351
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de Campos-Baptista MIM, Holtzman NG, Yelon D, Schier AF. Nodal signaling promotes the speed and directional movement of cardiomyocytes in zebrafish. Dev Dyn 2009; 237:3624-33. [PMID: 18985714 DOI: 10.1002/dvdy.21777] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Members of the Nodal family regulate left-right asymmetry during vertebrate organogenesis, but it is unclear how Nodal signaling controls asymmetric morphogenesis at the cellular level. We used high-resolution time-lapse imaging in zebrafish to compare the movements of cardiomyocytes in the presence or absence of Nodal signaling. Loss of Nodal signaling in late-zygotic mutants for the Nodal co-receptor one-eyed pinhead (LZoep) abolished the leftward movement of cardiomyocytes. Global heart rotation was blocked but cardiomyocyte neighbor relationships were maintained as in wild type. Cardiomyocytes in LZoep mutants moved more slowly and less directionally than their wild-type counterparts. The phenotypes observed in the absence of Nodal signaling strongly resemble abnormalities found in BMP signaling mutants. These results indicate that a Nodal-BMP signaling cascade drives left-right heart morphogenesis by regulating the speed and direction of cardiomyocyte movement.
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Affiliation(s)
- Maria Ines Medeiros de Campos-Baptista
- Department of Molecular and Cellular Biology, Center for Brain Science, Broad Institute, Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts 02138, USA
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352
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Tu CT, Yang TC, Tsai HJ. Nkx2.7 and Nkx2.5 function redundantly and are required for cardiac morphogenesis of zebrafish embryos. PLoS One 2009; 4:e4249. [PMID: 19158954 PMCID: PMC2626283 DOI: 10.1371/journal.pone.0004249] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2008] [Accepted: 12/08/2008] [Indexed: 11/18/2022] Open
Abstract
Background Nkx2.7 is the tinman-related gene, as well as orthologs of Nkx2.5 and Nkx-2.3. Nkx2.7 and Nkx2.5 express in zebrafish heart fields of lateral plate mesoderm. The temporal and spatial expression patterns of Nkx2.7 are similar to those of Nkx2.5, but their functions during cardiogenesis remain unclear. Methodology/Principal Findings Here, Nkx2.7 is demonstrated to compensate for Nkx2.5 loss of function and play a predominant role in the lateral development of the heart, including normal cardiac looping and chamber formation. Knocking down Nkx2.5 showed that heart development was normal from 24 to 72 hpf. However, when knocking down either Nkx2.7 or Nkx2.5 together with Nkx2.7, it appeared that the heart failed to undergo looping and showed defective chambers, although embryos developed normally before the early heart tube stage. Decreased ventricular myocardium proliferation and defective myocardial differentiation appeared to result from late-stage up-regulation of bmp4, versican, tbx5 and tbx20, which were all expressed normally in hearts at an early stage. We also found that tbx5 and tbx20 were modulated by Nkx2.7 through the heart maturation stage because an inducible overexpression of Nkx2.7 in the heart caused down-regulation of tbx5 and tbx20. Although heart defects were induced by overexpression of an injection of 150-pg Nkx2.5 or 5-pg Nkx2.7 mRNA, either Nkx2.5 or Nkx2.7 mRNA rescued the defects induced by Nkx2.7-morpholino(MO) and Nkx2.5-MO with Nkx2.7-MO. Conclusions and Significance Therefore, we conclude that redundant activities of Nkx2.5 and Nkx2.7 are required for cardiac morphogenesis, but that Nkx2.7 plays a more critical function, specifically indicated by the gain-of-function and loss-of- function experiments where Nkx2.7 is observed to regulate the expressions of tbx5 and tbx20 through the maturation stage.
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Affiliation(s)
- Chi-Tang Tu
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Tzu-Ching Yang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
| | - Huai-Jen Tsai
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
- * E-mail:
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353
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Schwerte T. Cardio-respiratory control during early development in the model animal zebrafish. Acta Histochem 2009; 111:230-43. [PMID: 19121852 DOI: 10.1016/j.acthis.2008.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Independent of species, the cardiovascular system is the first functioning component of developing vertebrate embryos. One of the main hypotheses is the assumption that larval and juvenile stages of fish and amphibians are not just smaller versions of an adult phenotype. In this review, the cardiovascular and respiratory responses to environmental, genetic and epigenetic perturbations are discussed in detail to understand the relationships between cardiac and respiratory performance, haematopoiesis for embryonic or larval stages with special focus on the popular model animal, the zebrafish. Zebrafish are tiny animals which have many advantages as a model organism in analysis of the cardio-respiratory system. It obtains sufficient amounts of oxygen via bulk diffusion, in contrast to convection-dependent mammals. It is possible to study genetic mutants even with extreme defective phenotypes of the cardio-respiratory system in order to understand its developmental and physiological mechanisms. It has become apparent that the cardio-respiratory system and its control starts functioning very early during development, long before oxygen uptake becomes diffusion limited in zebrafish. Finally, recent improvements in imaging techniques for the use of fish models relevant for developmental physiology and biomedical research are discussed.
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354
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The forkhead protein Foxj1 specifies node-like cilia in Xenopus and zebrafish embryos. Nat Genet 2008; 40:1454-60. [PMID: 19011629 PMCID: PMC4648715 DOI: 10.1038/ng.267] [Citation(s) in RCA: 240] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 09/03/2008] [Indexed: 11/08/2022]
Abstract
It has been proposed that ciliated cells that produce a leftward fluid flow mediate left-right patterning in many vertebrate embryos. The cilia on these cells combine features of primary sensory and motile cilia, but how this cilia subtype is specified is unknown. We address this issue by analyzing the Xenopus and zebrafish homologs of Foxj1, a forkhead transcription factor necessary for ciliogenesis in multiciliated cells of the mouse. We show that the cilia that underlie left-right patterning on the Xenopus gastrocoel roof plate (GRP) and zebrafish Kupffer's vesicle are severely shortened or fail to form in Foxj1 morphants. We also show that misexpressing Foxj1 is sufficient to induce ectopic GRP-like cilia formation in frog embryos. Microarray analysis indicates that Xenopus Foxj1 induces the formation of cilia by upregulating the expression of motile cilia genes. These results indicate that Foxj1 is a critical determinant in the specification of cilia used in left-right patterning.
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355
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Lange M, Kaynak B, Forster UB, Tönjes M, Fischer JJ, Grimm C, Schlesinger J, Just S, Dunkel I, Krueger T, Mebus S, Lehrach H, Lurz R, Gobom J, Rottbauer W, Abdelilah-Seyfried S, Sperling S. Regulation of muscle development by DPF3, a novel histone acetylation and methylation reader of the BAF chromatin remodeling complex. Genes Dev 2008; 22:2370-84. [PMID: 18765789 DOI: 10.1101/gad.471408] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chromatin remodeling and histone modifications facilitate access of transcription factors to DNA by promoting the unwinding and destabilization of histone-DNA interactions. We present DPF3, a new epigenetic key factor for heart and muscle development characterized by a double PHD finger. DPF3 is associated with the BAF chromatin remodeling complex and binds methylated and acetylated lysine residues of histone 3 and 4. Thus, DPF3 may represent the first plant homeodomains that bind acetylated lysines, a feature previously only shown for the bromodomain. During development Dpf3 is expressed in the heart and somites of mouse, chicken, and zebrafish. Morpholino knockdown of dpf3 in zebrafish leads to incomplete cardiac looping and severely reduced ventricular contractility, with disassembled muscular fibers caused by transcriptional deregulation of structural and regulatory proteins. Promoter analysis identified Dpf3 as a novel downstream target of Mef2a. Taken together, DPF3 adds a further layer of complexity to the BAF complex by representing a tissue-specific anchor between histone acetylations as well as methylations and chromatin remodeling. Furthermore, this shows that plant homeodomain proteins play a yet unexplored role in recruiting chromatin remodeling complexes to acetylated histones.
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Affiliation(s)
- Martin Lange
- Group Cardiovascular Genetics, Department Vertebrate Genomics, Max Planck Institute for Molecular Genetics, Berlin 14195, Germany
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356
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Thomas NA, Koudijs M, van Eeden FJM, Joyner AL, Yelon D. Hedgehog signaling plays a cell-autonomous role in maximizing cardiac developmental potential. Development 2008; 135:3789-99. [PMID: 18842815 DOI: 10.1242/dev.024083] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Elucidation of the complete roster of signals required for myocardial specification is crucial to the future of cardiac regenerative medicine. Prior studies have implicated the Hedgehog (Hh) signaling pathway in the regulation of multiple aspects of heart development. However, our understanding of the contribution of Hh signaling to the initial specification of myocardial progenitor cells remains incomplete. Here, we show that Hh signaling promotes cardiomyocyte formation in zebrafish. Reduced Hh signaling creates a cardiomyocyte deficit, and increased Hh signaling creates a surplus. Through fate-mapping, we find that Hh signaling is required at early stages to ensure specification of the proper number of myocardial progenitors. Genetic inducible fate mapping in mouse indicates that myocardial progenitors respond directly to Hh signals, and transplantation experiments in zebrafish demonstrate that Hh signaling acts cell autonomously to promote the contribution of cells to the myocardium. Thus, Hh signaling plays an essential early role in defining the optimal number of cardiomyocytes, making it an attractive target for manipulation of multipotent progenitor cells.
