adjacent mammillary area, which expressed Nkx2.1 and Otp. All these results provide an important set of data on the interpretation of the hypothalamic organization in a reptile, and hence make a useful contribution to the understanding of hypothalamic evolution.
Collapse
Affiliation(s)
- Nerea Moreno
- Department of Cell Biology, Faculty of Biology, University Complutense of Madrid, 28040, Madrid, Spain.
| | | | | | | |
Collapse
|
36
|
Filippi A, Jainok C, Driever W. Analysis of transcriptional codes for zebrafish dopaminergic neurons reveals essential functions of Arx and Isl1 in prethalamic dopaminergic neuron development. Dev Biol 2012; 369:133-49. [PMID: 22728160 DOI: 10.1016/j.ydbio.2012.06.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 05/16/2012] [Accepted: 06/12/2012] [Indexed: 11/29/2022]
Abstract
Distinct groups of dopaminergic neurons develop at defined anatomical sites in the brain to modulate function of a large diversity of local and far-ranging circuits. However, the molecular identity as judged from transcription factor expression has not been determined for all dopaminergic groups. Here, we analyze regional expression of transcription factors in the larval zebrafish brain to determine co-expression with the Tyrosine hydroxylase marker in dopaminergic neurons. We define sets of transcription factors that clearly identify each dopaminergic group. These data confirm postulated relations to dopaminergic groups defined for mammalian systems. We focus our functional analysis on prethalamic dopaminergic neurons, which co-express the transcription factors Arx and Isl1. Morpholino-based knockdown reveals that both Arx and Isl1 are strictly required for prethalamic dopaminergic neuron development and appear to act in parallel. We further show that Arx contributes to patterning in the prethalamic region, while Isl1 is required for differentiation of prethalamic dopaminergic neurons.
Collapse
Affiliation(s)
- Alida Filippi
- Developmental Biology, Institute Biology 1, University of Freiburg, Hauptstrasse 1, D-79104 Freiburg, Germany
| | | | | |
Collapse
|
37
|
Lorente-Cánovas B, Marín F, Corral-San-Miguel R, Hidalgo-Sánchez M, Ferrán JL, Puelles L, Aroca P. Multiple origins, migratory paths and molecular profiles of cells populating the avian interpeduncular nucleus. Dev Biol 2011; 361:12-26. [PMID: 22019302 DOI: 10.1016/j.ydbio.2011.09.032] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 09/26/2011] [Accepted: 09/27/2011] [Indexed: 01/22/2023]
Abstract
The interpeduncular nucleus (IP) is a key limbic structure, highly conserved evolutionarily among vertebrates. The IP receives indirect input from limbic areas of the telencephalon, relayed by the habenula via the fasciculus retroflexus. The function of the habenulo-IP complex is poorly understood, although there is evidence that in rodents it modulates behaviors such as learning and memory, avoidance, reward and affective states. The IP has been an important subject of interest for neuroscientists, and there are multiple studies about the adult structure, chemoarchitecture and its connectivity, with complex results, due to the presence of multiple cell types across a variety of subnuclei. However, the ontogenetic origins of these populations have not been examined, and there is some controversy about its location in the midbrain-anterior hindbrain area. To address these issues, we first investigated the anteroposterior (AP) origin of the IP complex by fate-mapping its neuromeric origin in the chick, discovering that the IP develops strictly within isthmus and rhombomere 1. Next, we studied the dorsoventral (DV) positional identity of subpopulations of the IP complex. Our results indicate that there are at least four IP progenitor domains along the DV axis. These specific domains give rise to distinct subtypes of cell populations that target the IP with variable subnuclear specificity. Interestingly, these populations can be characterized by differential expression of the transcription factors Pax7, Nkx6.1, Otp, and Otx2. Each of these subpopulations follows a specific route of migration from its source, and all reach the IP roughly at the same stage. Remarkably, IP progenitor domains were found both in the alar and basal plates. Some IP populations showed rostrocaudal restriction in their origins (isthmus versus anterior or posterior r1 regions). A tentative developmental model of the structure of the avian IP is proposed. The IP emerges as a plurisegmental and developmentally heterogeneous formation that forms ventromedially within the isthmus and r1. These findings are relevant since they help to understand the highly complex chemoarchitecture, hodology and functions of this important brainstem structure.
