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Yip E, Giousoh A, Fung C, Wilding B, Prakash MD, Williams C, Verkade H, Bryson-Richardson RJ, Bird PI. A transgenic zebrafish model of hepatocyte function in human Z α1-antitrypsin deficiency. Biol Chem 2020; 400:1603-1616. [PMID: 31091192 DOI: 10.1515/hsz-2018-0391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 05/06/2019] [Indexed: 12/28/2022]
Abstract
In human α1-antitrypsin deficiency, homozygous carriers of the Z (E324K) mutation in the gene SERPINA1 have insufficient circulating α1-antitrypsin and are predisposed to emphysema. Misfolding and accumulation of the mutant protein in hepatocytes also causes endoplasmic reticulum stress and underpins long-term liver damage. Here, we describe transgenic zebrafish (Danio rerio) expressing the wildtype or the Z mutant form of human α1-antitrypsin in hepatocytes. As observed in afflicted humans, and in rodent models, about 80% less α1-antitrypsin is evident in the circulation of zebrafish expressing the Z mutant. Although these zebrafish also show signs of liver stress, they do not accumulate α1-antitrypsin in hepatocytes. This new zebrafish model will provide useful insights into understanding and treatment of α1-antitrypsin deficiency.
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Affiliation(s)
- Evelyn Yip
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Victoria, Australia
| | - Aminah Giousoh
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Victoria, Australia
| | - Connie Fung
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Victoria, Australia
| | - Brendan Wilding
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Victoria, Australia
| | - Monica D Prakash
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Victoria, Australia
| | - Caitlin Williams
- School of Biological Sciences, Monash University, Melbourne 3800, Victoria, Australia
| | - Heather Verkade
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville 3052, Victoria, Australia
| | | | - Phillip I Bird
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne 3800, Victoria, Australia
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Advani G, Lim YC, Catimel B, Lio DSS, Ng NLY, Chüeh AC, Tran M, Anasir MI, Verkade H, Zhu HJ, Turk BE, Smithgall TE, Ang CS, Griffin M, Cheng HC. Csk-homologous kinase (Chk) is an efficient inhibitor of Src-family kinases but a poor catalyst of phosphorylation of their C-terminal regulatory tyrosine. Cell Commun Signal 2017; 15:29. [PMID: 28784162 PMCID: PMC5547543 DOI: 10.1186/s12964-017-0186-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 07/28/2017] [Indexed: 11/10/2022] Open
Abstract
Background C-terminal Src kinase (Csk) and Csk-homologous kinase (Chk) are the major endogenous inhibitors of Src-family kinases (SFKs). They employ two mechanisms to inhibit SFKs. First, they phosphorylate the C-terminal tail tyrosine which stabilizes SFKs in a closed inactive conformation by engaging the SH2 domain in cis. Second, they employ a non-catalytic inhibitory mechanism involving direct binding of Csk and Chk to the active forms of SFKs that is independent of phosphorylation of their C-terminal tail. Csk and Chk are co-expressed in many cell types. Contributions of the two mechanisms towards the inhibitory activity of Csk and Chk are not fully clear. Furthermore, the determinants in Csk and Chk governing their inhibition of SFKs by the non-catalytic inhibitory mechanism are yet to be defined. Methods We determined the contributions of the two mechanisms towards the inhibitory activity of Csk and Chk both in vitro and in transduced colorectal cancer cells. Specifically, we assayed the catalytic activities of Csk and Chk in phosphorylating a specific peptide substrate and a recombinant SFK member Src. We employed surface plasmon resonance spectroscopy to measure the kinetic parameters of binding of Csk, Chk and their mutants to a constitutively active mutant of the SFK member Hck. Finally, we determined the effects of expression of recombinant Chk on anchorage-independent growth and SFK catalytic activity in Chk-deficient colorectal cancer cells. Results Our results revealed Csk as a robust enzyme catalysing phosphorylation of the C-terminal tail tyrosine of SFKs but a weak non-catalytic inhibitor of SFKs. In contrast, Chk is a poor catalyst of SFK tail phosphorylation but binds SFKs with high affinity, enabling it to efficiently inhibit SFKs with the non-catalytic inhibitory mechanism both in vitro and in transduced colorectal cancer cells. Further analyses mapped some of the determinants governing this non-catalytic inhibitory mechanism of Chk to its kinase domain. Conclusions SFKs are activated by different upstream signals to adopt multiple active conformations in cells. SFKs adopting these conformations can effectively be constrained by the two complementary inhibitory mechanisms of Csk and Chk. Furthermore, the lack of this non-catalytic inhibitory mechanism accounts for SFK overactivation in the Chk-deficient colorectal cancer cells. Electronic supplementary material The online version of this article (doi:10.1186/s12964-017-0186-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gahana Advani
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia.,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ya Chee Lim
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,PAP Rashidah Sa'adatul Bolkiah Institute of Health Sciences, Universiti Brunei Darussalam, Gadong, Brunei Darussalam
| | - Bruno Catimel
- Walter and Eliza Hall Institute for Medical Research and Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Daisy Sio Seng Lio
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia.,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Nadia L Y Ng
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia.,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Anderly C Chüeh
- Walter and Eliza Hall Institute for Medical Research and Department of Medical Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Mai Tran
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Mohd Ishtiaq Anasir
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Heather Verkade
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Hong-Jian Zhu
- Department of Surgery, University of Melbourne, Royal Melbourne Hospital, Parkville, VIC, 3052, Australia
| | - Benjamin E Turk
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, USA
| | - Thomas E Smithgall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ching-Seng Ang
- Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Michael Griffin
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia.,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Heung-Chin Cheng
- Department of Biochemistry & Molecular Biology, University of Melbourne, Parkville, VIC, 3010, Australia. .,Bio21 Biotechnology and Molecular Science Institute, University of Melbourne, Parkville, VIC, 3010, Australia. .,Cell Signalling Research Laboratories, School of Biomedical Sciences, University of Melbourne, Parkville, VIC, 3010, Australia.
