1
|
Kelly JJ, Wen H, Brehm P. Single-cell RNAseq analysis of spinal locomotor circuitry in larval zebrafish. eLife 2023; 12:RP89338. [PMID: 37975797 PMCID: PMC10656102 DOI: 10.7554/elife.89338] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023] Open
Abstract
Identification of the neuronal types that form the specialized circuits controlling distinct behaviors has benefited greatly from the simplicity offered by zebrafish. Electrophysiological studies have shown that in addition to connectivity, understanding of circuitry requires identification of functional specializations among individual circuit components, such as those that regulate levels of transmitter release and neuronal excitability. In this study, we use single-cell RNA sequencing (scRNAseq) to identify the molecular bases for functional distinctions between motoneuron types that are causal to their differential roles in swimming. The primary motoneuron, in particular, expresses high levels of a unique combination of voltage-dependent ion channel types and synaptic proteins termed functional 'cassettes.' The ion channel types are specialized for promoting high-frequency firing of action potentials and augmented transmitter release at the neuromuscular junction, both contributing to greater power generation. Our transcriptional profiling of spinal neurons further assigns expression of this cassette to specific interneuron types also involved in the central circuitry controlling high-speed swimming and escape behaviors. Our analysis highlights the utility of scRNAseq in functional characterization of neuronal circuitry, in addition to providing a gene expression resource for studying cell type diversity.
Collapse
Affiliation(s)
- Jimmy J Kelly
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| | - Hua Wen
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| | - Paul Brehm
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| |
Collapse
|
2
|
D'Elia KP, Hameedy H, Goldblatt D, Frazel P, Kriese M, Zhu Y, Hamling KR, Kawakami K, Liddelow SA, Schoppik D, Dasen JS. Determinants of motor neuron functional subtypes important for locomotor speed. Cell Rep 2023; 42:113049. [PMID: 37676768 PMCID: PMC10600875 DOI: 10.1016/j.celrep.2023.113049] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/12/2023] [Accepted: 08/11/2023] [Indexed: 09/09/2023] Open
Abstract
Locomotion requires precise control of the strength and speed of muscle contraction and is achieved by recruiting functionally distinct subtypes of motor neurons (MNs). MNs are essential to movement and differentially susceptible in disease, but little is known about how MNs acquire functional subtype-specific features during development. Using single-cell RNA profiling in embryonic and larval zebrafish, we identify novel and conserved molecular signatures for MN functional subtypes and identify genes expressed in both early post-mitotic and mature MNs. Assessing MN development in genetic mutants, we define a molecular program essential for MN functional subtype specification. Two evolutionarily conserved transcription factors, Prdm16 and Mecom, are both functional subtype-specific determinants integral for fast MN development. Loss of prdm16 or mecom causes fast MNs to develop transcriptional profiles and innervation similar to slow MNs. These results reveal the molecular diversity of vertebrate axial MNs and demonstrate that functional subtypes are specified through intrinsic transcriptional codes.
Collapse
Affiliation(s)
- Kristen P D'Elia
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Hanna Hameedy
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Dena Goldblatt
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA; Center for Neural Science, New York University, New York, NY, USA
| | - Paul Frazel
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - Mercer Kriese
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Yunlu Zhu
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kyla R Hamling
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Koichi Kawakami
- Laboratory of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan
| | - Shane A Liddelow
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - David Schoppik
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA.
| | - Jeremy S Dasen
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA.
| |
Collapse
|
3
|
Kelly JJ, Wen H, Brehm P. Single cell RNA-seq analysis of spinal locomotor circuitry in larval zebrafish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.06.543939. [PMID: 37333232 PMCID: PMC10274715 DOI: 10.1101/2023.06.06.543939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Identification of the neuronal types that form the specialized circuits controlling distinct behaviors has benefited greatly from the simplicity offered by zebrafish. Electrophysiological studies have shown that additional to connectivity, understanding of circuitry requires identification of functional specializations among individual circuit components, such as those that regulate levels of transmitter release and neuronal excitability. In this study we use single cell RNA sequencing (scRNAseq) to identify the molecular bases for functional distinctions between motoneuron types that are causal to their differential roles in swimming. The primary motoneuron (PMn) in particular, expresses high levels of a unique combination of voltage-dependent ion channel types and synaptic proteins termed functional 'cassettes'. The ion channel types are specialized for promoting high frequency firing of action potentials and augmented transmitter release at the neuromuscular junction, both contributing to greater power generation. Our transcriptional profiling of spinal neurons further assigns expression of this cassette to specific interneuron types also involved in the central circuitry controlling high speed swimming and escape behaviors. Our analysis highlights the utility of scRNAseq in functional characterization of neuronal circuitry, in addition to providing a gene expression resource for studying cell type diversity.
Collapse
Affiliation(s)
- Jimmy J. Kelly
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA
| | - Hua Wen
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA
| | - Paul Brehm
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
4
|
Dasen JS. Establishing the Molecular and Functional Diversity of Spinal Motoneurons. ADVANCES IN NEUROBIOLOGY 2022; 28:3-44. [PMID: 36066819 DOI: 10.1007/978-3-031-07167-6_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Spinal motoneurons are a remarkably diverse class of neurons responsible for facilitating a broad range of motor behaviors and autonomic functions. Studies of motoneuron differentiation have provided fundamental insights into the developmental mechanisms of neuronal diversification, and have illuminated principles of neural fate specification that operate throughout the central nervous system. Because of their relative anatomical simplicity and accessibility, motoneurons have provided a tractable model system to address multiple facets of neural development, including early patterning, neuronal migration, axon guidance, and synaptic specificity. Beyond their roles in providing direct communication between central circuits and muscle, recent studies have revealed that motoneuron subtype-specific programs also play important roles in determining the central connectivity and function of motor circuits. Cross-species comparative analyses have provided novel insights into how evolutionary changes in subtype specification programs may have contributed to adaptive changes in locomotor behaviors. This chapter focusses on the gene regulatory networks governing spinal motoneuron specification, and how studies of spinal motoneurons have informed our understanding of the basic mechanisms of neuronal specification and spinal circuit assembly.
Collapse
Affiliation(s)
- Jeremy S Dasen
- NYU Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY, USA.
| |
Collapse
|
5
|
From Bipotent Neuromesodermal Progenitors to Neural-Mesodermal Interactions during Embryonic Development. Int J Mol Sci 2021; 22:ijms22179141. [PMID: 34502050 PMCID: PMC8431582 DOI: 10.3390/ijms22179141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 11/17/2022] Open
Abstract
To ensure the formation of a properly patterned embryo, multiple processes must operate harmoniously at sequential phases of development. This is implemented by mutual interactions between cells and tissues that together regulate the segregation and specification of cells, their growth and morphogenesis. The formation of the spinal cord and paraxial mesoderm derivatives exquisitely illustrate these processes. Following early gastrulation, while the vertebrate body elongates, a population of bipotent neuromesodermal progenitors resident in the posterior region of the embryo generate both neural and mesodermal lineages. At later stages, the somitic mesoderm regulates aspects of neural patterning and differentiation of both central and peripheral neural progenitors. Reciprocally, neural precursors influence the paraxial mesoderm to regulate somite-derived myogenesis and additional processes by distinct mechanisms. Central to this crosstalk is the activity of the axial notochord, which, via sonic hedgehog signaling, plays pivotal roles in neural, skeletal muscle and cartilage ontogeny. Here, we discuss the cellular and molecular basis underlying this complex developmental plan, with a focus on the logic of sonic hedgehog activities in the coordination of the neural-mesodermal axis.
Collapse
|
6
|
FAM19A5l Affects Mustard Oil-Induced Peripheral Nociception in Zebrafish. Mol Neurobiol 2021; 58:4770-4785. [PMID: 34176096 DOI: 10.1007/s12035-021-02449-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022]
Abstract
Family with sequence similarity 19 (chemokine (C-C motif)-like) member A5 (FAM19A5) is a chemokine-like secretory protein recently identified as involved in the regulation of osteoclast formation, post-injury neointima formation, and depression. Although roles for FAM19A5 have been described in nervous system development and psychiatric disorders, its role in the nervous system remains poorly understood. Here, we analyzed the evolutionary history of FAM19A genes in vertebrates and identified FAM19A5l, a paralogous zebrafish gene originating from a common ancestral FAM19A5 gene. Further, zebrafish FAM19A5l is expressed in trigeminal and dorsal root ganglion neurons as well as distinct neuronal subsets of the central nervous system. Interestingly, FAM19A5l+ trigeminal neurons are nociceptive neurons that localized with TRPA1b and TRPV1 and respond to mustard oil treatment. Behavioral analysis further revealed that the nociceptive response to mustard oil decreases in FAM19A5l-knockout zebrafish larvae. In addition, TRPA1b and NGFa mRNA levels are down- and upregulated in FAM19A5l-knockout and -overexpressing transgenic zebrafish, respectively. Together, our data suggest that FAM19A5l plays a role in nociceptive responses to mustard oil by regulating TRPA1b and NGFa expression in zebrafish.
Collapse
|
7
|
Mi P, Gao Q, Feng ZY, Zhang JW, Zhao X, Chen DY, Feng XZ. Melatonin attenuates 17β-trenbolone induced insomnia-like phenotype and movement deficiency in zebrafish. CHEMOSPHERE 2020; 253:126762. [PMID: 32302915 DOI: 10.1016/j.chemosphere.2020.126762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/07/2020] [Accepted: 04/07/2020] [Indexed: 06/11/2023]
Abstract
17β-trenbolone (17β-TBOH) is one of the dominant metabolites of trenbolone acetate, which is widely applied in beef cattle operations around the globe. The effects of environmental concentrations of 17β-trenbolone on the early development of zebrafish embryos have received very little attention. Melatonin could regulate sleep-wake cycle and plays a protective role in various adverse conditions. Here, environmentally realistic concentrations of 17β-trenbolone (1 ng/L, 10 ng/L, 50 ng/L) has been exposure to zebrafish embryos at 2 h postfertilization (hpf). The results showed that 10 ng/L and 50 ng/L 17β-trenbolone disturbed the distribution of caudal primary motoneurons and downregulated expression of motoneuron development related genes along with locomotion decreasing. While melatonin could recover the detrimental effects caused by 17β-trenbolone. Interestingly, 17β-trenbolone exposure increased waking activity and decreased rest even in a low dose (1 ng/L). Moreover, it upregulated hypocretin/orexin (Hcrt) signaling which promotes wakefulness. Melatonin restored the insomnia-like alternation induced by 17β-trenbolone exposure. Collectively, we conclude that 17β-trenbolone disturbed motoneuron development and altered sleep/wake behavior, while melatonin could alleviate the deleterious influence on motoneuron development and recover the circadian rhythm.