Collapse
Affiliation(s)
- Beatriz Lorente-Cánovas
- Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia, 30100 Murcia, Spain.
| | | | | | | | | | | | | |
Collapse
|
38
|
Fujimoto E, Gaynes B, Brimley CJ, Chien CB, Bonkowsky JL. Gal80 intersectional regulation of cell-type specific expression in vertebrates. Dev Dyn 2011; 240:2324-34. [PMID: 21905164 DOI: 10.1002/dvdy.22734] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2011] [Indexed: 11/09/2022] Open
Abstract
Characterization and functional manipulation of specific groups of neurons in the vertebrate central nervous system (CNS) remains a major hurdle for understanding complex circuitry and functions. In zebrafish, the Gal4/UAS system has permitted expression of transgenes and enhancer trap screens, but is often limited by broad expression domains. We have developed a method for cell-type specific expression using Gal80 inhibition of Gal4-dependent expression. We show that native Gal4 is able to drive strong expression, that Gal80 can inhibit this expression, and that overlapping Gal4 and Gal80 expression can achieve "intersectional" expression in spatially and genetically defined subsets of neurons. We also optimize Gal80 for expression in vertebrates, track Gal80 expression with a co-expressed fluorescent marker, and use a temperature-sensitive allele of Gal80 to temporally regulate its function. These data demonstrate that Gal80 is a powerful addition to the genetic techniques available to map and manipulate neural circuits in zebrafish.
Collapse
Affiliation(s)
- Esther Fujimoto
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | | | | | | | | |
Collapse
|
39
|
Flames N, Hobert O. Transcriptional Control of the Terminal Fate of Monoaminergic Neurons. Annu Rev Neurosci 2011; 34:153-84. [DOI: 10.1146/annurev-neuro-061010-113824] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nuria Flames
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University Medical Center, New York, New York 10032;
- Genes & Disease Program, Center for Genomic Regulation (CRG), Barcelona, Spain E-08003;
- Present address: Instituto de Biomedicina de Valencia IBV-CSIC, E-46010 Valencia, Spain
| | - Oliver Hobert
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Columbia University Medical Center, New York, New York 10032;
| |
Collapse
|
40
|
Fujimoto E, Stevenson TJ, Chien CB, Bonkowsky JL. Identification of a dopaminergic enhancer indicates complexity in vertebrate dopamine neuron phenotype specification. Dev Biol 2011; 352:393-404. [PMID: 21276790 PMCID: PMC3069253 DOI: 10.1016/j.ydbio.2011.01.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 01/13/2011] [Accepted: 01/19/2011] [Indexed: 01/05/2023]
Abstract
The dopaminergic neurons of the basal ganglia play critical roles in CNS function and human disease, but specification of dopamine neuron phenotype is poorly understood in vertebrates. We performed an in vivo screen in zebrafish to identify dopaminergic neuron enhancers, in order to facilitate studies on the specification of neuronal identity, connectivity, and function in the basal ganglia. Based primarily on identification of conserved non-coding elements, we tested 54 DNA elements from four species (zebrafish, pufferfish, mouse, and rat), that included 21 genes with known or putative roles in dopaminergic neuron specification or function. Most elements failed to drive CNS expression or did not express specifically in dopaminergic neurons. However, we did isolate a discrete enhancer from the otpb gene that drove specific expression in diencephalic dopaminergic neurons, although it did not share sequence conservation with regulatory regions of otpa or other dopamine-specific genes. For the otpb enhancer, regulation of expression in dopamine neurons requires multiple elements spread across a large genomic area. In addition, we compared our in vivo testing with in silico analysis of genomic regions for genes involved in dopamine neuron function, but failed to find conserved regions that functioned as enhancers. We conclude that regulation of dopaminergic neuron phenotype in vertebrates is regulated by dispersed regulatory elements.