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3
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Abstract
The zebrafish endoderm begins to develop at gastrulation stages as a monolayer of cells. The behaviour of the endoderm during gastrulation stages is well understood. However, knowledge of the morphogenic movements of the endoderm during somitogenesis stages, as it forms a mesenchymal rod, is lacking. Here we characterise endodermal development during somitogenesis stages, and describe the morphogenic movements as the endoderm transitions from a monolayer of cells into a mesenchymal endodermal rod. We demonstrate that, unlike the overlying mesoderm, endodermal cells are not polarised during their migration to the midline at early somitogenesis stages. Specifically, we describe the stage at which endodermal cells begin to leave the monolayer, a process we have termed 'midline aggregation'. The planar cell polarity (PCP) signalling pathway is known to regulate mesodermal and ectodermal cell convergence towards the dorsal midline. However, a role for PCP signalling in endoderm migration to the midline during somitogenesis stages has not been established. In this report, we investigate the role for PCP signalling in multiple phases of endoderm development during somitogenesis stages. Our data exclude involvement of PCP signalling in endodermal cells as they leave the monolayer.
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Affiliation(s)
- Lee B Miles
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - Takamasa Mizoguchi
- Graduate School of Pharmaceutical sciences, Chiba University, Chuo-ku 260-8675, Japan
| | - Yutaka Kikuchi
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Heather Verkade
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
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Gurevich DB, Nguyen PD, Siegel AL, Ehrlich OV, Sonntag C, Phan JMN, Berger S, Ratnayake D, Hersey L, Berger J, Verkade H, Hall TE, Currie PD. Asymmetric division of clonal muscle stem cells coordinates muscle regeneration in vivo. Science 2016; 353:aad9969. [PMID: 27198673 DOI: 10.1126/science.aad9969] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/10/2016] [Indexed: 12/11/2022]
Abstract
Skeletal muscle is an example of a tissue that deploys a self-renewing stem cell, the satellite cell, to effect regeneration. Recent in vitro studies have highlighted a role for asymmetric divisions in renewing rare "immortal" stem cells and generating a clonal population of differentiation-competent myoblasts. However, this model currently lacks in vivo validation. We define a zebrafish muscle stem cell population analogous to the mammalian satellite cell and image the entire process of muscle regeneration from injury to fiber replacement in vivo. This analysis reveals complex interactions between satellite cells and both injured and uninjured fibers and provides in vivo evidence for the asymmetric division of satellite cells driving both self-renewal and regeneration via a clonally restricted progenitor pool.
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Affiliation(s)
- David B Gurevich
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Phong Dang Nguyen
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Ashley L Siegel
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Ophelia V Ehrlich
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Carmen Sonntag
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Jennifer M N Phan
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Silke Berger
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Dhanushika Ratnayake
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Lucy Hersey
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Joachim Berger
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Heather Verkade
- School of Biological Sciences, Building 18, Monash University, Clayton, Victoria 3800, Australia
| | - Thomas E Hall
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
| | - Peter D Currie
- Australian Regenerative Medicine Institute, Level 1, 15 Innovation Walk, Monash University, Wellington Road, Clayton, Victoria 3800, Australia. European Molecular Biology Laboratory Australia Melbourne Node, Level 1, Building 75, Monash University, Wellington Road, Clayton, Victoria 3800, Australia.
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5
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Giousoh A, Vaz R, Bryson-Richardson RJ, Whisstock JC, Verkade H, Bird PI. Bone morphogenetic protein/retinoic acid inducible neural-specific protein (brinp) expression during Danio rerio development. Gene Expr Patterns 2015; 18:37-43. [DOI: 10.1016/j.gep.2015.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 04/15/2015] [Accepted: 05/02/2015] [Indexed: 11/30/2022]
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Jeffery J, Neyt C, Moore W, Paterson S, Bower NI, Chenevix‐Trench G, Verkade H, Hogan BM, Khanna KK. Cep55 regulates embryonic growth and development by promoting Akt stability in zebrafish. FASEB J 2015; 29:1999-2009. [DOI: 10.1096/fj.14-265090] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Affiliation(s)
- Jessie Jeffery
- Signal Transduction Laboratory, QIMR Berghofer Medical Research InstituteBrisbaneQueenslandAustralia
| | - Christine Neyt
- Vascular Biology and Development Laboratory, Institute for Molecular Bioscience, The University of QueenslandBrisbaneQueenslandAustralia
| | - Wade Moore
- Zebrafish Developmental Genetics Laboratory, Monash UniversityClaytonVictoriaAustralia
| | - Scott Paterson
- Vascular Biology and Development Laboratory, Institute for Molecular Bioscience, The University of QueenslandBrisbaneQueenslandAustralia
| | - Neil I. Bower
- Vascular Biology and Development Laboratory, Institute for Molecular Bioscience, The University of QueenslandBrisbaneQueenslandAustralia
| | - Georgia Chenevix‐Trench
- Cancer Genetics Laboratory, QIMR Berghofer Medical Research InstituteBrisbaneQueenslandAustralia
| | - Heather Verkade
- Zebrafish Developmental Genetics Laboratory, Monash UniversityClaytonVictoriaAustralia
| | - Benjamin M. Hogan
- Vascular Biology and Development Laboratory, Institute for Molecular Bioscience, The University of QueenslandBrisbaneQueenslandAustralia
| | - Kum Kum Khanna
- Signal Transduction Laboratory, QIMR Berghofer Medical Research InstituteBrisbaneQueenslandAustralia
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7
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Schonewille M, de Boer J, Boesjes M, Wolters H, Verkade H, Tietge U, Kremoser C, Groen A. Combination treatment of the novel pharmacological fxr-compound px20606 and ezetimibe leads to massively increased neutral sterols excretion in mice. Atherosclerosis 2014. [DOI: 10.1016/j.atherosclerosis.2014.05.535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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8
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Affiliation(s)
- Lee B. Miles
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Heather Verkade
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
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9
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Lancman JJ, Zvenigorodsky N, Gates KP, Zhang D, Solomon K, Humphrey RK, Kuo T, Setiawan L, Verkade H, Chi YI, Jhala US, Wright CVE, Stainier DYR, Dong PDS. Specification of hepatopancreas progenitors in zebrafish by hnf1ba and wnt2bb. Development 2013; 140:2669-79. [PMID: 23720049 PMCID: PMC3678338 DOI: 10.1242/dev.090993] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2013] [Indexed: 12/16/2022]
Abstract
Although the liver and ventral pancreas are thought to arise from a common multipotent progenitor pool, it is unclear whether these progenitors of the hepatopancreas system are specified by a common genetic mechanism. Efforts to determine the role of Hnf1b and Wnt signaling in this crucial process have been confounded by a combination of factors, including a narrow time frame for hepatopancreas specification, functional redundancy among Wnt ligands, and pleiotropic defects caused by either severe loss of Wnt signaling or Hnf1b function. Using a novel hypomorphic hnf1ba zebrafish mutant that exhibits pancreas hypoplasia, as observed in HNF1B monogenic diabetes, we show that hnf1ba plays essential roles in regulating β-cell number and pancreas specification, distinct from its function in regulating pancreas size and liver specification, respectively. By combining Hnf1ba partial loss of function with conditional loss of Wnt signaling, we uncover a crucial developmental window when these pathways synergize to specify the entire ventrally derived hepatopancreas progenitor population. Furthermore, our in vivo genetic studies demonstrate that hnf1ba generates a permissive domain for Wnt signaling activity in the foregut endoderm. Collectively, our findings provide a new model for HNF1B function, yield insight into pancreas and β-cell development, and suggest a new mechanism for hepatopancreatic specification.
