1
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Brown W, Wesalo J, Samanta S, Luo J, Caldwell SE, Tsang M, Deiters A. Genetically Encoded Aminocoumarin Lysine for Optical Control of Protein-Nucleotide Interactions in Zebrafish Embryos. ACS Chem Biol 2023; 18:1305-1314. [PMID: 37272594 PMCID: PMC10278064 DOI: 10.1021/acschembio.3c00028] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 05/17/2023] [Indexed: 06/06/2023]
Abstract
The strategic placement of unnatural amino acids into the active site of kinases and phosphatases has allowed for the generation of photocaged signaling proteins that offer spatiotemporal control over activation of these pathways through precise light exposure. However, deploying this technology to study cell signaling in the context of embryo development has been limited. The promise of optical control is especially useful in the early stages of an embryo where development is driven by tightly orchestrated signaling events. Here, we demonstrate light-induced activation of Protein Kinase A and a RASopathy mutant of NRAS in the zebrafish embryo using a new light-activated amino acid. We applied this approach to gain insight into the roles of these proteins in gastrulation and heart development and forge a path for further investigation of RASopathy mutant proteins in animals.
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Affiliation(s)
- Wes Brown
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Joshua Wesalo
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Subhas Samanta
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Ji Luo
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Steven E. Caldwell
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Michael Tsang
- Department
of Developmental Biology, University of
Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Alexander Deiters
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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2
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Hasanpour S, Eagderi S, Poorbagher H, Angrand PO, Hasanpour M, Lashkarbolok M. The effect of Activin pathway modulation on the expression of both pluripotency and differentiation markers during early zebrafish development compared with other vertebrates. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2021; 336:562-575. [PMID: 34254429 DOI: 10.1002/jez.b.23070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 05/22/2021] [Accepted: 06/24/2021] [Indexed: 11/09/2022]
Abstract
Activin-like factors control many developmental processes, including pluripotency maintenance and differentiation. Although Activin-like factors' action in mesendoderm induction has been demonstrated in zebrafish, their involvement in preserving the stemness remains unknown. To investigate the role of maternal Activin-like factors, their effects were promoted or blocked using synthetic human Activin A or SB-431542 treatments respectively until the maternal to zygotic transition. To study the role of zygotic Activin-like factors, SB-431542 treatment was also applied after the maternal to zygotic transition. The effect of the pharmacological modulations of the Activin/Smad pathway was then studied on the mRNA expressions of the ndr1, ndr2, tbxta (no tail/ntl) as the differentiation index, mych, nanog, and oct4 (pou5f3) as the pluripotency markers of the zebrafish embryonic cells as well as sox17 as a definitive endoderm marker. Expression of the target genes was measured at the 16-cell, 256-cell, 1K-cell, oblong, dome, and shield stages using the real-time quantitative polymerase chain reaction (RT-qPCR). Activation of the maternal Activin signaling pathway led to an increase in zygotic expression of the tbxta, particularly marked at the oblong stage. In other words, promotion of the maternal Activin/Smad pathway induced differentiation by advancing the major peaks of ndr1 and nanog, thereby eliciting tbxta expression. Whereas suppression of the maternal or zygotic Activin/Smad pathway sustained the pluripotency by preventing the major peaks of ndr1 and nanog as well as tbxta encoding.
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Affiliation(s)
- Shaghayegh Hasanpour
- Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran.,Development and Biosystematic Lab., Department of Fisheries and Animal Sciences, Faculty of Natural Resources, University of Tehran, Karaj, Iran
| | - Soheil Eagderi
- Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
| | - Hadi Poorbagher
- Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
| | - Pierre-Olivier Angrand
- Univ Lille, CNRS UMR 9020, Inserm UMR-S 1277, CHU Lille, Centre Oscar Lambret, UMR Canther-Cancer Heterogeneity, Plasticity and Resistance to Therapies, Lille, France
| | - Mohammad Hasanpour
- Department of Neurosurgery, Iran University of Medical Sciences, Tehran, Iran
| | - Maryam Lashkarbolok
- Department of Radiology, Isfahan University of Medical Sciences, Isfahan, Iran
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3
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Rogers KW, ElGamacy M, Jordan BM, Müller P. Optogenetic investigation of BMP target gene expression diversity. eLife 2020; 9:58641. [PMID: 33174840 PMCID: PMC7728441 DOI: 10.7554/elife.58641] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 11/10/2020] [Indexed: 12/15/2022] Open
Abstract
Signaling molecules activate distinct patterns of gene expression to coordinate embryogenesis, but how spatiotemporal expression diversity is generated is an open question. In zebrafish, a BMP signaling gradient patterns the dorsal-ventral axis. We systematically identified target genes responding to BMP and found that they have diverse spatiotemporal expression patterns. Transcriptional responses to optogenetically delivered high- and low-amplitude BMP signaling pulses indicate that spatiotemporal expression is not fully defined by different BMP signaling activation thresholds. Additionally, we observed negligible correlations between spatiotemporal expression and transcription kinetics for the majority of analyzed genes in response to BMP signaling pulses. In contrast, spatial differences between BMP target genes largely collapsed when FGF and Nodal signaling were inhibited. Our results suggest that, similar to other patterning systems, combinatorial signaling is likely to be a major driver of spatial diversity in BMP-dependent gene expression in zebrafish.
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Affiliation(s)
- Katherine W Rogers
- Systems Biology of Development Group, Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany
| | - Mohammad ElGamacy
- Systems Biology of Development Group, Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany.,Modeling Tumorigenesis Group, Translational Oncology Division, Eberhard Karls University Tübingen, Tübingen, Germany.,Heliopolis Biotechnology Ltd, London, United Kingdom
| | - Benjamin M Jordan
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
| | - Patrick Müller
- Systems Biology of Development Group, Friedrich Miescher Laboratory of the Max Planck Society, Tübingen, Germany.,Modeling Tumorigenesis Group, Translational Oncology Division, Eberhard Karls University Tübingen, Tübingen, Germany
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4
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Schauer A, Pinheiro D, Hauschild R, Heisenberg CP. Zebrafish embryonic explants undergo genetically encoded self-assembly. eLife 2020; 9:55190. [PMID: 32250246 PMCID: PMC7190352 DOI: 10.7554/elife.55190] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/05/2020] [Indexed: 12/20/2022] Open
Abstract
Embryonic stem cell cultures are thought to self-organize into embryoid bodies, able to undergo symmetry-breaking, germ layer specification and even morphogenesis. Yet, it is unclear how to reconcile this remarkable self-organization capacity with classical experiments demonstrating key roles for extrinsic biases by maternal factors and/or extraembryonic tissues in embryogenesis. Here, we show that zebrafish embryonic tissue explants, prepared prior to germ layer induction and lacking extraembryonic tissues, can specify all germ layers and form a seemingly complete mesendoderm anlage. Importantly, explant organization requires polarized inheritance of maternal factors from dorsal-marginal regions of the blastoderm. Moreover, induction of endoderm and head-mesoderm, which require peak Nodal-signaling levels, is highly variable in explants, reminiscent of embryos with reduced Nodal signals from the extraembryonic tissues. Together, these data suggest that zebrafish explants do not undergo bona fide self-organization, but rather display features of genetically encoded self-assembly, where intrinsic genetic programs control the emergence of order.