Collapse
Affiliation(s)
- Esther Fujimoto
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84132
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Tamara J. Stevenson
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Chi-Bin Chien
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah 84132
| | - Joshua L. Bonkowsky
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah 84132
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah 84132
| |
Collapse
|
41
|
|
42
|
Moreno N, González A. The non-evaginated secondary prosencephalon of vertebrates. Front Neuroanat 2011; 5:12. [PMID: 21427782 PMCID: PMC3049325 DOI: 10.3389/fnana.2011.00012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 02/16/2011] [Indexed: 01/22/2023] Open
Abstract
The secondary prosencephalon (telencephalon plus hypothalamus) is probably the most complex area of the brain, with complicated patterning specifications. As yet, no prosomeric subdivisions have been reported and only distinct histogenetic territories have been recognized. In the present comparative study we analyzed cross-correlated expression maps in the non-evaginated territories of the secondary prosencephalon in different vertebrates throughout development, to assess the existence of comparable divisions and subdivisions in the different groups. Each division is characterized by expression of a unique combination of developmental regulatory genes, and each appears to represent a self-regulated and topologically constant histogenetic brain compartment that gives rise to a specific cell group. The non-evaginated area of the telencephalon corresponds to the preoptic region, whereas the hypothalamus, topologically rostral to the diencephalic prethalamus, includes basal (mammillary and tuberal) and alar (paraventricular and suprachiasmatic) parts. This complex area is specified by a cascade of transcription factors, among which the Dlx family members and Nkx2.1 are essential for the correct development. The only exception is found in the subdivision named termed the supraoptoparaventricular area, in which the transcription factor Orthopedia is essential in restricting the fate of multiple categories of neuroendocrine neurons, in the absence of the Dlx/Nkx2.1 combination. Our analysis, based on own data and published results by other researchers, suggests that common features are shared at least by all tetrapods and, therefore, they most likely were present in the stem tetrapods. The available data for agnathans (lampreys) and other fish groups indicate that not all subdivisions of the secondary prosencephalon were present at the origin of vertebrates, raising important questions about their evolution.
Collapse
Affiliation(s)
- Nerea Moreno
- Departamento de Biología Celular, Facultad de Biología, Universidad Complutense of Madrid Madrid, Spain
| | | |
Collapse
|
43
|
Domínguez L, González A, Moreno N. Ontogenetic distribution of the transcription factor nkx2.2 in the developing forebrain of Xenopus laevis. Front Neuroanat 2011; 5:11. [PMID: 21415915 PMCID: PMC3049246 DOI: 10.3389/fnana.2011.00011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 02/16/2011] [Indexed: 11/20/2022] Open
Abstract
The expression of the Nkx2.2 gene is involved in the organization of the alar-basal boundary in the forebrain of vertebrates. Its expression in different diencephalic and telencephalic regions, helped to define distinct progenitor domains in mouse and chick. Here we investigated the pattern of Nkx2.2 protein distribution throughout the development of the forebrain of the anuran amphibian, Xenopus laevis. We used immunohistochemical and in situ hybridization techniques for its detection in combination with other essential territorial markers in the forebrain. No expression was observed in the telencephalon. In the alar hypothalamus, Nkx2.2 positive cells were scattered in the suprachiasmatic territory, but also in the supraopto-paraventricular area, as defined by the expression of the transcription factor Orthopedia (Otp) and the lack of xDll4. In the basal hypothalamus Nkx2.2 expressing cells were localized in the tuberal region, with the exception of the arcuate nucleus, rich in Otp expressing cells. In the diencephalon it was expressed in all three prosomeres (P1–P3) and not in the zona limitans intrathalamica. The presence of Nkx2.2 expressing cells in P3 was restricted to the alar portion, as well as in prosomere P2, whereas in P1 the Nkx2.2 expressing cells were located in the basal plate and identified the alar/basal boundary. These results showed that Nkx2.2 and Sonic hedgehog are expressed in parallel adjacent stripes along the anterior–posterior axis. The results of this study showed a conserved distribution pattern of Nkx2.2 among vertebrates, crucial to recognize subdivisions that are otherwise indistinct, and supported the relevance of this transcription factor in the organization of the forebrain, particularly in the delineation of the alar/basal boundary of the forebrain.