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Affiliation(s)
- Joseph J. Lancman
- Sanford Children’s Health Research Center, Programs in Genetic Disease, Development and Aging, and Stem Cell and Regenerative Biology, Graduate School of Biomedical Sciences, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Natasha Zvenigorodsky
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, and the Diabetes Center and Liver Center, University of California, San Francisco, 1550 Fourth Street, San Francisco, CA 94158, USA
| | - Keith P. Gates
- Sanford Children’s Health Research Center, Programs in Genetic Disease, Development and Aging, and Stem Cell and Regenerative Biology, Graduate School of Biomedical Sciences, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Danhua Zhang
- Sanford Children’s Health Research Center, Programs in Genetic Disease, Development and Aging, and Stem Cell and Regenerative Biology, Graduate School of Biomedical Sciences, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Keely Solomon
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Rohan K. Humphrey
- Pediatric Diabetes Research Center, UCSD School of Medicine, La Jolla CA 92037, USA
| | - Taiyi Kuo
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, and the Diabetes Center and Liver Center, University of California, San Francisco, 1550 Fourth Street, San Francisco, CA 94158, USA
| | - Linda Setiawan
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, and the Diabetes Center and Liver Center, University of California, San Francisco, 1550 Fourth Street, San Francisco, CA 94158, USA
| | - Heather Verkade
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, and the Diabetes Center and Liver Center, University of California, San Francisco, 1550 Fourth Street, San Francisco, CA 94158, USA
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Young-In Chi
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Ulupi S. Jhala
- Pediatric Diabetes Research Center, UCSD School of Medicine, La Jolla CA 92037, USA
| | - Christopher V. E. Wright
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Didier Y. R. Stainier
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, and the Diabetes Center and Liver Center, University of California, San Francisco, 1550 Fourth Street, San Francisco, CA 94158, USA
| | - P. Duc Si Dong
- Sanford Children’s Health Research Center, Programs in Genetic Disease, Development and Aging, and Stem Cell and Regenerative Biology, Graduate School of Biomedical Sciences, Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
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Koltowska K, Apitz H, Stamataki D, Hirst EMA, Verkade H, Salecker I, Ober EA. Ssrp1a controls organogenesis by promoting cell cycle progression and RNA synthesis. Development 2013; 140:1912-8. [PMID: 23515471 DOI: 10.1242/dev.093583] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Tightly controlled DNA replication and RNA transcription are essential for differentiation and tissue growth in multicellular organisms. Histone chaperones, including the FACT (facilitates chromatin transcription) complex, are central for these processes and act by mediating DNA access through nucleosome reorganisation. However, their roles in vertebrate organogenesis are poorly understood. Here, we report the identification of zebrafish mutants for the gene encoding Structure specific recognition protein 1a (Ssrp1a), which, together with Spt16, forms the FACT heterodimer. Focussing on the liver and eye, we show that zygotic Ssrp1a is essential for proliferation and differentiation during organogenesis. Specifically, gene expression indicative of progressive organ differentiation is disrupted and RNA transcription is globally reduced. Ssrp1a-deficient embryos exhibit DNA synthesis defects and prolonged S phase, uncovering a role distinct from that of Spt16, which promotes G1 phase progression. Gene deletion/replacement experiments in Drosophila show that Ssrp1b, Ssrp1a and N-terminal Ssrp1a, equivalent to the yeast homologue Pob3, can substitute Drosophila Ssrp function. These data suggest that (1) Ssrp1b does not compensate for Ssrp1a loss in the zebrafish embryo, probably owing to insufficient expression levels, and (2) despite fundamental structural differences, the mechanisms mediating DNA accessibility by FACT are conserved between yeast and metazoans. We propose that the essential functions of Ssrp1a in DNA replication and gene transcription, together with its dynamic spatiotemporal expression, ensure organ-specific differentiation and proportional growth, which are crucial for the forming embryo.
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Affiliation(s)
- Katarzyna Koltowska
- Developmental Biology, MRC National Institute for Medical Research, London, UK
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Curado S, Ober EA, Walsh S, Cortes-Hernandez P, Verkade H, Koehler CM, Stainier DYR. The mitochondrial import gene tomm22 is specifically required for hepatocyte survival and provides a liver regeneration model. Dis Model Mech 2010; 3:486-95. [PMID: 20483998 DOI: 10.1242/dmm.004390] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Understanding liver development should lead to greater insights into liver diseases and improve therapeutic strategies. In a forward genetic screen for genes regulating liver development in zebrafish, we identified a mutant--oliver--that exhibits liver-specific defects. In oliver mutants, the liver is specified, bile ducts form and hepatocytes differentiate. However, the hepatocytes die shortly after their differentiation, and thus the resulting mutant liver consists mainly of biliary tissue. We identified a mutation in the gene encoding translocase of the outer mitochondrial membrane 22 (Tomm22) as responsible for this phenotype. Mutations in tomm genes have been associated with mitochondrial dysfunction, but most studies on the effect of defective mitochondrial protein translocation have been carried out in cultured cells or unicellular organisms. Therefore, the tomm22 mutant represents an important vertebrate genetic model to study mitochondrial biology and hepatic mitochondrial diseases. We further found that the temporary knockdown of Tomm22 levels by morpholino antisense oligonucleotides causes a specific hepatocyte degeneration phenotype that is reversible: new hepatocytes repopulate the liver as Tomm22 recovers to wild-type levels. The specificity and reversibility of hepatocyte ablation after temporary knockdown of Tomm22 provides an additional model to study liver regeneration, under conditions where most hepatocytes have died. We used this regeneration model to analyze the signaling commonalities between hepatocyte development and regeneration.
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Affiliation(s)
- Silvia Curado
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, University of California-San Francisco, 1550 Fourth Street, San Francisco, CA 94158-2324, USA.
