1
|
Itoh T, Uehara M, Yura S, Wang JC, Fujii Y, Nakanishi A, Shimizu T, Hibi M. Foxp and Skor family proteins control differentiation of Purkinje cells from Ptf1a- and Neurog1-expressing progenitors in zebrafish. Development 2024; 151:dev202546. [PMID: 38456494 PMCID: PMC11057878 DOI: 10.1242/dev.202546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/01/2024] [Indexed: 03/09/2024]
Abstract
Cerebellar neurons, such as GABAergic Purkinje cells (PCs), interneurons (INs) and glutamatergic granule cells (GCs) are differentiated from neural progenitors expressing proneural genes, including ptf1a, neurog1 and atoh1a/b/c. Studies in mammals previously suggested that these genes determine cerebellar neuron cell fate. However, our studies on ptf1a;neurog1 zebrafish mutants and lineage tracing of ptf1a-expressing progenitors have revealed that the ptf1a/neurog1-expressing progenitors can generate diverse cerebellar neurons, including PCs, INs and a subset of GCs in zebrafish. The precise mechanisms of how each cerebellar neuron type is specified remains elusive. We found that genes encoding the transcriptional regulators Foxp1b, Foxp4, Skor1b and Skor2, which are reportedly expressed in PCs, were absent in ptf1a;neurog1 mutants. foxp1b;foxp4 mutants showed a strong reduction in PCs, whereas skor1b;skor2 mutants completely lacked PCs, and displayed an increase in immature GCs. Misexpression of skor2 in GC progenitors expressing atoh1c suppressed GC fate. These data indicate that Foxp1b/4 and Skor1b/2 function as key transcriptional regulators in the initial step of PC differentiation from ptf1a/neurog1-expressing neural progenitors, and that Skor1b and Skor2 control PC differentiation by suppressing their differentiation into GCs.
Collapse
Affiliation(s)
- Tsubasa Itoh
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Mari Uehara
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Shinnosuke Yura
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Jui Chun Wang
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Yukimi Fujii
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Akiko Nakanishi
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Takashi Shimizu
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Masahiko Hibi
- Department of Biological Science, Graduate School of Science, Nagoya University, Furo, Chikusa, Nagoya, Aichi 464-8602, Japan
| |
Collapse
|
2
|
Espinosa-Medina I, Feliciano D, Belmonte-Mateos C, Linda Miyares R, Garcia-Marques J, Foster B, Lindo S, Pujades C, Koyama M, Lee T. TEMPO enables sequential genetic labeling and manipulation of vertebrate cell lineages. Neuron 2023; 111:345-361.e10. [PMID: 36417906 DOI: 10.1016/j.neuron.2022.10.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/15/2022] [Accepted: 10/26/2022] [Indexed: 11/24/2022]
Abstract
During development, regulatory factors appear in a precise order to determine cell fates over time. Consequently, to investigate complex tissue development, it is necessary to visualize and manipulate cell lineages with temporal control. Current strategies for tracing vertebrate cell lineages lack genetic access to sequentially produced cells. Here, we present TEMPO (Temporal Encoding and Manipulation in a Predefined Order), an imaging-readable genetic tool allowing differential labeling and manipulation of consecutive cell generations in vertebrates. TEMPO is based on CRISPR and powered by a cascade of gRNAs that drive orderly activation and inactivation of reporters and/or effectors. Using TEMPO to visualize zebrafish and mouse neurogenesis, we recapitulated birth-order-dependent neuronal fates. Temporally manipulating cell-cycle regulators in mouse cortex progenitors altered the proportion and distribution of neurons and glia, revealing the effects of temporal gene perturbation on serial cell fates. Thus, TEMPO enables sequential manipulation of molecular factors, crucial to study cell-type specification.
Collapse
Affiliation(s)
| | - Daniel Feliciano
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Carla Belmonte-Mateos
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Barcelona 08003, Spain
| | - Rosa Linda Miyares
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Jorge Garcia-Marques
- Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Madrid 28049, Spain
| | - Benjamin Foster
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Sarah Lindo
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Cristina Pujades
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra, PRBB, Barcelona 08003, Spain
| | - Minoru Koyama
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA; Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON M1C 1A4, Canada
| | - Tzumin Lee
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
| |
Collapse
|
3
|
Shoenhard H, Jain RA, Granato M. The calcium-sensing receptor (CaSR) regulates zebrafish sensorimotor decision making via a genetically defined cluster of hindbrain neurons. Cell Rep 2022; 41:111790. [PMID: 36476852 PMCID: PMC9813870 DOI: 10.1016/j.celrep.2022.111790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 09/21/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Decision making is a fundamental nervous system function that ranges widely in complexity and speed of execution. We previously established larval zebrafish as a model for sensorimotor decision making and identified the G-protein-coupled calcium-sensing receptor (CaSR) to be critical for this process. Here, we report that CaSR functions in neurons to dynamically regulate the bias between two behavioral outcomes: escapes and reorientations. By employing a computational guided transgenic strategy, we identify a genetically defined neuronal cluster in the hindbrain as a key candidate site for CaSR function. Finally, we demonstrate that transgenic CaSR expression targeting this cluster consisting of a few hundred neurons shifts behavioral bias in wild-type animals and restores decision making deficits in CaSR mutants. Combined, our data provide a rare example of a G-protein-coupled receptor that biases vertebrate sensorimotor decision making via a defined neuronal cluster.
Collapse
Affiliation(s)
- Hannah Shoenhard
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Roshan A. Jain
- Department of Biology, Haverford College, Haverford, PA 19041, USA
| | - Michael Granato
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA,Lead contact,Correspondence:
| |
Collapse
|
4
|
Hayashi S, Tsukiyama T, Iida A, Kinoshita M, Koga A. The medaka fish Tol2 transposable element is in an early stage of decay: identification of a nonautonomous copy. Genome 2021; 65:183-187. [PMID: 34529924 DOI: 10.1139/gen-2021-0010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The majority of DNA-based transposable elements comprise autonomous and nonautonomous copies, or only nonautonomous copies, where the autonomous copy contains an intact gene for a transposase protein and the nonautonomous copy does not. Even if autonomous copies coexist, they are generally less frequent. The Tol2 element of medaka fish is one of the few elements for which a nonautonomous copy has not yet been found. Here we report the presence of a nonautonomous Tol2 copy that was identified by surveying the medaka genome sequence database. This copy contained 3 local sequence alterations that affected the deduced amino acid sequence of the transposase: a deletion of 15 nucleotides resulting in a deletion of 5 amino acids, a base substitution causing a single amino acid change, and another base substitution giving rise to a stop codon. Transposition assays using cultured human cells revealed that the transposase activity was reduced by the 15-nucleotide deletion and abolished by the nonsense mutation. This is the first example of a nonautonomous Tol2 copy. Thus, Tol2 is in an early stage of decay in the medaka genome, and is therefore a unique element to observe an almost whole decay process that progresses in natural populations.