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Affiliation(s)
- Natalie A Thomas
- Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA
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357
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Nitroreductase-mediated cell/tissue ablation in zebrafish: a spatially and temporally controlled ablation method with applications in developmental and regeneration studies. Nat Protoc 2008; 3:948-54. [PMID: 18536643 DOI: 10.1038/nprot.2008.58] [Citation(s) in RCA: 281] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ablation studies are used to elucidate cell lineage relationships, developmental roles for specific cells during embryogenesis and mechanisms of tissue regeneration. Previous chemical and genetic approaches to directed cell ablation have been hampered by poor specificity, limited efficacy, irreversibility, hypersensitivity to promoter leakiness, restriction to proliferating cells, slow inducibility or complex genetics. Here, we provide a step-by-step protocol for a hybrid chemical-genetic cell ablation method in zebrafish that, by combining spatial and temporal control, is cell-type specific, inducible, reversible, rapid and scaleable. Bacterial Nitroreductase (NTR) is used to catalyze the reduction of the innocuous prodrug metrodinazole (Mtz), thereby producing a cytotoxic product that induces cell death. Based on this principle, NTR is expressed in transgenic zebrafish using a tissue-specific promoter. Subsequent exposure to Mtz by adding it to the media induces cell death exclusively within NTR(+) cells. This approach can be applied to regeneration studies, as removing Mtz by washing permits tissue recovery. Using this protocol, cell ablation can be achieved in 12-72 h, depending on the transgenic line used, and recovery initiates within the following 24 h.
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358
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Leung T, Humbert JE, Stauffer AM, Giger KE, Chen H, Tsai HJ, Wang C, Mirshahi T, Robishaw JD. The orphan G protein-coupled receptor 161 is required for left-right patterning. Dev Biol 2008; 323:31-40. [PMID: 18755178 DOI: 10.1016/j.ydbio.2008.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 07/28/2008] [Accepted: 08/01/2008] [Indexed: 11/18/2022]
Abstract
Gpr161 (also known as RE2) is an orphan G protein-coupled receptor (GPCR) that is expressed during embryonic development in zebrafish. Determining its biological function has proven difficult due to lack of knowledge regarding its natural or synthetic ligands. Here, we show that targeted knockdown of gpr161 disrupts asymmetric gene expression in the lateral plate mesoderm, resulting in aberrant looping of the heart tube. This is associated with elevated Ca(2+) levels in cells lining the Kupffer's vesicle and normalization of Ca(2+) levels, by over-expression of ncx1 or pmca-RNA, is able to partially rescue the cardiac looping defect in gpr161 knockdown embryos. Taken together, these data support a model in which gpr161 plays an essential role in left-right (L-R) patterning by modulating Ca(2+) levels in the cells surrounding the Kupffer's vesicle.
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MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Genetically Modified
- Body Patterning/genetics
- Body Patterning/physiology
- Calcium/metabolism
- Calcium Signaling
- Embryo, Nonmammalian/metabolism
- Embryo, Nonmammalian/physiology
- Gene Expression Regulation, Developmental
- In Situ Hybridization
- Models, Biological
- Molecular Sequence Data
- Oligonucleotides, Antisense/pharmacology
- Protein Structure, Tertiary
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Sequence Homology, Amino Acid
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism
- Zebrafish Proteins/antagonists & inhibitors
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
- Zebrafish Proteins/physiology
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Affiliation(s)
- Tinchung Leung
- Weis Center for Research, Geisinger Clinic, Danville, PA 17822, USA.
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359
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Grimes AC, Erwin KN, Stadt HA, Hunter GL, Gefroh HA, Tsai HJ, Kirby ML. PCB126 exposure disrupts zebrafish ventricular and branchial but not early neural crest development. Toxicol Sci 2008; 106:193-205. [PMID: 18660518 DOI: 10.1093/toxsci/kfn154] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
We have used zebrafish and 3,3',4,4',5-pentachlorobiphenyl (PCB126) to investigate the developmental toxicity of polychlorinated biphenyls (PCBs) that exert their effects through the aryl hydrocarbon receptor (AHR). We found that cardiac and neural crest (NC)-derived jaw and branchial cartilages are specifically targeted early in development. The suite of malformations, which ultimately leads to circulatory failure, includes a severely dysmorphic heart with a reduced bulbus arteriosus and abnormal atrioventricular and outflow valve formation. Early NC migration and patterning of the jaw and branchial cartilages was normal. However, the jaw and branchial cartilages failed to grow to normal size. In the heart, the ventricular myocardium showed a reduction in cell number and size. The heart and jaw/branchial phenotype could be rescued by pifithrin-alpha, a blocker of p53. However, the function of pifithrin-alpha in this model may act as a competitive inhibitor of PCB at the AHR and is likely independent of p53. Morpholinos against p53 did not rescue the phenotype, nor were zebrafish with a mutant p53-null allele resistant to PCB126 toxicity. Morpholino knockdown of cardiac troponin T, which blocks the onset of cardiac function, prevented the PCB126-induced cardiac dysmorphogenesis but not the jaw/branchial phenotype. The cardiovascular characteristics appear to be similar to hypoplastic left heart syndrome (HLHS) and introduce the potential of zebrafish as a model to study this environmentally induced cardiovascular malformation. HLHS is a severe congenital cardiovascular malformation that has previously been linked to industrial releases of dioxins and PCBs.
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Affiliation(s)
- Adrian C Grimes
- Department of Molecular and Cellular Biology and Pathobiology, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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360
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Lu JH, Lu JK, Choo SL, Li YC, Yeh HW, Shiue JF, Yeh VC. Cascade effect of cardiac myogenesis gene expression during cardiac looping in tbx5 knockdown zebrafish embryos. J Biomed Sci 2008; 15:779-87. [PMID: 18661250 DOI: 10.1007/s11373-008-9268-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Accepted: 06/23/2008] [Indexed: 10/21/2022] Open
Abstract
Zebrafish tbx5 expresses in the heart, pectoral fins and eyes of zebrafish during embryonic development. In zebrafish, injection of tbx5 morpholino antisense RNA caused changes of heart conformation, defect of heart looping, pericardium effusion, dropsy of ventral position and decreased heart rate. We suggested that cardiac myogenesis genes might be responsible for this phenomenon. Morpholino antisense RNA which against the initiation site of tbx5 gene was designed in order to knockdown the expression of tbx5, and the results were analyzed by whole-mount in situ hybridization and quantitative real-time PCR. Expression of cardiac myogenesis genes amhc, vmhc and cmlc2 were expressed constantly at the early embryonic development and reached its highest rate right before cardiac looping initiated. These cardiac myogenesis genes showed insufficient expressions within different heart defect embryos. Moreover, vmhc showed ectopic expression in addition to heart looping defect in heart defective embryos at 36 hpf. Our data suggests that the heart failure caused by the knockdown of tbx5 gene might result from the down-regulation of cardiac myogenesis genes.
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Affiliation(s)
- Jen Her Lu
- Department of Pediatrics & Pediatric Cardiology, Veterans General Hospital-Taipei, National Yang Ming University, Taipei, Taiwan, ROC.
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361
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Bit-Avragim N, Hellwig N, Rudolph F, Munson C, Stainier DYS, Abdelilah-Seyfried S. Divergent polarization mechanisms during vertebrate epithelial development mediated by the Crumbs complex protein Nagie oko. J Cell Sci 2008; 121:2503-10. [PMID: 18628301 DOI: 10.1242/jcs.033167] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The zebrafish MAGUK protein Nagie oko is a member of the evolutionarily conserved Crumbs protein complex and functions as a scaffolding protein involved in the stabilization of multi-protein assemblies at the tight junction. During zebrafish embryogenesis, mutations in nagie oko cause defects in both epithelial polarity and cardiac morphogenesis. We used deletion constructs of Nagie oko in functional rescue experiments to define domains essential for cell polarity, maintenance of epithelial integrity and cardiac morphogenesis. Inability of Nagie oko to interact with Crumbs proteins upon deletion of the PDZ domain recreates all aspects of the nagie oko mutant phenotype. Consistent with this observation, apical localization of Nagie oko within the myocardium and neural tube is dependent on Oko meduzy/Crumbs2a. Disruption of direct interactions with Patj or Lin-7, two other members of the Crumbs protein complex, via the bipartite L27 domains produces only partial nagie oko mutant phenotypes and does not impair correct junctional localization of the truncated Nagie oko deletion protein within myocardial cells. Similarly, loss of the evolutionarily conserved region 1 domain, which mediates binding to Par6, causes only a subset of the nagie oko mutant epithelial phenotypes. Finally, deletion of the C-terminus, including the entire guanylate kinase and the SH3 domains, renders the truncated Nagie oko protein inactive and recreates all features of the nagie oko mutant phenotype when tested in functional complementation assays. Our observations reveal a previously unknown diversity of alternative multi-protein assembly compositions of the Crumbs-Nagie-oko and Par6-aPKC protein complexes that are highly dependent on the developmental context.
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362
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Chi NC, Shaw RM, De Val S, Kang G, Jan LY, Black BL, Stainier DYR. Foxn4 directly regulates tbx2b expression and atrioventricular canal formation. Genes Dev 2008; 22:734-9. [PMID: 18347092 DOI: 10.1101/gad.1629408] [Citation(s) in RCA: 294] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cardiac chamber formation represents an essential evolutionary milestone that allows for the heart to receive (atrium) and pump (ventricle) blood throughout a closed circulatory system. Here, we reveal a novel transcriptional pathway between foxn4 and tbx genes that facilitates this evolutionary event. We show that the zebrafish gene slipjig, which encodes Foxn4, regulates the formation of the atrioventricular (AV) canal to divide the heart. sli/foxn4 is expressed in the AV canal, and its encoded product binds to a highly conserved tbx2 enhancer domain that contains Foxn4- and T-box-binding sites, both necessary to regulate tbx2b expression in the AV canal.