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5
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Flanagan-Steet H, Christian C, Lu PN, Aarnio-Peterson M, Sanman L, Archer-Hartmann S, Azadi P, Bogyo M, Steet RA. TGF-ß Regulates Cathepsin Activation during Normal and Pathogenic Development. Cell Rep 2019. [PMID: 29539424 PMCID: PMC6247414 DOI: 10.1016/j.celrep.2018.02.066] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cysteine cathepsins play roles during development and disease beyond their function in lysosomal protein turnover. Here, we leverage a fluorescent activity-based probe (ABP), BMV109, to track cysteine cathepsins in normal and diseased zebrafish embryos. Using this probe in a model of mucolipidosis II, we show that loss of carbohydrate-dependent lysosomal sorting alters the activity of several cathepsin proteases. The data support a pathogenic mechanism where TGF-β signals enhance the proteolytic processing of pro-Ctsk by modulating the expression of chondroitin 4-sulfate (C4-S). In MLII, elevated C4-S corresponds with TGF-β-mediated increases in chst11 expression. Inhibiting chst11 impairs the proteolytic activation of Ctsk and alleviates the MLII phenotypes. These findings uncover a regulatory loop between TGF-β signaling and Ctsk activation that is altered in the context of lysosomal disease. This work highlights the power of ABPs to identify mechanisms underlying pathogenic development in living animals. Chondroitin sulfate is a known regulator of cathepsin protease activity. Flanagan-Steet et al. identify a positive feedback mechanism whereby cathepsins secreted from chondrocytes upon loss of lysosomal targeting activate TGF-β signaling in developing cartilage. This increased signaling, in turn, stimulates chondroitin-4 sulfation and enhances cathepsin activity.
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Affiliation(s)
| | - Courtney Christian
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30606, USA
| | - Po-Nien Lu
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30606, USA
| | | | - Laura Sanman
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305-5324, USA
| | | | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30606, USA
| | - Matthew Bogyo
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305-5324, USA
| | - Richard A Steet
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30606, USA
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6
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Yasuoka Y, Tando Y, Kubokawa K, Taira M. Evolution of cis-regulatory modules for the head organizer gene goosecoid in chordates: comparisons between Branchiostoma and Xenopus. ZOOLOGICAL LETTERS 2019; 5:27. [PMID: 31388442 PMCID: PMC6679436 DOI: 10.1186/s40851-019-0143-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 07/12/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND In cephalochordates (amphioxus), the notochord runs along the dorsal to the anterior tip of the body. In contrast, the vertebrate head is formed anterior to the notochord, as a result of head organizer formation in anterior mesoderm during early development. A key gene for the vertebrate head organizer, goosecoid (gsc), is broadly expressed in the dorsal mesoderm of amphioxus gastrula. Amphioxus gsc expression subsequently becomes restricted to the posterior notochord from the early neurula. This has prompted the hypothesis that a change in expression patterns of gsc led to development of the vertebrate head during chordate evolution. However, molecular mechanisms of head organizer evolution involving gsc have never been elucidated. RESULTS To address this question, we compared cis-regulatory modules of vertebrate organizer genes between amphioxus, Branchiostoma japonicum, and frogs, Xenopus laevis and Xenopus tropicalis. Here we show conservation and diversification of gene regulatory mechanisms through cis-regulatory modules for gsc, lim1/lhx1, and chordin in Branchiostoma and Xenopus. Reporter analysis using Xenopus embryos demonstrates that activation of gsc by Nodal/FoxH1 signal through the 5' upstream region, that of lim1 by Nodal/FoxH1 signal through the first intron, and that of chordin by Lim1 through the second intron, are conserved between amphioxus and Xenopus. However, activation of gsc by Lim1 and Otx through the 5' upstream region in Xenopus are not conserved in amphioxus. Furthermore, the 5' region of amphioxus gsc recapitulated the amphioxus-like posterior mesoderm expression of the reporter gene in transgenic Xenopus embryos. CONCLUSIONS On the basis of this study, we propose a model, in which the gsc gene acquired the cis-regulatory module bound with Lim1 and Otx at its 5' upstream region to be activated persistently in anterior mesoderm, in the vertebrate lineage. Because Gsc globally represses trunk (notochord) genes in the vertebrate head organizer, this cooption of gsc in vertebrates appears to have resulted in inhibition of trunk genes and acquisition of the head organizer and its derivative prechordal plate.
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Affiliation(s)
- Yuuri Yasuoka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495 Japan
- Laboratory for Comprehensive Genomic Analysis, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045 Japan
| | - Yukiko Tando
- Center for Advance Marine Research, Ocean Research Institute, The University of Tokyo, 1-15-1, Minamidai, Nakano-ku, Tokyo, 164-8639 Japan
- Present address: Cell Resource Center for Biomedical Research, Institute of Development, Aging and Cancer (IDAC), Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575 Japan
| | - Kaoru Kubokawa
- Center for Advance Marine Research, Ocean Research Institute, The University of Tokyo, 1-15-1, Minamidai, Nakano-ku, Tokyo, 164-8639 Japan
- Present address: SIRC, Teikyo University, 2-11-1, Itabashi-ku, Tokyo, 173-8605 Japan
| | - Masanori Taira
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
- Present address: Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551 Japan
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7
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Warga RM, Kane DA. Wilson cell origin for kupffer's vesicle in the zebrafish. Dev Dyn 2018; 247:1057-1069. [DOI: 10.1002/dvdy.24657] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 06/19/2018] [Accepted: 07/03/2018] [Indexed: 11/06/2022] Open
Affiliation(s)
- Rachel M. Warga
- Department of Biological Sciences; Western Michigan University; Kalamazoo Michigan
| | - Donald A. Kane
- Department of Biological Sciences; Western Michigan University; Kalamazoo Michigan
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8
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Kindt LM, Coughlin AR, Perosino TR, Ersfeld HN, Hampton M, Liang JO. Identification of transcripts potentially involved in neural tube closure using RNA sequencing. Genesis 2018; 56:e23096. [PMID: 29488319 DOI: 10.1002/dvg.23096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 02/02/2018] [Accepted: 02/19/2018] [Indexed: 01/08/2023]
Abstract
Anencephaly is a fatal human neural tube defect (NTD) in which the anterior neural tube remains open. Zebrafish embryos with reduced Nodal signaling display an open anterior neural tube phenotype that is analogous to anencephaly. Previous work from our laboratory suggests that Nodal signaling acts through induction of the head mesendoderm and mesoderm. Head mesendoderm/mesoderm then, through an unknown mechanism, promotes formation of the polarized neuroepithelium that is capable of undergoing the movements required for closure. We compared the transcriptome of embryos treated with a Nodal signaling inhibitor at sphere stage, which causes NTDs, to embryos treated at 30% epiboly, which does not cause NTDs. This screen identified over 3,000 transcripts with potential roles in anterior neurulation. Expression of several genes encoding components of tight and adherens junctions was significantly reduced, supporting the model that Nodal signaling regulates formation of the neuroepithelium. mRNAs involved in Wnt, FGF, and BMP signaling were also differentially expressed, suggesting these pathways might regulate anterior neurulation. In support of this, we found that pharmacological inhibition of FGF-receptor function causes an open anterior NTD as well as loss of mesodermal derivatives. This suggests that Nodal and FGF signaling both promote anterior neurulation through induction of head mesoderm.