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13
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de Jong-Curtain TA, Parslow AC, Trotter AJ, Hall NE, Verkade H, Tabone T, Christie EL, Crowhurst MO, Layton JE, Shepherd IT, Nixon SJ, Parton RG, Zon LI, Stainier DYR, Lieschke GJ, Heath JK. Abnormal nuclear pore formation triggers apoptosis in the intestinal epithelium of elys-deficient zebrafish. Gastroenterology 2009; 136:902-11. [PMID: 19073184 PMCID: PMC3804769 DOI: 10.1053/j.gastro.2008.11.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 10/02/2008] [Accepted: 11/03/2008] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Zebrafish mutants generated by ethylnitrosourea-mutagenesis provide a powerful tool for dissecting the genetic regulation of developmental processes, including organogenesis. One zebrafish mutant, "flotte lotte" (flo), displays striking defects in intestinal, liver, pancreas, and eye formation at 78 hours postfertilization (hpf). In this study, we sought to identify the underlying mutated gene in flo and link the genetic lesion to its phenotype. METHODS Positional cloning was employed to map the flo mutation. Subcellular characterization of flo embryos was achieved using histology, immunocytochemistry, bromodeoxyuridine incorporation analysis, and confocal and electron microscopy. RESULTS The molecular lesion in flo is a nonsense mutation in the elys (embryonic large molecule derived from yolk sac) gene, which encodes a severely truncated protein lacking the Elys C-terminal AT-hook DNA binding domain. Recently, the human ELYS protein has been shown to play a critical, and hitherto unsuspected, role in nuclear pore assembly. Although elys messenger RNA (mRNA) is expressed broadly during early zebrafish development, widespread early defects in flo are circumvented by the persistence of maternally expressed elys mRNA until 24 hpf. From 72 hpf, elys mRNA expression is restricted to proliferating tissues, including the intestinal epithelium, pancreas, liver, and eye. Cells in these tissues display disrupted nuclear pore formation; ultimately, intestinal epithelial cells undergo apoptosis. CONCLUSIONS Our results demonstrate that Elys regulates digestive organ formation.
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Affiliation(s)
- Tanya A. de Jong-Curtain
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Adam C. Parslow
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Andrew J. Trotter
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Nathan E. Hall
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Heather Verkade
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Tania Tabone
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Elizabeth L. Christie
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Meredith O. Crowhurst
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia
| | - Judith E. Layton
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
| | - Iain T. Shepherd
- Department of Biology, Emory University, 1510 Clifton Road, Atlanta GA 30322, United States of America
| | - Susan J. Nixon
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Robert G. Parton
- Institute for Molecular Bioscience and Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Leonard I. Zon
- Stem Cell Program and Division of Hematology and Oncology, Children’s Hospital, Dana-Farber Cancer Institute, Howard Hughes Medical Institute and Harvard Medical School, Boston, MA 02115, United States of America
| | - Didier Y. R. Stainier
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, United States of America
| | - Graham J. Lieschke
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
| | - Joan K. Heath
- Ludwig Institute for Cancer Research, Post Office Box 2008, Royal Melbourne Hospital, Parkville, Victoria 3050, Australia,Correspondence: Assoc. Prof. Joan K. Heath, Joint-Head, Colon Molecular and Cell Biology Laboratory, Ludwig Institute for Cancer Research, Post Office Royal Melbourne Hospital, Parkville, Victoria 3050, Australia, Tel: (+613) 9341 3155, Fax: (+613) 9341 3104,
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14
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Osborne N, Brand-Arzamendi K, Ober EA, Jin SW, Verkade H, Holtzman NG, Yelon D, Stainier DYR. The spinster homolog, two of hearts, is required for sphingosine 1-phosphate signaling in zebrafish. Curr Biol 2009; 18:1882-8. [PMID: 19062281 DOI: 10.1016/j.cub.2008.10.061] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 10/19/2008] [Accepted: 10/21/2008] [Indexed: 11/20/2022]
Abstract
The bioactive lipid sphingosine 1-phosphate (S1P) and its G protein-coupled receptors play critical roles in cardiovascular, immunological, and neural development and function. Despite its importance, many questions remain about S1P signaling, including how S1P, which is synthesized intracellularly, is released from cells. Mutations in the zebrafish gene encoding the S1P receptor Miles Apart (Mil)/S1P(2) disrupt the formation of the primitive heart tube. We find that mutations of another zebrafish locus, two of hearts (toh), cause phenotypes that are morphologically indistinguishable from those seen in mil/s1p2 mutants. Positional cloning of toh reveals that it encodes a member of the Spinster-like family of putative transmembrane transporters. The biological functions of these proteins are poorly understood, although phenotypes of the Drosophila spinster and zebrafish not really started mutants suggest that these proteins may play a role in lipid trafficking. Through gain- and loss-of-function analyses, we show that toh is required for signaling by S1P(2). Further evidence indicates that Toh is involved in the trafficking or cellular release of S1P.
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Affiliation(s)
- Nick Osborne
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, Cardiovascular Research Institute, University of California, San Francisco, 1550 Fourth Street, San Francisco, CA 94143, USA
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15
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Munson C, Huisken J, Bit-Avragim N, Kuo T, Dong PD, Ober EA, Verkade H, Abdelilah-Seyfried S, Stainier DYR. Regulation of neurocoel morphogenesis by Pard6 gamma b. Dev Biol 2008; 324:41-54. [PMID: 18817769 DOI: 10.1016/j.ydbio.2008.08.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 08/16/2008] [Accepted: 08/23/2008] [Indexed: 12/21/2022]
Abstract
The Par3/Par6/aPKC protein complex plays a key role in the establishment and maintenance of apicobasal polarity, a cellular characteristic essential for tissue and organ morphogenesis, differentiation and homeostasis. During a forward genetic screen for liver and pancreas mutants, we identified a pard6gammab mutant, representing the first known pard6 mutant in a vertebrate organism. pard6gammab mutants exhibit defects in epithelial tissue development as well as multiple lumens in the neural tube. Analyses of the cells lining the neural tube cavity, or neurocoel, in wildtype and pard6gammab mutant embryos show that lack of Pard6gammab function leads to defects in mitotic spindle orientation during neurulation. We also found that the PB1 (aPKC-binding) and CRIB (Cdc-42-binding) domains and the KPLG amino acid sequence within the PDZ domain (Pals1-and Crumbs binding) are not required for Pard6gammab localization but are essential for its function in neurocoel morphogenesis. Apical membranes are reduced, but not completely absent, in mutants lacking the zygotic, or both the maternal and zygotic, function of pard6gammab, leading us to examine the localization and function of the three additional zebrafish Pard6 proteins. We found that Pard6alpha, but not Pard6beta or Pard6gammaa, could partially rescue the pard6gammab(s441) mutant phenotypes. Altogether, these data indicate a previously unappreciated functional diversity and complexity within the vertebrate pard6 gene family.