Collapse
Affiliation(s)
- Ping Mi
- State Key Laboratory of Medicinal Chemical Biology, The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Qian Gao
- Tianjin Key Laboratory of Tumor Microenvironment and Neurovascular Regulation, Department of Histology and Embryology, School of Medicine, Nankai University, Tianjin, 300071, China
| | - Ze-Yang Feng
- Institute of Robotics and Automatic Information System, Tianjin Key Laboratory of Intelligent Robotics, Nankai University, Tianjin, 300350, China
| | - Jing-Wen Zhang
- State Key Laboratory of Medicinal Chemical Biology, The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Xin Zhao
- Institute of Robotics and Automatic Information System, Tianjin Key Laboratory of Intelligent Robotics, Nankai University, Tianjin, 300350, China.
| | - Dong-Yan Chen
- Tianjin Key Laboratory of Tumor Microenvironment and Neurovascular Regulation, Department of Histology and Embryology, School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Xi-Zeng Feng
- State Key Laboratory of Medicinal Chemical Biology, The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China.
| |
Collapse
|
8
|
Raja DA, Subramaniam Y, Aggarwal A, Gotherwal V, Babu A, Tanwar J, Motiani RK, Sivasubbu S, Gokhale RS, Natarajan VT. Histone variant dictates fate biasing of neural crest cells to melanocyte lineage. Development 2020; 147:dev.182576. [PMID: 32098766 DOI: 10.1242/dev.182576] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/24/2020] [Indexed: 11/20/2022]
Abstract
In the neural crest lineage, progressive fate restriction and stem cell assignment are crucial for both development and regeneration. Whereas fate commitment events have distinct transcriptional footprints, fate biasing is often transitory and metastable, and is thought to be moulded by epigenetic programmes. Therefore, the molecular basis of specification is difficult to define. In this study, we established a role for a histone variant, H2a.z.2, in specification of the melanocyte lineage from multipotent neural crest cells. H2a.z.2 silencing reduces the number of melanocyte precursors in developing zebrafish embryos and from mouse embryonic stem cells in vitro We demonstrate that this histone variant occupies nucleosomes in the promoter of the key melanocyte determinant mitf, and enhances its induction. CRISPR/Cas9-based targeted mutagenesis of this gene in zebrafish drastically reduces adult melanocytes, as well as their regeneration. Thereby, our study establishes the role of a histone variant upstream of the core gene regulatory network in the neural crest lineage. This epigenetic mark is a key determinant of cell fate and facilitates gene activation by external instructive signals, thereby establishing melanocyte fate identity.
Collapse
Affiliation(s)
- Desingu Ayyappa Raja
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Academy of Scientific and Innovative Research, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201002, India
| | - Yogaspoorthi Subramaniam
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Academy of Scientific and Innovative Research, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201002, India
| | - Ayush Aggarwal
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Academy of Scientific and Innovative Research, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201002, India
| | - Vishvabandhu Gotherwal
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Academy of Scientific and Innovative Research, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201002, India
| | - Aswini Babu
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India
| | - Jyoti Tanwar
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India.,Academy of Scientific and Innovative Research, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201002, India
| | - Rajender K Motiani
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India
| | - Sridhar Sivasubbu
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India
| | - Rajesh S Gokhale
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India
| | - Vivek T Natarajan
- Pigment Cell Biology Group, CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India .,Academy of Scientific and Innovative Research, Kamla Nehru Nagar, Ghaziabad, Uttar Pradesh, 201002, India
| |
Collapse
|
9
|
Vetrivel S, Tiso N, Kügler A, Irmler M, Horsch M, Beckers J, Hladik D, Giesert F, Gailus-Durner V, Fuchs H, Sabrautzki S, Hrabě de Angelis M, Graw J. Mutation in the mouse histone gene Hist2h3c1 leads to degeneration of the lens vesicle and severe microphthalmia. Exp Eye Res 2019; 188:107632. [PMID: 30991053 PMCID: PMC6876282 DOI: 10.1016/j.exer.2019.03.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 03/20/2019] [Accepted: 03/30/2019] [Indexed: 12/21/2022]
Abstract
During an ENU (N-ethyl-N-nitrosourea) mutagenesis screen, we observed a dominant small-eye mutant mouse with viable homozygotes. A corresponding mutant line was established and referred to as Aey69 (abnormality of the eye #69). Comprehensive phenotyping of the homozygous Aey69 mutants in the German Mouse Clinic revealed only a subset of statistically significant alterations between wild types and homozygous mutants. The mutation causes microphthalmia without a lens but with retinal hyperproliferation. Linkage was demonstrated to mouse chromosome 3 between the markers D3Mit188 and D3Mit11. Sequencing revealed a 358 A-> C mutation (Ile120Leu) in the Hist2h3c1 gene and a 71 T-> C (Val24Ala) mutation in the Gja8 gene. Detailed analysis of eye development in the homozygous mutant mice documented a perturbed lens development starting from the lens vesicle stage including decreasing expression of crystallins as well as of lens-specific transcription factors like PITX3 and FOXE3. In contrast, we observed an early expression of retinal progenitor cells characterized by several markers including BRN3 (retinal ganglion cells) and OTX2 (cone photoreceptors). The changes in the retina at the early embryonic stages of E11.5-E15.5 happen in parallel with apoptotic processes in the lens at the respective stages. The excessive retinal hyperproliferation is characterized by an increased level of Ki67. The hyperproliferation, however, does not disrupt the differentiation and appearance of the principal retinal cell types at postnatal stages, even if the overgrowing retina covers finally the entire bulbus of the eye. Morpholino-mediated knock-down of the hist2h3ca1 gene in zebrafish leads to a specific perturbation of lens development. When injected into zebrafish zygotes, only the mutant mouse mRNA leads to severe malformations, ranging from cyclopia to severe microphthalmia. The wild-type Hist2h3c1 mRNA can rescue the morpholino-induced defects corroborating its specific function in lens development. Based upon these data, it is concluded that the ocular function of the Hist2h3c1 gene (encoding a canonical H3.2 variant) is conserved throughout evolution. Moreover, the data highlight also the importance of Hist2h3c1 in the coordinated formation of lens and retina during eye development. A dominant small-eye mutant mouse is caused by a mutation in the histone gene Hist2H3c1. Morpholino-mediated knock-down of hist2h3ca1 in the zebrafish validated this finding. The mutation leads to degeneration of the lens vesicle and retina hyperproliferation.
Collapse
Affiliation(s)
- Sharmilee Vetrivel
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Developmental Genetics, D-85764 Neuherberg, Germany
| | - Natascia Tiso
- Department of Biology, University of Padova, I-35131 Padova, Italy.
| | - Andrea Kügler
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Developmental Genetics, D-85764 Neuherberg, Germany
| | - Martin Irmler
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Experimental Genetics, D-85764 Neuherberg, Germany
| | - Marion Horsch
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Experimental Genetics, D-85764 Neuherberg, Germany
| | - Johannes Beckers
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Experimental Genetics, D-85764 Neuherberg, Germany; Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, D-85354 Freising, Germany; German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany
| | - Daniela Hladik
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Developmental Genetics, D-85764 Neuherberg, Germany
| | - Florian Giesert
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Developmental Genetics, D-85764 Neuherberg, Germany
| | - Valerie Gailus-Durner
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Experimental Genetics, D-85764 Neuherberg, Germany
| | - Helmut Fuchs
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Experimental Genetics, D-85764 Neuherberg, Germany
| | - Sibylle Sabrautzki
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Experimental Genetics, D-85764 Neuherberg, Germany; Helmholtz Center Munich, German Research Center for Environmental Health, Research Unit Comparative Medicine, D-85764 Neuherberg, Germany
| | - Martin Hrabě de Angelis
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Experimental Genetics, D-85764 Neuherberg, Germany; Chair of Experimental Genetics, School of Life Science Weihenstephan, Technische Universität München, D-85354 Freising, Germany; German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany
| | - Jochen Graw
- Helmholtz Center Munich, German Research Center for Environmental Health, Institute of Developmental Genetics, D-85764 Neuherberg, Germany.
| |
Collapse
|
10
|
Baeuml SW, Biechl D, Wullimann MF. Adult islet1 Expression Outlines Ventralized Derivatives Along Zebrafish Neuraxis. Front Neuroanat 2019; 13:19. [PMID: 30863287 PMCID: PMC6399416 DOI: 10.3389/fnana.2019.00019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/01/2019] [Indexed: 01/16/2023] Open
Abstract
Signals issued by dorsal roof and ventral floor plates, respectively, underlie the major patterning process of dorsalization and ventralization during vertebrate neural tube development. The ventrally produced morphogen Sonic hedgehog (SHH) is crucial for vertebrate hindbrain and spinal motor neuron development. One diagnostic gene for motor neurons is the LIM/homeodomain gene islet1, which has additional ventral expression domains extending into mid- and forebrain. In order to corroborate motor neuron development and, in particular, to improve on the identification of poorly documented zebrafish forebrain islet1 populations, we studied adult brains of transgenic islet1-GFP zebrafish (3 and 6 months). This molecular neuroanatomical analysis was supported by immunostaining these brains for tyrosine hydroxylase (TH) or choline acetyltransferase (ChAT), respectively, revealing zebrafish catecholaminergic and cholinergic neurons. The present analysis of ChAT and islet1-GFP label confirms ongoing adult expression of islet1 in zebrafish (basal plate) midbrain, hindbrain, and spinal motor neurons. In contrast, non-motor cholinergic systems lack islet1 expression. Additional presumed basal plate islet1 positive systems are described in detail, aided by TH staining which is particularly informative in the diencephalon. Finally, alar plate zebrafish forebrain systems with islet1 expression are described (i.e., thalamus, preoptic region, and subpallium). We conclude that adult zebrafish continue to express islet1 in the same brain systems as in the larva. Further, pending functional confirmation we hypothesize that the larval expression of sonic hedgehog (shh) might causally underlie much of adult islet1 expression because it explains findings beyond ventrally located systems, for example regarding shh expression in the zona limitans intrathalamica and correlated islet1-GFP expression in the thalamus.
Collapse
Affiliation(s)
- Stephan W Baeuml
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Daniela Biechl
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mario F Wullimann
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-Universität München, Munich, Germany
| |
Collapse
|
11
|
Investigation of Islet2a function in zebrafish embryos: Mutants and morphants differ in morphologic phenotypes and gene expression. PLoS One 2018; 13:e0199233. [PMID: 29927984 PMCID: PMC6013100 DOI: 10.1371/journal.pone.0199233] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 06/04/2018] [Indexed: 12/19/2022] Open
Abstract
Zebrafish primary motor neurons differ from each other with respect to morphology, muscle targets and electrophysiological properties. For example, CaP has 2-3-fold larger densities of both inward and outward currents than do other motor neurons. We tested whether the transcription factor Islet2a, uniquely expressed in CaP, but not other primary motor neurons, plays a role in specifying its stereotypic electrophysiological properties. We used both TALEN-based gene editing and antisense morpholino approaches to disrupt Islet2a function. Our electrophysiology results do not support a specific role for Islet2a in determining CaP’s unique electrical properties. However, we also found that the morphological phenotypes of CaP and a later-born motor neuron differed between islet2a mutants and morphants. Using microarrays, we tested whether the gene expression profiles of whole embryo morphants, mutants and controls also differed. Morphants had 174 and 201 genes that were differentially expressed compared to mutants and controls, respectively. Further, islet2a was identified as a differentially expressed gene. To examine how mutation of islet2a affected islet gene expression specifically in CaPs, we performed RNA in situ hybridization. We detected no obvious differences in expression of islet1, islet2a, or islet2b in CaPs of mutant versus sibling control embryos. However, immunolabeling studies revealed that an Islet protein persisted in CaPs of mutants, albeit at a reduced level compared to controls. While we cannot exclude requirement for some Islet protein, we conclude that differentiation of the CaP’s stereotypic large inward and outward currents does not have a specific requirement for Islet2a.