Collapse
Affiliation(s)
- Sakura Hayashi
- Kyoto University, 12918, Primate Research Institute, Inuyama, Japan;
| | | | - Atsuo Iida
- Nagoya University, 12965, Graduate School of Bioagricultural Sciences, Nagoya, Japan;
| | - Masato Kinoshita
- Kyoto University, 12918, Graduate School of Agriculture, Kyoto, Japan;
| | - Akihiko Koga
- Kyoto University, 12918, Primate Research Institute, Inuyama, Japan;
| |
Collapse
|
5
|
Elsaey MA, Namikawa K, Köster RW. Genetic Modeling of the Neurodegenerative Disease Spinocerebellar Ataxia Type 1 in Zebrafish. Int J Mol Sci 2021; 22:7351. [PMID: 34298970 PMCID: PMC8306488 DOI: 10.3390/ijms22147351] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 06/29/2021] [Accepted: 07/06/2021] [Indexed: 12/26/2022] Open
Abstract
Dominant spinocerebellar ataxias (SCAs) are progredient neurodegenerative diseases commonly affecting the survival of Purkinje cells (PCs) in the human cerebellum. Spinocerebellar ataxia type 1 (SCA1) is caused by the mutated ataxin1 (Atx1) gene product, in which a polyglutamine stretch encoded by CAG repeats is extended in affected SCA1 patients. As a monogenetic disease with the Atx1-polyQ protein exerting a gain of function, SCA1 can be genetically modelled in animals by cell type-specific overexpression. We have established a transgenic PC-specific SCA1 model in zebrafish coexpressing the fluorescent reporter protein mScarlet together with either human wild type Atx1[30Q] as control or SCA1 patient-derived Atx1[82Q]. SCA1 zebrafish display an age-dependent PC degeneration starting at larval stages around six weeks postfertilization, which continuously progresses during further juvenile and young adult stages. Interestingly, PC degeneration is observed more severely in rostral than in caudal regions of the PC population. Although such a neuropathology resulted in no gross locomotor control deficits, SCA1-fish with advanced PC loss display a reduced exploratory behaviour. In vivo imaging in this SCA1 model may help to better understand such patterned PC death known from PC neurodegeneration diseases, to elucidate disease mechanisms and to provide access to neuroprotective compound characterization in vivo.
Collapse
Affiliation(s)
- Mohamed A. Elsaey
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany;
- Zoology Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt
| | - Kazuhiko Namikawa
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany;
| | - Reinhard W. Köster
- Division of Cellular & Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Spielmannstraße 7, 38106 Braunschweig, Germany;
| |
Collapse
|
6
|
Buchberger A, Schepergerdes L, Flaßhoff M, Kunick C, Köster RW. A novel inhibitor rescues cerebellar defects in a zebrafish model of Down syndrome-associated kinase Dyrk1A overexpression. J Biol Chem 2021; 297:100853. [PMID: 34090874 PMCID: PMC8239740 DOI: 10.1016/j.jbc.2021.100853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/25/2021] [Accepted: 06/02/2021] [Indexed: 12/31/2022] Open
Abstract
The highly conserved dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A) plays crucial roles during central nervous system development and homeostasis. Furthermore, its hyperactivity is considered responsible for some neurological defects in individuals with Down syndrome. We set out to establish a zebrafish model expressing human Dyrk1A that could be further used to characterize the interaction between Dyrk1A and neurological phenotypes. First, we revealed the prominent expression of dyrk1a homologs in cerebellar neurons in the zebrafish larval and adult brains. Overexpression of human dyrk1a in postmitotic cerebellar Purkinje neurons resulted in a structural misorganization of the Purkinje cells in cerebellar hemispheres and a compaction of this cell population. This impaired Purkinje cell organization was progressive, leading to an age-dependent dispersal of Purkinje neurons throughout the cerebellar molecular layer with larval swim deficits resulting in miscoordination of swimming and reduced exploratory behavior in aged adults. We also found that the structural misorganization of the larval Purkinje cell layer could be rescued by pharmacological treatment with Dyrk1A inhibitors. We further reveal the in vivo efficiency of a novel selective Dyrk1A inhibitor, KuFal194. These findings demonstrate that the zebrafish is a well-suited vertebrate organism to genetically model severe neurological diseases with single cell type specificity. Such models can be used to relate molecular malfunction to cellular deficits, impaired tissue formation, and organismal behavior and can also be used for pharmacological compound testing and validation.
Collapse
Affiliation(s)
- Astrid Buchberger
- Division of Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Lena Schepergerdes
- Division of Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Maren Flaßhoff
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Conrad Kunick
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany; Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Braunschweig, Germany
| | - Reinhard W Köster
- Division of Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.
| |
Collapse
|
7
|
Sandoval-Villegas N, Nurieva W, Amberger M, Ivics Z. Contemporary Transposon Tools: A Review and Guide through Mechanisms and Applications of Sleeping Beauty, piggyBac and Tol2 for Genome Engineering. Int J Mol Sci 2021; 22:ijms22105084. [PMID: 34064900 PMCID: PMC8151067 DOI: 10.3390/ijms22105084] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 01/19/2023] Open
Abstract
Transposons are mobile genetic elements evolved to execute highly efficient integration of their genes into the genomes of their host cells. These natural DNA transfer vehicles have been harnessed as experimental tools for stably introducing a wide variety of foreign DNA sequences, including selectable marker genes, reporters, shRNA expression cassettes, mutagenic gene trap cassettes, and therapeutic gene constructs into the genomes of target cells in a regulated and highly efficient manner. Given that transposon components are typically supplied as naked nucleic acids (DNA and RNA) or recombinant protein, their use is simple, safe, and economically competitive. Thus, transposons enable several avenues for genome manipulations in vertebrates, including transgenesis for the generation of transgenic cells in tissue culture comprising the generation of pluripotent stem cells, the production of germline-transgenic animals for basic and applied research, forward genetic screens for functional gene annotation in model species and therapy of genetic disorders in humans. This review describes the molecular mechanisms involved in transposition reactions of the three most widely used transposon systems currently available (Sleeping Beauty, piggyBac, and Tol2), and discusses the various parameters and considerations pertinent to their experimental use, highlighting the state-of-the-art in transposon technology in diverse genetic applications.
Collapse
Affiliation(s)
| | | | | | - Zoltán Ivics
- Correspondence: ; Tel.: +49-6103-77-6000; Fax: +49-6103-77-1280
| |
Collapse
|
8
|
Dalle Nogare DE, Natesh N, Vishwasrao HD, Shroff H, Chitnis AB. Zebrafish Posterior Lateral Line primordium migration requires interactions between a superficial sheath of motile cells and the skin. eLife 2020; 9:58251. [PMID: 33237853 PMCID: PMC7688310 DOI: 10.7554/elife.58251] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 10/27/2020] [Indexed: 12/12/2022] Open
Abstract
The Zebrafish Posterior Lateral Line primordium migrates in a channel between the skin and somites. Its migration depends on the coordinated movement of its mesenchymal-like leading cells and trailing cells, which form epithelial rosettes, or protoneuromasts. We describe a superficial population of flat primordium cells that wrap around deeper epithelialized cells and extend polarized lamellipodia to migrate apposed to the overlying skin. Polarization of lamellipodia extended by both superficial and deeper protoneuromast-forming cells depends on Fgf signaling. Removal of the overlying skin has similar effects on superficial and deep cells: lamellipodia are lost, blebs appear instead, and collective migration fails. When skinned embryos are embedded in Matrigel, basal and superficial lamellipodia are recovered; however, only the directionality of basal protrusions is recovered, and migration is not rescued. These observations support a key role played by superficial primordium cells and the skin in directed migration of the Posterior Lateral Line primordium.
Collapse
Affiliation(s)
- Damian E Dalle Nogare
- Section on Neural Developmental Dynamics, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Naveen Natesh
- Section on Neural Developmental Dynamics, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Harshad D Vishwasrao
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, United States
| | - Hari Shroff
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, United States.,Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, United States
| | - Ajay B Chitnis
- Section on Neural Developmental Dynamics, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| |
Collapse
|
9
|
Cantu Gutierrez A, Cantu Gutierrez M, Rhyner AM, Ruiz OE, Eisenhoffer GT, Wythe JD. FishNET: An automated relational database for zebrafish colony management. PLoS Biol 2019; 17:e3000343. [PMID: 31220074 PMCID: PMC6605666 DOI: 10.1371/journal.pbio.3000343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 07/02/2019] [Accepted: 06/13/2019] [Indexed: 12/15/2022] Open
Abstract
The zebrafish Danio rerio is a powerful model system to study the genetics of development and disease. However, maintenance of zebrafish husbandry records is both time intensive and laborious, and a standardized way to manage and track the large amount of unique lines in a given laboratory or centralized facility has not been embraced by the field. Here, we present FishNET, an intuitive, open-source, relational database for managing data and information related to zebrafish husbandry and maintenance. By creating a "virtual facility," FishNET enables users to remotely inspect the rooms, racks, tanks, and lines within a given facility. Importantly, FishNET scales from one laboratory to an entire facility with several laboratories to multiple facilities, generating a cohesive laboratory and community-based platform. Automated data entry eliminates confusion regarding line nomenclature and streamlines maintenance of individual lines, while flexible query forms allow researchers to retrieve database records based on user-defined criteria. FishNET also links associated embryonic and adult biological samples with data, such as genotyping results or confocal images, to enable robust and efficient colony management and storage of laboratory information. A shared calendar function with email notifications and automated reminders for line turnover, automated tank counts, and census reports promote communication with both end users and administrators. The expected benefits of FishNET are improved vivaria efficiency, increased quality control for experimental numbers, and flexible data reporting and retrieval. FishNET's easy, intuitive record management and open-source, end-user-modifiable architecture provides an efficient solution to real-time zebrafish colony management for users throughout a facility and institution and, in some cases, across entire research hubs.