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Affiliation(s)
- Chantilly Munson
- Department of Biochemistry and Biophysics, Genetics and Human Genetics, University of California, San Francisco, CA 94158, USA
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16
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Noël ES, Casal-Sueiro A, Busch-Nentwich E, Verkade H, Dong PDS, Stemple DL, Ober EA. Organ-specific requirements for Hdac1 in liver and pancreas formation. Dev Biol 2008; 322:237-50. [PMID: 18687323 PMCID: PMC3710974 DOI: 10.1016/j.ydbio.2008.06.040] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 05/28/2008] [Accepted: 06/20/2008] [Indexed: 12/14/2022]
Abstract
Liver, pancreas and lung originate from the presumptive foregut in temporal and spatial proximity. This requires precisely orchestrated transcriptional activation and repression of organ-specific gene expression within the same cell. Here, we show distinct roles for the chromatin remodelling factor and transcriptional repressor Histone deacetylase 1 (Hdac1) in endodermal organogenesis in zebrafish. Loss of Hdac1 causes defects in timely liver specification and in subsequent differentiation. Mosaic analyses reveal a cell-autonomous requirement for hdac1 within the hepatic endoderm. Our studies further reveal specific functions for Hdac1 in pancreas development. Loss of hdac1 causes the formation of ectopic endocrine clusters anteriorly to the main islet, as well as defects in exocrine pancreas specification and differentiation. In addition, we observe defects in extrahepatopancreatic duct formation and morphogenesis. Finally, loss of hdac1 results in an expansion of the foregut endoderm in the domain from which the liver and pancreas originate. Our genetic studies demonstrate that Hdac1 is crucial for regulating distinct steps in endodermal organogenesis. This suggests a model in which Hdac1 may directly or indirectly restrict foregut fates while promoting hepatic and exocrine pancreatic specification and differentiation, as well as pancreatic endocrine islet morphogenesis. These findings establish zebrafish as a tractable system to investigate chromatin remodelling factor functions in controlling gene expression programmes in vertebrate endodermal organogenesis.
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Affiliation(s)
- Emily S Noël
- National Institute for Medical Research, Division of Developmental Biology, The Ridgeway, Mill Hill, London, UK
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17
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Mizoguchi T, Verkade H, Heath JK, Kuroiwa A, Kikuchi Y. Sdf1/Cxcr4 signaling controls the dorsal migration of endodermal cells during zebrafish gastrulation. Development 2008; 135:2521-9. [PMID: 18579679 DOI: 10.1242/dev.020107] [Citation(s) in RCA: 152] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
During vertebrate gastrulation, both mesodermal and endodermal cells internalize through the blastopore beneath the ectoderm. In zebrafish, the internalized mesodermal cells move towards the dorsal side of the gastrula and, at the same time, they extend anteriorly by convergence and extension (C&E) movements. Endodermal cells showing characteristic filopodia then migrate into the inner layer within the hypoblast next to the yolk syncytial layer (YSL). However, little is known about how the movement of endodermal cells is regulated during gastrulation. Here we show that sdf1a- and sdf1b-expressing mesodermal cells control the movements of the cxcr4a-expressing endodermal cells. The directional migration of endodermal cells during gastrulation is inhibited by knockdown of either cxcr4a or sdf1a/sdf1b (sdf1). We also show that misexpressed Sdf1 acts as a chemoattractant for cxcr4a-expressing endodermal cells. We further found, using the endoderm-specific transgenic line Tg(sox17:EGFP), that Sdf1/Cxcr4 signaling regulates both the formation and orientation of filopodial processes in endodermal cells. Moreover, the accumulation of phosphoinositide 3,4,5-trisphosphate (PIP(3)), which is known to occur at the leading edge of migrating cells, is not observed at the filopodia of endodermal cells. Based on our results, we propose that sdf1-expressing mesodermal cells, which overlie the endodermal layer, guide the cxcr4a-expressing endodermal cells to the dorsal side of the embryo during gastrulation, possibly through a PIP(3)-independent pathway.
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Affiliation(s)
- Takamasa Mizoguchi
- Department of Biological Science, Graduate School of Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima, Hiroshima, Japan
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18
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Petersen C, Harder D, Abola Z, Alberti D, Becker T, Chardot C, Davenport M, Deutschmann A, Khelif K, Kobayashi H, Kvist N, Leonhardt J, Melter M, Pakarinen M, Pawlowska J, Petersons A, Pfister ED, Rygl M, Schreiber R, Sokol R, Ure B, Veiga C, Verkade H, Wildhaber B, Yerushalmi B, Kelly D. European biliary atresia registries: summary of a symposium. Eur J Pediatr Surg 2008; 18:111-6. [PMID: 18437656 DOI: 10.1055/s-2008-1038479] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Biliary atresia (BA) is a rare but potentially devastating disease. The European Biliary Atresia Registry (EBAR) was set up to improve data collection and to develop a pan-national and interdisciplinary strategy to improve clinical outcomes. From 2001 to 2005, 100 centers from 22 countries registered with EBAR via its website (www.biliary-atresia.com). In June 2006, the first meeting was held to evaluate results and launch further initiatives. During a 5-year period, 60 centers from 19 European countries and Israel sent completed registration forms for a total of 514 BA patients. Assuming the estimated incidence of BA in Europe is 1:18,000 live births, 35% of the expected 1488 patients from all EBAR participating countries were captured, suggesting that reporting arrangements need improvement. At the meeting, the cumulative evaluation of 928 BA patients including patients from other registries with variable follow-up revealed an overall survival of 78% (range from 41% to 92%), of whom 342 patients (37%) have had liver transplants. Survival with native liver ranged from 14% to 75%. There was a marked variance in reported management and outcome by country (e.g., referral patterns, timing of surgery, centralization of surgery). In conclusion, EBAR represents the first attempt at an overall evaluation of the outcome of BA from a pan-European perspective. The natural history and outcome of biliary atresia is of considerable relevance to a European population. It is essential that there is further support for a pan-European registry with coordination of clinical standards, further participation of parent support groups, and implementation of online data entry and multidisciplinary clinical and basic research projects.
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Affiliation(s)
- C Petersen
- Department of Pediatric Surgery, Medical School Hannover, Hannover, Germany.