Collapse
|
12
|
D'Elia KP, Dasen JS. Development, functional organization, and evolution of vertebrate axial motor circuits. Neural Dev 2018; 13:10. [PMID: 29855378 PMCID: PMC5984435 DOI: 10.1186/s13064-018-0108-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022] Open
Abstract
Neuronal control of muscles associated with the central body axis is an ancient and essential function of the nervous systems of most animal species. Throughout the course of vertebrate evolution, motor circuits dedicated to control of axial muscle have undergone significant changes in their roles within the motor system. In most fish species, axial circuits are critical for coordinating muscle activation sequences essential for locomotion and play important roles in postural correction. In tetrapods, axial circuits have evolved unique functions essential to terrestrial life, including maintaining spinal alignment and breathing. Despite the diverse roles of axial neural circuits in motor behaviors, the genetic programs underlying their assembly are poorly understood. In this review, we describe recent studies that have shed light on the development of axial motor circuits and compare and contrast the strategies used to wire these neural networks in aquatic and terrestrial vertebrate species.
Collapse
Affiliation(s)
- Kristen P D'Elia
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY, 10016, USA
| | - Jeremy S Dasen
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY, 10016, USA.
| |
Collapse
|
13
|
Jung H, Baek M, D'Elia KP, Boisvert C, Currie PD, Tay BH, Venkatesh B, Brown SM, Heguy A, Schoppik D, Dasen JS. The Ancient Origins of Neural Substrates for Land Walking. Cell 2018; 172:667-682.e15. [PMID: 29425489 PMCID: PMC5808577 DOI: 10.1016/j.cell.2018.01.013] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 10/18/2017] [Accepted: 01/05/2018] [Indexed: 01/30/2023]
Abstract
Walking is the predominant locomotor behavior expressed by land-dwelling vertebrates, but it is unknown when the neural circuits that are essential for limb control first appeared. Certain fish species display walking-like behaviors, raising the possibility that the underlying circuitry originated in primitive marine vertebrates. We show that the neural substrates of bipedalism are present in the little skate Leucoraja erinacea, whose common ancestor with tetrapods existed ∼420 million years ago. Leucoraja exhibits core features of tetrapod locomotor gaits, including left-right alternation and reciprocal extension-flexion of the pelvic fins. Leucoraja also deploys a remarkably conserved Hox transcription factor-dependent program that is essential for selective innervation of fin/limb muscle. This network encodes peripheral connectivity modules that are distinct from those used in axial muscle-based swimming and has apparently been diminished in most modern fish. These findings indicate that the circuits that are essential for walking evolved through adaptation of a genetic regulatory network shared by all vertebrates with paired appendages. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Heekyung Jung
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY 10016, USA
| | - Myungin Baek
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY 10016, USA
| | - Kristen P D'Elia
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY 10016, USA
| | - Catherine Boisvert
- Department of Environment and Agriculture, Curtin University, Bentley, WA 6102, Australia; Australian Regenerative Medicine Institute (ARMI), Monash University, Clayton, VIC 3800, Australia
| | - Peter D Currie
- Australian Regenerative Medicine Institute (ARMI), Monash University, Clayton, VIC 3800, Australia; EMBL Australia, Melbourne Node, Monash University, Clayton, VIC 3800, Australia
| | - Boon-Hui Tay
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Biopolis, Singapore 138673, Singapore
| | - Byrappa Venkatesh
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Biopolis, Singapore 138673, Singapore; Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Stuart M Brown
- Applied Bioinformatics Laboratory, NYU School of Medicine, New York, NY 10016, USA
| | - Adriana Heguy
- Genome Technology Center, Division for Advanced Research Technologies, and Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - David Schoppik
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY 10016, USA; Department of Otolaryngology, NYU School of Medicine, New York, NY 10016, USA
| | - Jeremy S Dasen
- Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY 10016, USA.
| |
Collapse
|
14
|
Aguillon R, Batut J, Subramanian A, Madelaine R, Dufourcq P, Schilling TF, Blader P. Cell-type heterogeneity in the early zebrafish olfactory epithelium is generated from progenitors within preplacodal ectoderm. eLife 2018; 7. [PMID: 29292696 PMCID: PMC5749950 DOI: 10.7554/elife.32041] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/15/2017] [Indexed: 12/25/2022] Open
Abstract
The zebrafish olfactory epithelium comprises a variety of neuronal populations, which are thought to have distinct embryonic origins. For instance, while ciliated sensory neurons arise from preplacodal ectoderm (PPE), previous lineage tracing studies suggest that both Gonadotropin releasing hormone 3 (Gnrh3) and microvillous sensory neurons derive from cranial neural crest (CNC). We find that the expression of Islet1/2 is restricted to Gnrh3 neurons associated with the olfactory epithelium. Unexpectedly, however, we find no change in Islet1/2+ cell numbers in sox10 mutant embryos, calling into question their CNC origin. Lineage reconstruction based on backtracking in time-lapse confocal datasets, and confirmed by photoconversion experiments, reveals that Gnrh3 neurons derive from the anterior PPE. Similarly, all of the microvillous sensory neurons we have traced arise from preplacodal progenitors. Our results suggest that rather than originating from separate ectodermal populations, cell-type heterogeneity is generated from overlapping pools of progenitors within the preplacodal ectoderm.
Collapse
Affiliation(s)
- Raphaël Aguillon
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI, FR3743), Université de Toulouse, Toulouse, France
| | - Julie Batut
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI, FR3743), Université de Toulouse, Toulouse, France
| | - Arul Subramanian
- Department of Developmental and Cell Biology, University of California, Irvine, United States
| | - Romain Madelaine
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI, FR3743), Université de Toulouse, Toulouse, France
| | - Pascale Dufourcq
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI, FR3743), Université de Toulouse, Toulouse, France
| | - Thomas F Schilling
- Department of Developmental and Cell Biology, University of California, Irvine, United States
| | - Patrick Blader
- Centre de Biologie du Développement (CBD, UMR5547), Centre de Biologie Intégrative (CBI, FR3743), Université de Toulouse, Toulouse, France
| |
Collapse
|
15
|
Glycerophosphodiesterase GDE2/GDPD5 affects pancreas differentiation in zebrafish. Int J Biochem Cell Biol 2017; 94:71-78. [PMID: 29203233 DOI: 10.1016/j.biocel.2017.11.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 10/18/2017] [Accepted: 11/30/2017] [Indexed: 02/08/2023]
Abstract
Notch signaling plays an essential role in the proliferation, differentiation and cell fate determination of various tissues, including the developing pancreas. One regulator of the Notch pathway is GDE2 (or GDPD5), a transmembrane ecto-phosphodiesterase that cleaves GPI-anchored proteins at the plasma membrane, including a Notch ligand regulator. Here we report that Gdpd5-knockdown in zebrafish embryos leads to developmental defects, particularly, impaired motility and reduced pancreas differentiation, as shown by decreased expression of insulin and other pancreatic markers. Exogenous expression of human GDE2, but not catalytically dead GDE2, similarly leads to developmental defects. Human GDE2 restores insulin expression in Gdpd5a-depleted zebrafish embryos. Importantly, zebrafish Gdpd5 orthologues localize to the plasma membrane where they show catalytic activity against GPI-anchored GPC6. Thus, our data reveal functional conservation between zebrafish Gdpd5 and human GDE2, and suggest that strict regulation of GDE2 expression and catalytic activity is critical for correct embryonic patterning. In particular, our data uncover a role for GDE2 in regulating pancreas differentiation.
Collapse
|
16
|
Morrow ZT, Maxwell AM, Hoshijima K, Talbot JC, Grunwald DJ, Amacher SL. tbx6l and tbx16 are redundantly required for posterior paraxial mesoderm formation during zebrafish embryogenesis. Dev Dyn 2017; 246:759-769. [PMID: 28691257 DOI: 10.1002/dvdy.24547] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 05/19/2017] [Accepted: 07/04/2017] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND T-box genes encode a large transcription factor family implicated in many aspects of development. We are focusing on two related zebrafish T-box genes, tbx6l and tbx16, that are expressed in highly overlapping patterns in embryonic paraxial mesoderm. tbx16 mutants are deficient in trunk, but not tail, somites; we explored whether presence of tail somites in tbx16 mutants was due to compensatory function provided by the tbx6l gene. RESULTS We generated two zebrafish tbx6l mutant alleles. Loss of tbx6l has no apparent effect on embryonic development, nor does tbx6l loss enhance the phenotype of two other T-box gene mutants, ta and tbx6, or of the mesp family gene mutant msgn1. In contrast, loss of tbx6l function dramatically enhances the paraxial mesoderm deficiency of tbx16 mutants. CONCLUSIONS These data demonstrate that tbx6l and tbx16 genes function redundantly to direct tail somite development. tbx6l single mutants develop normally because tbx16 fully compensates for loss of tbx6l function. However, tbx6l only partially compensates for loss of tbx16 function. These results resolve the question of why loss of function of tbx16 gene, which is expressed throughout the ventral and paraxial mesoderm, profoundly affects somite development in the trunk but not the tail. Developmental Dynamics 246:759-769, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Zachary T Morrow
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio
| | - Adrienne M Maxwell
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio
| | - Kazuyuki Hoshijima
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Jared C Talbot
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio.,Department of Biological Chemistry and Pharmacology, The Ohio State University School of Medicine, Columbus, Ohio.,Center for Muscle Health and Neuromuscular Disorders, The Ohio State University and Nationwide Children's Hospital, Columbus, Ohio
| | - David J Grunwald
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Sharon L Amacher
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio.,Department of Biological Chemistry and Pharmacology, The Ohio State University School of Medicine, Columbus, Ohio.,Center for Muscle Health and Neuromuscular Disorders, The Ohio State University and Nationwide Children's Hospital, Columbus, Ohio.,Center for RNA Biology, The Ohio State University, Columbus, Ohio
| |
Collapse
|
17
|
Ahmed MU, Maurya AK, Cheng L, Jorge EC, Schubert FR, Maire P, Basson MA, Ingham PW, Dietrich S. Engrailed controls epaxial-hypaxial muscle innervation and the establishment of vertebrate three-dimensional mobility. Dev Biol 2017; 430:90-104. [PMID: 28807781 DOI: 10.1016/j.ydbio.2017.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/07/2017] [Accepted: 08/08/2017] [Indexed: 11/16/2022]
Abstract
Chordates are characterised by contractile muscle on either side of the body that promotes movement by side-to-side undulation. In the lineage leading to modern jawed vertebrates (crown group gnathostomes), this system was refined: body muscle became segregated into distinct dorsal (epaxial) and ventral (hypaxial) components that are separately innervated by the medial and hypaxial motors column, respectively, via the dorsal and ventral ramus of the spinal nerves. This allows full three-dimensional mobility, which in turn was a key factor in their evolutionary success. How the new gnathostome system is established during embryogenesis and how it may have evolved in the ancestors of modern vertebrates is not known. Vertebrate Engrailed genes have a peculiar expression pattern as they temporarily demarcate a central domain of the developing musculature at the epaxial-hypaxial boundary. Moreover, they are the only genes known with this particular expression pattern. The aim of this study was to investigate whether Engrailed genes control epaxial-hypaxial muscle development and innervation. Investigating chick, mouse and zebrafish as major gnathostome model organisms, we found that the Engrailed expression domain was associated with the establishment of the epaxial-hypaxial boundary of muscle in all three species. Moreover, the outgrowing epaxial and hypaxial nerves orientated themselves with respect to this Engrailed domain. In the chicken, loss and gain of Engrailed function changed epaxial-hypaxial somite patterning. Importantly, in all animals studied, loss and gain of Engrailed function severely disrupted the pathfinding of the spinal motor axons, suggesting that Engrailed plays an evolutionarily conserved role in the separate innervation of vertebrate epaxial-hypaxial muscle.