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Affiliation(s)
- Lexy M Kindt
- Department of Biology, University of Minnesota Duluth, Duluth.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth
| | - Alicia R Coughlin
- Department of Biology, University of Minnesota Duluth, Duluth.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth
| | | | - Haley N Ersfeld
- Department of Biology, University of Minnesota Duluth, Duluth
| | - Marshall Hampton
- Integrated Biosciences Graduate Program, University of Minnesota, Duluth.,Department of Mathematics and Statistics, University of Minnesota Duluth, Duluth
| | - Jennifer O Liang
- Department of Biology, University of Minnesota Duluth, Duluth.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth
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9
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Rogers KW, Lord ND, Gagnon JA, Pauli A, Zimmerman S, Aksel DC, Reyon D, Tsai SQ, Joung JK, Schier AF. Nodal patterning without Lefty inhibitory feedback is functional but fragile. eLife 2017; 6. [PMID: 29215332 PMCID: PMC5720593 DOI: 10.7554/elife.28785] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 11/07/2017] [Indexed: 12/12/2022] Open
Abstract
Developmental signaling pathways often activate their own inhibitors. Such inhibitory feedback has been suggested to restrict the spatial and temporal extent of signaling or mitigate signaling fluctuations, but these models are difficult to rigorously test. Here, we determine whether the ability of the mesendoderm inducer Nodal to activate its inhibitor Lefty is required for development. We find that zebrafish lefty mutants exhibit excess Nodal signaling and increased specification of mesendoderm, resulting in embryonic lethality. Strikingly, development can be fully restored without feedback: Lethal patterning defects in lefty mutants can be rescued by ectopic expression of lefty far from its normal expression domain or by spatially and temporally uniform exposure to a Nodal inhibitor drug. While drug-treated mutants are less tolerant of mild perturbations to Nodal signaling levels than wild type embryos, they can develop into healthy adults. These results indicate that patterning without inhibitory feedback is functional but fragile. During animal development, a single fertilized cell gives rise to different tissues and organs. This ‘patterning’ process depends on signaling molecules that instruct cells in different positions in the embryo to acquire different identities. To avoid mistakes during patterning, each cell must receive the correct amount of signal at the appropriate time. In a process called ‘inhibitory feedback’, a signaling molecule instructs cells to produce molecules that block its own signaling. Although inhibitory feedback is widely used during patterning in organisms ranging from sea urchins to mammals, its exact purpose is often not clear. In part this is because feedback is challenging to experimentally manipulate. Removing the inhibitor disrupts feedback, but also increases signaling. Since the effects of broken feedback and increased signaling are intertwined, any resulting developmental defects do not provide information about what feedback specifically does. In order to examine the role of feedback, it is therefore necessary to disconnect the production of the inhibitor from the signaling process. In developing embryos, a well-known signaling molecule called Nodal instructs cells to become specific types – for example, a heart or gut cell. Nodal also promotes the production of its inhibitor, Lefty. To understand how this feedback system works, Rogers, Lord et al. first removed Lefty from zebrafish embryos. These embryos had excessive levels of Nodal signaling, did not develop correctly, and could not survive. Bathing the embryos in a drug that inhibits Nodal reduced excess signaling and allowed them to develop successfully. In these drug-treated embryos, inhibitor production is disconnected from the signaling process, allowing the role of feedback to be examined. Drug-treated embryos were less able to tolerate fluctuations in Nodal signaling than normal zebrafish embryos, which could compensate for such disturbances by adjusting Lefty levels. Overall, it appears that inhibitory feedback in this patterning system is important to compensate for alterations in Nodal signaling, but is not essential for development. Understanding the role of inhibitory feedback will be useful for efforts to grow tissues and organs in the laboratory for clinical use. The results presented by Rogers, Lord et al. also suggest the possibility that drug treatments could be developed to help correct birth defects in the womb.
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Affiliation(s)
- Katherine W Rogers
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Nathan D Lord
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - James A Gagnon
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Andrea Pauli
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Steven Zimmerman
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Deniz C Aksel
- Program in Biophysics, Harvard Medical School, Boston, United States
| | - Deepak Reyon
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, United States.,Department of Pathology, Harvard Medical School, Boston, United States.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, United States.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, United States
| | - Shengdar Q Tsai
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, United States.,Department of Pathology, Harvard Medical School, Boston, United States.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, United States.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, United States
| | - J Keith Joung
- Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, United States.,Department of Pathology, Harvard Medical School, Boston, United States.,Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, United States.,Center for Cancer Research, Massachusetts General Hospital, Charlestown, United States
| | - Alexander F Schier
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States.,Broad Institute of MIT and Harvard University, Cambridge, United States.,Center for Brain Science, Harvard University, Cambridge, United States.,Harvard Stem Cell Institute, Harvard University, Cambridge, United States.,Center for Systems Biology, Harvard University, Cambridge, United States
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10
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Tseng WC, Munisha M, Gutierrez JB, Dougan ST. Establishment of the Vertebrate Germ Layers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:307-381. [PMID: 27975275 DOI: 10.1007/978-3-319-46095-6_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The process of germ layer formation is a universal feature of animal development. The germ layers separate the cells that produce the internal organs and tissues from those that produce the nervous system and outer tissues. Their discovery in the early nineteenth century transformed embryology from a purely descriptive field into a rigorous scientific discipline, in which hypotheses could be tested by observation and experimentation. By systematically addressing the questions of how the germ layers are formed and how they generate overall body plan, scientists have made fundamental contributions to the fields of evolution, cell signaling, morphogenesis, and stem cell biology. At each step, this work was advanced by the development of innovative methods of observing cell behavior in vivo and in culture. Here, we take an historical approach to describe our current understanding of vertebrate germ layer formation as it relates to the long-standing questions of developmental biology. By comparing how germ layers form in distantly related vertebrate species, we find that highly conserved molecular pathways can be adapted to perform the same function in dramatically different embryonic environments.
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Affiliation(s)
- Wei-Chia Tseng
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Mumingjiang Munisha
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Juan B Gutierrez
- Department of Mathematics, University of Georgia, Athens, GA, 30602, USA.,Institute of Bioinformatics, University of Georgia, Athens, GA, 30602, USA
| | - Scott T Dougan
- Department of Cellular Biology, University of Georgia, Athens, GA, 30602, USA.