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Affiliation(s)
- Neil C Chi
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, University of California, San Francisco, San Francisco, California 94158, USA
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363
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Chi NC, Shaw RM, Jungblut B, Huisken J, Ferrer T, Arnaout R, Scott I, Beis D, Xiao T, Baier H, Jan LY, Tristani-Firouzi M, Stainier DYR. Genetic and physiologic dissection of the vertebrate cardiac conduction system. PLoS Biol 2008; 6:e109. [PMID: 18479184 PMCID: PMC2430899 DOI: 10.1371/journal.pbio.0060109] [Citation(s) in RCA: 204] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 03/20/2008] [Indexed: 12/05/2022] Open
Abstract
Vertebrate hearts depend on highly specialized cardiomyocytes that form the cardiac conduction system (CCS) to coordinate chamber contraction and drive blood efficiently and unidirectionally throughout the organism. Defects in this specialized wiring system can lead to syncope and sudden cardiac death. Thus, a greater understanding of cardiac conduction development may help to prevent these devastating clinical outcomes. Utilizing a cardiac-specific fluorescent calcium indicator zebrafish transgenic line, Tg(cmlc2:gCaMP)(s878), that allows for in vivo optical mapping analysis in intact animals, we identified and analyzed four distinct stages of cardiac conduction development that correspond to cellular and anatomical changes of the developing heart. Additionally, we observed that epigenetic factors, such as hemodynamic flow and contraction, regulate the fast conduction network of this specialized electrical system. To identify novel regulators of the CCS, we designed and performed a new, physiology-based, forward genetic screen and identified for the first time, to our knowledge, 17 conduction-specific mutations. Positional cloning of hobgoblin(s634) revealed that tcf2, a homeobox transcription factor gene involved in mature onset diabetes of the young and familial glomerulocystic kidney disease, also regulates conduction between the atrium and the ventricle. The combination of the Tg(cmlc2:gCaMP)(s878) line/in vivo optical mapping technique and characterization of cardiac conduction mutants provides a novel multidisciplinary approach to further understand the molecular determinants of the vertebrate CCS.
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Affiliation(s)
- Neil C Chi
- Department of Biochemistry and Biophysics and Programs in Developmental Biology, Genetics, and Human Genetics, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Robin M Shaw
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Benno Jungblut
- Department of Biochemistry and Biophysics and Programs in Developmental Biology, Genetics, and Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Jan Huisken
- Department of Biochemistry and Biophysics and Programs in Developmental Biology, Genetics, and Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Tania Ferrer
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah, United States of America
| | - Rima Arnaout
- Department of Biochemistry and Biophysics and Programs in Developmental Biology, Genetics, and Human Genetics, University of California San Francisco, San Francisco, California, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ian Scott
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, and Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Dimitris Beis
- Developmental Biology, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Tong Xiao
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
- Programs in Neuroscience, Genetics, Human Genetics, and Developmental Biology, University of California San Francisco, San Francisco, California, United States of America
| | - Herwig Baier
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
- Programs in Neuroscience, Genetics, Human Genetics, and Developmental Biology, University of California San Francisco, San Francisco, California, United States of America
| | - Lily Y Jan
- Department of Biochemistry and Biophysics and Programs in Developmental Biology, Genetics, and Human Genetics, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Martin Tristani-Firouzi
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Didier Y. R Stainier
- Department of Biochemistry and Biophysics and Programs in Developmental Biology, Genetics, and Human Genetics, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
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364
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Smith KA, Chocron S, von der Hardt S, de Pater E, Soufan A, Bussmann J, Schulte-Merker S, Hammerschmidt M, Bakkers J. Rotation and asymmetric development of the zebrafish heart requires directed migration of cardiac progenitor cells. Dev Cell 2008; 14:287-97. [PMID: 18267096 DOI: 10.1016/j.devcel.2007.11.015] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 10/23/2007] [Accepted: 11/16/2007] [Indexed: 12/11/2022]
Abstract
We have used high-resolution 4D imaging of cardiac progenitor cells (CPCs) in zebrafish to investigate the earliest left-right asymmetric movements during cardiac morphogenesis. Differential migratory behavior within the heart field was observed, resulting in a rotation of the heart tube. The leftward displacement and rotation of the tube requires hyaluronan synthase 2 expression within the CPCs. Furthermore, by reducing or ectopically activating BMP signaling or by implantation of BMP beads we could demonstrate that BMP signaling, which is asymmetrically activated in the lateral plate mesoderm and regulated by early left-right signals, is required to direct CPC migration and cardiac rotation. Together, these results support a model in which CPCs migrate toward a BMP source during development of the linear heart tube, providing a mechanism by which the left-right axis drives asymmetric development of the vertebrate heart.
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Affiliation(s)
- Kelly A Smith
- Hubrecht Institute for Developmental Biology and Stem Cell Research, 3584 CT Utrecht, The Netherlands
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365
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Qu X, Jia H, Garrity DM, Tompkins K, Batts L, Appel B, Zhong TP, Baldwin HS. Ndrg4 is required for normal myocyte proliferation during early cardiac development in zebrafish. Dev Biol 2008; 317:486-96. [PMID: 18407257 DOI: 10.1016/j.ydbio.2008.02.044] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 02/01/2008] [Accepted: 02/20/2008] [Indexed: 11/25/2022]
Abstract
NDRG4 is a novel member of the NDRG family (N-myc downstream-regulated gene). The roles of NDRG4 in development have not previously been evaluated. We show that, during zebrafish embryonic development, ndrg4 is expressed exclusively in the embryonic heart, the central nervous system (CNS) and the sensory system. Ndrg4 knockdown in zebrafish embryos causes a marked reduction in proliferative myocytes and results in hypoplastic hearts. This growth defect is associated with cardiac phenotypes in morphogenesis and function, including abnormal heart looping, inefficient circulation and weak contractility. We reveal that ndrg4 is required for restricting the expression of versican and bmp4 to the developing atrioventricular canal. This constellation of ndrg4 cardiac defects phenocopies those seen in mutant hearts of heartstrings (hst), the tbx5 loss-of-function mutants in zebrafish. We further show that ndrg4 expression is significantly decreased in hearts with reduced tbx5 activities. Conversely, increased expression of tbx5 that is due to tbx20 knockdown leads to an increase in ndrg4 expression. Together, our studies reveal an essential role of ndrg4 in regulating proliferation and growth of cardiomyocytes, suggesting that ndrg4 may function downstream of tbx5 during heart development and growth.
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Affiliation(s)
- Xianghu Qu
- Department of Pediatric Cardiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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366
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Rohr S, Otten C, Abdelilah-Seyfried S. Asymmetric involution of the myocardial field drives heart tube formation in zebrafish. Circ Res 2008; 102:e12-9. [PMID: 18202314 DOI: 10.1161/circresaha.107.165241] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Many vertebrate organs are derived from monolayered epithelia that undergo morphogenesis to acquire their shape. Whereas asymmetric left/right gene expression within the zebrafish heart field has been well documented, little is known about the tissue movements and cellular changes underlying early cardiac morphogenesis. Here, we demonstrate that asymmetric involution of the myocardium of the right-posterior heart field generates the ventral floor, whereas the noninvoluting left heart field gives rise to the dorsal roof of the primary heart tube. During heart tube formation, asymmetric left/right gene expression within the myocardium correlates with asymmetric tissue morphogenesis. Disruption of left/right gene expression causes randomized myocardial tissue involution. Time-lapse analysis combined with genetic analyses reveals that motility of the myocardial epithelium is a tissue migration process. Our results demonstrate that asymmetric morphogenetic movements of the 2 bilateral myocardial cell populations generate different dorsoventral regions of the zebrafish heart tube. Failure to generate a heart tube does not affect the acquisition of atrial versus ventricular cardiac cell shapes. Therefore, establishment of basic cardiac cell shapes precedes cardiac function. Together, these results provide the framework for the integration of single cell behaviors during the formation of the vertebrate primary heart tube.
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Affiliation(s)
- Stefan Rohr
- Max Delbrück Center for Molecular Medicine, University of Freiburg, Germany
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367
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Kwan KM, Fujimoto E, Grabher C, Mangum BD, Hardy ME, Campbell DS, Parant JM, Yost HJ, Kanki JP, Chien CB. The Tol2kit: a multisite gateway-based construction kit for Tol2 transposon transgenesis constructs. Dev Dyn 2007; 236:3088-99. [PMID: 17937395 DOI: 10.1002/dvdy.21343] [Citation(s) in RCA: 1310] [Impact Index Per Article: 77.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Transgenesis is an important tool for assessing gene function. In zebrafish, transgenesis has suffered from three problems: the labor of building complex expression constructs using conventional subcloning; low transgenesis efficiency, leading to mosaicism in transient transgenics and infrequent germline incorporation; and difficulty in identifying germline integrations unless using a fluorescent marker transgene. The Tol2kit system uses site-specific recombination-based cloning (multisite Gateway technology) to allow quick, modular assembly of [promoter]-[coding sequence]-[3' tag] constructs in a Tol2 transposon backbone. It includes a destination vector with a cmlc2:EGFP (enhanced green fluorescent protein) transgenesis marker and a variety of widely useful entry clones, including hsp70 and beta-actin promoters; cytoplasmic, nuclear, and membrane-localized fluorescent proteins; and internal ribosome entry sequence-driven EGFP cassettes for bicistronic expression. The Tol2kit greatly facilitates zebrafish transgenesis, simplifies the sharing of clones, and enables large-scale projects testing the functions of libraries of regulatory or coding sequences.