Collapse
Affiliation(s)
- Mohi U Ahmed
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK
| | - Ashish K Maurya
- Institute of Molecular&Cell Biology, Proteos, 61 Biopolis Drive, Singapore 138673, Republic of Singapore
| | - Louise Cheng
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK; Peter MacCallum Cancer Centre, East Melbourne, Victoria 3002, Australia
| | - Erika C Jorge
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK; Universidade Federal de Minas Gerais - Departamento de Morfologia, Av Antônio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil
| | - Frank R Schubert
- Institute of Biomedical and Biomolecular Science, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
| | - Pascal Maire
- Institut Cochin, INSERM U567, CNRS UMR 8104, Univ. Paris Descartes, Département Génétique et Développement, Equipegénétique et développement du systèmeneuromusculaire, 24 Rue du Fg St Jacques, 75014 Paris, France
| | - M Albert Basson
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK
| | - Philip W Ingham
- Institute of Molecular&Cell Biology, Proteos, 61 Biopolis Drive, Singapore 138673, Republic of Singapore; Dept. of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Republic of Singapore
| | - Susanne Dietrich
- King's College London, Dept. of Craniofacial Development and Stem Cell Biology, Floor 27, Guy's Hospital Tower Wing, London SE1 9RT, UK; Institute of Biomedical and Biomolecular Science, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK.
| |
Collapse
|
18
|
Bhati M, Llamosas E, Jacques DA, Jeffries CM, Dastmalchi S, Ripin N, Nicholas HR, Matthews JM. Interactions between LHX3- and ISL1-family LIM-homeodomain transcription factors are conserved in Caenorhabditis elegans. Sci Rep 2017; 7:4579. [PMID: 28676648 PMCID: PMC5496915 DOI: 10.1038/s41598-017-04587-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/17/2017] [Indexed: 02/07/2023] Open
Abstract
LIM-Homeodomain (LIM-HD) transcription factors are highly conserved in animals where they are thought to act in a transcriptional ‘LIM code’ that specifies cell types, particularly in the central nervous system. In chick and mammals the interaction between two LIM-HD proteins, LHX3 and Islet1 (ISL1), is essential for the development of motor neurons. Using yeast two-hybrid analysis we showed that the Caenorhabditis elegans orthologs of LHX3 and ISL1, CEH-14 and LIM-7 can physically interact. Structural characterisation of a complex comprising the LIM domains from CEH-14 and a LIM-interaction domain from LIM-7 showed that these nematode proteins assemble to form a structure that closely resembles that of their vertebrate counterparts. However, mutagenic analysis across the interface indicates some differences in the mechanisms of binding. We also demonstrate, using fluorescent reporter constructs, that the two C. elegans proteins are co-expressed in a small subset of neurons. These data show that the propensity for LHX3 and Islet proteins to interact is conserved from C. elegans to mammals, raising the possibility that orthologous cell specific LIM-HD-containing transcription factor complexes play similar roles in the development of neuronal cells across diverse species.
Collapse
Affiliation(s)
- Mugdha Bhati
- School of Life and Environmental Sciences, University of Sydney, NSW, 2006, Australia.,Teva Pharmaceuticals Australia Pty Ltd, Macquarie Park, NSW, 2113, Australia
| | - Estelle Llamosas
- School of Life and Environmental Sciences, University of Sydney, NSW, 2006, Australia.,School of Women's and Children's Health, University of New South Wales, NSW, Australia
| | - David A Jacques
- School of Life and Environmental Sciences, University of Sydney, NSW, 2006, Australia.,iThree Institute, University of Technology, NSW, 2007, Australia
| | - Cy M Jeffries
- School of Life and Environmental Sciences, University of Sydney, NSW, 2006, Australia.,European Molecular Biology Laboratory (EMBL) Hamburg Outstation, c/o DESY, Notkestrasse 85, 22607, Hamburg, Germany
| | - Siavoush Dastmalchi
- Biotechnology Research Center and School of Pharmacy, Tabritz Univeristy of Medical Science, Tabritz, Iran
| | - Nina Ripin
- School of Life and Environmental Sciences, University of Sydney, NSW, 2006, Australia.,Department of Biology, ETH, Zurich, 8093, Switzerland
| | - Hannah R Nicholas
- School of Life and Environmental Sciences, University of Sydney, NSW, 2006, Australia.
| | - Jacqueline M Matthews
- School of Life and Environmental Sciences, University of Sydney, NSW, 2006, Australia.
| |
Collapse
|
19
|
Juárez-Morales JL, Martinez-De Luna RI, Zuber ME, Roberts A, Lewis KE. Zebrafish transgenic constructs label specific neurons in Xenopus laevis spinal cord and identify frog V0v spinal neurons. Dev Neurobiol 2017; 77:1007-1020. [PMID: 28188691 DOI: 10.1002/dneu.22490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/26/2017] [Accepted: 02/08/2017] [Indexed: 12/19/2022]
Abstract
A correctly functioning spinal cord is crucial for locomotion and communication between body and brain but there are fundamental gaps in our knowledge of how spinal neuronal circuitry is established and functions. To understand the genetic program that regulates specification and functions of this circuitry, we need to connect neuronal molecular phenotypes with physiological analyses. Studies using Xenopus laevis tadpoles have increased our understanding of spinal cord neuronal physiology and function, particularly in locomotor circuitry. However, the X. laevis tetraploid genome and long generation time make it difficult to investigate how neurons are specified. The opacity of X. laevis embryos also makes it hard to connect functional classes of neurons and the genes that they express. We demonstrate here that Tol2 transgenic constructs using zebrafish enhancers that drive expression in specific zebrafish spinal neurons label equivalent neurons in X. laevis and that the incorporation of a Gal4:UAS amplification cassette enables cells to be observed in live X. laevis tadpoles. This technique should enable the molecular phenotypes, morphologies and physiologies of distinct X. laevis spinal neurons to be examined together in vivo. We have used an islet1 enhancer to label Rohon-Beard sensory neurons and evx enhancers to identify V0v neurons, for the first time, in X. laevis spinal cord. Our work demonstrates the homology of spinal cord circuitry in zebrafish and X. laevis, suggesting that future work could combine their relative strengths to elucidate a more complete picture of how vertebrate spinal cord neurons are specified, and function to generate behavior. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1007-1020, 2017.
Collapse
Affiliation(s)
- José L Juárez-Morales
- Department of Biology, Syracuse University, 107 College Place, Syracuse, New York, 13244.,Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, United Kingdom
| | - Reyna I Martinez-De Luna
- The Center for Vision Research, Department of Ophthalmology, SUNY Upstate Medical University, Institute for Human Performance, 505 Irving Ave. Syracuse, New York, 13210
| | - Michael E Zuber
- The Center for Vision Research, Department of Ophthalmology, SUNY Upstate Medical University, Institute for Human Performance, 505 Irving Ave. Syracuse, New York, 13210
| | - Alan Roberts
- School of Biological Sciences, Bristol University, 24 Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom
| | - Katharine E Lewis
- Department of Biology, Syracuse University, 107 College Place, Syracuse, New York, 13244
| |
Collapse
|
20
|
Myosin phosphatase Fine-tunes Zebrafish Motoneuron Position during Axonogenesis. PLoS Genet 2016; 12:e1006440. [PMID: 27855159 PMCID: PMC5147773 DOI: 10.1371/journal.pgen.1006440] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 10/21/2016] [Indexed: 01/30/2023] Open
Abstract
During embryogenesis the spinal cord shifts position along the anterior-posterior axis relative to adjacent tissues. How motor neurons whose cell bodies are located in the spinal cord while their axons reside in adjacent tissues compensate for such tissue shift is not well understood. Using live cell imaging in zebrafish, we show that as motor axons exit from the spinal cord and extend through extracellular matrix produced by adjacent notochord cells, these cells shift several cell diameters caudally. Despite this pronounced shift, individual motoneuron cell bodies stay aligned with their extending axons. We find that this alignment requires myosin phosphatase activity within motoneurons, and that mutations in the myosin phosphatase subunit mypt1 increase myosin phosphorylation causing a displacement between motoneuron cell bodies and their axons. Thus, we demonstrate that spinal motoneurons fine-tune their position during axonogenesis and we identify the myosin II regulatory network as a key regulator.
Collapse
|
21
|
Warga RM, Wicklund A, Webster SE, Kane DA. Progressive loss of RacGAP1/ ogre activity has sequential effects on cytokinesis and zebrafish development. Dev Biol 2016; 418:307-22. [PMID: 27339293 DOI: 10.1016/j.ydbio.2016.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/27/2016] [Accepted: 06/16/2016] [Indexed: 12/20/2022]
|
22
|
Asad Z, Pandey A, Babu A, Sun Y, Shevade K, Kapoor S, Ullah I, Ranjan S, Scaria V, Bajpai R, Sachidanandan C. Rescue of neural crest-derived phenotypes in a zebrafish CHARGE model by Sox10 downregulation. Hum Mol Genet 2016; 25:3539-3554. [PMID: 27418670 PMCID: PMC5179949 DOI: 10.1093/hmg/ddw198] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 05/27/2016] [Accepted: 06/20/2016] [Indexed: 12/20/2022] Open
Abstract
CHD7 mutations are implicated in a majority of cases of the congenital disorder, CHARGE syndrome. CHARGE, an autosomal dominant syndrome, is known to affect multiple tissues including eye, heart, ear, craniofacial nerves and skeleton and genital organs. Using a morpholino-antisense-oligonucleotide-based zebrafish model for CHARGE syndrome, we uncover a complex spectrum of abnormalities in the neural crest and the crest-derived cell types. We report for the first time, defects in myelinating Schwann cells, enteric neurons and pigment cells in a CHARGE model. We also observe defects in the specification of peripheral neurons and the craniofacial skeleton as previously reported. Chd7 morphants have impaired migration of neural crest cells and deregulation of sox10 expression from the early stages. Knocking down Sox10 in the zebrafish CHARGE model rescued the defects in Schwann cells and craniofacial cartilage. Our zebrafish CHARGE model thus reveals important regulatory roles for Chd7 at multiple points of neural crest development viz., migration, fate choice and differentiation and we suggest that sox10 deregulation is an important driver of the neural crest-derived aspects of Chd7 dependent CHARGE syndrome.