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11
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The guanine nucleotide exchange factor Net1 facilitates the specification of dorsal cell fates in zebrafish embryos by promoting maternal β-catenin activation. Cell Res 2016; 27:202-225. [PMID: 27910850 DOI: 10.1038/cr.2016.141] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 09/18/2016] [Accepted: 09/27/2016] [Indexed: 12/14/2022] Open
Abstract
Wnt/β-catenin signaling is essential for the initiation of dorsal-ventral patterning during vertebrate embryogenesis. Maternal β-catenin accumulates in dorsal marginal nuclei during cleavage stages, but its critical target genes essential for dorsalization are silent until mid-blastula transition (MBT). Here, we find that zebrafish net1, a guanine nucleotide exchange factor, is specifically expressed in dorsal marginal blastomeres after MBT, and acts as a zygotic factor to promote the specification of dorsal cell fates. Loss- and gain-of-function experiments show that the GEF activity of Net1 is required for the activation of Wnt/β-catenin signaling in zebrafish embryos and mammalian cells. Net1 dissociates and activates PAK1 dimers, and PAK1 kinase activation causes phosphorylation of S675 of β-catenin after MBT, which ultimately leads to the transcription of downstream target genes. In summary, our results reveal that Net1-regulated β-catenin activation plays a crucial role in the dorsal axis formation during zebrafish development.
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12
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Sampath K, Robertson EJ. Keeping a lid on nodal: transcriptional and translational repression of nodal signalling. Open Biol 2016; 6:150200. [PMID: 26791244 PMCID: PMC4736825 DOI: 10.1098/rsob.150200] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Nodal is an evolutionarily conserved member of the transforming growth factor-β (TGF-β) superfamily of secreted signalling factors. Nodal factors are known to play key roles in embryonic development and asymmetry in a variety of organisms ranging from hydra and sea urchins to fish, mice and humans. In addition to embryonic patterning, Nodal signalling is required for maintenance of human embryonic stem cell pluripotency and mis-regulated Nodal signalling has been found associated with tumour metastases. Therefore, precise and timely regulation of this pathway is essential. Here, we discuss recent evidence from sea urchins, frogs, fish, mice and humans that show a role for transcriptional and translational repression of Nodal signalling during early development.
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Affiliation(s)
- Karuna Sampath
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AJ, UK
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13
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Gonsar N, Coughlin A, Clay-Wright JA, Borg BR, Kindt LM, Liang JO. Temporal and spatial requirements for Nodal-induced anterior mesendoderm and mesoderm in anterior neurulation. Genesis 2016; 54:3-18. [PMID: 26528772 DOI: 10.1002/dvg.22908] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 10/29/2015] [Accepted: 10/30/2015] [Indexed: 01/28/2023]
Abstract
Zebrafish with defective Nodal signaling have a phenotype analogous to the fatal human birth defect anencephaly, which is caused by an open anterior neural tube. Previous work in our laboratory found that anterior open neural tube phenotypes in Nodal signaling mutants were caused by lack of mesendodermal/mesodermal tissues. Defects in these mutants are already apparent at neural plate stage, before the neuroepithelium starts to fold into a tube. Consistent with this, we found that the requirement for Nodal signaling maps to mid-late blastula stages. This timing correlates with the timing of prechordal plate mesendoderm and anterior mesoderm induction, suggesting these tissues act to promote neurulation. To further identify tissues important for neurulation, we took advantage of the variable phenotypes in Nodal signaling-deficient sqt mutant and Lefty1-overexpressing embryos. Statistical analysis indicated a strong, positive correlation between a closed neural tube and presence of several mesendoderm/mesoderm-derived tissues (hatching glands, cephalic paraxial mesoderm, notochord, and head muscles). However, the neural tube was closed in a subset of embryos that lacked any one of these tissues. This suggests that several types of Nodal-induced mesendodermal/mesodermal precursors are competent to promote neurulation.
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Affiliation(s)
- Ngawang Gonsar
- Department of Biology, University of Minnesota Duluth, Duluth, MN.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth, MN
| | - Alicia Coughlin
- Department of Biology, University of Minnesota Duluth, Duluth, MN.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth, MN
| | | | - Bethanie R Borg
- Department of Biology, University of Minnesota Duluth, Duluth, MN
| | - Lexy M Kindt
- Department of Biology, University of Minnesota Duluth, Duluth, MN.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth, MN
| | - Jennifer O Liang
- Department of Biology, University of Minnesota Duluth, Duluth, MN.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth, MN
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14
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Ma P, Swartz MR, Kindt LM, Kangas AM, Liang JO. Temperature Sensitivity of Neural Tube Defects in Zoep Mutants. Zebrafish 2015; 12:448-56. [PMID: 26366681 DOI: 10.1089/zeb.2015.1113] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Neural tube defects (NTD) occur when the flat neural plate epithelium fails to fold into the neural tube, the precursor to the brain and spinal cord. Squint (Sqt/Ndr1), a Nodal ligand, and One-eyed pinhead (Oep), a component of the Nodal receptor, are required for anterior neural tube closure in zebrafish. The NTD in sqt and Zoep mutants are incompletely penetrant. The penetrance of several defects in sqt mutants increases upon heat or cold shock. In this project, undergraduate students tested whether temperature influences the Zoep open neural tube phenotype. Single pairs of adults were spawned at 28.5°C, the normal temperature for zebrafish, and one half of the resulting embryos were moved to 34°C at different developmental time points. Analysis of variance indicated temperature and clutch/genetic background significantly contributed to the penetrance of the open neural tube phenotype. Heat shock affected the embryos only at or before the midblastula stage. Many factors, including temperature changes in the mother, nutrition, and genetic background, contribute to NTD in humans. Thus, sqt and Zoep mutants may serve as valuable models for studying the interactions between genetics and the environment during neurulation.
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Affiliation(s)
- Phyo Ma
- 1 Department of Biology, University of Minnesota Duluth , Duluth, Minnesota
| | - Morgan R Swartz
- 1 Department of Biology, University of Minnesota Duluth , Duluth, Minnesota
| | - Lexy M Kindt
- 1 Department of Biology, University of Minnesota Duluth , Duluth, Minnesota.,2 Integrated Biosciences Graduate Program, University of Minnesota , Duluth, Minnesota
| | - Ashley M Kangas
- 1 Department of Biology, University of Minnesota Duluth , Duluth, Minnesota
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15
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The Chromatin Remodeling Protein Bptf Promotes Posterior Neuroectodermal Fate by Enhancing Smad2-Activated wnt8a Expression. J Neurosci 2015; 35:8493-506. [PMID: 26041917 DOI: 10.1523/jneurosci.0377-15.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During vertebrate embryogenesis, the neuroectoderm is induced from dorsal ectoderm and then partitioned into anterior and posterior neuroectodermal domains by posteriorizing signals, such as Wnt and fibroblast growth factor. However, little is known about epigenetic regulation of posteriorizing gene expression. Here, we report a requirement of the chromatin remodeling protein Bptf for neuroectodermal posteriorization in zebrafish embryos. Knockdown of bptf leads to an expansion of the anterior neuroectoderm at the expense of the posterior ectoderm. Bptf functionally and physically interacts with p-Smad2, which is activated by non-Nodal TGF-β signaling, to promote the expression of wnt8a, a critical gene for neural posteriorization. Bptf and Smad2 directly bind to and activate the wnt8a promoter through recruiting NURF remodeling complex. When bptf function or TGF-β signal transduction is inhibited, the nucleosome density on the wnt8a promoter is increased. We propose that Bptf and TGF-β/Smad2 mediate nucleosome remodeling to regulate wnt8a expression and hence neural posteriorization.