Collapse
Affiliation(s)
- Abiud Cantu Gutierrez
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Manuel Cantu Gutierrez
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Alexander M. Rhyner
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Oscar E. Ruiz
- Department of Genetics, MD Anderson Cancer Center, Houston, Texas, United States of America
| | - George T. Eisenhoffer
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Genetics, MD Anderson Cancer Center, Houston, Texas, United States of America
| | - Joshua D. Wythe
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas, United States of America
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
| |
Collapse
|
10
|
Namikawa K, Dorigo A, Zagrebelsky M, Russo G, Kirmann T, Fahr W, Dübel S, Korte M, Köster RW. Modeling Neurodegenerative Spinocerebellar Ataxia Type 13 in Zebrafish Using a Purkinje Neuron Specific Tunable Coexpression System. J Neurosci 2019; 39:3948-3969. [PMID: 30862666 PMCID: PMC6520513 DOI: 10.1523/jneurosci.1862-18.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 02/19/2019] [Accepted: 02/25/2019] [Indexed: 12/17/2022] Open
Abstract
Purkinje cells (PCs) are primarily affected in neurodegenerative spinocerebellar ataxias (SCAs). For generating animal models for SCAs, genetic regulatory elements specifically targeting PCs are required, thereby linking pathological molecular effects with impaired function and organismic behavior. Because cerebellar anatomy and function are evolutionary conserved, zebrafish represent an excellent model to study SCAs in vivo We have isolated a 258 bp cross-species PC-specific enhancer element that can be used in a bidirectional manner for bioimaging of transgene-expressing PCs in zebrafish (both sexes) with variable copy numbers for tuning expression strength. Emerging ectopic expression at high copy numbers can be further eliminated by repurposing microRNA-mediated posttranslational mRNA regulation.Subsequently, we generated a transgenic SCA type 13 (SCA13) model, using a zebrafish-variant mimicking a human pathological SCA13R420H mutation, resulting in cell-autonomous progressive PC degeneration linked to cerebellum-driven eye-movement deficits as observed in SCA patients. This underscores that investigating PC-specific cerebellar neuropathologies in zebrafish allows for interconnecting bioimaging of disease mechanisms with behavioral analysis suitable for therapeutic compound testing.SIGNIFICANCE STATEMENT SCA13 patients carrying a KCNC3R420H allele have been shown to display mid-onset progressive cerebellar atrophy, but genetic modeling of SCA13 by expressing this pathogenic mutant in different animal models has not resulted in neuronal degeneration so far; likely because the transgene was expressed in heterologous cell types. We developed a genetic system for tunable PC-specific coexpression of several transgenes to manipulate and simultaneously monitor cerebellar PCs. We modeled a SCA13 zebrafish accessible for bioimaging to investigate disease progression, revealing robust PC degeneration, resulting in impaired eye movement. Our transgenic zebrafish mimicking both neuropathological and behavioral changes manifested in SCA-affected patients will be suitable for investigating causes of cerebellar diseases in vivo from the molecular to the behavioral level.
Collapse
Affiliation(s)
| | | | - Marta Zagrebelsky
- Cellular Neurobiology, Zoological Institute, Technical University Braunschweig, Braunschweig 38106, Germany
| | - Giulio Russo
- Cellular and Molecular Neurobiology
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technical University Braunschweig 38106, Germany, and
| | | | - Wieland Fahr
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technical University Braunschweig 38106, Germany, and
| | - Stefan Dübel
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technical University Braunschweig 38106, Germany, and
| | - Martin Korte
- Cellular Neurobiology, Zoological Institute, Technical University Braunschweig, Braunschweig 38106, Germany
- Research Group Neuroinflammation and Neurodegeneration, Helmholtz Centre for Infection Research, Braunschweig 38106, Germany
| | | |
Collapse
|
11
|
Abstract
The zebrafish (Danio rerio) possesses a vertebrate-type retina that is extraordinarily conserved in evolution. This well-organized and anatomically easily accessible part of the central nervous system has been widely investigated in zebrafish, promoting general understanding of retinal development, morphology, function and associated diseases. Over the recent years, genome and protein engineering as well as imaging techniques have experienced revolutionary advances and innovations, creating new possibilities and methods to study zebrafish development and function. In this review, we focus on some of these emerging technologies and how they may impact retinal research in the future. We place an emphasis on genetic techniques, such as transgenic approaches and the revolutionizing new possibilities in genome editing.
Collapse
Affiliation(s)
- Stephanie Niklaus
- a Institute of Molecular Life Sciences , University of Zurich , Zurich , Switzerland.,b Life Science Zurich Graduate Program - Neuroscience , Zurich , Switzerland
| | - Stephan C F Neuhauss
- a Institute of Molecular Life Sciences , University of Zurich , Zurich , Switzerland
| |
Collapse
|
12
|
Weber T, Namikawa K, Winter B, Müller-Brown K, Kühn R, Wurst W, Köster RW. Caspase-mediated apoptosis induction in zebrafish cerebellar Purkinje neurons. Development 2016; 143:4279-4287. [PMID: 27729409 DOI: 10.1242/dev.122721] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 09/30/2016] [Indexed: 01/11/2023]
Abstract
The zebrafish is a well-established model organism in which to study in vivo mechanisms of cell communication, differentiation and function. Existing cell ablation methods are either invasive or they rely on the cellular expression of prokaryotic enzymes and the use of antibiotic drugs as cell death-inducing compounds. We have recently established a novel inducible genetic cell ablation system based on tamoxifen-inducible Caspase 8 activity, thereby exploiting mechanisms of cell death intrinsic to most cell types. Here, we prove its suitability in vivo by monitoring the ablation of cerebellar Purkinje cells (PCs) in transgenic zebrafish that co-express the inducible caspase and a fluorescent reporter. Incubation of larvae in tamoxifen for 8 h activated endogenous Caspase 3 and cell death, whereas incubation for 16 h led to the near-complete loss of PCs by apoptosis. We observed synchronous cell death autonomous to the PC population and phagocytosing microglia in the cerebellum, reminiscent of developmental apoptosis in the forebrain. Thus, induction of apoptosis through targeted activation of caspase by tamoxifen (ATTACTM) further expands the repertoire of genetic tools for conditional interrogation of cellular functions.