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Affiliation(s)
- Kristen M Kwan
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah, USA
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368
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Auman HJ, Coleman H, Riley HE, Olale F, Tsai HJ, Yelon D. Functional modulation of cardiac form through regionally confined cell shape changes. PLoS Biol 2007; 5:e53. [PMID: 17311471 PMCID: PMC1802756 DOI: 10.1371/journal.pbio.0050053] [Citation(s) in RCA: 214] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Accepted: 12/18/2006] [Indexed: 11/30/2022] Open
Abstract
Developing organs acquire a specific three-dimensional form that ensures their normal function. Cardiac function, for example, depends upon properly shaped chambers that emerge from a primitive heart tube. The cellular mechanisms that control chamber shape are not yet understood. Here, we demonstrate that chamber morphology develops via changes in cell morphology, and we determine key regulatory influences on this process. Focusing on the development of the ventricular chamber in zebrafish, we show that cardiomyocyte cell shape changes underlie the formation of characteristic chamber curvatures. In particular, cardiomyocyte elongation occurs within a confined area that forms the ventricular outer curvature. Because cardiac contractility and blood flow begin before chambers emerge, cardiac function has the potential to influence chamber curvature formation. Employing zebrafish mutants with functional deficiencies, we find that blood flow and contractility independently regulate cell shape changes in the emerging ventricle. Reduction of circulation limits the extent of cardiomyocyte elongation; in contrast, disruption of sarcomere formation releases limitations on cardiomyocyte dimensions. Thus, the acquisition of normal cardiomyocyte morphology requires a balance between extrinsic and intrinsic physical forces. Together, these data establish regionally confined cell shape change as a cellular mechanism for chamber emergence and as a link in the relationship between form and function during organ morphogenesis. As organs develop, they acquire a characteristic shape; the factors governing this complex process, however, are not understood. Shape may be sculpted by cell movement, cell division, or changes in cell size and shape, all of which can be influenced by the local environment. Here we investigate heart formation to understand how organs develop. The heart appears as a simple tube early in development; later, the tube walls bulge outward to form the cardiac chambers. Using transgenic zebrafish in which we can watch individual cardiac cells, we found that cells change size and shape, enlarging and elongating to form the bulges in the heart tube and eventually the chambers. Since the heart is beating as it develops, we asked whether cardiac function influences cell shape. Using zebrafish mutants with functional defects, we found that both blood flow and cardiac contractility influence cardiac cell shape. We propose that a balance of the cell's internal forces (through contractility) with external forces (such as blood flow) is necessary to create the cell shapes that generate chamber curvatures. Disruption of this balance may underlie the aberrations observed in some types of heart disease. Cardiac function depends upon properly shaped heart chambers. Here the authors show that blood flow and contractility independently regulate cell shape changes in the emerging ventricle.
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Affiliation(s)
- Heidi J Auman
- Developmental Genetics Program and Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York, United States of America
| | - Hope Coleman
- Developmental Genetics Program and Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York, United States of America
| | - Heather E Riley
- Developmental Genetics Program and Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York, United States of America
| | - Felix Olale
- Developmental Genetics Program and Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York, United States of America
| | - Huai-Jen Tsai
- Institute of Molecular and Cell Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Deborah Yelon
- Developmental Genetics Program and Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York, United States of America
- * To whom correspondence should be addressed. E-mail:
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369
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Lee HC, Tsai JN, Liao PY, Tsai WY, Lin KY, Chuang CC, Sun CK, Chang WC, Tsai HJ. Glycogen synthase kinase 3 alpha and 3 beta have distinct functions during cardiogenesis of zebrafish embryo. BMC DEVELOPMENTAL BIOLOGY 2007; 7:93. [PMID: 17683539 PMCID: PMC1988812 DOI: 10.1186/1471-213x-7-93] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2007] [Accepted: 08/03/2007] [Indexed: 11/24/2022]
Abstract
Background Glycogen synthase kinase 3 (GSK3) encodes a serine/threonine protein kinase, is known to play roles in many biological processes. Two closely related GSK3 isoforms encoded by distinct genes: GSK3α (51 kDa) and GSK3β (47 kDa). In previously studies, most GSK3 inhibitors are not only inhibiting GSK3, but are also affecting many other kinases. In addition, because of highly similarity in amino acid sequence between GSK3α and GSK3β, making it difficult to identify an inhibitor that can be selective against GSK3α or GSK3β. Thus, it is relatively difficult to address the functions of GSK3 isoforms during embryogenesis. At this study, we attempt to specifically inhibit either GSK3α or GSK3β and uncover the isoform-specific roles that GSK3 plays during cardiogenesis. Results We blocked gsk3α and gsk3β translations by injection of morpholino antisense oligonucleotides (MO). Both gsk3α- and gsk3β-MO-injected embryos displayed similar morphological defects, with a thin, string-like shaped heart and pericardial edema at 72 hours post-fertilization. However, when detailed analysis of the gsk3α- and gsk3β-MO-induced heart defects, we found that the reduced number of cardiomyocytes in gsk3α morphants during the heart-ring stage was due to apoptosis. On the contrary, gsk3β morphants did not exhibit significant apoptosis in the cardiomyocytes, and the heart developed normally during the heart-ring stage. Later, however, the heart positioning was severely disrupted in gsk3β morphants. bmp4 expression in gsk3β morphants was up-regulated and disrupted the asymmetry pattern in the heart. The cardiac valve defects in gsk3β morphants were similar to those observed in axin1 and apcmcr mutants, suggesting that GSK3β might play a role in cardiac valve development through the Wnt/β-catenin pathway. Finally, the phenotypes of gsk3α mutant embryos cannot be rescued by gsk3β mRNA, and vice versa, demonstrating that GSK3α and GSK3β are not functionally redundant. Conclusion We conclude that (1) GSK3α, but not GSK3β, is necessary in cardiomyocyte survival; (2) the GSK3β plays important roles in modulating the left-right asymmetry and affecting heart positioning; and (3) GSK3α and GSK3β play distinct roles during zebrafish cardiogenesis.
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Affiliation(s)
- Huang-Chieh Lee
- Institute of Molecular and Cellular Biology, National Taiwan University, NO. 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan
| | - Jen-Ning Tsai
- School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan
| | - Pei-Yin Liao
- Institute of Molecular and Cellular Biology, National Taiwan University, NO. 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan
| | - Wei-Yuan Tsai
- Institute of Molecular and Cellular Biology, National Taiwan University, NO. 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan
| | - Kai-Yen Lin
- Institute of Molecular and Cellular Biology, National Taiwan University, NO. 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan
| | - Chung-Cheng Chuang
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University and Research Center for Applied Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Chi-Kuang Sun
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering, National Taiwan University and Research Center for Applied Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Wen-Chang Chang
- Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan
- Institute of Biological Chemistry, Academia Sinica, Nankang 115, Taiwan
| | - Huai-Jen Tsai
- Institute of Molecular and Cellular Biology, National Taiwan University, NO. 1, Roosevelt Road, Sec. 4, Taipei 106, Taiwan
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370
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Curado S, Anderson RM, Jungblut B, Mumm J, Schroeter E, Stainier DYR. Conditional targeted cell ablation in zebrafish: a new tool for regeneration studies. Dev Dyn 2007; 236:1025-35. [PMID: 17326133 DOI: 10.1002/dvdy.21100] [Citation(s) in RCA: 381] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Conditional targeted cell ablation in zebrafish would greatly expand the utility of this genetic model system in developmental and regeneration studies, given its extensive regenerative capabilities. Here, we show that, by combining chemical and genetic tools, one can ablate cells in a temporal- and spatial-specific manner in zebrafish larvae. For this purpose, we used the bacterial Nitroreductase (NTR) enzyme to convert the prodrug Metronidazole (Mtz) into a cytotoxic DNA cross-linking agent. To investigate the efficiency of this system, we targeted three different cell lineages in the heart, pancreas, and liver. Expression of the fusion protein Cyan Fluorescent Protein-NTR (CFP-NTR) under control of tissue-specific promoters allowed us to induce the death of cardiomyocytes, pancreatic beta-cells, and hepatocytes at specific times. Moreover, we have observed that Mtz can be efficiently washed away and that, upon Mtz withdrawal, the profoundly affected tissue can quickly recover. These findings show that the NTR/Mtz system is effective for temporally and spatially controlled cell ablation in zebrafish, thereby constituting a most promising genetic tool to analyze tissue interactions as well as the mechanisms underlying regeneration.
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Affiliation(s)
- Silvia Curado
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California 94158-2324, USA
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371
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Holtzman NG, Schoenebeck JJ, Tsai HJ, Yelon D. Endocardium is necessary for cardiomyocyte movement during heart tube assembly. Development 2007; 134:2379-86. [PMID: 17537802 DOI: 10.1242/dev.02857] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Embryonic heart formation requires the union of bilateral populations of cardiomyocytes and their reorganization into a simple tube. Little is known about the morphogenetic mechanisms that coordinate assembly of the heart tube and determine its dimensions. Using time-lapse confocal microscopy to track individual cardiomyocyte movements in the zebrafish embryo, we identify two morphologically and genetically separable phases of cell movement that coordinate heart tube assembly. First, all cardiomyocytes undergo coherent medial movement. Next, peripherally located cardiomyocytes change their direction of movement, angling toward the endocardial precursors and thereby establishing the initial circumference of the nascent heart tube. These two phases of cardiomyocyte behavior are independently regulated. Furthermore, we find that myocardial-endocardial interactions influence the second phase by regulating the induction, direction and duration of cardiomyocyte movement. Thus, the endocardium plays a crucial early role in cardiac morphogenesis, organizing cardiomyocytes into a configuration appropriate for heart tube assembly. Together, our data reveal a dynamic cellular mechanism by which tissue interactions establish organ architecture.