Collapse
Affiliation(s)
- Zainab Asad
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India and
| | - Aditi Pandey
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
| | - Aswini Babu
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India and
| | - Yuhan Sun
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Kaivalya Shevade
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Shruti Kapoor
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India and
| | - Ikram Ullah
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
| | - Shashi Ranjan
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
| | - Vinod Scaria
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India and
| | - Ruchi Bajpai
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry and Department of Biochemistry and Molecular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Chetana Sachidanandan
- CSIR-Institute of Genomics & Integrative Biology, South Campus, New Delhi, 110025, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India and
| |
Collapse
|
23
|
Johnson K, Barragan J, Bashiruddin S, Smith CJ, Tyrrell C, Parsons MJ, Doris R, Kucenas S, Downes GB, Velez CM, Schneider C, Sakai C, Pathak N, Anderson K, Stein R, Devoto SH, Mumm JS, Barresi MJF. Gfap-positive radial glial cells are an essential progenitor population for later-born neurons and glia in the zebrafish spinal cord. Glia 2016; 64:1170-89. [PMID: 27100776 PMCID: PMC4918407 DOI: 10.1002/glia.22990] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 03/27/2016] [Accepted: 03/30/2016] [Indexed: 11/12/2022]
Abstract
Radial glial cells are presumptive neural stem cells (NSCs) in the developing nervous system. The direct requirement of radial glia for the generation of a diverse array of neuronal and glial subtypes, however, has not been tested. We employed two novel transgenic zebrafish lines and endogenous markers of NSCs and radial glia to show for the first time that radial glia are essential for neurogenesis during development. By using the gfap promoter to drive expression of nuclear localized mCherry we discerned two distinct radial glial-derived cell types: a major nestin+/Sox2+ subtype with strong gfap promoter activity and a minor Sox2+ subtype lacking this activity. Fate mapping studies in this line indicate that gfap+ radial glia generate later-born CoSA interneurons, secondary motorneurons, and oligodendroglia. In another transgenic line using the gfap promoter-driven expression of the nitroreductase enzyme, we induced cell autonomous ablation of gfap+ radial glia and observed a reduction in their specific derived lineages, but not Blbp+ and Sox2+/gfap-negative NSCs, which were retained and expanded at later larval stages. Moreover, we provide evidence supporting classical roles of radial glial in axon patterning, blood-brain barrier formation, and locomotion. Our results suggest that gfap+ radial glia represent the major NSC during late neurogenesis for specific lineages, and possess diverse roles to sustain the structure and function of the spinal cord. These new tools will both corroborate the predicted roles of astroglia and reveal novel roles related to development, physiology, and regeneration in the vertebrate nervous system. GLIA 2016;64:1170-1189.
Collapse
Affiliation(s)
- Kimberly Johnson
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts
| | - Jessica Barragan
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Sarah Bashiruddin
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Cody J Smith
- Department of Biology, University of Virginia, Charlottesville, Virginia
| | - Chelsea Tyrrell
- Program in Neuroscience and Behavior, University of Massachusetts, Amherst, Massachusetts
| | - Michael J Parsons
- Department of Surgery, Johns Hopkins University, Baltimore, Maryland
| | - Rosemarie Doris
- Department of Biology, Wesleyan University, Middletown, Connecticut
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, Virginia
| | - Gerald B Downes
- Department of Biology, University of Massachusetts, Amherst, Massachusetts
| | - Carla M Velez
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Caitlin Schneider
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Catalina Sakai
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Narendra Pathak
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Katrina Anderson
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Rachael Stein
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Stephen H Devoto
- Department of Biology, Wesleyan University, Middletown, Connecticut
| | - Jeff S Mumm
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
| | - Michael J F Barresi
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts
- Program in Neuroscience and Behavior, University of Massachusetts, Amherst, Massachusetts
| |
Collapse
|
24
|
Lien HW, Yuan RY, Chou CM, Chen YC, Hung CC, Hu CH, Hwang SPL, Hwang PP, Shen CN, Chen CL, Cheng CH, Huang CJ. Zebrafish cyclin Dx is required for development of motor neuron progenitors, and its expression is regulated by hypoxia-inducible factor 2α. Sci Rep 2016; 6:28297. [PMID: 27323909 PMCID: PMC4915019 DOI: 10.1038/srep28297] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/01/2016] [Indexed: 01/31/2023] Open
Abstract
Cyclins play a central role in cell-cycle regulation; in mammals, the D family of cyclins consists of cyclin D1, D2, and D3. In Xenopus, only homologs of cyclins D1 and D2 have been reported, while a novel cyclin, cyclin Dx (ccndx), was found to be required for the maintenance of motor neuron progenitors during embryogenesis. It remains unknown whether zebrafish possess cyclin D3 or cyclin Dx. In this study, we identified a zebrafish ccndx gene encoding a protein which can form a complex with Cdk4. Through whole-mount in situ hybridization, we observed that zccndx mRNA is expressed in the motor neurons of hindbrain and spinal cord during development. Analysis of a 4-kb promoter sequence of the zccndx gene revealed the presence of HRE sites, which can be regulated by HIF2α. Morpholino knockdown of zebrafish Hif2α and cyclin Dx resulted in the abolishment of isl1 and oligo2 expression in the precursors of motor neurons, and also disrupted axon growth. Overexpression of cyclin Dx mRNA in Hif2α morphants partially rescued zccndx expression. Taken together, our data indicate that zebrafish cyclin Dx plays a role in maintaining the precursors of motor neurons.
Collapse
Affiliation(s)
- Huang-Wei Lien
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Rey-Yue Yuan
- Department of Neurology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 115, Taiwan
| | - Chih-Ming Chou
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 115, Taiwan
| | - Yi-Chung Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Chin-Chun Hung
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| | - Chin-Hwa Hu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Sheng-Ping L Hwang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Pung-Pung Hwang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 115, Taiwan
| | - Chia-Ning Shen
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Chih-Lung Chen
- Genomics Research Center, Academia Sinica, Taipei 115, Taiwan
| | - Chia-Hsiung Cheng
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 115, Taiwan
| | - Chang-Jen Huang
- Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan
| |
Collapse
|
25
|
Ghosh S, Hui SP. Regeneration of Zebrafish CNS: Adult Neurogenesis. Neural Plast 2016; 2016:5815439. [PMID: 27382491 PMCID: PMC4921647 DOI: 10.1155/2016/5815439] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/18/2016] [Indexed: 12/13/2022] Open
Abstract
Regeneration in the animal kingdom is one of the most fascinating problems that have allowed scientists to address many issues of fundamental importance in basic biology. However, we came to know that the regenerative capability may vary across different species. Among vertebrates, fish and amphibians are capable of regenerating a variety of complex organs through epimorphosis. Zebrafish is an excellent animal model, which can repair several organs like damaged retina, severed spinal cord, injured brain and heart, and amputated fins. The focus of the present paper is on spinal cord regeneration in adult zebrafish. We intend to discuss our current understanding of the cellular and molecular mechanism(s) that allows formation of proliferating progenitors and controls neurogenesis, which involve changes in epigenetic and transcription programs. Unlike mammals, zebrafish retains radial glia, a nonneuronal cell type in their adult central nervous system. Injury induced proliferation involves radial glia which proliferate, transcribe embryonic genes, and can give rise to new neurons. Recent technological development of exquisite molecular tools in zebrafish, such as cell ablation, lineage analysis, and novel and substantial microarray, together with advancement in stem cell biology, allowed us to investigate how progenitor cells contribute to the generation of appropriate structures and various underlying mechanisms like reprogramming.
Collapse
Affiliation(s)
- Sukla Ghosh
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| | - Subhra Prakash Hui
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| |
Collapse
|
26
|
Greaney MR, Privorotskiy AE, D'Elia KP, Schoppik D. Extraocular motoneuron pools develop along a dorsoventral axis in zebrafish, Danio rerio. J Comp Neurol 2016; 525:65-78. [PMID: 27197595 PMCID: PMC5116274 DOI: 10.1002/cne.24042] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 05/16/2016] [Accepted: 05/17/2016] [Indexed: 12/24/2022]
Abstract
Both spatial and temporal cues determine the fate of immature neurons. A major challenge at the interface of developmental and systems neuroscience is to relate this spatiotemporal trajectory of maturation to circuit-level functional organization. This study examined the development of two extraocular motor nuclei (nIII and nIV), structures in which a motoneuron's identity, or choice of muscle partner, defines its behavioral role. We used retro-orbital dye fills, in combination with fluorescent markers for motoneuron location and birthdate, to probe spatial and temporal organization of the oculomotor (nIII) and trochlear (nIV) nuclei in the larval zebrafish. We describe a dorsoventral organization of the four nIII motoneuron pools, in which inferior and medial rectus motoneurons occupy dorsal nIII, while inferior oblique and superior rectus motoneurons occupy distinct divisions of ventral nIII. Dorsal nIII motoneurons are, moreover, born before motoneurons of ventral nIII and nIV. The order of neurogenesis can therefore account for the dorsoventral organization of nIII and may play a primary role in determining motoneuron identity. We propose that the temporal development of extraocular motoneurons plays a key role in assembling a functional oculomotor circuit. J. Comp. Neurol. 525:65-78, 2017. © 2016 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Marie R Greaney
- Departments of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute New York University Langone School of Medicine, New York, New York, USA
| | - Ann E Privorotskiy
- Departments of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute New York University Langone School of Medicine, New York, New York, USA
| | - Kristen P D'Elia
- Departments of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute New York University Langone School of Medicine, New York, New York, USA
| | - David Schoppik
- Departments of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute New York University Langone School of Medicine, New York, New York, USA
| |
Collapse
|
27
|
The LIM-homeodomain transcription factor Islet2a promotes angioblast migration. Dev Biol 2016; 414:181-92. [PMID: 27126199 DOI: 10.1016/j.ydbio.2016.04.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 03/25/2016] [Accepted: 04/24/2016] [Indexed: 02/04/2023]
Abstract
Angioblasts of the developing vascular system require many signaling inputs to initiate their migration, proliferation and differentiation into endothelial cells. What is less studied is which intrinsic cell factors interpret these extrinsic signals. Here, we show the Lim homeodomain transcription factor islet2a (isl2a) is expressed in the lateral posterior mesoderm prior to angioblast migration. isl2a deficient angioblasts show disorganized migration to the midline to form axial vessels and fail to spread around the tailbud of the embryo. Isl2a morphants have fewer vein cells and decreased vein marker expression. We demonstrate that isl2a is required cell autonomously in angioblasts to promote their incorporation into the vein, and is permissive for vein identity. Knockout of isl2a results in decreased migration and proliferation of angioblasts during intersegmental artery growth. Since Notch signaling controls both artery-vein identity and tip-stalk cell formation, we explored the interaction of isl2a and Notch. We find that isl2a expression is negatively regulated by Notch activity, and that isl2a positively regulates flt4, a VEGF-C receptor repressed by Notch during angiogenesis. Thus Isl2a may act as an intermediate between Notch signaling and genetic programs controlling angioblast number and migration, placing it as a novel transcriptional regulator of early angiogenesis.
Collapse
|
28
|
Abstract
Evolutionary modifications in nervous systems enabled organisms to adapt to their specific environments and underlie the remarkable diversity of behaviors expressed by animals. Resolving the pathways that shaped and modified neural circuits during evolution remains a significant challenge. Comparative studies have revealed a surprising conservation in the intrinsic signaling systems involved in early patterning of bilaterian nervous systems but also raise the question of how neural circuit compositions and architectures evolved within specific animal lineages. In this review, we discuss the mechanisms that contributed to the emergence and diversity of animal nervous systems, focusing on the circuits governing vertebrate locomotion.