Collapse
Affiliation(s)
- Thomas Weber
- TU Braunschweig, Zoological Institute, Cellular and Molecular Neurobiology, Spielmannstr. 7, Braunschweig 38106, Germany.,Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Ingolstädter Landstr. 1, Neuherberg 85764, Germany
| | - Kazuhiko Namikawa
- TU Braunschweig, Zoological Institute, Cellular and Molecular Neurobiology, Spielmannstr. 7, Braunschweig 38106, Germany
| | - Barbara Winter
- TU Braunschweig, Zoological Institute, Cellular and Molecular Neurobiology, Spielmannstr. 7, Braunschweig 38106, Germany
| | - Karina Müller-Brown
- TU Braunschweig, Zoological Institute, Cellular and Molecular Neurobiology, Spielmannstr. 7, Braunschweig 38106, Germany
| | - Ralf Kühn
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Ingolstädter Landstr. 1, Neuherberg 85764, Germany
| | - Wolfgang Wurst
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Ingolstädter Landstr. 1, Neuherberg 85764, Germany.,Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), Standort München, Feodor-Lynen-Str. 17, München 81377, Germany.,Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Str. 17, München 81377, Germany.,Technische Universität München-Weihenstephan, Lehrstuhl für Entwicklungsgenetik, c/o Helmholtz Zentrum München, Ingolstädter Landstr. 1, Neuherberg 85764, Germany
| | - Reinhard W Köster
- TU Braunschweig, Zoological Institute, Cellular and Molecular Neurobiology, Spielmannstr. 7, Braunschweig 38106, Germany
| |
Collapse
|
13
|
Shin M, Male I, Beane TJ, Villefranc JA, Kok FO, Zhu LJ, Lawson ND. Vegfc acts through ERK to induce sprouting and differentiation of trunk lymphatic progenitors. Development 2016; 143:3785-3795. [PMID: 27621059 DOI: 10.1242/dev.137901] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 08/25/2016] [Indexed: 01/03/2023]
Abstract
Vascular endothelial growth factor C (Vegfc) activates its receptor, Flt4, to induce lymphatic development. However, the signals that act downstream of Flt4 in this context in vivo remain unclear. To understand Flt4 signaling better, we generated zebrafish bearing a deletion in the Flt4 cytoplasmic domain that eliminates tyrosines Y1226 and 1227. Embryos bearing this deletion failed to initiate sprouting or differentiation of trunk lymphatic vessels and did not form a thoracic duct. Deletion of Y1226/7 prevented ERK phosphorylation in lymphatic progenitors, and ERK inhibition blocked trunk lymphatic sprouting and differentiation. Conversely, endothelial autonomous ERK activation rescued lymphatic sprouting and differentiation in flt4 mutants. Interestingly, embryos bearing the Y1226/7 deletion formed a functional facial lymphatic network enabling them to develop normally to adulthood. By contrast, flt4 null larvae displayed hypoplastic facial lymphatics and severe lymphedema. Thus, facial lymphatic vessels appear to be the first functional lymphatic network in the zebrafish, whereas the thoracic duct is initially dispensable for lymphatic function. Moreover, distinct signaling pathways downstream of Flt4 govern lymphatic morphogenesis and differentiation in different anatomical locations.
Collapse
Affiliation(s)
- Masahiro Shin
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Ira Male
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Timothy J Beane
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Jacques A Villefranc
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Fatma O Kok
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Lihua J Zhu
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Nathan D Lawson
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| |
Collapse
|
14
|
Marquart GD, Tabor KM, Brown M, Strykowski JL, Varshney GK, LaFave MC, Mueller T, Burgess SM, Higashijima SI, Burgess HA. A 3D Searchable Database of Transgenic Zebrafish Gal4 and Cre Lines for Functional Neuroanatomy Studies. Front Neural Circuits 2015; 9:78. [PMID: 26635538 PMCID: PMC4656851 DOI: 10.3389/fncir.2015.00078] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 11/06/2015] [Indexed: 01/08/2023] Open
Abstract
Transgenic methods enable the selective manipulation of neurons for functional mapping of neuronal circuits. Using confocal microscopy, we have imaged the cellular-level expression of 109 transgenic lines in live 6 day post fertilization larvae, including 80 Gal4 enhancer trap lines, 9 Cre enhancer trap lines and 20 transgenic lines that express fluorescent proteins in defined gene-specific patterns. Image stacks were acquired at single micron resolution, together with a broadly expressed neural marker, which we used to align enhancer trap reporter patterns into a common 3-dimensional reference space. To facilitate use of this resource, we have written software that enables searching for transgenic lines that label cells within a selectable 3-dimensional region of interest (ROI) or neuroanatomical area. This software also enables the intersectional expression of transgenes to be predicted, a feature which we validated by detecting cells with co-expression of Cre and Gal4. Many of the imaged enhancer trap lines show intrinsic brain-specific expression. However, to increase the utility of lines that also drive expression in non-neuronal tissue we have designed a novel UAS reporter, that suppresses expression in heart, muscle, and skin through the incorporation of microRNA binding sites in a synthetic 3′ untranslated region. Finally, we mapped the site of transgene integration, thus providing molecular identification of the expression pattern for most lines. Cumulatively, this library of enhancer trap lines provides genetic access to 70% of the larval brain and is therefore a powerful and broadly accessible tool for the dissection of neural circuits in larval zebrafish.
Collapse
Affiliation(s)
- Gregory D Marquart
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA ; Neuroscience and Cognitive Science Program, University of Maryland College Park, MD, USA
| | - Kathryn M Tabor
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA
| | - Mary Brown
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA
| | - Jennifer L Strykowski
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA
| | - Gaurav K Varshney
- Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health Bethesda, MD, USA
| | - Matthew C LaFave
- Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health Bethesda, MD, USA
| | - Thomas Mueller
- Division of Biology, Kansas State University Manhattan, KS, USA
| | - Shawn M Burgess
- Translational and Functional Genomics Branch, National Human Genome Research Institute, National Institutes of Health Bethesda, MD, USA
| | - Shin-Ichi Higashijima
- National Institutes of Natural Sciences, Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences Aichi, Japan
| | - Harold A Burgess
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA ; Neuroscience and Cognitive Science Program, University of Maryland College Park, MD, USA
| |
Collapse
|
15
|
Bergeron SA, Carrier N, Li GH, Ahn S, Burgess HA. Gsx1 expression defines neurons required for prepulse inhibition. Mol Psychiatry 2015; 20:974-85. [PMID: 25224259 PMCID: PMC4362800 DOI: 10.1038/mp.2014.106] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 07/09/2014] [Accepted: 08/04/2014] [Indexed: 02/07/2023]
Abstract
In schizophrenia, cognitive overload is thought to reflect an inability to suppress non-salient information, a process which is studied using prepulse inhibition (PPI) of the startle response. PPI is reduced in schizophrenia and routinely tested in animal models and preclinical trials of antipsychotic drugs. However, the underlying neuronal circuitry is not well understood. We used a novel genetic screen in larval zebrafish to reveal the molecular identity of neurons that are required for PPI in fish and mice. Ablation or optogenetic silencing of neurons with developmental expression of the transcription factor genomic screen homeobox 1 (gsx1) produced profound defects in PPI in zebrafish, and PPI was similarly impaired in Gsx1 knockout mice. Gsx1-expressing neurons reside in the dorsal brainstem and form synapses closely apposed to neurons that initiate the startle response. Surprisingly, brainstem Gsx1 neurons are primarily glutamatergic despite their role in a functionally inhibitory pathway. As Gsx1 has an important role in regulating interneuron development in the forebrain, these findings reveal a molecular link between control of interneuron specification and circuits that gate sensory information across brain regions.
Collapse
Affiliation(s)
- Sadie A. Bergeron
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Nicole Carrier
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Grace H. Li
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Sohyun Ahn
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Harold A. Burgess
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA,6 Center Drive, Building 6B, Rm 3B308, Bethesda, MD 20892, , tel: 301-402-6018; fax: 301-496-0243
| |
Collapse
|
16
|
Horstick EJ, Jordan DC, Bergeron SA, Tabor KM, Serpe M, Feldman B, Burgess HA. Increased functional protein expression using nucleotide sequence features enriched in highly expressed genes in zebrafish. Nucleic Acids Res 2015; 43:e48. [PMID: 25628360 PMCID: PMC4402511 DOI: 10.1093/nar/gkv035] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/12/2015] [Indexed: 12/18/2022] Open
Abstract
Many genetic manipulations are limited by difficulty in obtaining adequate levels of protein expression. Bioinformatic and experimental studies have identified nucleotide sequence features that may increase expression, however it is difficult to assess the relative influence of these features. Zebrafish embryos are rapidly injected with calibrated doses of mRNA, enabling the effects of multiple sequence changes to be compared in vivo. Using RNAseq and microarray data, we identified a set of genes that are highly expressed in zebrafish embryos and systematically analyzed for enrichment of sequence features correlated with levels of protein expression. We then tested enriched features by embryo microinjection and functional tests of multiple protein reporters. Codon selection, releasing factor recognition sequence and specific introns and 3′ untranslated regions each increased protein expression between 1.5- and 3-fold. These results suggested principles for increasing protein yield in zebrafish through biomolecular engineering. We implemented these principles for rational gene design in software for codon selection (CodonZ) and plasmid vectors incorporating the most active non-coding elements. Rational gene design thus significantly boosts expression in zebrafish, and a similar approach will likely elevate expression in other animal models.