Collapse
Affiliation(s)
- Laura Domínguez
- Faculty of Biology, Department of Cell Biology, University Complutense of Madrid Madrid, Spain
| | | | | |
Collapse
|
44
|
Comprehensive catecholaminergic projectome analysis reveals single-neuron integration of zebrafish ascending and descending dopaminergic systems. Nat Commun 2011; 2:171. [PMID: 21266970 PMCID: PMC3105308 DOI: 10.1038/ncomms1171] [Citation(s) in RCA: 219] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 12/16/2010] [Indexed: 11/09/2022] Open
Abstract
Essential components of animal behaviour are modulated by dopaminergic (DA) and noradrenergic circuitry. In this study, we reveal at cellular resolution the complete set of projections ('projectome') of every single type of DA and noradrenergio neurons in the central nervous system of zebrafish larvae. The most extensive DA projections are established by posterior tubercular otp-dependent neurons, with individual somata integrating the ascending DA system, the descending diencephalospinal, as well as the endohypothalamic circuitry. These findings suggest a major role in the modulation of physiology and behaviour for otp-dependent DA neurons, which correlate with the mammalian A11 group. We further identified an endogenous subpallial DA system that not only provides most of the local DA projections, but also connects to the ventral diencephalon. The catecholaminergic projectome map provides a framework to understand the evolution and function of these neuromodulatory systems.
Collapse
|
45
|
DeltaA/DeltaD regulate multiple and temporally distinct phases of notch signaling during dopaminergic neurogenesis in zebrafish. J Neurosci 2011; 30:16621-35. [PMID: 21148001 DOI: 10.1523/jneurosci.4769-10.2010] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dopaminergic neurons develop at distinct anatomical sites to form some of the major neuromodulatory systems in the vertebrate brain. Despite their relevance in neurodegenerative diseases and the interests in reconstitutive therapies from stem cells, mechanisms of the neurogenic switch from precursor populations to dopaminergic neurons are not well understood. Here, we investigated neurogenesis of different dopaminergic and noradrenergic neuron populations in the zebrafish embryo. Birth-dating analysis by EdU (5-ethynyl-2'-deoxyuridine) incorporation revealed temporal dynamics of catecholaminergic neurogenesis. Analysis of Notch signaling mutants and stage-specific pharmacological inhibition of Notch processing revealed that dopaminergic neurons form by temporally distinct mechanisms: dopaminergic neurons of the posterior tuberculum derive directly from neural plate cells during primary neurogenesis, whereas other dopaminergic groups form in continuous or wavelike neurogenesis phases from proliferating precursor pools. Systematic analysis of Notch ligands revealed that the two zebrafish co-orthologs of mammalian Delta1, DeltaA and DeltaD, control the neurogenic switch of all early developing dopaminergic neurons in a partially redundant manner. DeltaA/D may also be involved in maintenance of dopaminergic precursor pools, as olig2 expression in ventral diencephalic dopaminergic precursors is affected in dla/dld mutants. DeltaA/D act upstream of sim1a and otpa during dopaminergic specification. However, despite the fact that both dopaminergic and corticotropin-releasing hormone neurons derive from sim1a- and otpa-expressing precursors, DeltaA/D does not act as a lineage switch between these two neuronal types. Rather, DeltaA/D limits the size of the sim1a- and otpa-expressing precursor pool from which dopaminergic neurons differentiate.
Collapse
|
46
|
Tsai PS, Brooks LR, Rochester JR, Kavanaugh SI, Chung WCJ. Fibroblast growth factor signaling in the developing neuroendocrine hypothalamus. Front Neuroendocrinol 2011; 32:95-107. [PMID: 21129392 PMCID: PMC3050526 DOI: 10.1016/j.yfrne.2010.11.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 11/03/2010] [Accepted: 11/24/2010] [Indexed: 11/29/2022]
Abstract
Fibroblast growth factor (FGF) signaling is pivotal to the formation of numerous central regions. Increasing evidence suggests FGF signaling also directs the development of the neuroendocrine hypothalamus, a collection of neuroendocrine neurons originating primarily within the nose and the ventricular zone of the diencephalon. This review outlines evidence for a role of FGF signaling in the prenatal and postnatal development of several hypothalamic neuroendocrine systems. The emphasis is placed on the nasally derived gonadotropin-releasing hormone neurons, which depend on neurotrophic cues from FGF signaling throughout the neurons' lifetime. Although less is known about neuroendocrine neurons derived from the diencephalon, recent studies suggest they also exhibit variable levels of dependence on FGF signaling. Overall, FGF signaling provides a broad spectrum of cues that ranges from genesis, cell survival/death, migration, morphological changes, to hormone synthesis in the neuroendocrine hypothalamus. Abnormal FGF signaling will deleteriously impact multiple hypothalamic neuroendocrine systems, resulting in the disruption of diverse physiological functions.