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19
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Shin CH, Chung WS, Hong SK, Ober EA, Verkade H, Field HA, Huisken J, Stainier DYR. Multiple roles for Med12 in vertebrate endoderm development. Dev Biol 2008; 317:467-79. [PMID: 18394596 DOI: 10.1016/j.ydbio.2008.02.031] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Revised: 02/14/2008] [Accepted: 02/15/2008] [Indexed: 02/02/2023]
Abstract
In zebrafish, the endoderm originates at the blastula stage from the most marginal blastomeres. Through a series of complex morphogenetic movements and differentiation events, the endodermal germ layer gives rise to the epithelial lining of the digestive tract as well as its associated organs such as the liver, pancreas, and swim bladder. How endodermal cells differentiate into distinct cell types such as hepatocytes or endocrine and exocrine pancreatic cells remains a major question. In a forward genetic screen for genes regulating endodermal organ development, we identified mutations at the shiri locus that cause defects in the development of a number of endodermal organs including the liver and pancreas. Detailed phenotypic analyses indicate that these defects are partially due to a reduction in endodermal expression of the hairy/enhancer of split-related gene, her5, at mid to late gastrulation stages. Using the Tg(0.7her5:EGFP)(ne2067) line, we show that her5 is expressed in the endodermal precursors that populate the pharyngeal region as well as the organ-forming region. We also find that knocking down her5 recapitulates some of the endodermal phenotypes of shiri mutants, further revealing the role of her5 in endoderm development. Positional cloning reveals that shiri encodes Med12, a regulatory subunit of the transcriptional Mediator complex recently associated with two human syndromes. Additional studies indicate that Med12 modulates the ability of Casanova/Sox32 to induce sox17 expression. Thus, detailed phenotypic analyses of embryos defective in a component of the Mediator complex have revealed new insights into discrete aspects of vertebrate endoderm development, and provide possible explanations for the craniofacial and digestive system defects observed in humans with mutations in MED12.
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Affiliation(s)
- Chong Hyun Shin
- Department of Biochemistry and Biophysics, Liver Center, University of California, San Francisco, CA 94158, USA.
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20
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Hogan BM, Verkade H, Lieschke GJ, Heath JK. Manipulation of gene expression during zebrafish embryonic development using transient approaches. Methods Mol Biol 2008; 469:273-300. [PMID: 19109716 DOI: 10.1007/978-1-60327-469-2_19] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The rapid embryonic development and high fecundity of zebrafish contribute to the great advantages of this model for the study of developmental genetics. Transient disruption of the normal function of a gene during development can be achieved by microinjecting mRNA, DNA or short chemically stabilized anti-sense oligomers, called morpholinos (MOs), into early zebrafish embryos. The ensuing develop ment of the microinjected embryos is observed over the following hours and days to analyze the impact of the microinjected products on embryogenesis. Compared to stable reverse genetic approaches (sta ble transgenesis, targeted mutants recovered by TILLING), these transient reverse genetic approaches are vastly quicker, relatively affordable, and require little animal facility space. Common applications of these methodologies allow analysis of gain-of-function (gene overexpression or dominant active), loss-of-function (gene knock down or dominant negative), mosaic analysis, lineage-restricted studies and cell tracing experiments. The use of these transient approaches for the manipulation of gene expression has improved our understanding of many key developmental pathways including both the Wnt/beta-catenin and Wnt/PCP pathways, as covered in some detail in Chapter 17 of this book. This chapter describes the most common and versatile approaches: gain of function and loss of function using DNA and mRNA injections and loss of function using MOs.
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Affiliation(s)
- Benjamin M Hogan
- Hubrecht Institute for Developmental Biology and Stem Cell Research, Uppsalalaan 8, 3584, CT Utrecht, The Netherlands
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21
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Abstract
A combination of forward and reverse genetic approaches in zebrafish has revealed novel roles for canonical Wnt and Wnt/PCP signaling during vertebrate development. Forward genetics in zebrafish provides an exceptionally powerful tool to assign roles in vertebrate developmental processes to novel genes, as well as elucidating novel roles played by known genes. This has indeed turned out to be the case for components of the canonical Wnt signaling pathway. Non-canonical Wnt signaling in the zebrafish is also currently a topic of great interest, due to the identified roles of this pathway in processes requiring the integration of cell polarity and cell movement, such as the directed migration movements that drive the narrowing and lengthening (convergence and extension) of the embryo during early development.
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Affiliation(s)
- Heather Verkade
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
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22
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Wilkins SJ, Yoong S, Verkade H, Mizoguchi T, Plowman SJ, Hancock JF, Kikuchi Y, Heath JK, Perkins AC. Mtx2 directs zebrafish morphogenetic movements during epiboly by regulating microfilament formation. Dev Biol 2007; 314:12-22. [PMID: 18154948 DOI: 10.1016/j.ydbio.2007.10.050] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 10/17/2007] [Accepted: 10/19/2007] [Indexed: 11/16/2022]
Abstract
The homeobox transcription factor Mtx2 is essential for epiboly, the first morphogenetic movement of gastrulation in zebrafish. Morpholino knockdown of Mtx2 results in stalling of epiboly and lysis due to yolk rupture. However, the mechanism of Mtx2 action is unknown. The role of mtx2 is surprising as most mix/bix family genes are thought to have roles in mesendoderm specification. Using a transgenic sox17-promoter driven EGFP line, we show that Mtx2 is not required for endoderm specification but is required for correct morphogenetic movements of endoderm and axial mesoderm. During normal zebrafish development, mtx2 is expressed at both the blastoderm margin and in the zebrafish equivalent of visceral endoderm, the extra-embryonic yolk syncytial layer (YSL). We show that formation of the YSL is not Mtx2 dependent, but that Mtx2 directs spatial arrangement of YSL nuclei. Furthermore, we demonstrate that Mtx2 knockdown results in loss of the YSL F-actin ring, a microfilament structure previously shown to be necessary for epiboly progression. In summary, we propose that Mtx2 acts within the YSL to regulate morphogenetic movements of both embryonic and extra-embryonic tissues, independently of cell fate specification.