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16
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Papanayotou C, Collignon J. Activin/Nodal signalling before implantation: setting the stage for embryo patterning. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0539. [PMID: 25349448 DOI: 10.1098/rstb.2013.0539] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Activins and Nodal are members of the transforming growth factor beta (TGF-β) family of growth factors. Their Smad2/3-dependent signalling pathway is well known for its implication in the patterning of the embryo after implantation. Although this pathway is active early on at preimplantation stages, embryonic phenotypes for loss-of-function mutations of prominent components of the pathway are not detected before implantation. It is only fairly recently that an understanding of the role of the Activin/Nodal signalling pathway at these stages has started to emerge, notably from studies detailing how it controls the expression of target genes in embryonic stem cells. We review here what is currently known of the TGF-β-related ligands that determine the activity of Activin/Nodal signalling at preimplantation stages, and recent advances in the elucidation of the Smad2/3-dependent mechanisms underlying developmental progression.
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Affiliation(s)
- Costis Papanayotou
- Université Paris-Diderot, Sorbonne Paris Cité, Institut Jacques Monod, CNRS UMR 7592, 75205 Paris, France
| | - Jérôme Collignon
- Université Paris-Diderot, Sorbonne Paris Cité, Institut Jacques Monod, CNRS UMR 7592, 75205 Paris, France
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17
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Papanayotou C, Benhaddou A, Camus A, Perea-Gomez A, Jouneau A, Mezger V, Langa F, Ott S, Sabéran-Djoneidi D, Collignon J. A novel nodal enhancer dependent on pluripotency factors and smad2/3 signaling conditions a regulatory switch during epiblast maturation. PLoS Biol 2014; 12:e1001890. [PMID: 24960041 PMCID: PMC4068991 DOI: 10.1371/journal.pbio.1001890] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 05/15/2014] [Indexed: 02/07/2023] Open
Abstract
HBE, a newly discovered enhancer element, mediates the influence of pluripotency factors and Activin/Nodal signaling on early Nodal expression in the mouse embryo, and controls the activation of later-acting Nodal enhancers. During early development, modulations in the expression of Nodal, a TGFβ family member, determine the specification of embryonic and extra-embryonic cell identities. Nodal has been extensively studied in the mouse, but aspects of its early expression remain unaccounted for. We identified a conserved hotspot for the binding of pluripotency factors at the Nodal locus and called this sequence “highly bound element” (HBE). Luciferase-based assays, the analysis of fluorescent HBE reporter transgenes, and a conditional mutation of HBE allowed us to establish that HBE behaves as an enhancer, is activated ahead of other Nodal enhancers in the epiblast, and is essential to Nodal expression in embryonic stem cells (ESCs) and in the mouse embryo. We also showed that HBE enhancer activity is critically dependent on its interaction with the pluripotency factor Oct4 and on Activin/Nodal signaling. Use of an in vitro model of epiblast maturation, relying on the differentiation of ESCs into epiblast stem cells (EpiSCs), revealed that this process entails a shift in the regulation of Nodal expression from an HBE-driven phase to an ASE-driven phase, ASE being another autoregulatory Nodal enhancer. Deletion of HBE in ESCs or in EpiSCs allowed us to show that HBE, although not necessary for Nodal expression in EpiSCs, is required in differentiating ESCs to activate the differentiation-promoting ASE and therefore controls this regulatory shift. Our findings clarify how early Nodal expression is regulated and suggest how this regulation can promote the specification of extra-embryonic precusors without inducing premature differentiation of epiblast cells. More generally, they open new perspectives on how pluripotency factors achieve their function. In the early mouse embryo, Nodal, a member of the TGFbeta superfamily of signalling proteins, promotes the differentiation of extra-embryonic tissues, as well as tissues within the developing embryo itself. Characterising the regulation of Nodal gene expression is essential to understand how Nodal signals in diverse tissue types and at different stages of embryonic development. Four distinct enhancer sequences have been shown to regulate Nodal expression, although none could account for it in the preimplantation epiblast or in embryonic stem cells. We identified a novel enhancer, HBE, responsible for the earliest aspects of Nodal expression. We show that activation of HBE depends on its interaction with a well-known pluripotency factor called Oct4. HBE itself also controls the activation of at least one other Nodal enhancer. Our findings clarify how early Nodal expression is regulated and reveal how pluripotency factors may control the onset of differentiation in embryonic tissues.
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Affiliation(s)
- Costis Papanayotou
- Institut Jacques Monod, UMR 7592, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
- * E-mail: (JC); (CP)
| | - Ataaillah Benhaddou
- Institut Jacques Monod, UMR 7592, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Anne Camus
- Institut Jacques Monod, UMR 7592, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Aitana Perea-Gomez
- Institut Jacques Monod, UMR 7592, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Alice Jouneau
- Unité de Biologie du Développement et de la reproduction, UMR INRA-ENVA, INRA, Jouy-en-Josas, France
| | - Valérie Mezger
- Epigenetics and Cell Fate, UMR7216, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Francina Langa
- Centre d'Ingénierie Génétique Murine, Institut Pasteur, Paris, France
| | - Sascha Ott
- Warwick Systems Biology Centre, University of Warwick, Coventry, United Kingdom
| | - Délara Sabéran-Djoneidi
- Institut Jacques Monod, UMR 7592, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
- Epigenetics and Cell Fate, UMR7216, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Jérôme Collignon
- Institut Jacques Monod, UMR 7592, CNRS, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
- * E-mail: (JC); (CP)
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18
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Integration of nodal and BMP signals in the heart requires FoxH1 to create left-right differences in cell migration rates that direct cardiac asymmetry. PLoS Genet 2013; 9:e1003109. [PMID: 23358434 PMCID: PMC3554567 DOI: 10.1371/journal.pgen.1003109] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 10/05/2012] [Indexed: 12/18/2022] Open
Abstract
Failure to properly establish the left–right (L/R) axis is a major cause of congenital heart defects in humans, but how L/R patterning of the embryo leads to asymmetric cardiac morphogenesis is still unclear. We find that asymmetric Nodal signaling on the left and Bmp signaling act in parallel to establish zebrafish cardiac laterality by modulating cell migration velocities across the L/R axis. Moreover, we demonstrate that Nodal plays the crucial role in generating asymmetry in the heart and that Bmp signaling via Bmp4 is dispensable in the presence of asymmetric Nodal signaling. In addition, we identify a previously unappreciated role for the Nodal-transcription factor FoxH1 in mediating cell responsiveness to Bmp, further linking the control of these two pathways in the heart. The interplay between these TGFβ pathways is complex, with Nodal signaling potentially acting to limit the response to Bmp pathway activation and the dosage of Bmp signals being critical to limit migration rates. These findings have implications for understanding the complex genetic interactions that lead to congenital heart disease in humans. Defects in left–right (L/R) patterning can lead to severe defects in the formation of the heart. In fact, three of the most common forms of congenital heart disease, transposition of the great arteries, chamber septation defects, and chamber isomerisms, can be caused by earlier defects in L/R asymmetry. The Nodal and Bmp signaling pathways influence the development of cardiac asymmetry, but how these signals function in this process is not well understood. In this report, we have clarified the specific roles for the Nodal versus Bmp pathways in the heart. We find that Nodal signals increase the rate of cardiac cell migration, while Bmp signals decrease cardiac cell velocities. We demonstrate that asymmetric Nodal signaling plays a critical role in directing asymmetry in the heart in contrast to reports suggesting that signaling via Bmp4 is the more critical pathway. In fact, we find that Bmp4 signaling is dispensable for correct asymmetry in the heart in the presence of asymmetric Nodal signals. In addition, we have identified a novel integration between these two pathways at the level of the transcription factor FoxH1, which is required for cardiac cell responsiveness to both Nodal and Bmp signals. Taken together, this work significantly increases our understanding of how the signals regulating cardiac asymmetry function and integrate to consistently establish cardiac laterality. These results also suggest that human congenital heart defects that have not been found to result from single mutations within individual genes may develop due to combinations of mutations within components of these two separate pathways.