Collapse
Affiliation(s)
- Pei-San Tsai
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado, Boulder, CO 80309-0354, USA.
| | | | | | | | | |
Collapse
|
47
|
Mazza ME, Pang K, Reitzel AM, Martindale MQ, Finnerty JR. A conserved cluster of three PRD-class homeobox genes (homeobrain, rx and orthopedia) in the Cnidaria and Protostomia. EvoDevo 2010; 1:3. [PMID: 20849646 PMCID: PMC2938728 DOI: 10.1186/2041-9139-1-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 07/05/2010] [Indexed: 01/25/2023] Open
Abstract
Background Homeobox genes are a superclass of transcription factors with diverse developmental regulatory functions, which are found in plants, fungi and animals. In animals, several Antennapedia (ANTP)-class homeobox genes reside in extremely ancient gene clusters (for example, the Hox, ParaHox, and NKL clusters) and the evolution of these clusters has been implicated in the morphological diversification of animal bodyplans. By contrast, similarly ancient gene clusters have not been reported among the other classes of homeobox genes (that is, the LIM, POU, PRD and SIX classes). Results Using a combination of in silico queries and phylogenetic analyses, we found that a cluster of three PRD-class homeobox genes (Homeobrain (hbn), Rax (rx) and Orthopedia (otp)) is present in cnidarians, insects and mollusks (a partial cluster comprising hbn and rx is present in the placozoan Trichoplax adhaerens). We failed to identify this 'HRO' cluster in deuterostomes; in fact, the Homeobrain gene appears to be missing from the chordate genomes we examined, although it is present in hemichordates and echinoderms. To illuminate the ancestral organization and function of this ancient cluster, we mapped the constituent genes against the assembled genome of a model cnidarian, the sea anemone Nematostella vectensis, and characterized their spatiotemporal expression using in situ hybridization. In N. vectensis, these genes reside in a span of 33 kb with the same gene order as previously reported in insects. Comparisons of genomic sequences and expressed sequence tags revealed the presence of alternative transcripts of Nv-otp and two highly unusual protein-coding polymorphisms in the terminal helix of the Nv-rx homeodomain. A population genetic survey revealed the Rx polymorphisms to be widespread in natural populations. During larval development, all three genes are expressed in the ectoderm, in non-overlapping territories along the oral-aboral axis, with distinct temporal expression. Conclusion We report the first evidence for a PRD-class homeobox cluster that appears to have been conserved since the time of the cnidarian-bilaterian ancestor, and possibly even earlier, given the presence of a partial cluster in the placozoan Trichoplax. Very similar clusters comprising these three genes exist in Nematostella and diverse protostomes. Interestingly, in chordates, one member of the ancestral cluster (homeobrain) has apparently been lost, and there is no linkage between rx and orthopedia in any of the vertebrates. In Nematostella, the spatial expression of these three genes along the body column is not colinear with their physical order in the cluster but the temporal expression is, therefore, using the terminology that has been applied to the Hox cluster genes, the HRO cluster would appear to exhibit temporal but not spatial colinearity. It remains to be seen whether the mechanisms responsible for the evolutionary conservation of the HRO cluster are the same mechanisms responsible for cohesion of the Hox cluster and other ANTP-class homeobox clusters that have been widely conserved throughout animal evolution.