Collapse
Affiliation(s)
- Heekyung Jung
- Howard Hughes Medical Institute (HHMI), NYU Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA
| | - Jeremy S Dasen
- Howard Hughes Medical Institute (HHMI), NYU Neuroscience Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA.
| |
Collapse
|
29
|
Allan DW, Thor S. Transcriptional selectors, masters, and combinatorial codes: regulatory principles of neural subtype specification. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:505-28. [PMID: 25855098 PMCID: PMC4672696 DOI: 10.1002/wdev.191] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 03/04/2015] [Accepted: 03/04/2015] [Indexed: 01/08/2023]
Abstract
The broad range of tissue and cellular diversity of animals is generated to a large extent by the hierarchical deployment of sequence-specific transcription factors and co-factors (collectively referred to as TF's herein) during development. Our understanding of these developmental processes has been facilitated by the recognition that the activities of many TF's can be meaningfully described by a few functional categories that usefully convey a sense for how the TF's function, and also provides a sense for the regulatory organization of the developmental processes in which they participate. Here, we draw on examples from studies in Caenorhabditis elegans, Drosophila melanogaster, and vertebrates to discuss how the terms spatial selector, temporal selector, tissue/cell type selector, terminal selector and combinatorial code may be usefully applied to categorize the activities of TF's at critical steps of nervous system construction. While we believe that these functional categories are useful for understanding the organizational principles by which TF's direct nervous system construction, we however caution against the assumption that a TF's function can be solely or fully defined by any single functional category. Indeed, most TF's play diverse roles within different functional categories, and their roles can blur the lines we draw between these categories. Regardless, it is our belief that the concepts discussed here are helpful in clarifying the regulatory complexities of nervous system development, and hope they prove useful when interpreting mutant phenotypes, designing future experiments, and programming specific neuronal cell types for use in therapies. WIREs Dev Biol 2015, 4:505–528. doi: 10.1002/wdev.191 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Douglas W Allan
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Stefan Thor
- Department of Clinical and Experimental Medicine, Linkoping University, Linkoping, Sweden
| |
Collapse
|
30
|
Focareta L, Sesso S, Cole AG. Characterization of homeobox genes reveals sophisticated regionalization of the central nervous system in the European cuttlefish Sepia officinalis. PLoS One 2014; 9:e109627. [PMID: 25286399 PMCID: PMC4186843 DOI: 10.1371/journal.pone.0109627] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 09/11/2014] [Indexed: 01/21/2023] Open
Abstract
Cephalopod mollusks possess a number of anatomical traits that often parallel vertebrates in morphological complexity, including a centralized nervous system with sophisticated cognitive functionality. Very little is known about the genetic mechanisms underlying patterning of the cephalopod embryo to arrive at this anatomical structure. Homeodomain (HD) genes are transcription factors that regulate transcription of downstream genes through DNA binding, and as such are integral parts of gene regulatory networks controlling the specification and patterning of body parts across lineages. We have used a degenerate primer strategy to isolate homeobox genes active during late-organogenesis from the European cuttlefish Sepia officinalis. With this approach we have isolated fourteen HD gene fragments and examine the expression profiles of five of these genes during late stage (E24-28) embryonic development (Sof-Gbx, Sof-Hox3, Sof-Arx, Sof-Lhx3/4, Sof-Vsx). All five genes are expressed within the developing central nervous system in spatially restricted and largely non-overlapping domains. Our data provide a first glimpse into the diversity of HD genes in one of the largest, yet least studied, metazoan clades and illustrate how HD gene expression patterns reflect the functional partitioning of the cephalopod brain.
Collapse
|
31
|
Seredick S, Hutchinson SA, Van Ryswyk L, Talbot JC, Eisen JS. Lhx3 and Lhx4 suppress Kolmer-Agduhr interneuron characteristics within zebrafish axial motoneurons. Development 2014; 141:3900-9. [PMID: 25231761 DOI: 10.1242/dev.105718] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A central problem in development is how fates of closely related cells are segregated. Lineally related motoneurons (MNs) and interneurons (INs) express many genes in common yet acquire distinct fates. For example, in mouse and chick Lhx3 plays a pivotal role in the development of both cell classes. Here, we utilize the ability to recognize individual zebrafish neurons to examine the roles of Lhx3 and its paralog Lhx4 in the development of MNs and ventral INs. We show that Lhx3 and Lhx4 are expressed by post-mitotic axial MNs derived from the MN progenitor (pMN) domain, p2 domain progenitors and by several types of INs derived from pMN and p2 domains. In the absence of Lhx3 and Lhx4, early-developing primary MNs (PMNs) adopt a hybrid fate, with morphological and molecular features of both PMNs and pMN-derived Kolmer-Agduhr' (KA') INs. In addition, we show that Lhx3 and Lhx4 distinguish the fates of two pMN-derived INs. Finally, we demonstrate that Lhx3 and Lhx4 are necessary for the formation of late-developing V2a and V2b INs. In conjunction with our previous work, these data reveal that distinct transcription factor families are deployed in post-mitotic MNs to unequivocally assign MN fate and suppress the development of alternative pMN-derived IN fates.
Collapse
Affiliation(s)
- Steve Seredick
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR 97403, USA
| | - Sarah A Hutchinson
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR 97403, USA
| | - Liesl Van Ryswyk
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR 97403, USA
| | - Jared C Talbot
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR 97403, USA
| | - Judith S Eisen
- Institute of Neuroscience, 1254 University of Oregon, Eugene, OR 97403, USA
| |
Collapse
|
32
|
Al Oustah A, Danesin C, Khouri-Farah N, Farreny MA, Escalas N, Cochard P, Glise B, Soula C. Dynamics of sonic hedgehog signaling in the ventral spinal cord are controlled by intrinsic changes in source cells requiring sulfatase 1. Development 2014; 141:1392-403. [PMID: 24595292 DOI: 10.1242/dev.101717] [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] [Indexed: 01/20/2023]
Abstract
In the ventral spinal cord, generation of neuronal and glial cell subtypes is controlled by Sonic hedgehog (Shh). This morphogen contributes to cell diversity by regulating spatial and temporal sequences of gene expression during development. Here, we report that establishing Shh source cells is not sufficient to induce the high-threshold response required to specify sequential generation of ventral interneurons and oligodendroglial cells at the right time and place in zebrafish. Instead, we show that Shh-producing cells must repeatedly upregulate the secreted enzyme Sulfatase1 (Sulf1) at two critical time points of development to reach their full inductive capacity. We provide evidence that Sulf1 triggers Shh signaling activity to establish and, later on, modify the spatial arrangement of gene expression in ventral neural progenitors. We further present arguments in favor of Sulf1 controlling Shh temporal activity by stimulating production of active forms of Shh from its source. Our work, by pointing out the key role of Sulf1 in regulating Shh-dependent neural cell diversity, highlights a novel level of regulation, which involves temporal evolution of Shh source properties.
Collapse
Affiliation(s)
- Amir Al Oustah
- University of Toulouse, Center for Developmental Biology, UMR 5547 CNRS, 118 Route de Narbonne, 31062 Toulouse, France
| | | | | | | | | | | | | | | |
Collapse
|
33
|
The role of inab in axon morphology of an identified zebrafish motoneuron. PLoS One 2014; 9:e88631. [PMID: 24533123 PMCID: PMC3922942 DOI: 10.1371/journal.pone.0088631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 01/15/2014] [Indexed: 12/15/2022] Open
Abstract
The ability of an animal to move and to interact with its environment requires that motoneurons correctly innervate specific muscles. Although many genes that regulate motoneuron development have been identified, our understanding of motor axon branching remains incomplete. We used transcriptional expression profiling to identify potential candidate genes involved in development of zebrafish identified motoneurons. Here we focus on inab, an intermediate filament encoding gene dynamically expressed in a subset of motoneurons as well as in an identified interneuron. We show that inab is necessary for proper axon morphology of a specific motoneuron subtype.
Collapse
|
34
|
Lacin H, Rusch J, Yeh RT, Fujioka M, Wilson BA, Zhu Y, Robie AA, Mistry H, Wang T, Jaynes JB, Skeath JB. Genome-wide identification of Drosophila Hb9 targets reveals a pivotal role in directing the transcriptome within eight neuronal lineages, including activation of nitric oxide synthase and Fd59a/Fox-D. Dev Biol 2014; 388:117-33. [PMID: 24512689 DOI: 10.1016/j.ydbio.2014.01.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 01/11/2014] [Accepted: 01/31/2014] [Indexed: 11/25/2022]
Abstract
Hb9 is a homeodomain-containing transcription factor that acts in combination with Nkx6, Lim3, and Tail-up (Islet) to guide the stereotyped differentiation, connectivity, and function of a subset of neurons in Drosophila. The role of Hb9 in directing neuronal differentiation is well documented, but the lineage of Hb9(+) neurons is only partly characterized, its regulation is poorly understood, and most of the downstream genes through which it acts remain at large. Here, we complete the lineage tracing of all embryonic Hb9(+) neurons (to eight neuronal lineages) and provide evidence that hb9, lim3, and tail-up are coordinately regulated by a common set of upstream factors. Through the parallel use of micro-array gene expression profiling and the Dam-ID method, we searched for Hb9-regulated genes, uncovering transcription factors as the most over-represented class of genes regulated by Hb9 (and Nkx6) in the CNS. By a nearly ten-to-one ratio, Hb9 represses rather than activates transcription factors, highlighting transcriptional repression of other transcription factors as a core mechanism by which Hb9 governs neuronal determination. From the small set of genes activated by Hb9, we characterized the expression and function of two - fd59a/foxd, which encodes a transcription factor, and Nitric oxide synthase. Under standard lab conditions, both genes are dispensable for Drosophila development, but Nos appears to inhibit hyper-active behavior and fd59a appears to act in octopaminergic neurons to control egg-laying behavior. Together our data clarify the mechanisms through which Hb9 governs neuronal specification and differentiation and provide an initial characterization of the expression and function of Nos and fd59a in the Drosophila CNS.
Collapse
Affiliation(s)
- Haluk Lacin
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA
| | - Jannette Rusch
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA
| | - Raymond T Yeh
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA
| | - Miki Fujioka
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Beth A Wilson
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA
| | - Yi Zhu
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA
| | - Alice A Robie
- Howard Hughes Medical Institute, Janelia Farm Research Campus (HHMI JFRC), Ashburn, VA, USA
| | - Hemlata Mistry
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA
| | - Ting Wang
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA
| | - James B Jaynes
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - James B Skeath
- Department of Genetics, Washington University School of Medicine, St. Louis 4566, Scott Avenue, St. Louis, MO 63110, USA.
| |
Collapse
|
35
|
Johnson K, Moriarty C, Tania N, Ortman A, DiPietrantonio K, Edens B, Eisenman J, Ok D, Krikorian S, Barragan J, Golé C, Barresi MJF. Kif11 dependent cell cycle progression in radial glial cells is required for proper neurogenesis in the zebrafish neural tube. Dev Biol 2013; 387:73-92. [PMID: 24370453 DOI: 10.1016/j.ydbio.2013.12.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 12/11/2013] [Accepted: 12/13/2013] [Indexed: 10/25/2022]
Abstract
Radial glia serve as the resident neural stem cells in the embryonic vertebrate nervous system, and their proliferation must be tightly regulated to generate the correct number of neuronal and glial cell progeny in the neural tube. During a forward genetic screen, we recently identified a zebrafish mutant in the kif11 loci that displayed a significant increase in radial glial cell bodies at the ventricular zone of the spinal cord. Kif11, also known as Eg5, is a kinesin-related, plus-end directed motor protein responsible for stabilizing and separating the bipolar mitotic spindle. We show here that Gfap+ radial glial cells express kif11 in the ventricular zone and floor plate. Loss of Kif11 by mutation or pharmacological inhibition with S-trityl-L-cysteine (STLC) results in monoastral spindle formation in radial glial cells, which is characteristic of mitotic arrest. We show that M-phase radial glia accumulate over time at the ventricular zone in kif11 mutants and STLC treated embryos. Mathematical modeling of the radial glial accumulation in kif11 mutants not only confirmed an ~226× delay in mitotic exit (likely a mitotic arrest), but also predicted two modes of increased cell death. These modeling predictions were supported by an increase in the apoptosis marker, anti-activated Caspase-3, which was also found to be inversely proportional to a decrease in cell proliferation. In addition, treatment with STLC at different stages of neural development uncovered two critical periods that most significantly require Kif11 function for stem cell progression through mitosis. We also show that loss of Kif11 function causes specific reductions in oligodendroglia and secondary interneurons and motorneurons, suggesting these later born populations require proper radial glia division. Despite these alterations to cell cycle dynamics, survival, and neurogenesis, we document unchanged cell densities within the neural tube in kif11 mutants, suggesting that a mechanism of compensatory regulation may exist to maintain overall proportions in the neural tube. We propose a model in which Kif11 normally functions during mitotic spindle formation to facilitate the progression of radial glia through mitosis, which leads to the maturation of progeny into specific secondary neuronal and glial lineages in the developing neural tube.