Collapse
Affiliation(s)
- Eric J Horstick
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Diana C Jordan
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Sadie A Bergeron
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Kathryn M Tabor
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Mihaela Serpe
- Program in Cellular Regulation and Metabolism, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Benjamin Feldman
- Zebrafish Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Harold A Burgess
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| |
Collapse
|
17
|
Takeuchi M, Matsuda K, Yamaguchi S, Asakawa K, Miyasaka N, Lal P, Yoshihara Y, Koga A, Kawakami K, Shimizu T, Hibi M. Establishment of Gal4 transgenic zebrafish lines for analysis of development of cerebellar neural circuitry. Dev Biol 2014; 397:1-17. [PMID: 25300581 DOI: 10.1016/j.ydbio.2014.09.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 09/03/2014] [Accepted: 09/26/2014] [Indexed: 02/02/2023]
Abstract
The cerebellum is involved in some forms of motor coordination and motor learning. Here we isolated transgenic (Tg) zebrafish lines that express a modified version of Gal4-VP16 (GFF) in the cerebellar neural circuits: granule, Purkinje, or eurydendroid cells, Bergmann glia, or the neurons in the inferior olive nuclei (IO) which send climbing fibers to Purkinje cells, with the transposon Tol2 system. By combining GFF lines with Tg lines carrying a reporter gene located downstream of Gal4 binding sequences (upstream activating sequence: UAS), we investigated the anatomy and developmental processes of the cerebellar neural circuitry. Combining an IO-specific Gal4 line with a UAS reporter line expressing the photoconvertible fluorescent protein Kaede demonstrated the contralateral projections of climbing fibers. Combining a granule cell-specific Gal4 line with a UAS reporter line expressing wheat germ agglutinin (WGA) confirmed direct and/or indirect connections of granule cells with Purkinje cells, eurydendroid cells, and IO neurons in zebrafish. Time-lapse analysis of a granule cell-specific Gal4 line revealed initial random movements and ventral migration of granule cell nuclei. Transgenesis of a reporter gene with another transposon Tol1 system visualized neuronal structure at a single cell resolution. Our findings indicate the usefulness of these zebrafish Gal4 Tg lines for studying the development and function of cerebellar neural circuits.
Collapse
Affiliation(s)
- Miki Takeuchi
- Laboratory of Organogenesis and Organ Function, Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Koji Matsuda
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Shingo Yamaguchi
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Kazuhide Asakawa
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | | | - Pradeep Lal
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | | | - Akihiko Koga
- Primate Research Institute, Kyoto University, Inuyama 464-8506, Japan
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Takashi Shimizu
- Laboratory of Organogenesis and Organ Function, Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi 464-8601, Japan; Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Masahiko Hibi
- Laboratory of Organogenesis and Organ Function, Bioscience and Biotechnology Center, Nagoya University, Nagoya, Aichi 464-8601, Japan; Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan.
| |
Collapse
|
18
|
Abstract
Discoveries in cytogenetics, molecular biology, and genomics have revealed that genome change is an active cell-mediated physiological process. This is distinctly at variance with the pre-DNA assumption that genetic changes arise accidentally and sporadically. The discovery that DNA changes arise as the result of regulated cell biochemistry means that the genome is best modelled as a read-write (RW) data storage system rather than a read-only memory (ROM). The evidence behind this change in thinking and a consideration of some of its implications are the subjects of this article. Specific points include the following: cells protect themselves from accidental genome change with proofreading and DNA damage repair systems; localized point mutations result from the action of specialized trans-lesion mutator DNA polymerases; cells can join broken chromosomes and generate genome rearrangements by non-homologous end-joining (NHEJ) processes in specialized subnuclear repair centres; cells have a broad variety of natural genetic engineering (NGE) functions for transporting, diversifying and reorganizing DNA sequences in ways that generate many classes of genomic novelties; natural genetic engineering functions are regulated and subject to activation by a range of challenging life history events; cells can target the action of natural genetic engineering functions to particular genome locations by a range of well-established molecular interactions, including protein binding with regulatory factors and linkage to transcription; and genome changes in cancer can usefully be considered as consequences of the loss of homeostatic control over natural genetic engineering functions.
Collapse
Affiliation(s)
- James A Shapiro
- Department of Biochemistry and Molecular Biology, University of Chicago, GCISW123B, 979 E. 57th Street, Chicago, IL 60637, USA
| |
Collapse
|
19
|
Watanabe K, Koga H, Nakamura K, Fujita A, Hattori A, Matsuda M, Koga A. Spontaneous germline excision of Tol1, a DNA-based transposable element naturally occurring in the medaka fish genome. Genome 2014; 57:193-9. [PMID: 24905071 DOI: 10.1139/gen-2014-0011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
DNA-based transposable elements are ubiquitous constituents of eukaryotic genomes. Vertebrates are, however, exceptional in that most of their DNA-based elements appear to be inactivated. The Tol1 element of the medaka fish, Oryzias latipes, is one of the few elements for which copies containing an undamaged gene have been found. Spontaneous transposition of this element in somatic cells has previously been demonstrated, but there is only indirect evidence for its germline transposition. Here, we show direct evidence of spontaneous excision in the germline. Tyrosinase is the key enzyme in melanin biosynthesis. In an albino laboratory strain of medaka fish, which is homozygous for a mutant tyrosinase gene in which a Tol1 copy is inserted, we identified de novo reversion mutations related to melanin pigmentation. The gamete-based reversion rate was as high as 0.4%. The revertant fish carried the tyrosinase gene from which the Tol1 copy had been excised. We previously reported the germline transposition of Tol2, another DNA-based element that is thought to be a recent invader of the medaka fish genome. Tol1 is an ancient resident of the genome. Our results indicate that even an old element can contribute to genetic variation in the host genome as a natural mutator.
Collapse
Affiliation(s)
- Kohei Watanabe
- a Matsuyama High School, Higashimatsuyama 355-0018, Japan
| | | | | | | | | | | | | |
Collapse
|
20
|
Grajevskaja V, Balciuniene J, Balciunas D. Chicken β-globin insulators fail to shield the nkx2.5 promoter from integration site effects in zebrafish. Mol Genet Genomics 2013; 288:717-25. [PMID: 24036575 PMCID: PMC4104600 DOI: 10.1007/s00438-013-0778-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 08/23/2013] [Indexed: 10/26/2022]
Abstract
Genetic lineage tracing and conditional mutagenesis are developmental genetics techniques reliant on precise tissue-specific expression of transgenes. In the mouse, high specificity is usually achieved by inserting the transgene into the locus of interest through homologous recombination in embryonic stem cells. In the zebrafish, DNA containing the transgenic construct is randomly integrated into the genome, usually through transposon-mediated transgenesis. Expression of such transgenes is affected by regulatory features surrounding the integration site from general accessibility of chromatin to tissue-specific enhancers. We tested if the 1.2 kb cHS4 insulators derived from the chicken β-globin locus can shield a transgene from chromosomal position effects in the zebrafish genome. As our test promoters, we used two different-length versions of the zebrafish nkx2.5. We found that flanking a transgenic construct by cHS4 insulation sequences leads to overall increase in the expression of nkx2.5:mRFP. However, we also observed a very high degree of variability of mRFP expression, indicating that cHS4 insulators fail to protect nkx2.5:mRFP from falling under the control of enhancers in the vicinity of integration site.