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Affiliation(s)
- Simon J Wilkins
- Institute for Molecular Bioscience, University of Queensland, Brisbane, 4072, Australia
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23
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Jin SW, Herzog W, Santoro MM, Mitchell TS, Frantsve J, Jungblut B, Beis D, Scott IC, D'Amico LA, Ober EA, Verkade H, Field HA, Chi NC, Wehman AM, Baier H, Stainier DYR. A transgene-assisted genetic screen identifies essential regulators of vascular development in vertebrate embryos. Dev Biol 2007; 307:29-42. [PMID: 17531218 PMCID: PMC2695512 DOI: 10.1016/j.ydbio.2007.03.526] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 03/30/2007] [Accepted: 03/30/2007] [Indexed: 11/18/2022]
Abstract
Formation of a functional vasculature during mammalian development is essential for embryonic survival. In addition, imbalance in blood vessel growth contributes to the pathogenesis of numerous disorders. Most of our understanding of vascular development and blood vessel growth comes from investigating the Vegf signaling pathway as well as the recent observation that molecules involved in axon guidance also regulate vascular patterning. In order to take an unbiased, yet focused, approach to identify novel genes regulating vascular development, we performed a three-step ENU mutagenesis screen in zebrafish. We first screened live embryos visually, evaluating blood flow in the main trunk vessels, which form by vasculogenesis, and the intersomitic vessels, which form by angiogenesis. Embryos that displayed reduced or absent circulation were fixed and stained for endogenous alkaline phosphatase activity to reveal blood vessel morphology. All putative mutants were then crossed into the Tg(flk1:EGFP)(s843) transgenic background to facilitate detailed examination of endothelial cells in live and fixed embryos. We screened 4015 genomes and identified 30 mutations affecting various aspects of vascular development. Specifically, we identified 3 genes (or loci) that regulate the specification and/or differentiation of endothelial cells, 8 genes that regulate vascular tube and lumen formation, 8 genes that regulate vascular patterning, and 11 genes that regulate vascular remodeling, integrity and maintenance. Only 4 of these genes had previously been associated with vascular development in zebrafish illustrating the value of this focused screen. The analysis of the newly defined loci should lead to a greater understanding of vascular development and possibly provide new drug targets to treat the numerous pathologies associated with dysregulated blood vessel growth.
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Affiliation(s)
- Suk-Won Jin
- Department of Biochemistry and Biophysics, Genetics and Human Genetics, and Cardiovascular Research Institute, University of California San Francisco, CA 94158, USA.
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24
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Ober EA, Verkade H, Field HA, Stainier DYR. Mesodermal Wnt2b signalling positively regulates liver specification. Nature 2006; 442:688-91. [PMID: 16799568 DOI: 10.1038/nature04888] [Citation(s) in RCA: 268] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 05/15/2006] [Indexed: 11/09/2022]
Abstract
Endodermal organs such as the lung, liver and pancreas emerge at precise locations along the primitive gut tube. Although several signalling pathways have been implicated in liver formation, so far no single gene has been identified that exclusively regulates liver specification. In zebrafish, the onset of liver specification is marked by the localized endodermal expression of hhex and prox1 at 22 hours post fertilization. Here we used a screen for mutations affecting endodermal organ morphogenesis to identify a unique phenotype: prometheus (prt) mutants exhibit profound, though transient, defects in liver specification. Positional cloning reveals that prt encodes a previously unidentified Wnt2b homologue. prt/wnt2bb is expressed in restricted bilateral domains in the lateral plate mesoderm directly adjacent to the liver-forming endoderm. Mosaic analyses show the requirement for Prt/Wnt2bb in the lateral plate mesoderm, in agreement with the inductive properties of Wnt signalling. Taken together, these data reveal an unexpected positive role for Wnt signalling in liver specification, and indicate a possible common theme for the localized formation of endodermal organs along the gut tube.
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Affiliation(s)
- Elke A Ober
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, and the Liver Center, University of California, San Francisco, 1550 Fourth Street, San Francisco, California 94143, USA.
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25
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Beis D, Bartman T, Jin SW, Scott IC, D'Amico LA, Ober EA, Verkade H, Frantsve J, Field HA, Wehman A, Baier H, Tallafuss A, Bally-Cuif L, Chen JN, Stainier DYR, Jungblut B. Genetic and cellular analyses of zebrafish atrioventricular cushion and valve development. Development 2005; 132:4193-204. [PMID: 16107477 DOI: 10.1242/dev.01970] [Citation(s) in RCA: 253] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Defects in cardiac valve morphogenesis and septation of the heart chambers constitute some of the most common human congenital abnormalities. Some of these defects originate from errors in atrioventricular (AV) endocardial cushion development. Although this process is being extensively studied in mouse and chick, the zebrafish system presents several advantages over these models, including the ability to carry out forward genetic screens and study vertebrate gene function at the single cell level. In this paper, we analyze the cellular and subcellular architecture of the zebrafish heart during stages of AV cushion and valve development and gain an unprecedented level of resolution into this process. We find that endocardial cells in the AV canal differentiate morphologically before the onset of epithelial to mesenchymal transformation, thereby defining a previously unappreciated step during AV valve formation. We use a combination of novel transgenic lines and fluorescent immunohistochemistry to analyze further the role of various genetic (Notch and Calcineurin signaling) and epigenetic (heart function) pathways in this process. In addition, from a large-scale forward genetic screen we identified 55 mutants, defining 48 different genes, that exhibit defects in discrete stages of AV cushion development. This collection of mutants provides a unique set of tools to further our understanding of the genetic basis of cell behavior and differentiation during AV valve development.
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Affiliation(s)
- Dimitris Beis
- Department of Biochemistry and Biophysics and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, USA
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26
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Abstract
Early in vertebrate development, the processes of gastrulation lead to the formation of the three germ layers: ectoderm, mesoderm, and endoderm. The mechanisms leading to the segregation of the endoderm and mesoderm are not well understood. In mid-blastula stage zebrafish embryos, single marginal cells can give rise to both endoderm and mesoderm (reviewed by Warga and Stainier [2002] The guts of endoderm formation. In: Solnica-Krezel L, editor. Pattern formation in zebrafish. Berlin: Springer-Verlag. p 28-47). By the late blastula stage, however, single marginal cells generally give rise to either endoderm or mesoderm. To investigate this segregation of the blastoderm into cells with either endodermal or mesodermal fates, we analyzed the role of Notch signaling in this process. We show that deltaC, deltaD, and notch1 are expressed in the marginal domain of blastula stage embryos and that this expression is dependent on Nodal signaling. Activation of Notch signaling from an early stage leads to a reduction of endodermal cells, as assessed by sox17 and foxA2 expression. We further find that this reduction in endoderm formation by the activation of Notch signaling is preceded by a reduction in the expression of bonnie and clyde (bon) and faust/gata5, two genes necessary for endoderm formation (Reiter et al. [1999] Genes Dev 13:2983-2995; Reiter et al. [2001] Development 128:125-135; Kikuchi et al. [2001] Genes Dev 14:1279-1289). However, activation of Notch signaling in bon mutant embryos leads to a further reduction in endodermal cells, also arguing for a bon-independent role for Notch signaling in endoderm formation. Altogether, these results suggest that Notch signaling plays a role in the formation of the endoderm, possibly in its segregation from the mesoderm.