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Affiliation(s)
- Nathalia Glickman Holtzman
- Developmental Genetics Program and Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
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372
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Arnaout R, Ferrer T, Huisken J, Spitzer K, Stainier DYR, Tristani-Firouzi M, Chi NC. Zebrafish model for human long QT syndrome. Proc Natl Acad Sci U S A 2007; 104:11316-21. [PMID: 17592134 PMCID: PMC2040896 DOI: 10.1073/pnas.0702724104] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Indexed: 11/18/2022] Open
Abstract
Long QT syndrome (LQTS) is a disorder of ventricular repolarization that predisposes affected individuals to lethal cardiac arrhythmias. To date, an appropriate animal model of inherited LQTS does not exist. The zebrafish is a powerful vertebrate model used to dissect molecular pathways of cardiovascular development and disease. Because fundamental electrical properties of the zebrafish heart are remarkably similar to those of the human heart, the zebrafish may be an appropriate model for studying human inherited arrhythmias. Here we describe the molecular, cellular, and electrophysiological basis of a zebrafish mutant characterized by ventricular asystole. Genetic mapping and direct sequencing identify the affected gene as kcnh2, which encodes the channel responsible for the rapidly activating delayed rectifier K(+) current (I(Kr)). We show that complete loss of functional I(Kr) in embryonic hearts leads to ventricular cell membrane depolarization, inability to generate action potentials (APs), and disrupted calcium release. A small hyperpolarizing current restores spontaneous APs, implying wild-type function of other ionic currents critical for AP generation. Heterozygous fish manifest overt cellular and electrocardiographic evidence for delayed ventricular repolarization. Our findings provide insight into the pathogenesis of homozygous kcnh2 mutations and expand the use of zebrafish mutants as a model system to study human arrhythmias.
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Affiliation(s)
- Rima Arnaout
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics, and Human Genetics, Cardiovascular Research Institute, University of California, 1550 Fourth Street, San Francisco, CA 94158
- Harvard Medical School, 260 Longwood Avenue, Boston, MA 02115
| | - Tania Ferrer
- Department of Pediatrics and Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 South 2000 East, Salt Lake City, UT 84112; and
| | - Jan Huisken
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics, and Human Genetics, Cardiovascular Research Institute, University of California, 1550 Fourth Street, San Francisco, CA 94158
| | - Kenneth Spitzer
- Department of Pediatrics and Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 South 2000 East, Salt Lake City, UT 84112; and
| | - Didier Y. R. Stainier
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics, and Human Genetics, Cardiovascular Research Institute, University of California, 1550 Fourth Street, San Francisco, CA 94158
| | - Martin Tristani-Firouzi
- Department of Pediatrics and Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 South 2000 East, Salt Lake City, UT 84112; and
| | - Neil C. Chi
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics, and Human Genetics, Cardiovascular Research Institute, University of California, 1550 Fourth Street, San Francisco, CA 94158
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373
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D'Amico L, Scott IC, Jungblut B, Stainier DYR. A mutation in zebrafish hmgcr1b reveals a role for isoprenoids in vertebrate heart-tube formation. Curr Biol 2007; 17:252-9. [PMID: 17276918 DOI: 10.1016/j.cub.2006.12.023] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2006] [Revised: 11/01/2006] [Accepted: 11/22/2006] [Indexed: 10/23/2022]
Abstract
In vertebrates, the morphogenetic assembly of the primitive heart tube requires the medial migration and midline fusion of the bilateral myocardial epithelia. Several mutations that result in abnormal heart-tube formation have been studied; however, an understanding of the underlying molecular and cellular mechanisms of the migration and fusion of these epithelial sheets is far from complete. In a forward genetic screen to identify genes regulating early zebrafish heart development, we identified a mutation in the 3-hydroxy-3-methylglutaryl-Coenzyme A reductase 1b (hmgcr1b) gene that affects myocardial migration to the midline and subsequent heart-tube morphogenesis. The mutant phenotype can be rescued with injections of mevalonate, the direct product of HMGCR activity. Furthermore, treatment of embryos with pharmacological inhibitors of isoprenoid synthesis, which occurs downstream of mevalonate production, resulted in defective heart-tube formation. Interestingly, in hmgcr1b mutant embryos and embryos treated with HMGCR inhibitors, both RasCT20-eGFP and RhoaCT32-eGFP fusion proteins were mislocalized away from the plasma membrane in embryonic myocardial cells. We conclude that protein prenylation, acting downstream of Hmgcr1b and possibly through Ras and, or, Rho signaling, is required for the morphogenesis of the myocardial sheets for formation of the primitive heart tube.
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Affiliation(s)
- Leonard D'Amico
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, 1550 Fourth Street, San Francisco, California 94158, USA
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374
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Cibrián-Uhalte E, Langenbacher A, Shu X, Chen JN, Abdelilah-Seyfried S. Involvement of zebrafish Na+,K+ ATPase in myocardial cell junction maintenance. ACTA ACUST UNITED AC 2007; 176:223-30. [PMID: 17227894 PMCID: PMC2063941 DOI: 10.1083/jcb.200606116] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Na+,K+ ATPase is an essential ion pump involved in regulating ionic concentrations within epithelial cells. The zebrafish heart and mind (had) mutation, which disrupts the α1B1 subunit of Na+,K+ ATPase, causes heart tube elongation defects and other developmental abnormalities that are reminiscent of several epithelial cell polarity mutants, including nagie oko (nok). We demonstrate genetic interactions between had and nok in maintaining Zonula occludens-1 (ZO-1)–positive junction belts within myocardial cells. Functional tests and pharmacological inhibition experiments demonstrate that Na+,K+ ATPase activity is positively regulated via an N-terminal phosphorylation site that is necessary for correct heart morphogenesis to occur, and that maintenance of ZO-1 junction belts requires ion pump activity. These findings suggest that the correct ionic balance of myocardial cells is essential for the maintenance of epithelial integrity during heart morphogenesis.
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375
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Ribeiro I, Kawakami Y, Büscher D, Raya Á, Rodríguez-León J, Morita M, Rodríguez Esteban C, Izpisúa Belmonte JC. Tbx2 and Tbx3 regulate the dynamics of cell proliferation during heart remodeling. PLoS One 2007; 2:e398. [PMID: 17460765 PMCID: PMC1851989 DOI: 10.1371/journal.pone.0000398] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Accepted: 03/23/2007] [Indexed: 01/12/2023] Open
Abstract
Background The heart forms from a linear tube that is subject to complex remodeling during embryonic development. Hallmarks of this remodeling are the looping of the heart tube and the regionalization into chamber and non-chamber myocardium. Cardiomyocytes in the future chamber myocardium acquire different cellular and physiological characteristics through activation of a chamber-specific genetic program, which is in part mediated by T-box genes. Methodology/Principal Finding We characterize two new zebrafish T-box transcription factors, tbx3b and tbx2a, and analyze their role during the development of the atrioventricular canal. Loss- and gain-of-function analyses demonstrate that tbx3b and tbx2a are necessary to repress the chamber-genetic program in the non-chamber myocardium. We also show that tbx3b and tbx2a are required to control cell proliferation in the atrioventricular canal and that misregulation of cell proliferation in the heart tube influences looping. Furthermore, we characterize the heart phenotype of a novel Tbx3 mutation in mice and show that both the control of cell proliferation and the repression of chamber-specific genetic program in the non-chamber myocardium are conserved roles of Tbx3 in this species. Conclusions/Significance Taken together, our results uncover an evolutionarily conserved role of Tbx2/3 transcription factors during remodeling of the heart myocardium and highlight the importance of controlling cell proliferation as a driving force of morphogenesis.
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Affiliation(s)
- Inês Ribeiro
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Yasuhiko Kawakami
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Dirk Büscher
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Ángel Raya
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | | | - Masanobu Morita
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Concepción Rodríguez Esteban
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Juan Carlos Izpisúa Belmonte
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, California, United States of America
- * To whom correspondence should be addressed. E-mail:
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376
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Lu G, Ren S, Korge P, Choi J, Dong Y, Weiss J, Koehler C, Chen JN, Wang Y. A novel mitochondrial matrix serine/threonine protein phosphatase regulates the mitochondria permeability transition pore and is essential for cellular survival and development. Genes Dev 2007; 21:784-96. [PMID: 17374715 PMCID: PMC1838530 DOI: 10.1101/gad.1499107] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mitochondria play a central role in the regulation of programmed cell death signaling. Here, we report the finding of a mitochondrial matrix-targeted protein phosphatase 2C family member (PP2Cm) that regulates mitochondrial membrane permeability transition pore (MPTP) opening and is essential for cell survival, embryonic development, and cardiac function. PP2Cm is highly conserved among vertebrates, with the highest expression levels detected in the heart and brain. Small hairpin RNA (shRNA)-mediated knockdown of PP2Cm resulted in cell death associated with loss of mitochondrial membrane potential in cultured cardiac mycoytes and an induction of hepatocyte apoptosis in vivo. PP2Cm-deficient mitochondria showed elevated susceptibility to calcium-induced MPTP opening, whereas mitochondrial oxidative phosphorylation activities were not affected. Finally, inactivation of PP2Cm in developing zebrafish embryos caused abnormal cardiac and neural development as well as heart failure associated with induced apoptosis. These data suggest that PP2Cm is a novel mitochondrial protein phosphatase that has a critical function in cell death and survival, and may play a role in regulating the MPTP opening.