Collapse
Affiliation(s)
- Viktorija Grajevskaja
- Department of Biology, Temple University, Philadelphia, PA 19122, USA
- Department of Zoology, Faculty of Natural Sciences, Vilnius University, Vilnius, Lithuania
| | | | - Darius Balciunas
- Department of Biology, Temple University, Philadelphia, PA 19122, USA
| |
Collapse
|
21
|
Poon KL, Brand T. The zebrafish model system in cardiovascular research: A tiny fish with mighty prospects. Glob Cardiol Sci Pract 2013; 2013:9-28. [PMID: 24688998 PMCID: PMC3963735 DOI: 10.5339/gcsp.2013.4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 01/29/2013] [Indexed: 12/26/2022] Open
Affiliation(s)
- Kar Lai Poon
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Hill End Road, Harefield, Middlesex, UB9 6JH, United Kingdom
| | - Thomas Brand
- Harefield Heart Science Centre, National Heart and Lung Institute, Imperial College London, Hill End Road, Harefield, Middlesex, UB9 6JH, United Kingdom
| |
Collapse
|
22
|
Mosimann C, Puller AC, Lawson KL, Tschopp P, Amsterdam A, Zon LI. Site-directed zebrafish transgenesis into single landing sites with the phiC31 integrase system. Dev Dyn 2013; 242:949-963. [PMID: 23723152 PMCID: PMC3775328 DOI: 10.1002/dvdy.23989] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2013] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Linear DNA-based and Tol2-mediated transgenesis are powerful tools for the generation of transgenic zebrafish. However, the integration of multiple copies or transgenes at random genomic locations complicates comparative transgene analysis and makes long-term transgene stability unpredictable with variable expression. Targeted, site-directed transgene integration into pre-determined genomic loci can circumvent these issues. The phiC31 integrase catalyzes the unidirectional recombination reaction between heterotypic attP and attB sites and is an efficient platform for site-directed transgenesis. RESULTS We report the implementation of the phiC31 integrase-mediated attP/attB recombination for site-directed zebrafish transgenics of attB-containing transgene vectors into single genomic attP landing sites. We generated Tol2-based single-insertion attP transgenic lines and established their performance in phiC31 integrase-catalyzed integration of an attB-containing transgene vector. We found stable germline transmission into the next generation of an attB reporter transgene in 34% of all tested animals. We further characterized two functional attP landing site lines and determined their genomic location. Our experiments also demonstrate tissue-specific transgene applications as well as long-term stability of phiC31-mediated transgenes. CONCLUSIONS Our results establish phiC31 integrase-controlled site-directed transgenesis into single, genomic attP sites as space-, time-, and labor-efficient zebrafish transgenesis technique. The described reagents are available for distribution to the zebrafish community.
Collapse
Affiliation(s)
- Christian Mosimann
- Howard Hughes Medical Institute, Boston, MA 02115, USA
- Stem Cell Program, Children’s Hospital Boston, Boston, MA 02115, USA
- Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ann-Christin Puller
- Howard Hughes Medical Institute, Boston, MA 02115, USA
- Stem Cell Program, Children’s Hospital Boston, Boston, MA 02115, USA
- Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Katy L. Lawson
- Howard Hughes Medical Institute, Boston, MA 02115, USA
- Stem Cell Program, Children’s Hospital Boston, Boston, MA 02115, USA
- Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Patrick Tschopp
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Adam Amsterdam
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02319, USA
| | - Leonard I. Zon
- Howard Hughes Medical Institute, Boston, MA 02115, USA
- Stem Cell Program, Children’s Hospital Boston, Boston, MA 02115, USA
- Division of Hematology/Oncology, Children’s Hospital Boston, Harvard Stem Cell Institute, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
23
|
Abstract
During waking behavior, animals adapt their state of arousal in response to environmental pressures. Sensory processing is regulated in aroused states, and several lines of evidence imply that this is mediated at least partly by the serotonergic system. However, there is little information directly showing that serotonergic function is required for state-dependent modulation of sensory processing. Here we find that zebrafish larvae can maintain a short-term state of arousal during which neurons in the dorsal raphe modulate sensory responsiveness to behaviorally relevant visual cues. After a brief exposure to water flow, larvae show elevated activity and heightened sensitivity to perceived motion. Calcium imaging of neuronal activity after flow revealed increased activity in serotonergic neurons of the dorsal raphe. Genetic ablation of these neurons abolished the increase in visual sensitivity during arousal without affecting baseline visual function or locomotor activity. We traced projections from the dorsal raphe to a major visual area, the optic tectum. Laser ablation of the tectum demonstrated that this structure, like the dorsal raphe, is required for improved visual sensitivity during arousal. These findings reveal that serotonergic neurons of the dorsal raphe have a state-dependent role in matching sensory responsiveness to behavioral context.
Collapse
|
24
|
Bergeron SA, Hannan MC, Codore H, Fero K, Li GH, Moak Z, Yokogawa T, Burgess HA. Brain selective transgene expression in zebrafish using an NRSE derived motif. Front Neural Circuits 2012; 6:110. [PMID: 23293587 PMCID: PMC3531662 DOI: 10.3389/fncir.2012.00110] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/07/2012] [Indexed: 11/13/2022] Open
Abstract
Transgenic technologies enable the manipulation and observation of circuits controlling behavior by permitting expression of genetically encoded reporter genes in neurons. Frequently though, neuronal expression is accompanied by transgene expression in non-neuronal tissues, which may preclude key experimental manipulations, including assessment of the contribution of neurons to behavior by ablation. To better restrict transgene expression to the nervous system in zebrafish larvae, we have used DNA sequences derived from the neuron-restrictive silencing element (NRSE). We find that one such sequence, REx2, when used in conjunction with several basal promoters, robustly suppresses transgene expression in non-neuronal tissues. Both in transient transgenic experiments and in stable enhancer trap lines, suppression is achieved without compromising expression within the nervous system. Furthermore, in REx2 enhancer trap lines non-neuronal expression can be de-repressed by knocking down expression of the NRSE binding protein RE1-silencing transcription factor (Rest). In one line, we show that the resulting pattern of reporter gene expression coincides with that of the adjacent endogenous gene, hapln3. We demonstrate that three common basal promoters are susceptible to the effects of the REx2 element, suggesting that this method may be useful for confining expression from many other promoters to the nervous system. This technique enables neural specific targeting of reporter genes and thus will facilitate the use of transgenic methods to manipulate circuit function in freely behaving larvae.
Collapse
Affiliation(s)
- Sadie A Bergeron
- Program in Genomics of Differentiation, Unit on Behavioral Neurogenetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development Bethesda, MD, USA
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Campbell LJ, Willoughby JJ, Jensen AM. Two types of Tet-On transgenic lines for doxycycline-inducible gene expression in zebrafish rod photoreceptors and a gateway-based tet-on toolkit. PLoS One 2012; 7:e51270. [PMID: 23251476 PMCID: PMC3520995 DOI: 10.1371/journal.pone.0051270] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 10/31/2012] [Indexed: 11/18/2022] Open
Abstract
The ability to control transgene expression within specific tissues is an important tool for studying the molecular and cellular mechanisms of development, physiology, and disease. We developed a Tet-On system for spatial and temporal control of transgene expression in zebrafish rod photoreceptors. We generated two transgenic lines using the Xenopus rhodopsin promoter to drive the reverse tetracycline-controlled transcriptional transactivator (rtTA), one with self-reporting GFP activity and one with an epitope tagged rtTA. The self-reporting line includes a tetracycline response element (TRE)-driven GFP and, in the presence of doxycycline, expresses GFP in larval and adult rods. A time-course of doxycycline treatment demonstrates that maximal induction of GFP expression, as determined by the number of GFP-positive rods, is reached within approximately 24 hours of drug treatment. The epitope-tagged transgenic line eliminates the need for the self-reporting GFP activity by expressing a FLAG-tagged rtTA protein. Both lines demonstrate strong induction of TRE-driven transgenes from plasmids microinjected into one-cell embryos. These results show that spatial and temporal control of transgene expression can be achieved in rod photoreceptors. Additionally, system components are constructed in Gateway compatible vectors for the rapid cloning of doxycycline-inducible transgenes and use in other areas of zebrafish research.