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Zhang J, Webb SE, Ma LH, Chan CM, Miller AL. Necessary role for intracellular Ca2+ transients in initiating the apical-basolateral thinning of enveloping layer cells during the early blastula period of zebrafish development. Dev Growth Differ 2011; 53:679-96. [PMID: 21671916 DOI: 10.1111/j.1440-169x.2011.01275.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
During the early blastula period of zebrafish embryos, the outermost blastomeres begin to undergo a significant thinning in the apical/basolateral dimension to form the first distinct cellular domain of the embryo, the enveloping layer (EVL). During this shape transformation, only the EVL-precursor cells generate a coincidental series of highly restricted Ca(2+) transients. To investigate the role of these localized Ca(2+) transients in this shape-change process, embryos were treated with a Ca(2+) chelator (5,5'-difluoro BAPTA AM; DFB), or the Ca(2+) ionophore (A23187), to downregulate and upregulate the transients, respectively, while the shape-change of the forming EVL cells was measured. DFB was shown to significantly slow, and A23187 to significantly facilitate the shape change of the forming EVL cells. In addition, to investigate the possible involvement of the phosphoinositide and Wnt/Ca(2+) signaling pathways in the Ca(2+) transient generation and/or shape-change processes, embryos were treated with antagonists (thapsigargin, 2-APB and U73122) or an agonist (Wnt-5A) of these pathways. Wnt-5A upregulated the EVL-restricted Ca(2+) transients and facilitated the change in shape of the EVL cells, while 2-APB downregulated the Ca(2+) transients and significantly slowed the cell shape-change process. Furthermore, thapsigargin and U73122 also both inhibited the EVL cell shape-change. We hypothesize, therefore, that the highly localized and coincidental Ca(2+) transients play a necessary role in initiating the shape-change of the EVL cells.
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Affiliation(s)
- Jiao Zhang
- Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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20
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Narayanan A, Thompson SA, Lee JJ, Lekven AC. A transgenic wnt8a:PAC reporter reveals biphasic regulation of vertebrate mesoderm development. Dev Dyn 2011; 240:898-907. [PMID: 21384472 DOI: 10.1002/dvdy.22599] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2011] [Indexed: 12/25/2022] Open
Affiliation(s)
- Anand Narayanan
- Department of Biology, Texas A&M University, College Station, Texas, USA
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21
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Hong SK, Jang MK, Brown JL, McBride AA, Feldman B. Embryonic mesoderm and endoderm induction requires the actions of non-embryonic Nodal-related ligands and Mxtx2. Development 2011; 138:787-95. [PMID: 21266414 DOI: 10.1242/dev.058974] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Vertebrate mesoderm and endoderm formation requires signaling by Nodal-related ligands from the TGFβ superfamily. The factors that initiate Nodal-related gene transcription are unknown in most species and the relative contributions of Nodal-related ligands from embryonic, extraembryonic and maternal sources remain uncertain. In zebrafish, signals from the yolk syncytial layer (YSL), an extraembryonic domain, are required for mesoderm and endoderm induction, and YSL expression of nodal-related 1 (ndr1) and ndr2 accounts for a portion of this activity. A variable requirement of maternally derived Ndr1 for dorsal and anterior axis formation has also been documented. Here we show that Mxtx2 directly activates expression of ndr2 via binding to its first intron and is required for ndr2 expression in the YSL. Mxtx2 is also required for the Nodal signaling-independent expression component of the no tail a (ntla) gene, which is required for posterior (tail) mesoderm formation. Therefore, Mxtx2 defines a new pathway upstream of Nodal signaling and posterior mesoderm formation. We further show that the co-disruption of extraembryonic Ndr2, extraembryonic Ndr1 and maternal Ndr1 eliminates endoderm and anterior (head and trunk) mesoderm, recapitulating the loss of Nodal signaling phenotype. Therefore, non-embryonic sources of Nodal-related ligands account for the complete spectrum of early Nodal signaling requirements. In summary, the induction of mesoderm and endoderm depends upon the combined actions of Mxtx2 and Nodal-related ligands from non-embryonic sources.
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Affiliation(s)
- Sung-Kook Hong
- Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
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22
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Granier C, Gurchenkov V, Perea-Gomez A, Camus A, Ott S, Papanayotou C, Iranzo J, Moreau A, Reid J, Koentges G, Sabéran-Djoneidi D, Collignon J. Nodal cis-regulatory elements reveal epiblast and primitive endoderm heterogeneity in the peri-implantation mouse embryo. Dev Biol 2011; 349:350-62. [PMID: 21047506 DOI: 10.1016/j.ydbio.2010.10.036] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 10/02/2010] [Accepted: 10/25/2010] [Indexed: 12/12/2022]
Abstract
Nodal, a secreted factor known for its conserved functions in cell-fate specification and the establishment of embryonic axes, is also required in mammals to maintain the pluripotency of the epiblast, the tissue that gives rise to all fetal lineages. Although Nodal is expressed as early as E3.5 in the mouse embryo, its regulation and functions at pre- and peri-implantation stages are currently unknown. Sensitive reporter transgenes for two Nodal cis-regulatory regions, the PEE and the ASE, exhibit specific expression profiles before implantation. Mutant and inhibitor studies find them respectively regulated by Wnt/β-catenin signaling and Activin/Nodal signaling, and provide evidence for localized and heterogeneous activities of these pathways in the inner cell mass, the epiblast and the primitive endoderm. These studies also show that Nodal and its prime effector, FoxH1, are not essential to preimplantation Activin/Nodal signaling. Finally, a strong upregulation of the ASE reporter in implanting blastocysts correlates with a downregulation of the pluripotency factor Nanog in the maturing epiblast. This study uncovers conservation in the mouse blastocyst of Wnt/β-catenin and Activin/Nodal-dependent activities known to govern Nodal expression and the establishment of polarity in the blastula of other deuterostomes. Our results indicate that these pathways act early on to initiate distinct cell-specification processes in the ICM derivatives. Our data also suggest that the activity of the Activin/Nodal pathway is dampened by interactions with the molecular machinery of pluripotency until just before implantation, possibly delaying cell-fate decisions in the mouse embryo.