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Affiliation(s)
- Gang Lu
- Department of Anesthesiology, University of California at Los Angeles, Los Angeles, California 90095, USA
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Shuxun Ren
- Department of Anesthesiology, University of California at Los Angeles, Los Angeles, California 90095, USA
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Paavo Korge
- Department of Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Jayoung Choi
- Department of Molecular, Cellular, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Yuan Dong
- Department of Molecular, Cellular, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - James Weiss
- Department of Physiology, University of California at Los Angeles, Los Angeles, California 90095, USA
- Department of Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Carla Koehler
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Jau-nian Chen
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
- Department of Molecular, Cellular, and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Yibin Wang
- Department of Anesthesiology, University of California at Los Angeles, Los Angeles, California 90095, USA
- Department of Physiology, University of California at Los Angeles, Los Angeles, California 90095, USA
- Department of Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, USA
- Corresponding author.E-MAIL ; FAX (310) 206-5097
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377
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Scott IC, Masri B, D'Amico LA, Jin SW, Jungblut B, Wehman AM, Baier H, Audigier Y, Stainier DYR. The G Protein-Coupled Receptor Agtrl1b Regulates Early Development of Myocardial Progenitors. Dev Cell 2007; 12:403-13. [PMID: 17336906 DOI: 10.1016/j.devcel.2007.01.012] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 12/18/2006] [Accepted: 01/17/2007] [Indexed: 02/06/2023]
Abstract
While many factors that modulate the morphogenesis and patterning of the embryonic heart have been identified, relatively little is known about the molecular events that regulate the differentiation of progenitor cells fated to form the myocardium. Here, we show that zebrafish grinch (grn) mutants form a reduced number of myocardial progenitor cells, which results in a profound deficit in cardiomyocyte numbers in the most severe cases. We show that grn encodes the G protein-coupled receptor (GPCR) Agtrl1b, a known regulator of adult cardiovascular physiology. Ectopic expression of Apelin, an Agtrl1b ligand, results in the complete absence of cardiomyocytes. Data from transplantation and transgenic approaches indicate that Agtrl1 signaling plays a cell-autonomous role in myocardial specification, with activity being required coincident with the onset of gastrulation movements. These results support a model in which agtrl1b regulates the migration of cells fated to form myocardial progenitors.
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Affiliation(s)
- Ian C Scott
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, and Cardiovascular Research Institute, University of California, San Francisco, 1550 4th Street, San Francisco, CA 94158, USA.
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378
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Esengil H, Chang V, Mich JK, Chen JK. Small-molecule regulation of zebrafish gene expression. Nat Chem Biol 2007; 3:154-5. [PMID: 17237798 DOI: 10.1038/nchembio858] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Accepted: 01/02/2007] [Indexed: 11/09/2022]
Abstract
The zebrafish has emerged as a versatile model organism for biomedical research, yet its potential has been limited by a lack of conditional reverse-genetic tools. Here we report a chemically inducible gene expression technology that has orthogonality to vertebrate signaling processes, high induction levels, and rapid kinetics. Coupled with tissue-specific promoters, this system provides multidimensional control of gene expression and will enable new models of human disorders and diseases.
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Affiliation(s)
- Hanife Esengil
- Department of Chemical and Systems Biology, Stanford University School of Medicine, 269 Campus Drive, Center for Clinical Sciences Research, Room 3155, Stanford, California 94305, USA
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379
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Sakaguchi T, Kikuchi Y, Kuroiwa A, Takeda H, Stainier DYR. The yolk syncytial layer regulates myocardial migration by influencing extracellular matrix assembly in zebrafish. Development 2007; 133:4063-72. [PMID: 17008449 DOI: 10.1242/dev.02581] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The roles of extra-embryonic tissues in early vertebrate body patterning have been extensively studied, yet we know little about their function during later developmental events. Here, we analyze the function of the zebrafish extra-embryonic yolk syncytial layer (YSL) specific transcription factor, Mtx1, and find that it plays an essential role in myocardial migration. Downregulating the function of Mtx1 in the YSL leads to cardia bifida, a phenotype in which the myocardial cells fail to migrate to the midline. Mtx1 in the extra-embryonic YSL appears to regulate the embryonic expression of fibronectin, a gene previously implicated in myocardial migration. We further show dosage-sensitive genetic interactions between mtx1 and fibronectin. Based on these data, we propose that the extra-embryonic YSL regulates myocardial migration, at least in part by influencing fibronectin expression and subsequent assembly of the extracellular matrix in embryonic tissues.
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Affiliation(s)
- Takuya Sakaguchi
- Department of Biochemistry and Biophysics and Programs in Developmental Biology, Genetics and Human Genetics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143-2711, USA
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380
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Ho YL, Lin YH, Tsai IJ, Hsieh FJ, Tsai HJ. In Vivo Assessment of Cardiac Morphology and Function in Heart-specific Green Fluorescent Zebrafish. J Formos Med Assoc 2007; 106:181-6. [PMID: 17389161 DOI: 10.1016/s0929-6646(09)60238-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND/PURPOSE The zebrafish (Danio rerio) is a new animal model for cardiac research. Zebrafish possessing a green fluorescent heart facilitates the dynamic observation of cardiac development, morphology, and function in vivo. However, the effect of an excessive expression of green fluorescent protein (GFP) in cardiac muscle on the heart function of zebrafish has not been reported. METHODS We cloned a 1.6 kb polymerase chain reaction (PCR) product containing the upstream sequence (870 bp), exon 1 (39 bp), intron 1 (682 bp), and exon 2 (69 bp) of the zebrafish cardiac myosin light chain 2 gene. A germ line-transmitted zebrafish possessing a green fluorescent heart was generated by injecting this PCR product fused with the GFP gene with ends consisting of inverted terminal repeats of an adeno-associated virus. RESULTS Green fluorescence was intensively and specifically expressed in the myocardial cells located around both the heart chambers. Two lines with different GFP expression were bred (A26 and A277). The luminance of A277 was brighter than that of A26 (1.7-fold). The 4 days postfertilization (dpf) cardiac function and morphology were similar between these two groups. However, the 8 dpf cardiac growth seemed to be retarded in the A277 group. The 8 dpf heart rate, stroke volume, and cardiac output were also significantly lower in the A277 group. CONCLUSION Excess expression of GFP seems to exert some detrimental effects on zebrafish hearts.
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Affiliation(s)
- Yi-Lwun Ho
- Graduate Institute of Clinical Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
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381
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Schoenebeck JJ, Yelon D. Illuminating cardiac development: Advances in imaging add new dimensions to the utility of zebrafish genetics. Semin Cell Dev Biol 2006; 18:27-35. [PMID: 17241801 PMCID: PMC1876688 DOI: 10.1016/j.semcdb.2006.12.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The use of the zebrafish as a model organism for the analysis of cardiac development is no longer proof-of-principle science. Over the last decade, the identification of a variety of zebrafish mutations and the subsequent cloning of mutated genes have revealed many critical regulators of cardiogenesis. More recently, increasingly sophisticated techniques for phenotypic characterization have facilitated analysis of the specific mechanisms by which key genes drive cardiac specification, morphogenesis, and function. Future enrichment of the arsenal of experimental strategies available for zebrafish should continue the yield of high returns from such a small source.
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Affiliation(s)
- Jeffrey J Schoenebeck
- Developmental Genetics Program and Department of Cell Biology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
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382
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Oishi I, Kawakami Y, Raya A, Callol-Massot C, Izpisúa Belmonte JC. Regulation of primary cilia formation and left-right patterning in zebrafish by a noncanonical Wnt signaling mediator, duboraya. Nat Genet 2006; 38:1316-22. [PMID: 17013396 DOI: 10.1038/ng1892] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Accepted: 09/05/2006] [Indexed: 11/09/2022]
Abstract
Primary cilia are microtubule-based organelles that project from the surface of nearly every animal cell. Although important functions of primary cilia in morphogenesis and tissue homeostasis have been identified, the mechanisms that control the formation of primary cilia are not understood. Here we characterize a zebrafish gene, termed duboraya (dub), that is essential for ciliogenesis. Knockdown of dub in zebrafish embryos results in both defects in primary cilia formation in Kupffer's vesicle and randomization of left-right organ asymmetries. We show that, at the molecular level, the function of dub in ciliogenesis is regulated by phosphorylation, which in turn depends on Frizzled-2-mediated noncanonical Wnt signaling. We also provide evidence that, at the cellular level, dub function is essential for actin organization in the cells lining Kupffer's vesicle. Taken together, our findings identify a molecular factor that links noncanonical Wnt signaling with the control of left-right axis specification, and provide an entry point for analyzing the mechanisms that regulate primary cilia formation.
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Affiliation(s)
- Isao Oishi
- Gene Expression Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
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383
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Sato M, Tsai HJ, Yost HJ. Semaphorin3D regulates invasion of cardiac neural crest cells into the primary heart field. Dev Biol 2006; 298:12-21. [PMID: 16860789 DOI: 10.1016/j.ydbio.2006.05.033] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 05/24/2006] [Accepted: 05/25/2006] [Indexed: 11/25/2022]
Abstract
The primary heart field in all vertebrates is thought to be derived exclusively from lateral plate mesoderm (LPM), which gives rise to a cardiac tube shortly after gastrulation. The heart tube then begins looping and additional cells are added from other embryonic regions, including the secondary heart field, cardiac neural crest and the proepicardial organ. Here we show in zebrafish that neural crest cells invade and contribute cardiac myosin light chain2 (cmlc2)-positive cardiomyocytes to the primary heart field. Knockdown of semaphorin3D, which is expressed in the neural crest but apparently not in LPM, reduces the size of the primary heart field and the number of cardiomyocytes in the primary heart field by 20% before formation of the primary heart tube. Sema3D morphants have subsequent complex congenital heart defects, including hypertrophic cardiomyocytes, decreased ventricular size and defects in trabeculation and in atrioventricular (AV) valve development. Neuropilin1A, a semaphorin receptor, is expressed in LPM but apparently not in the neural crest, and nrp1A morphants have cardiac development defects. We propose that a population of sema3D-dependent neural crest cells follow a novel migratory pathway, perhaps toward nrp1A-expressing LPM, and serve as an important early source of cardiomyocytes in the primary heart field.