Collapse
Affiliation(s)
- Leah J. Campbell
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - John J. Willoughby
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Abbie M. Jensen
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
- Molecular and Cellular Biology Program, University of Massachusetts, Amherst, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
26
|
Huang P, Xu L, Liang W, Tam CI, Zhang Y, Qi F, Zhu Z, Lin S, Zhang B. Genomic deletion induced by Tol2 transposon excision in zebrafish. Nucleic Acids Res 2012; 41:e36. [PMID: 23143102 PMCID: PMC3553969 DOI: 10.1093/nar/gks1035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Genomic deletions induced by imprecise excision of transposons have been used to disrupt gene functions in Drosophila. To determine the excision properties of Tol2, a popular transposon in zebrafish, we took advantage of two transgenic zebrafish lines Et(gata2a:EGFP)pku684 and Et(gata2a:EGFP)pku760, and mobilized the transposon by injecting transposase mRNA into homozygous transgenic embryos. Footprint analysis showed that the Tol2 transposons were excised in either a precise or an imprecise manner. Furthermore, we identified 1093-bp and 1253-bp genomic deletions in Et(gata2a:EGFP)pku684 founder embryos flanking the 5′ end of the original Tol2 insertion site, and a 1340-bp deletion in the Et(gata2a:EGFP)pku760 founder embryos flanking the 3′ end of the insertion site. The mosaic Et(gata2a:EGFP)pku684 embryos were raised to adulthood and screened for germline transmission of Tol2 excision in their F1 progeny. On average, ∼42% of the F1 embryos displayed loss or altered EGFP patterns, demonstrating that this transposon could be efficiently excised from the zebrafish genome in the germline. Furthermore, from 59 founders, we identified one that transmitted the 1093-bp genomic deletion to its offspring. These results suggest that imprecise Tol2 transposon excision can be used as an alternative strategy to achieve gene targeting in zebrafish.
Collapse
Affiliation(s)
- Peng Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing 100871, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Huang P, Zhu Z, Lin S, Zhang B. Reverse genetic approaches in zebrafish. J Genet Genomics 2012; 39:421-33. [PMID: 23021542 DOI: 10.1016/j.jgg.2012.07.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Revised: 07/03/2012] [Accepted: 07/07/2012] [Indexed: 12/14/2022]
Abstract
Zebrafish (Danio rerio) is a well-established vertebrate animal model. A comprehensive collection of reverse genetics tools has been developed for studying gene function in this useful organism. Morpholino is the most widely used reagent to knock down target gene expression post-transcriptionally. For a long time, targeted genome modification has been heavily relied on large-scale traditional forward genetic screens, such as ENU (N-ethyl-N-nitrosourea) mutagenesis derived TILLING (Targeting Induced Local Lesions IN Genomes) strategy and pseudo-typed retrovirus mediated insertional mutagenesis. Recently, engineered endonucleases, including ZFNs (zinc finger nucleases) and TALENs (transcription activator-like effector nucleases), provide new and efficient strategies to directly generate site-specific indel mutations by inducing double strand breaks in target genes. Here we summarize the major reverse genetic approaches for loss-of-function studies used and emerging in zebrafish, including strategies based on genome-wide mutagenesis and methods for site-specific gene targeting. Future directions and expectations will also be discussed.
Collapse
Affiliation(s)
- Peng Huang
- Key Laboratory of Cell Proliferation and Differentiation of Ministry of Education, College of Life Sciences, Peking University, Beijing, China
| | | | | | | |
Collapse
|
28
|
Garrels W, Ivics Z, Kues WA. Precision genetic engineering in large mammals. Trends Biotechnol 2012; 30:386-93. [DOI: 10.1016/j.tibtech.2012.03.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 03/19/2012] [Accepted: 03/22/2012] [Indexed: 12/19/2022]
|
29
|
Yergeau DA, Kelley CM, Zhu H, Kuliyev E, Mead PE. Forward genetic screens in Xenopus using transposon-mediated insertional mutagenesis. Methods Mol Biol 2012; 917:111-127. [PMID: 22956084 DOI: 10.1007/978-1-61779-992-1_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The class II DNA "cut-and-paste" transposons have been used to efficiently modify the Xenopus genome for transgenesis applications. Once integrated, the transposon is an effective substrate for excision and re-integration (remobilization) elsewhere in the genome by simply supplying the transposase enzyme in trans. We have used two methods to remobilize transposons resident in the frog genome: micro-injection of transposase mRNA at the one-cell stage and expression of the enzyme in the germline from a transgene. Double-transgenic frogs (hoppers) that harbor transgenes for both the substrate transposon and the transposase enzyme are outcrossed to wild-type animals and the progeny are scored for changes in reporter gene expression. Although both methods work effectively to remobilize transposons, the breeding-mediated strategy eliminates the time-consuming micro-injection step; novel integration events are produced by simply outcrossing the hopper frogs. As each outcross of Xenopus tropicalis typically produces 2,000, or more, progeny, this method can be used to perform large-scale insertional mutagenesis screens in this highly tractable developmental model system.
Collapse
Affiliation(s)
- Donald A Yergeau
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | | | | | | |
Collapse
|
30
|
Kelley CM, Yergeau DA, Zhu H, Kuliyev E, Mead PE. Xenopus transgenics: methods using transposons. Methods Mol Biol 2012; 917:231-43. [PMID: 22956092 DOI: 10.1007/978-1-61779-992-1_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
The generation of transgenic animals is an essential tool for many genetic strategies. DNA "cut-and-paste" transposon systems can be used to efficiently modify the Xenopus genome. The DNA transposon substrate, harbored on a circularized plasmid, is co-injected into fertilized Xenopus embryos at the one-cell stage together with mRNA encoding the cognate transposase enzyme. The cellular machinery rapidly translates the exogenous mRNA to produce active transposase enzyme that catalyzes excision of the transposon substrate from the plasmid and stable integration into the genomic DNA.
Collapse
Affiliation(s)
- Clair M Kelley
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | | | | | | |
Collapse
|
31
|
Transposon-Mediated Transgenesis in the Short-Lived African Killifish Nothobranchius furzeri, a Vertebrate Model for Aging. G3-GENES GENOMES GENETICS 2011; 1:531-8. [PMID: 22384364 PMCID: PMC3276177 DOI: 10.1534/g3.111.001271] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Accepted: 10/07/2011] [Indexed: 01/12/2023]
Abstract
The African killifish Nothobranchius furzeri is the shortest-lived vertebrate that can be bred in captivity. N. furzeri comprises several wild-derived strains with striking differences in longevity ranging from 3 to 9 months, which makes it a powerful vertebrate model for aging research. The short life cycle of N. furzeri should also facilitate studies on adult traits that are specific to vertebrates. Although progress has been made to generate a genetic linkage map and to start sequencing the genome of N. furzeri, tools to genetically manipulate this species of fish have not yet been developed. Here, we report the first establishment of transgenesis in N. furzeri. We use the Tol2 transposase system to generate transgenic N. furzeri that express green fluorescent protein driven by the Xenopus cytoskeletal actin promoter or the zebrafish heat-shock protein 70 promoter. We successfully generate stable transgenic lines of N. furzeri with germline transmission of integrated transgene. The development of transgenesis in N. furzeri provides a powerful tool to investigate the mechanisms underlying aging and longevity in a short-lived vertebrate model. Transgenesis in this fish will also facilitate the study of other phenotypes, including adult tissue regeneration and cognitive behavior.