Collapse
Affiliation(s)
- Maureen E Mazza
- Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA
| | - Kevin Pang
- Kewalo Marine Lab, Pacific Biosciences Research Center, University of Hawaii, 41 Ahui St., Honolulu, HI 96813, USA
| | - Adam M Reitzel
- Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA.,Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Mark Q Martindale
- Kewalo Marine Lab, Pacific Biosciences Research Center, University of Hawaii, 41 Ahui St., Honolulu, HI 96813, USA
| | - John R Finnerty
- Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA
| |
Collapse
|
48
|
Guella I, Pistocchi A, Asselta R, Rimoldi V, Ghilardi A, Sironi F, Trotta L, Primignani P, Zini M, Zecchinelli A, Coviello D, Pezzoli G, Del Giacco L, Duga S, Goldwurm S. Mutational screening and zebrafish functional analysis of GIGYF2 as a Parkinson-disease gene. Neurobiol Aging 2010; 32:1994-2005. [PMID: 20060621 DOI: 10.1016/j.neurobiolaging.2009.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 12/20/2009] [Accepted: 12/21/2009] [Indexed: 11/16/2022]
Abstract
The Grb10-Interacting GYF Protein-2 (GIGYF2) gene has been proposed as the Parkinson-disease (PD) gene underlying the PARK11 locus. However, association of GIGYF2 with PD has been challenged and a functional validation of GIGYF2 mutations is lacking. In this frame, we performed a mutational screening of GIGYF2 in an Italian PD cohort. Exons containing known mutations were analyzed in 552 cases and 552 controls. Thereafter, a subset of 184 familial PD cases and controls were subjected to a full coding-exon screening. These analyses identified 8 missense variations in 9 individuals (4 cases, 5 controls). Furthermore, we developed a zebrafish model of gigyf2 deficiency. Abrogation of gigyf2 function in zebrafish embryos did not lead to a drastic cell loss in diencephalic dopaminergic (DA) neuron clusters, suggesting that gigyf2 is not required for DA neuron differentiation. Notably, gigyf2 functional abrogation did not increase diencephalic DA neurons susceptibility to the PD-inducing drug MPP+. These data, together with those recently reported by other groups, suggest that GIGYF2 is unlikely to be the PARK11 gene.
Collapse
Affiliation(s)
- Ilaria Guella
- Dipartimento di Biologia e Genetica per le Scienze Mediche, Università degli Studi di Milano, Milan, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Borodovsky N, Ponomaryov T, Frenkel S, Levkowitz G. Neural protein Olig2 acts upstream of the transcriptional regulator Sim1 to specify diencephalic dopaminergic neurons. Dev Dyn 2009; 238:826-34. [PMID: 19253397 DOI: 10.1002/dvdy.21894] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Neural factors are expressed in neural progenitors and regulate neurogenesis and gliogenesis. Recent studies suggested that these factors are also involved in determining specific neuronal fates by regulating the expression of their target genes, thereby creating transcriptional codes for neuronal subtype specification. In the present study, we show that in the zebrafish the neural gene Olig2 and the transcriptional regulator Sim1 are co-expressed in a subset of diencephalic progenitors destined towards the dopaminergic (DA) neuronal fate. While sim1 mRNA is also detected in mature DA neurons, the expression of olig2 is extinguished prior to terminal DA differentiation. Loss of function of either Olig2 or Sim1 leads to impaired DA development. Finally, Olig2 regulates the expression of Sim1 and gain of function of Sim1 rescues the deficits in DA differentiation caused by targeted knockdown of Olig2. Our findings demonstrate for the first time that commitment of basal diencephalic DA neurons is regulated by the combined action of the neural protein Olig2 and its downstream neuronal specific effector Sim1.
Collapse
Affiliation(s)
- Nataliya Borodovsky
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | | | | | | |
Collapse
|
50
|
Löhr H, Ryu S, Driever W. Zebrafish diencephalic A11-related dopaminergic neurons share a conserved transcriptional network with neuroendocrine cell lineages. Development 2009; 136:1007-17. [PMID: 19234064 DOI: 10.1242/dev.033878] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vertebrate dopaminergic neurons develop in distinct neural territories to constitute one of the major neuromodulatory systems. We have identified a zebrafish mutation in the bHLH-PAS family member arnt2, based on a strong reduction in cell number of specific dopaminergic neuron groups in the hypothalamus and posterior tuberculum. Knockdown of sim1 causes a dopaminergic phenotype similar to arnt2 mutants, suggesting that Sim1 acts as a binding partner of Arnt2, similar to their role in hypothalamic neuroendocrine cell specification. sim1, arnt2 and otp are co-expressed in dopaminergic neurons, and combined overexpression of Sim1 and Otp leads to formation of supernumerary dopaminergic neurons in the ventral diencephalon. Arnt2, Sim1 and Otp thus are core components of a conserved transcriptional network, which specifies neuroendocrine as well as A11-related dopaminergic neurons in the fish hypothalamus and posterior tuberculum. Our data suggest a common evolutionary origin of specific hypothalamic neuroendocrine and dopaminergic systems.
Collapse
Affiliation(s)
- Heiko Löhr
- Developmental Biology, Institute Biology I, Faculty of Biology, University of Freiburg, Hauptstrasse 1, D-79104 Freiburg, Germany
| | | | | |
Collapse
|