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Affiliation(s)
- Mariko Sato
- Huntsman Cancer Institute, Center for Children, Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112, USA
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384
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Anzenberger U, Bit-Avragim N, Rohr S, Rudolph F, Dehmel B, Willnow TE, Abdelilah-Seyfried S. Elucidation of megalin/LRP2-dependent endocytic transport processes in the larval zebrafish pronephros. J Cell Sci 2006; 119:2127-37. [PMID: 16638803 DOI: 10.1242/jcs.02954] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Megalin/LRP2 is an endocytic receptor in the proximal tubules of the mammalian kidney that plays a central role in the clearance of metabolites from the glomerular filtrate. To establish a genetic model system for elucidation of molecular components of this retrieval pathway, we characterized orthologous transport processes in the zebrafish. We show that expression of megalin/LRP2 and its co-receptor cubilin is conserved in the larval zebrafish pronephros and demarcates a segment of the pronephric duct that is active in clearance of tracer from the ultrafiltrate. Knock-down of megalin/LRP2 causes lack of Rab4-positive endosomes in the proximal pronephric duct epithelium and abrogates apical endocytosis. Similarly, knock-down of the megalin/LRP2 adaptor Disabled 2 also blocks renal clearance processes. These results demonstrate the conservation of the megalin/LRP2 retrieval pathway between the larval zebrafish pronephros and the mammalian kidney and set the stage for dissection of the renal endocytic machinery in a simple model organism. Using this model system, we provide first genetic evidence that renal tubular endocytosis and formation of endosomes is a ligand-induced process that crucially depends on megalin/LRP2 activity.
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Affiliation(s)
- Uwe Anzenberger
- Max Delbrueck Center (MDC) for Molecular Medicine, Robert-Roessle Str. 10, 13125 Berlin, Germany
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385
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Tsai TH, Lin CY, Tsai HJ, Chen SY, Tai SP, Lin KH, Sun CK. Biomolecular imaging based on far-red fluorescent protein with a high two-photon excitation action cross section. OPTICS LETTERS 2006; 31:930-2. [PMID: 16599215 DOI: 10.1364/ol.31.000930] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Received October 14, 2005; revised January 7, 2006; accepted January 9, 2006; posted January 12, 2006 (Doc. ID 65391) The two-photon excitation action cross section of Hc-Red fluorescent proteins (Hc-RFPs) is measured and found to be of the same order as that of enhanced green fluorescent proteins. With a 618 nm emission wavelength in the far-red region and with an excitation wavelength around 1200 nm, Hc-RPF-based two-photon fluorescence microscopy (2PFM) can offer deep penetration capability inside live samples and is ideal for in vivo gene expression study and biomolecular imaging in live objects. In vivo 2PFM of the developing heart deep inside a transgenic zebrafish embryo tagged by Hc-RFP is also successfully demonstrated.
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Affiliation(s)
- Tsung-Han Tsai
- Graduate Institute of Electro-Optical Engineering, National Taiwan University, Taipei 10617, Taiwan
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386
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Abstract
Zebrafish are vertebrate organisms that are of growing interest for preclinical drug discovery applications. Zebrafish embryos develop most of the major organ systems present in mammals, including the cardiovascular, nervous and digestive systems, in < 1 week. Additional characteristics that make them advantageous for compound screening are their small size, transparency and ability to absorb compounds through the water. Furthermore, gene function analysis with antisense technology is now routine procedure. Thus, it is relatively simple to assess whether compounds or gene knockdowns cause toxic effects in zebrafish. Assays are being developed to exploit the unique characteristics of zebrafish for pharmacological toxicology. This review discusses assays that may be used to assess in vivo toxicity and provides examples of compounds known to be toxic to humans that have been demonstrated to function similarly in zebrafish.
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Affiliation(s)
- Amy L Rubinstein
- Zygogen LLC, 520 Kell Hall, 24 Peachtree Center Avenue, Atlanta, GA 30303, USA.
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387
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Chun CZ, Tsai HJ, Chen TT. Trout Ea4- or human Eb-peptide of pro-IGF-I disrupts heart, red blood cell, and vasculature development in zebrafish embryos. Mol Reprod Dev 2006; 73:1112-21. [PMID: 16807888 DOI: 10.1002/mrd.20473] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
E-peptide of the pro-insulin-like growth factor (pro-IGF)-I is produced by proteolytic cleavage of the pro-hormone in post-translational processing. Introduction of a transgene encoding a secreted form of rtEa4- or hEb-peptide into newly fertilized zebrafish (Danio rerio) eggs by electroporation or microinjection resulted in embryos with abnormal cardiovascular features and reduced red blood cells and vasculature. Two different phenocopies of heart developmental defects were observed: (i) Group I embryos exhibited heart development arrested at the heart muscle stage and (ii) group II embryos exhibited heart development arrested at the heart tube stage. Both groups of embryos also exhibited reduction of red blood cells and vasculature. The mRNA levels of genes essential for heart development (GATA 5 and NKX2.5), hematopoiesis (GATA 1 and GATA 2), and vasculogenesis (VEGF) in normal and defective embryos were determined by quantitative real-time RT-PCR at 36 hr post-fertilization (hpf). Significant reduction of GATA 5, NKX2.5, GATA 1, GATA 2, and VEGF mRNA levels was observed in both groups of defective embryos. These results suggest that overexpression of rtEa4 or hEb transgene in zebrafish embryos disrupts heart development, hematopoiesis, and vasculogenesis by reducing the levels of GATA 5, NKX2.5, GATA 1, GATA 2, and VEGF mRNA.
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Affiliation(s)
- Chang Zoon Chun
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, 06269-3125, USA
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388
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Rohr S, Bit-Avragim N, Abdelilah-Seyfried S. Heart and soul/PRKCi and nagie oko/Mpp5 regulate myocardial coherence and remodeling during cardiac morphogenesis. Development 2005; 133:107-15. [PMID: 16319113 DOI: 10.1242/dev.02182] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Organ morphogenesis requires cellular shape changes and tissue rearrangements that occur in a precisely timed manner. Here, we show that zebrafish heart and soul (Has)/protein kinase C iota (PRKCi) is required tissue-autonomously within the myocardium for normal heart morphogenesis and that this function depends on its catalytic activity. In addition, we demonstrate that nagie oko (Nok) is the functional homolog of mammalian protein associated with Lin-seven 1 (Pals1)/MAGUK p55 subfamily member 5 (Mpp5), and we dissect its earlier and later functions during myocardial morphogenesis. Has/PRKCi and Nok/Mpp5 are required early for the polarized epithelial organization and coherence of myocardial cells during heart cone formation. Zygotic nok/mpp5 mutants have later myocardial defects, including an incomplete heart tube elongation corresponding with a failure of myocardial cells to correctly expand in size. Furthermore, we show that nok/mpp5 acts within myocardial cells during heart tube elongation. Together, these results demonstrate that cardiac morphogenesis depends on the polarized organization and coherence of the myocardium, and that the expansion of myocardial cell size contributes to the transformation of the heart cone into an elongated tube.
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Affiliation(s)
- Stefan Rohr
- Max Delbrück Center (MDC Strasse 10, 13125 Berlin, Germany
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389
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Langenbacher AD, Dong Y, Shu X, Choi J, Nicoll DA, Goldhaber JI, Philipson KD, Chen JN. Mutation in sodium-calcium exchanger 1 (NCX1) causes cardiac fibrillation in zebrafish. Proc Natl Acad Sci U S A 2005; 102:17699-704. [PMID: 16314583 PMCID: PMC1308881 DOI: 10.1073/pnas.0502679102] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cardiac fibrillation, a form of cardiac arrhythmia, is the most common cause of embolic stroke and death associated with heart failure. The molecular mechanisms underlying cardiac fibrillation are largely unknown. Here we report a zebrafish model for cardiac fibrillation. The hearts of zebrafish tremblor (tre) mutants exhibit chaotic movements and fail to develop synchronized contractions. Calcium imaging showed that normal calcium transients are absent in tre cardiomyocytes, and molecular cloning of the tre mutation revealed that the tre locus encodes the zebrafish cardiac-specific sodium-calcium exchanger (NCX) 1, NCX1h. Forced expression of NCX1h or other calcium-handling molecules restored synchronized heartbeats in tre mutant embryos in a dosage-dependent manner, demonstrating the critical role of calcium homeostasis in maintaining embryonic cardiac function. By creating mosaic zebrafish embryos, we showed that sporadic NCX1h-null cells were not sufficient to disrupt normal cardiac function, but clustered wild-type cardiomyocytes contract in unison in tre mutant hearts. These data signify the essential role of calcium homeostasis and NCX1h in establishing rhythmic contraction in the embryonic zebrafish heart.
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Affiliation(s)
- Adam D Langenbacher
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, CA 90095, USA
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390
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Shin JT, Priest JR, Ovcharenko I, Ronco A, Moore RK, Burns CG, MacRae CA. Human-zebrafish non-coding conserved elements act in vivo to regulate transcription. Nucleic Acids Res 2005; 33:5437-45. [PMID: 16179648 PMCID: PMC1236720 DOI: 10.1093/nar/gki853] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Whole genome comparisons of distantly related species effectively predict biologically important sequences--core genes and cis-acting regulatory elements (REs)--but require experimentation to verify biological activity. To examine the efficacy of comparative genomics in identification of active REs from anonymous, non-coding (NC) sequences, we generated a novel alignment of the human and draft zebrafish genomes, and contrasted this set to existing human and fugu datasets. We tested the transcriptional regulatory potential of candidate sequences using two in vivo assays. Strict selection of non-genic elements which are deeply conserved in vertebrate evolution identifies 1744 core vertebrate REs in human and two fish genomes. We tested 16 elements in vivo for cis-acting gene regulatory properties using zebrafish transient transgenesis and found that 10 (63%) strongly modulate tissue-specific expression of a green fluorescent protein reporter vector. We also report a novel quantitative enhancer assay with potential for increased throughput based on normalized luciferase activity in vivo. This complementary system identified 11 (69%; including 9 of 10 GFP-confirmed elements) with cis-acting function. Together, these data support the utility of comparative genomics of distantly related vertebrate species to identify REs and provide a scaleable, in vivo quantitative assay to define functional activity of candidate REs.