Collapse
Affiliation(s)
- Kimberly Johnson
- Biological Sciences, Smith College, Northampton, MA 01063, United States; Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003, United States
| | - Chelsea Moriarty
- Biological Sciences, Smith College, Northampton, MA 01063, United States
| | - Nessy Tania
- Mathematics and Statistics, Smith College, Northampton, MA 01063, United States
| | - Alissa Ortman
- Biological Sciences, Smith College, Northampton, MA 01063, United States
| | | | - Brittany Edens
- Biological Sciences, Smith College, Northampton, MA 01063, United States
| | - Jean Eisenman
- Biological Sciences, Smith College, Northampton, MA 01063, United States
| | - Deborah Ok
- Biological Sciences, Smith College, Northampton, MA 01063, United States
| | - Sarah Krikorian
- Biological Sciences, Smith College, Northampton, MA 01063, United States
| | - Jessica Barragan
- Biological Sciences, Smith College, Northampton, MA 01063, United States
| | - Christophe Golé
- Mathematics and Statistics, Smith College, Northampton, MA 01063, United States
| | - Michael J F Barresi
- Biological Sciences, Smith College, Northampton, MA 01063, United States; Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003, United States.
| |
Collapse
|
36
|
Kastenhuber E, Gesemann M, Mickoleit M, Neuhauss SCF. Phylogenetic analysis and expression of zebrafish transient receptor potential melastatin family genes. Dev Dyn 2013; 242:1236-49. [PMID: 23908157 DOI: 10.1002/dvdy.24020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/02/2013] [Accepted: 07/17/2013] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND The transient receptor potential melastatin (TRPM) gene family belongs to the superfamily of nonselective TRP ion channels. TRP channels are cellular sensors, detecting a multitude of inputs, including temperature, light, chemical, and mechanical stimuli. Recent studies revealed diverse roles during development, linking TRP channels to differentiation, proliferation, cell motility, cell death, and survival. A detailed description of this gene family in the zebrafish is still missing. RESULTS Phylogenetic analysis revealed 11 trpm genes in the zebrafish genome. The zebrafish orthologs of mammalian TRPM1 and TRPM4 are duplicated and quadruplicated, respectively, and TRPM8, a cold sensitive channel has been lost in zebrafish. Whole-mount in situ hybridization experiments revealed dynamic expression pattern of trpm genes in the developing embryo and early larva. Transcripts were mainly found in neural cell clusters, but also in tissues involved in ion homeostasis. CONCLUSIONS Our results suggest a role of TRPM channels in sensory information processing, including vision, olfaction, taste, and mechanosensation. An involvement in developmental processes is likely, as some trpm genes were found to be expressed in differentiating cells. Our data now provide a basis for functional analyses of this gene family of ion channels in the vertebrate model organism Danio rerio.
Collapse
Affiliation(s)
- Edda Kastenhuber
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | | | | | | |
Collapse
|
37
|
Morimura R, Nozawa K, Tanaka H, Ohshima T. Phosphorylation of Dpsyl2 (CRMP2) and Dpsyl3 (CRMP4) is required for positioning of caudal primary motor neurons in the zebrafish spinal cord. Dev Neurobiol 2013; 73:911-20. [DOI: 10.1002/dneu.22117] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/23/2013] [Accepted: 07/28/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Rii Morimura
- Department of Life Science and Medical Bioscience; Waseda University; 2-2 Wakamatsu-cho, Shinjuku-ku Tokyo 162-8480 Japan
| | - Keisuke Nozawa
- Department of Life Science and Medical Bioscience; Waseda University; 2-2 Wakamatsu-cho, Shinjuku-ku Tokyo 162-8480 Japan
| | - Hideomi Tanaka
- Department of Life Science and Medical Bioscience; Waseda University; 2-2 Wakamatsu-cho, Shinjuku-ku Tokyo 162-8480 Japan
- Laboratory for Developmental Gene Regulation; RIKEN Brain Science Institute (BSI); 2-1 Hirosawa, Wako Saitama 351-0198 Japan
| | - Toshio Ohshima
- Department of Life Science and Medical Bioscience; Waseda University; 2-2 Wakamatsu-cho, Shinjuku-ku Tokyo 162-8480 Japan
| |
Collapse
|
38
|
Wei C, Thatcher EJ, Olena AF, Cha DJ, Perdigoto AL, Marshall AF, Carter BD, Broadie K, Patton JG. miR-153 regulates SNAP-25, synaptic transmission, and neuronal development. PLoS One 2013; 8:e57080. [PMID: 23451149 PMCID: PMC3581580 DOI: 10.1371/journal.pone.0057080] [Citation(s) in RCA: 49] [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: 12/01/2012] [Accepted: 01/16/2013] [Indexed: 01/01/2023] Open
Abstract
SNAP-25 is a core component of the trimeric SNARE complex mediating vesicle exocytosis during membrane addition for neuronal growth, neuropeptide/growth factor secretion, and neurotransmitter release during synaptic transmission. Here, we report a novel microRNA mechanism of SNAP-25 regulation controlling motor neuron development, neurosecretion, synaptic activity, and movement in zebrafish. Loss of miR-153 causes overexpression of SNAP-25 and consequent hyperactive movement in early zebrafish embryos. Conversely, overexpression of miR-153 causes SNAP-25 down regulation resulting in near complete paralysis, mimicking the effects of treatment with Botulinum neurotoxin. miR-153-dependent changes in synaptic activity at the neuromuscular junction are consistent with the observed movement defects. Underlying the movement defects, perturbation of miR-153 function causes dramatic developmental changes in motor neuron patterning and branching. Together, our results indicate that precise control of SNAP-25 expression by miR-153 is critically important for proper neuronal patterning as well as neurotransmission.
Collapse
Affiliation(s)
- Chunyao Wei
- Department of Biological Sciences, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - Elizabeth J. Thatcher
- Department of Biological Sciences, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - Abigail F. Olena
- Department of Biological Sciences, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - Diana J. Cha
- Department of Biological Sciences, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - Ana L. Perdigoto
- Department of Biochemistry, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - Andrew F. Marshall
- Department of Biological Sciences, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - Bruce D. Carter
- Department of Biochemistry, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
| | - James G. Patton
- Department of Biological Sciences, Vanderbilt University and Medical School, Nashville, Tennessee, United States of America
- * E-mail:
| |
Collapse
|
39
|
Plexin A3 and turnout regulate motor axonal branch morphogenesis in zebrafish. PLoS One 2013; 8:e54071. [PMID: 23349787 PMCID: PMC3549987 DOI: 10.1371/journal.pone.0054071] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 12/10/2012] [Indexed: 02/01/2023] Open
Abstract
During embryogenesis motor axons navigate to their target muscles, where individual motor axons develop complex branch morphologies. The mechanisms that control axonal branching morphogenesis have been studied intensively, yet it still remains unclear when branches begin to form or how branch locations are determined. Live cell imaging of individual zebrafish motor axons reveals that the first axonal branches are generated at the ventral extent of the myotome via bifurcation of the growth cone. Subsequent branches are generated by collateral branching restricted to their synaptic target field along the distal portion of the axon. This precisely timed and spatially restricted branching process is disrupted in turnout mutants we identified in a forward genetic screen. Molecular genetic mapping positioned the turnout mutation within a 300 kb region encompassing eight annotated genes, however sequence analysis of all eight open reading frames failed to unambiguously identify the turnout mutation. Chimeric analysis and single cell labeling reveal that turnout function is required cell non-autonomously for intraspinal motor axon guidance and peripheral branch formation. turnout mutant motor axons form the first branch on time via growth cone bifurcation, but unlike wild-type they form collateral branches precociously, when the growth cone is still navigating towards the ventral myotome. These precocious collateral branches emerge along the proximal region of the axon shaft typically devoid of branches, and they develop into stable, permanent branches. Furthermore, we find that null mutants of the guidance receptor plexin A3 display identical motor axon branching defects, and time lapse analysis reveals that precocious branch formation in turnout and plexin A3 mutants is due to increased stability of otherwise short-lived axonal protrusions. Thus, plexin A3 dependent intrinsic and turnout dependent extrinsic mechanisms suppress collateral branch morphogenesis by destabilizing membrane protrusions before the growth cone completes navigation into the synaptic target field.
Collapse
|
40
|
Activity-dependent competition regulates motor neuron axon pathfinding via PlexinA3. Proc Natl Acad Sci U S A 2013; 110:1524-9. [PMID: 23302694 DOI: 10.1073/pnas.1213048110] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The role of electrical activity in axon guidance has been extensively studied in vitro. To better understand its role in the intact nervous system, we imaged intracellular Ca(2+) in zebrafish primary motor neurons (PMN) during axon pathfinding in vivo. We found that PMN generate specific patterns of Ca(2+) spikes at different developmental stages. Spikes arose in the distal axon of PMN and were propagated to the cell body. Suppression of Ca(2+) spiking activity in single PMN led to stereotyped errors, but silencing all electrical activity had no effect on axon guidance, indicating that an activity-based competition rule regulates this process. This competition was not mediated by synaptic transmission. Combination of PlexinA3 knockdown with suppression of Ca(2+) activity in single PMN produced a synergistic increase in the incidence of pathfinding errors. However, expression of PlexinA3 transcripts was not regulated by activity. Our results provide an in vivo demonstration of the intersection of spontaneous electrical activity with the PlexinA3 guidance molecule receptor in regulation of axon pathfinding.
Collapse
|
41
|
Liu C, Ma W, Su W, Zhang J. Prdm14 acts upstream of islet2 transcription to regulate axon growth of primary motoneurons in zebrafish. Development 2012; 139:4591-600. [PMID: 23136389 DOI: 10.1242/dev.083055] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The precise formation of three-dimensional motor circuits is essential for movement control. Within these circuits, motoneurons (MNs) are specified from spinal progenitors by dorsoventral signals and distinct transcriptional programs. Different MN subpopulations have stereotypic cell body positions and show specific spatial axon trajectories. Our knowledge of MN axon outgrowth remains incomplete. Here, we report a zebrafish gene-trap mutant, short lightning (slg), in which prdm14 expression is disrupted. slg mutant embryos show shortened axons in caudal primary (CaP) MNs resulting in defective embryonic movement. Both the CaP neuronal defects and behavior abnormality of the mutants can be phenocopied by injection of a prdm14 morpholino into wild-type embryos. By removing a copy of the inserted transposon from homozygous mutants, prdm14 expression and normal embryonic movement were restored, confirming that loss of prdm14 expression accounts for the observed defects. Mechanistically, Prdm14 protein binds to the promoter region of islet2, a known transcription factor required for CaP development. Notably, disruption of islet2 function caused similar CaP axon outgrowth defects as observed in slg mutant embryos. Furthermore, overexpression of islet2 in slg mutant embryos rescued the shortened CaP axon phenotypes. Together, these data reveal that prdm14 regulates CaP axon outgrowth through activation of islet2 expression.