Collapse
|
32
|
Garrels W, Holler S, Taylor U, Herrmann D, Struckmann C, Klein S, Barg-Kues B, Nowak-Imialek M, Ehling C, Rath D, Ivics Z, Niemann H, Kues WA. Genotype-independent transmission of transgenic fluorophore protein by boar spermatozoa. PLoS One 2011; 6:e27563. [PMID: 22110672 PMCID: PMC3217978 DOI: 10.1371/journal.pone.0027563] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 10/19/2011] [Indexed: 12/24/2022] Open
Abstract
Recently, we generated transposon-transgenic boars (Sus scrofa), which carry three monomeric copies of a fluorophore marker gene. Amazingly, a ubiquitous fluorophore expression in somatic, as well as in germ cells was found. Here, we characterized the prominent fluorophore load in mature spermatozoa of these animals. Sperm samples were analyzed for general fertility parameters, sorted according to X and Y chromosome-bearing sperm fractions, assessed for potential detrimental effects of the reporter, and used for inseminations into estrous sows. Independent of their genotype, all spermatozoa were uniformly fluorescent with a subcellular compartmentalization of the fluorophore protein in postacrosomal sheath, mid piece and tail. Transmission of the fluorophore protein to fertilized oocytes was shown by confocal microscopic analysis of zygotes. The monomeric copies of the transgene segregated during meiosis, rendering a certain fraction of the spermatozoa non-transgenic (about 10% based on analysis of 74 F1 offspring). The genotype-independent transmission of the fluorophore protein by spermatozoa to oocytes represents a non-genetic contribution to the mammalian embryo.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Detlef Rath
- Friedrich-Loeffler-Institut, Mariensee, Germany
| | - Zoltán Ivics
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | | | | |
Collapse
|
33
|
Abstract
The medaka fish, Oryzias latipes, is an emerging vertebrate model and now has a high quality draft genome and a number of unique mutants. The long history of medaka research in Japan has provided medaka with unique features, which are complementary to other vertebrate models. A large collection of spontaneous mutants collected over a century, the presence of highly polymorphic inbred lines established over decades, and the recently completed genome sequence all give the medaka a big boost. This review focuses on the state of the art in medaka genetics and genomics, such as the first isolation of active transposons in vertebrates, the influence of chromatin structure on sequence variation, fine quantitative trait locus (QTL) analysis, and versatile mutants as human disease models.
Collapse
Affiliation(s)
- Hiroyuki Takeda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan.
| | | |
Collapse
|
34
|
Clark KJ, Urban MD, Skuster KJ, Ekker SC. Transgenic zebrafish using transposable elements. Methods Cell Biol 2011; 104:137-49. [PMID: 21924161 DOI: 10.1016/b978-0-12-374814-0.00008-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
DNA transposons are effective chromosomal engineering vehicles for making transgenic zebrafish. We describe both autonomous and non-autonomous transposable elements, and we compare and contrast popular transposon systems. The Tol2 system is a robust gene transfer tool and has been selected as the primary transposon platform, facilitating the development of an array of reagents readily shared within the zebrafish community. We present common transposon and transposase vectors within the field based on the Tol2 system. We describe methods with a high success rate of generating transgenic zebrafish using Tol2 vectors, including key quality control steps during the transgenesis process. Together, these data should enable the ready generation of transgenic zebrafish for scientific inquiry.
Collapse
Affiliation(s)
- Karl J Clark
- Mayo Clinic, Department of Biochemistry and Molecular Biology, Mayo Addiction Research Center, Rochester, Minnesota, USA
| | | | | | | |
Collapse
|
35
|
Ivics Z, Izsvák Z. The expanding universe of transposon technologies for gene and cell engineering. Mob DNA 2010; 1:25. [PMID: 21138556 PMCID: PMC3016246 DOI: 10.1186/1759-8753-1-25] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 12/07/2010] [Indexed: 12/16/2022] Open
Abstract
Transposable elements can be viewed as natural DNA transfer vehicles that, similar to integrating viruses, are capable of efficient genomic insertion. The mobility of class II transposable elements (DNA transposons) can be controlled by conditionally providing the transposase component of the transposition reaction. Thus, a DNA of interest (be it a fluorescent marker, a small hairpin (sh)RNA expression cassette, a mutagenic gene trap or a therapeutic gene construct) cloned between the inverted repeat sequences of a transposon-based vector can be used for stable genomic insertion in a regulated and highly efficient manner. This methodological paradigm opened up a number of avenues for genome manipulations in vertebrates, including transgenesis for the generation of transgenic cells in tissue culture, the production of germline transgenic animals for basic and applied research, forward genetic screens for functional gene annotation in model species, and therapy of genetic disorders in humans. Sleeping Beauty (SB) was the first transposon shown to be capable of gene transfer in vertebrate cells, and recent results confirm that SB supports a full spectrum of genetic engineering including transgenesis, insertional mutagenesis, and therapeutic somatic gene transfer both ex vivo and in vivo. The first clinical application of the SB system will help to validate both the safety and efficacy of this approach. In this review, we describe the major transposon systems currently available (with special emphasis on SB), discuss the various parameters and considerations pertinent to their experimental use, and highlight the state of the art in transposon technology in diverse genetic applications.
Collapse
Affiliation(s)
- Zoltán Ivics
- Max Delbrück Center for Molecular Medicine, Berlin, Germany.
| | | |
Collapse
|
36
|
Koga A, Wakamatsu Y, Sakaizumi M, Hamaguchi S, Shimada A. Distribution of complete and defective copies of the Tol1 transposable element in natural populations of the medaka fish Oryzias latipes. Genes Genet Syst 2010; 84:345-52. [PMID: 20154421 DOI: 10.1266/ggs.84.345] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
DNA-based transposable elements are present in the genomes of various organisms, and generally occur in autonomous and nonautonomous forms, with a good correspondence to complete and defective copies, respectively. In vertebrates, however, the vast majority of DNA-based elements occur only in the nonautonomous form. Until now, the only clear exception known has been the Tol2 element of the medaka fish, which still causes mutations in genes of the host species. Here, we report another exception: the Tol1 element of the same species. This element was thought likely to be a "dead" element like the vast majority of vertebrate elements, but recent identification of an autonomous Tol1 copy in a laboratory medaka strain gave rise to the possibility that the element is still "alive" in medaka natural populations. We examined variation in the structure of Tol1 copies through genomic Southern blot analysis, and revealed that 10 of the 32 fish samples examined contained full-length Tol1 copies in their genomes. The frequency at which these copies occur among Tol1 copies is at most 0.5%, yet some of them still have the ability to produce a functional transposase. The medaka fish thus harbors two active DNA-based elements in its genome, and is in this respect unique among vertebrates.
Collapse
Affiliation(s)
- Akihiko Koga
- Primate Research Institute, Kyoto University, Inuyama City 464-8506, Japan
| | | | | | | | | |
Collapse
|
37
|
Abstract
Transposable elements are DNA segments with the unique ability to move about in the genome. This inherent feature can be exploited to harness these elements as gene vectors for genome manipulation. Transposon-based genetic strategies have been established in vertebrate species over the last decade, and current progress in this field suggests that transposable elements will serve as indispensable tools. In particular, transposons can be applied as vectors for somatic and germline transgenesis, and as insertional mutagens in both loss-of-function and gain-of-function forward mutagenesis screens. In addition, transposons will gain importance in future cell-based clinical applications, including nonviral gene transfer into stem cells and the rapidly developing field of induced pluripotent stem cells. Here we provide an overview of transposon-based methods used in vertebrate model organisms with an emphasis on the mouse system and highlight the most important considerations concerning genetic applications of the transposon systems.
Collapse
|
38
|
Ni J, Clark KJ, Fahrenkrug SC, Ekker SC. Transposon tools hopping in vertebrates. BRIEFINGS IN FUNCTIONAL GENOMICS AND PROTEOMICS 2009; 7:444-53. [PMID: 19109308 DOI: 10.1093/bfgp/eln049] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In the past decade, tools derived from DNA transposons have made major contributions to vertebrate genetic studies from gene delivery to gene discovery. Multiple, highly complementary systems have been developed, and many more are in the pipeline. Judging which DNA transposon element will work the best in diverse uses from zebrafish genetic manipulation to human gene therapy is currently a complex task. We have summarized the major transposon vector systems active in vertebrates, comparing and contrasting known critical biochemical and in vivo properties, for future tool design and new genetic applications.
Collapse
Affiliation(s)
- Jun Ni
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | | | | | | |
Collapse
|