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Affiliation(s)
- Jordan T Shin
- Cardiovascular Research Center and Cardiology Division, Massachusetts General Hospital and Harvard Medical School Charlestown, MA 02129, USA.
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391
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Burns CG, Milan DJ, Grande EJ, Rottbauer W, MacRae CA, Fishman MC. High-throughput assay for small molecules that modulate zebrafish embryonic heart rate. Nat Chem Biol 2005; 1:263-4. [PMID: 16408054 DOI: 10.1038/nchembio732] [Citation(s) in RCA: 256] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Accepted: 08/23/2005] [Indexed: 12/22/2022]
Abstract
To increase the facility and throughput of scoring phenotypic traits in embryonic zebrafish, we developed an automated micro-well assay for heart rate using automated fluorescence microscopy of transgenic embryos expressing green fluorescent protein in myocardium. The assay measures heart rates efficiently and accurately over a large linear dynamic range, and it rapidly characterizes dose dependence and kinetics of small molecule-induced changes in heart rate. This is the first high-throughput micro-well assay for organ function in an intact vertebrate.
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Affiliation(s)
- C Geoffrey Burns
- Developmental Biology Laboratory, Cardiovascular Research Center, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA.
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392
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Trinh LA, Yelon D, Stainier DYR. Hand2 regulates epithelial formation during myocardial diferentiation. Curr Biol 2005; 15:441-6. [PMID: 15786591 DOI: 10.1016/j.cub.2004.12.083] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Myocardial differentiation is initiated by the activation of terminal-differentiation gene expression within a subset of cells in the anterior lateral plate mesoderm. We have previously shown that shortly after this activation, myocardial cells undergo epithelial maturation [1], suggesting that myocardial differentiation encompasses both molecular and cellular changes. To address the question of how the molecular programs driving myocardial gene expression and the formation of the myocardial epithelium are integrated, we analyzed the role of two essential myocardial terminal-differentiation factors, Hand2 and Gata5, in myocardial epithelia formation. hand2 and gata5 mutants exhibit a much-reduced number of myocardial cells and defects in myocardial gene expression [2,3]. We find that the few myocardial precursors that are present in hand2 mutants do not polarize. In contrast, embryos with reduced Gata5 function exhibit polarized myocardial epithelia despite a similar reduction in myocardial precursor number, indicating that proper cell number is not required for epithelial formation. Taken thogether, these results indicate that Hand2 is uniquely required for myocardial polarization, a previously unappreciated role for this critical transcription factor. Furthermore, these results demonstrate that two independent processes, the polarizaton of myocardial precursors and the allocation of proper cell number, contribute to myocardial development.
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Affiliation(s)
- Le A Trinh
- Department of Biochemistry and Biophysics Programs in Developmental Biology, Genetics, and Human Genetics, University of California, San Francisco, San Francisco, California 94143, USA
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393
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Huang H, Zhang B, Hartenstein PA, Chen JN, Lin S. NXT2 is required for embryonic heart development in zebrafish. BMC DEVELOPMENTAL BIOLOGY 2005; 5:7. [PMID: 15790397 PMCID: PMC1079804 DOI: 10.1186/1471-213x-5-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Accepted: 03/24/2005] [Indexed: 11/10/2022]
Abstract
Background NXT2 is a member of NXT family proteins that are generally involved in exporting nuclear RNA in eukaryotic cells. It is not known if NXT2 has any function in specific biological processes. Results A zebrafish mutant exhibiting specific heart defects during embryogenesis was generated by animal cloning-mediated retroviral insertions. Molecular analysis indicated that the mutant phenotype was caused by a disruption of NXT2. Whole-mount RNA in situ hybridization showed that NXT2 transcripts were clearly detectable in embryonic heart as well as other tissues. Further analysis revealed that expression level of one form of alternative splicing NXT2 mRNA transcripts was significantly reduced, resulting in deficient myocardial cell differentiation and the malformation of cardiac valve at the atrioventricular boundary. The defects could be reproduced by morpholino anti-sense oligo knockdown of NXT2. Conclusion NXT2 has a critical role in maintaining morphogenetic integrity of embryonic heart in vertebrate species.
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MESH Headings
- Active Transport, Cell Nucleus
- Alternative Splicing
- Animals
- Cell Differentiation/genetics
- Cloning, Organism
- DNA Transposable Elements
- Edema, Cardiac/genetics
- Edema, Cardiac/pathology
- Heart/embryology
- Heart/physiology
- Heart Defects, Congenital/genetics
- Heart Defects, Congenital/pathology
- Heart Valves/pathology
- Myocardium/chemistry
- Myocardium/cytology
- Myocardium/pathology
- Nuclear Export Signals/genetics
- Nuclear Export Signals/physiology
- Phenotype
- RNA, Antisense
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription, Genetic
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish Proteins/genetics
- Zebrafish Proteins/physiology
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Affiliation(s)
- Haigen Huang
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Bo Zhang
- Center of Developmental Biology and Genetics, College of Life Sciences Peking University, Beijing 100871, P. R. CHINA
| | - Parvana A Hartenstein
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Jau-nian Chen
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095, USA
| | - Shuo Lin
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California 90095, USA
- Center of Developmental Biology and Genetics, College of Life Sciences Peking University, Beijing 100871, P. R. CHINA
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394
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Huang CJ, Jou TS, Ho YL, Lee WH, Jeng YT, Hsieh FJ, Tsai HJ. Conditional expression of a myocardium-specific transgene in zebrafish transgenic lines. Dev Dyn 2005; 233:1294-303. [PMID: 15977161 DOI: 10.1002/dvdy.20485] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
To develop the first heart-specific tetracycline (Tet)-On system in zebrafish, we constructed plasmids in which the cardiac myosin light chain 2 promoter of zebrafish was used to drive the reverse Tet-controlled transactivator (rtTA) and the green fluorescent protein (GFP) reporter gene was preceded by an rtTA-responsive element. In the zebrafish fibroblast cell-line, rtTA-M2, one of rtTA's derivatives, demonstrated the highest increase in luciferase activity upon doxycycline (Dox) induction. We then generated two germ lines of transgenic zebrafish: line T03 was derived from microinjection of a plasmid containing rtTA-M2 and a plasmid containing a responsive reporter gene, whereas line T21 was derived from microinjection of a single dual plasmid. Results showed that line T21 was superior to line T03 in terms of greater GFP intensity after induction and with of minimal leakiness before induction. The photographic images of induced GFP in the heart of F2 larvae showed that the fluorescent level of GFP was dose-responsive. The level of GFP expressed in the F3 3 days postfertilization larvae that were treated with Dox for 1 hr decreased gradually after the withdrawal of the inducer; and the fluorescent signal disappeared after 5 days. The GFP induction and reduction were also tightly controlled by Dox in the F3 adult fish from line T21. This Tet-On system developed in zebrafish shows much promise for the study of the gene function in a specific tissue at the later developmental stage.
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Affiliation(s)
- Chiu-Ju Huang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan
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395
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Heicklen-Klein A, McReynolds LJ, Evans T. Using the zebrafish model to study GATA transcription factors. Semin Cell Dev Biol 2004; 16:95-106. [PMID: 15659344 DOI: 10.1016/j.semcdb.2004.10.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The zebrafish is an established animal model system that profits from the availability of strong experimental approaches in both genetics and embryology. As a vertebrate, zebrafish can be used to model many aspects of human development and disease. GATA transcription factors play important roles in the development of many organ systems, including those for hematopoietic, cardiovascular, reproductive, and gut-endoderm derived tissues. The six vertebrate GATA factors are highly conserved in zebrafish at the level of sequence, expression pattern, and function. The identification of mutants, establishment of transgenic GFP reporter fish, and the ease of performing loss- and gain-of-function experiments have all contributed new insight into our understanding of the regulation and function of GATA factors. We review recent advances toward this goal using the zebrafish system with a focus on hematopoiesis and cardiogenesis, and suggest how comparative genetics using the zebrafish genes might reveal core conserved properties, as well as changes in gene function that reflect different morphogenetic programs utilized by various vertebrate embryos.
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Affiliation(s)
- Alice Heicklen-Klein
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Chanin Room 501, Bronx, NY 10461, USA
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396
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Trinh LA, Stainier DYR. Fibronectin regulates epithelial organization during myocardial migration in zebrafish. Dev Cell 2004; 6:371-82. [PMID: 15030760 DOI: 10.1016/s1534-5807(04)00063-2] [Citation(s) in RCA: 260] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Revised: 01/20/2004] [Accepted: 01/21/2004] [Indexed: 10/26/2022]
Abstract
Several genes have been implicated in heart tube formation, yet we know little about underlying cellular mechanisms. We analyzed the cellular architecture of the migrating myocardial precursors, and find that they form coherent epithelia that mature as they move medially. Mutant analyses indicate that the cardia bifida locus natter (nat) is required for the integrity of the myocardial epithelia. We positionally cloned nat and show that it encodes Fibronectin. During myocardial migration, Fibronectin is deposited at the midline between the endoderm and endocardial precursors, and laterally around the myocardial precursors. Further analyses show that Fibronectin deposition at the midline is required for the timely migration of myocardial precursors, but dispensable for the migration process itself. In the complete absence of Fibronectin, adherens junctions between myocardial precursors do not form properly, suggesting that cell-substratum interactions are required for epithelial organization. These data suggest that myocardial migration is dependent on epithelial integrity.
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Affiliation(s)
- L A Trinh
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA
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