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Affiliation(s)
- Céline Granier
- Université Paris-Diderot, CNRS, Institut Jacques Monod, UMR 7592, Development and Neurobiology programme, F-75013 Paris, France
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23
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Abstract
Due to the powerful combination of genetic and embryological techniques, the teleost fish Danio rerio has emerged in the last decade as an important model organism for the study of embryonic development. It is relatively easy to inject material such as mRNA or synthetic oligonucleotides to reduce or increase the expression of a gene product. Changes in gene expression can be analyzed at the level of mRNA, by whole-mount in situ hybridization, or at the level of protein, by immunofluorescence. It is also possible to quantitatively analyze protein levels by Western and immunoprecipitation. Cell behavior can be analyzed in detail by cell transplantation and by fate mapping. Because a large number of mutations have been identified in recent years, these methods can be applied in a variety of contexts to provide a deep understanding of gene function that is often more difficult to achieve in other vertebrate model systems.
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Affiliation(s)
- Yuhua Sun
- Department of Cellular Biology, The University of Georgia, Athens, GA, USA.
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Lade AG, Monga SPS. Beta-catenin signaling in hepatic development and progenitors: which way does the WNT blow? Dev Dyn 2010; 240:486-500. [PMID: 21337461 DOI: 10.1002/dvdy.22522] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2010] [Indexed: 12/19/2022] Open
Abstract
The Wnt/β-catenin pathway is an evolutionarily conserved signaling cascade that plays key roles in development and adult tissue homeostasis and is aberrantly activated in many tumors. Over a decade of work in mouse, chick, xenopus, and zebrafish models has uncovered multiple functions of this pathway in hepatic pathophysiology. Specifically, beta-catenin, the central component of the canonical Wnt pathway, is implicated in the regulation of liver regeneration, development, and carcinogenesis. Wnt-independent activation of beta-catenin by receptor tyrosine kinases has also been observed in the liver. In liver development across various species, through regulation of cell proliferation, differentiation, and maturation, beta-catenin directs foregut endoderm specification, hepatic specification of the foregut, and hepatic morphogenesis. Its role has also been defined in adult hepatic progenitors or oval cells especially in their expansion and differentiation. Thus, beta-catenin undergoes tight temporal regulation to exhibit pleiotropic effects during hepatic development and in hepatic progenitor biology.
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25
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Onai T, Yu JK, Blitz IL, Cho KWY, Holland LZ. Opposing Nodal/Vg1 and BMP signals mediate axial patterning in embryos of the basal chordate amphioxus. Dev Biol 2010; 344:377-89. [PMID: 20488174 PMCID: PMC4781670 DOI: 10.1016/j.ydbio.2010.05.016] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Revised: 05/10/2010] [Accepted: 05/11/2010] [Indexed: 12/12/2022]
Abstract
The basal chordate amphioxus resembles vertebrates in having a dorsal, hollow nerve cord, a notochord and somites. However, it lacks extensive gene duplications, and its embryos are small and gastrulate by simple invagination. Here we demonstrate that Nodal/Vg1 signaling acts from early cleavage through the gastrula stage to specify and maintain dorsal/anterior development while, starting at the early gastrula stage, BMP signaling promotes ventral/posterior identity. Knockdown and gain-of-function experiments show that these pathways act in opposition to one another. Signaling by these pathways is modulated by dorsally and/or anteriorly expressed genes including Chordin, Cerberus, and Blimp1. Overexpression and/or reporter assays in Xenopus demonstrate that the functions of these proteins are conserved between amphioxus and vertebrates. Thus, a fundamental genetic mechanism for axial patterning involving opposing Nodal and BMP signaling is present in amphioxus and probably also in the common ancestor of amphioxus and vertebrates or even earlier in deuterostome evolution.
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Affiliation(s)
- Takayuki Onai
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0202 USA
| | - Jr-Kai Yu
- Institute of Cellular and Organismic Biology, Academia Sinica,128 Academia Road, Sec., Nankang, Taipei 11529, Taiwan
| | - Ira L. Blitz
- Department of Developmental and Cell Biology, and Developmental Biology Center, University of California Irvine, Irvine CA 92697-2300
| | - Ken W. Y. Cho
- Department of Developmental and Cell Biology, and Developmental Biology Center, University of California Irvine, Irvine CA 92697-2300
| | - Linda Z. Holland
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0202 USA
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26
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Nojima H, Rothhämel S, Shimizu T, Kim CH, Yonemura S, Marlow FL, Hibi M. Syntabulin, a motor protein linker, controls dorsal determination. Development 2010; 137:923-33. [PMID: 20150281 DOI: 10.1242/dev.046425] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In amphibian and teleost embryos, the dorsal determinants (DDs) are believed to be initially localized to the vegetal pole and then transported to the prospective dorsal side of the embryo along a microtubule array. The DDs are known to activate the canonical Wnt pathway and thereby promote the expression of genes that induce the dorsal organizer. Here, by identifying the locus of the maternal-effect ventralized mutant tokkaebi, we show that Syntabulin, a linker of the kinesin I motor protein, is essential for dorsal determination in zebrafish. We found that syntabulin mRNA is transported to the vegetal pole during oogenesis through the Bucky ball (Buc)-mediated Balbiani body-dependent pathway, which is necessary for establishment of animal-vegetal (AV) oocyte polarity. We demonstrate that Syntabulin is translocated from the vegetal pole in a microtubule-dependent manner. Our findings suggest that Syntabulin regulates the microtubule-dependent transport of the DDs, and provide evidence for the link between AV and dorsoventral axis formation.
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Affiliation(s)
- Hideaki Nojima
- Laboratory for Vertebrate Axis Formation, RIKEN Center for Developmental Biology, Hyogo 650-0047, Japan
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27
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28
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Pei W, Feldman B. Identification of common and unique modifiers of zebrafish midline bifurcation and cyclopia. Dev Biol 2009; 326:201-11. [PMID: 19046963 PMCID: PMC2666472 DOI: 10.1016/j.ydbio.2008.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 11/10/2008] [Accepted: 11/10/2008] [Indexed: 01/26/2023]
Abstract
Loss of the zebrafish Nodal-related protein Squint causes a spectrum of phenotypes including cyclopia and midline bifurcations (MB). Here we examine MBs and their relation to cyclopia in maternal-zygotic squint (MZsqt) mutants. There is a concordance of MB with cyclopia in MZsqt embryos. Heat treatment and depletion of Hsp90a are "common" risk factors, each of which increases the incidence of both phenotypes. Midline identity is specified on both sides of MBs, and deep-layer cells are initially lacking within bifurcations, whereas enveloping layer cells are intact. Bifurcations do not appear until the completion of gastrulation and are preceded by gaps in the expression of wnt5b, an essential regulator of dorsal convergence. The incidence of early MBs and wnt5b expression defects in heated MZsqt embryos is high, but there is also substantial recovery. Wnt5b depletion increases the incidence of MB, but not cyclopia, and as such Wnt5b is a "unique" risk factor for MB. Reciprocally, depletion of Wnt11 or Hsp90b increases cyclopia only. In summary, we find that MB arises after gastrulation in regions that fail to express wnt5b, and we show that two complex dysmorphologies - MB and cyclopia - can be promoted by either common or unique risk factors.