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Affiliation(s)
- Yutaka Kikuchi
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Japan.
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27
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Loosli F, Staub W, Finger-Baier KC, Ober EA, Verkade H, Wittbrodt J, Baier H. Loss of eyes in zebrafish caused by mutation of chokh/rx3. EMBO Rep 2003; 4:894-9. [PMID: 12947416 PMCID: PMC1326357 DOI: 10.1038/sj.embor.embor919] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2003] [Revised: 07/14/2003] [Accepted: 07/15/2003] [Indexed: 11/08/2022] Open
Abstract
The vertebrate eye forms by specification of the retina anlage and subsequent morphogenesis of the optic vesicles, from which the neural retina differentiates. chokh (chk) mutant zebrafish lack eyes from the earliest stages in development. Marker gene analysis indicates that retinal fate is specified normally, but optic vesicle evagination and neuronal differentiation are blocked. We show that the chk gene encodes the homeodomain-containing transcription factor, Rx3. Loss of Rx3 function in another teleost,medaka, has also been shown to result in an eyeless phenotype. The medaka rx3 locus can fully rescue the zebrafish mutant phenotype. We provide evidence that the regulation of rx3 is evolutionarily conserved, whereas the downstream cascade contains significant differences in gene regulation. Thus, these mutations in orthologous genes allow us to study the evolution of vertebrate eye development at the molecular level.
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Affiliation(s)
- Felix Loosli
- Developmental Biology Programme, European
Molecular Biology Laboratory, Meyerhofstrasse 1, PO Box
10.2209, 69012 Heidelberg,
Germany
| | - Wendy Staub
- Department of Physiology, Programs in Genetics,
Human Genetics, Neuroscience, and Developmental Biology, 513 Parnassus Avenue,
University of California, San Francisco, California
94143 0444, USA
| | - Karin C. Finger-Baier
- Department of Physiology, Programs in Genetics,
Human Genetics, Neuroscience, and Developmental Biology, 513 Parnassus Avenue,
University of California, San Francisco, California
94143 0444, USA
| | - Elke A. Ober
- Department of Biochemistry, Programs in Genetics,
Human Genetics, Neuroscience, and Developmental Biology, 513 Parnassus Avenue,
University of California, San Francisco, California
94143 0444, USA
| | - Heather Verkade
- Department of Biochemistry, Programs in Genetics,
Human Genetics, Neuroscience, and Developmental Biology, 513 Parnassus Avenue,
University of California, San Francisco, California
94143 0444, USA
| | - Joachim Wittbrodt
- Developmental Biology Programme, European
Molecular Biology Laboratory, Meyerhofstrasse 1, PO Box
10.2209, 69012 Heidelberg,
Germany
| | - Herwig Baier
- Department of Physiology, Programs in Genetics,
Human Genetics, Neuroscience, and Developmental Biology, 513 Parnassus Avenue,
University of California, San Francisco, California
94143 0444, USA
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Abstract
Members of both the bone morphogenetic protein (Bmp) and EGF-CFC families have been implicated in vertebrate myocardial development. Zebrafish swirl (swr) encodes Bmp2b, a member of the Bmp family required for patterning the dorsoventral axis. Zebrafish one-eyed pinhead (oep) encodes a maternally and zygotically expressed member of the EGF-CFC family essential for Nodal signaling. Both swr/bmp2b and oep mutants exhibit severe defects in myocardial development. swr/bmp2b mutants exhibit reduced or absent expression of nkx2.5, an early marker of the myocardial precursors. Embryos lacking zygotic oep (Zoep mutants) display cardia bifida and, as we show here, also display reduced or absent nkx2.5 expression. Recently, we have demonstrated that the zinc finger transcription factor Gata5 is an essential regulator of nkx2.5 expression. In this paper, we investigate the relationships between bmp2b, oep, gata5, and nkx2.5. We show that both swr/bmp2b and Zoep mutants exhibit defects in gata5 expression in the myocardial precursors. Forced expression of gata5 in swr/bmp2b and Zoep mutants restores robust nkx2.5 expression. Moreover, overexpression of gata5 in Zoep mutants restores expression of cmlc1, a myocardial sarcomeric gene. These results indicate that both Bmp2b and Oep regulate gata5 expression in the myocardial precursors, and that Gata5 does not require Bmp2b or Oep to promote early myocardial differentiation. We conclude that Bmp2b and Oep function at least partly through Gata5 to regulate nkx2.5 expression and promote myocardial differentiation. We integrate these and other data to propose a pathway of the molecular events regulating early myocardial differentiation in zebrafish.
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Affiliation(s)
- J F Reiter
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143-0448, USA
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Rusiñol A, Verkade H, Vance JE. Assembly of rat hepatic very low density lipoproteins in the endoplasmic reticulum. J Biol Chem 1993; 268:3555-62. [PMID: 8429031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The intracellular site of assembly of hepatic very low density lipoproteins has been investigated. Two endoplasmic reticulum fractions and Golgi vesicles (relatively free from endosomal contamination) were isolated from rat liver and the luminal contents were released. The apoB-containing entities were separated from the lumen of the endoplasmic reticulum and Golgi vesicles by an immunoaffinity isolation procedure. The amount of each lipid moiety (triacylglycerols, cholesterol plus cholesteryl esters and phospholipids) associated with a unit mass of apoB was shown to be very similar in the luminal contents isolated from each of the three fractions. Moreover, the apoB-containing particles that were isolated from the endoplasmic reticulum and Golgi were mainly present in a fraction of density < 1.02 g/ml. The average diameter of these lipoprotein particles was shown by negative staining electron microscopy to be in the size range of very low density lipoproteins and low density lipoproteins. The size and composition of the intracellular lipoproteins were very similar to those of both very low density lipoproteins isolated from the culture medium from rat hepatocytes and plasma very low density lipoproteins. The conclusion from this study is that the full complement of lipids associate with apoB at an early stage during the secretory pathway, in the endoplasmic reticulum.
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Affiliation(s)
- A Rusiñol
- Department of Medicine, University of Alberta, Edmonton, Canada
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