Collapse
Affiliation(s)
- Chao Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | | | | | | |
Collapse
|
42
|
Seredick SD, Van Ryswyk L, Hutchinson SA, Eisen JS. Zebrafish Mnx proteins specify one motoneuron subtype and suppress acquisition of interneuron characteristics. Neural Dev 2012; 7:35. [PMID: 23122226 PMCID: PMC3570319 DOI: 10.1186/1749-8104-7-35] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 10/16/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Precise matching between motoneuron subtypes and the muscles they innervate is a prerequisite for normal behavior. Motoneuron subtype identity is specified by the combination of transcription factors expressed by the cell during its differentiation. Here we investigate the roles of Mnx family transcription factors in specifying the subtypes of individually identified zebrafish primary motoneurons. RESULTS Zebrafish has three Mnx family members. We show that each of them has a distinct and temporally dynamic expression pattern in each primary motoneuron subtype. We also show that two Mnx family members are expressed in identified VeLD interneurons derived from the same progenitor domain that generates primary motoneurons. Surprisingly, we found that Mnx proteins appear unnecessary for differentiation of VeLD interneurons or the CaP motoneuron subtype. Mnx proteins are, however, required for differentiation of the MiP motoneuron subtype. We previously showed that MiPs require two temporally-distinct phases of Islet1 expression for normal development. Here we show that in the absence of Mnx proteins, the later phase of Islet1 expression is initiated but not sustained, and MiPs become hybrids that co-express morphological and molecular features of motoneurons and V2a interneurons. Unexpectedly, these hybrid MiPs often extend CaP-like axons, and some MiPs appear to be entirely transformed to a CaP morphology. CONCLUSIONS Our results suggest that Mnx proteins promote MiP subtype identity by suppressing both interneuron development and CaP axon pathfinding. This is, to our knowledge, the first report of transcription factors that act to distinguish CaP and MiP subtype identities. Our results also suggest that MiP motoneurons are more similar to V2 interneurons than are CaP motoneurons.
Collapse
Affiliation(s)
- Steve D Seredick
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | | | | | | |
Collapse
|
43
|
Wolfram V, Southall TD, Brand AH, Baines RA. The LIM-homeodomain protein islet dictates motor neuron electrical properties by regulating K(+) channel expression. Neuron 2012; 75:663-74. [PMID: 22920257 PMCID: PMC3427859 DOI: 10.1016/j.neuron.2012.06.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2012] [Indexed: 11/24/2022]
Abstract
Neuron electrical properties are critical to function and generally subtype specific, as are patterns of axonal and dendritic projections. Specification of motoneuron morphology and axon pathfinding has been studied extensively, implicating the combinatorial action of Lim-homeodomain transcription factors. However, the specification of electrical properties is not understood. Here, we address the key issues of whether the same transcription factors that specify morphology also determine subtype specific electrical properties. We show that Drosophila motoneuron subtypes express different K+ currents and that these are regulated by the conserved Lim-homeodomain transcription factor Islet. Specifically, Islet is sufficient to repress a Shaker-mediated A-type K+ current, most likely due to a direct transcriptional effect. A reduction in Shaker increases the frequency of action potential firing. Our results demonstrate the deterministic role of Islet on the excitability patterns characteristic of motoneuron subtypes.
Collapse
|
44
|
Flowers GP, Topczewska JM, Topczewski J. A zebrafish Notum homolog specifically blocks the Wnt/β-catenin signaling pathway. Development 2012; 139:2416-25. [PMID: 22669824 DOI: 10.1242/dev.063206] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Multiple developmental processes require tightly controlled Wnt signaling, and its misregulation leads to congenital abnormalities and diseases. Glypicans are extracellular proteins that modulate the Wnt pathway. In addition to interacting with Wnts, these glycosophosphotidylinositol (GPI)-anchored, heparan-sulfate proteoglycans bind ligands of several other signaling pathways in both vertebrates and invertebrates. In Drosophila, Notum, a secreted α/β-hydrolase, antagonizes the signaling of the prototypical Wnt Wingless (Wg), by releasing glypicans from the cell surface. Studies of mammalian Notum indicate promiscuous target specificity in cell culture, but the role of Notum in vertebrate development has not been studied. Our work shows that zebrafish Notum 1a, an ortholog of mammalian Notum, contributes to a self-regulatory loop that restricts Wnt/β-catenin signaling. Notum 1a does not interact with Glypican 4, an essential component of the Wnt/planar cell polarity (PCP) pathway. Our results suggest a surprising specific role of Notum in the developing vertebrate embryo.
Collapse
Affiliation(s)
- G Parker Flowers
- Northwestern University Feinberg School of Medicine, Department of Pediatrics, Children's Memorial Research Center, Children's Plaza 2300, Box 204, Chicago, IL 60614, USA
| | | | | |
Collapse
|
45
|
England S, Batista MF, Mich JK, Chen JK, Lewis KE. Roles of Hedgehog pathway components and retinoic acid signalling in specifying zebrafish ventral spinal cord neurons. Development 2012; 138:5121-34. [PMID: 22069186 DOI: 10.1242/dev.066159] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In mouse, Hedgehog (Hh) signalling is required for most ventral spinal neurons to form. Here, we analyse the spinal cord phenotype of zebrafish maternal-zygotic smoothened (MZsmo) mutants that completely lack Hh signalling. We find that most V3 domain cells and motoneurons are lost, whereas medial floorplate still develops normally and V2, V1 and V0v cells form in normal numbers. This phenotype resembles that of mice that lack both Hh signalling and Gli repressor activity. Ventral spinal cord progenitor domain transcription factors are not expressed at 24 hpf in zebrafish MZsmo mutants. However, pMN, p2 and p1 domain markers are expressed at early somitogenesis stages in these mutants. This suggests that Gli repressor activity does not extend into zebrafish ventral spinal cord at these stages, even in the absence of Hh signalling. Consistent with this, ectopic expression of Gli3R represses ventral progenitor domain expression at these early stages and knocking down Gli repressor activity rescues later expression. We investigated whether retinoic acid (RA) signalling specifies ventral spinal neurons in the absence of Hh signalling. The results suggest that RA is required for the correct number of many different spinal neurons to form. This is probably mediated, in part, by an effect on cell proliferation. However, V0v, V1 and V2 cells are still present, even in the absence of both Hh and RA signalling. We demonstrate that Gli1 has a Hh-independent role in specifying most of the remaining motoneurons and V3 domain cells in embryos that lack Hh signalling, but removal of Gli1 activity does not affect more dorsal neurons.
Collapse
Affiliation(s)
- Samantha England
- Biology Department, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
| | | | | | | | | |
Collapse
|
46
|
Murakami Y, Tanaka M. Evolution of motor innervation to vertebrate fins and limbs. Dev Biol 2011; 355:164-72. [DOI: 10.1016/j.ydbio.2011.04.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Revised: 04/08/2011] [Accepted: 04/13/2011] [Indexed: 01/04/2023]
|
47
|
Isl1 is required for multiple aspects of motor neuron development. Mol Cell Neurosci 2011; 47:215-22. [PMID: 21569850 DOI: 10.1016/j.mcn.2011.04.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 04/26/2011] [Indexed: 12/23/2022] Open
Abstract
The LIM homeodomain transcription factor Islet1 (Isl1) is expressed in multiple organs and plays essential roles during embryogenesis. Isl1 is required for the survival and specification of spinal cord motor neurons. Due to early embryonic lethality and loss of motor neurons, the role of Isl1 in other aspects of motor neuron development remains unclear. In this study, we generated Isl1 mutant mouse lines expressing graded doses of Isl1. Our study has revealed essential roles of Isl1 in multiple aspects of motor neuron development, including motor neuron cell body localization, motor column formation and axon growth. In addition, Isl1 is required for survival of cranial ganglia neurons.
Collapse
|
48
|
Ghassibe-Sabbagh M, Desmyter L, Langenberg T, Claes F, Boute O, Bayet B, Pellerin P, Hermans K, Backx L, Mansilla MA, Imoehl S, Nowak S, Ludwig KU, Baluardo C, Ferrian M, Mossey PA, Noethen M, Dewerchin M, François G, Revencu N, Vanwijck R, Hecht J, Mangold E, Murray J, Rubini M, Vermeesch JR, Poirel HA, Carmeliet P, Vikkula M. FAF1, a gene that is disrupted in cleft palate and has conserved function in zebrafish. Am J Hum Genet 2011; 88:150-61. [PMID: 21295280 DOI: 10.1016/j.ajhg.2011.01.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 11/24/2010] [Accepted: 01/06/2011] [Indexed: 10/18/2022] Open
Abstract
Cranial neural crest (CNC) is a multipotent migratory cell population that gives rise to most of the craniofacial bones. An intricate network mediates CNC formation, epithelial-mesenchymal transition, migration along distinct paths, and differentiation. Errors in these processes lead to craniofacial abnormalities, including cleft lip and palate. Clefts are the most common congenital craniofacial defects. Patients have complications with feeding, speech, hearing, and dental and psychological development. Affected by both genetic predisposition and environmental factors, the complex etiology of clefts remains largely unknown. Here we show that Fas-associated factor-1 (FAF1) is disrupted and that its expression is decreased in a Pierre Robin family with an inherited translocation. Furthermore, the locus is strongly associated with cleft palate and shows an increased relative risk. Expression studies show that faf1 is highly expressed in zebrafish cartilages during embryogenesis. Knockdown of zebrafish faf1 leads to pharyngeal cartilage defects and jaw abnormality as a result of a failure of CNC to differentiate into and express cartilage-specific markers, such as sox9a and col2a1. Administration of faf1 mRNA rescues this phenotype. Our findings therefore identify FAF1 as a regulator of CNC differentiation and show that it predisposes humans to cleft palate and is necessary for lower jaw development in zebrafish.
Collapse
|
49
|
Tanaka H, Nojima Y, Shoji W, Sato M, Nakayama R, Ohshima T, Okamoto H. Islet1 selectively promotes peripheral axon outgrowth in Rohon-Beard primary sensory neurons. Dev Dyn 2010; 240:9-22. [DOI: 10.1002/dvdy.22499] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
|
50
|
Olesnicky E, Hernandez-Lagunas L, Artinger KB. prdm1a Regulates sox10 and islet1 in the development of neural crest and Rohon-Beard sensory neurons. Genesis 2010; 48:656-66. [PMID: 20836130 DOI: 10.1002/dvg.20673] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 09/01/2010] [Accepted: 09/02/2010] [Indexed: 01/09/2023]
Abstract
The PR domain containing 1a, with ZNF domain factor, gene (prdm1a) plays an integral role in the development of a number of different cell types during vertebrate embryogenesis, including neural crest cells, Rohon-Beard (RB) sensory neurons and the cranial neural crest-derived craniofacial skeletal elements. To better understand how Prdm1a regulates the development of various cell types in zebrafish, we performed a microarray analysis comparing wild type and prdm1a mutant embryos and identified a number of genes with altered expression in the absence of prdm1a. Rescue analysis determined that two of these, sox10 and islet1, lie downstream of Prdm1a in the development of neural crest cells and RB neurons, respectively. In addition, we identified a number of other novel downstream targets of Prdm1a that may be important for the development of diverse tissues during zebrafish embryogenesis.
Collapse
Affiliation(s)
- Eugenia Olesnicky
- Department of Craniofacial Biology, University of Colorado, Denver School of Dental Medicine, Aurora, Colorado 80045, USA
| | | | | |
Collapse
|