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Affiliation(s)
- Wuhong Pei
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Benjamin Feldman
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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29
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Woodland HR, Zorn AM. The core endodermal gene network of vertebrates: combining developmental precision with evolutionary flexibility. Bioessays 2008; 30:757-65. [PMID: 18623060 DOI: 10.1002/bies.20785] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Embryonic development combines paradoxical properties: it has great precision, it is usually conducted at breakneck speed and it is flexible on relatively short evolutionary time scales, particularly at early stages. While these features appear mutually exclusive, we consider how they may be reconciled by the properties of key early regulatory networks. We illustrate these ideas with the network that controls development of endoderm progenitors. We argue that this network enables precision because of its intrinsic stability, self propagation and dependence on signalling. The network enables high developmental speed because it is rapidly established by maternal inputs at multiple points. In turn these properties confer flexibility on an evolutionary time scale because they can be initiated in many ways, while buffering essential progenitor cell populations against changes in their embryonic environment on both evolutionary and developmental time scales. Although stable, these networks must be capable of rapid dissolution as cell differentiation progresses. While we focus on the core early endodermal network of vertebrates, we argue that these properties are likely to be general in early embryonic stem cell populations, such as mammalian ES cells.
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Affiliation(s)
- Hugh R Woodland
- Department of Biological Sciences, University of Warwick, Coventry, UK.
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Tian J, Andrée B, Jones CM, Sampath K. The pro-domain of the zebrafish Nodal-related protein Cyclops regulates its signaling activities. Development 2008; 135:2649-58. [DOI: 10.1242/dev.019794] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nodal proteins are secreted signaling factors of the transforming growth factor β (TGFβ) family with essential roles in embryonic development in vertebrates. Mutations affecting the Nodal factors have severe consequences in mammals and fish. Furthermore, increased Nodal levels have been associated with melanoma tumor progression. Like other TGFβ-related proteins, Nodal factors consist of a pro-domain and a mature domain. The pro-domain of mouse Nodal protein stabilizes its precursor. However, the mechanisms by which the pro-domains exert their activities are unknown. Here, we characterize the zebrafish Nodal-related factor Cyclops (Cyc) and find unexpected functions for the pro-domain in regulating Cyc activity. We identified a lysosome-targeting region in the Cyc pro-domain that destabilizes the precursor and restricts Cyc activity, revealing the molecular basis for the short-range signaling activities of Cyc. We show that both the pro- and mature-domains of Cyc regulate its stability. We also characterize a mutation in the pro-domain of human NODAL (hNODAL) that underlies congenital heterotaxia. Heterologous expression of mutant hNODAL increases expression of Nodal-response genes. Our studies reveal unexpected roles for the pro-domain of the Nodal factors and provide a possible mechanism for familial heterotaxia.
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Affiliation(s)
- Jing Tian
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604
| | - Birgit Andrée
- Institute of Medical Biology, Immunos, 8A Biomedical Grove, Singapore 138648
| | - C. Michael Jones
- Institute of Medical Biology, Immunos, 8A Biomedical Grove, Singapore 138648
| | - Karuna Sampath
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore 117543
- School of Biological Sciences, Nanyang Technological University, 30 Nanyang Drive, Singapore 637551
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31
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Fan X, Dougan ST. The evolutionary origin of nodal-related genes in teleosts. Dev Genes Evol 2007; 217:807-13. [PMID: 17992538 DOI: 10.1007/s00427-007-0191-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 10/10/2007] [Indexed: 11/29/2022]
Abstract
Because of an extra whole-genome duplication, zebrafish and other teleosts have two copies of genes that are present in a single copy in tetrapod genomes. Some zebrafish genes, however, are present in triplicate. For example, the nodal-related genes encode secreted proteins of the transforming growth factor beta superfamily that are required in all vertebrates to induce the mesoderm and endoderm, pattern all three germ layers, and establish the left-right axis. Zebrafish have three nodal-related genes, called ndr1/squint, ndr2/cyclops, and ndr3/southpaw. As part of an analysis of enhancer elements controlling zebrafish nodal-related gene expression, we analyzed the nodal loci in the sequenced genomes of five teleost species and four tetrapod species. Each teleost genome contains three nodal-related genes, indicating that squint, cyclops, and southpaw orthologues were present early in the teleost lineage. The genes flanking the nodal-related genes are also conserved, demonstrating a high degree of conserved synteny. Although we found little homology outside of the coding sequences in this region, pufferfish enhancer sequences work in zebrafish embryos to drive reporter gene expression in the squint expression pattern. This indicates a high degree of functional conservation of enhancer elements within the teleosts. We conclude that the ancestral squint and cyclops genes arose during the teleost-specific whole-genome duplication event and that southpaw emerged from a subsequent duplication event involving ancestral squint.
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Affiliation(s)
- Xiang Fan
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602, USA
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33
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Xiang F, Hagos EG, Xu B, Sias C, Kawakami K, Burdine RD, Dougan ST. Nodal signals mediate interactions between the extra-embryonic and embryonic tissues in zebrafish. Dev Biol 2007; 310:363-78. [PMID: 17850782 PMCID: PMC2044568 DOI: 10.1016/j.ydbio.2007.08.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 07/18/2007] [Accepted: 08/03/2007] [Indexed: 10/23/2022]
Abstract
In many vertebrates, extra-embryonic tissues are important signaling centers that induce and pattern the germ layers. In teleosts, the mechanism by which the extra-embryonic yolk syncytial layer (YSL) patterns the embryo is not understood. Although the Nodal-related protein Squint is expressed in the YSL, its role in this tissue is not known. We generated a series of stable transgenic lines with GFP under the control of squint genomic sequences. In all species, nodal-related genes induce their own expression through a positive feedback loop. We show that two tissue specific enhancers in the zebrafish squint gene mediate the response to Nodal signals. Expression in the blastomeres depends upon a conserved Nodal response element (NRE) in the squint first intron, while expression in the extra-embryonic enveloping layer (EVL) is mediated by an element upstream of the transcription start site. Targeted depletion experiments demonstrate that the zebrafish Nodal-related proteins Squint and Cyclops are required in the YSL for endoderm and head mesoderm formation. Thus, Nodal signals mediate interactions between embryonic and extra-embryonic tissues in zebrafish that maintain nodal-related gene expression in the margin. Our results demonstrate a high degree of functional conservation between the extra-embryonic tissues of mouse and zebrafish.
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Affiliation(s)
- Fan Xiang
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602
| | - Engda G. Hagos
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602
| | - Bo Xu
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Christina Sias
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | - Rebecca D. Burdine
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Scott T. Dougan
- Department of Cellular Biology, The University of Georgia, Athens, GA 30602
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