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Johal S, Elsayed R, Panfilio KA, Nelson AC. The molecular basis for functional divergence of duplicated SOX factors controlling endoderm formation and left-right patterning in zebrafish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579092. [PMID: 39605568 PMCID: PMC11601245 DOI: 10.1101/2024.02.06.579092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2024]
Abstract
Endoderm, one of three primary germ layers of vertebrate embryos, makes major contributions to the respiratory and gastrointestinal tracts and associated organs, including liver and pancreas. In mammals, the transcription factor SOX17 is vital for endoderm organ formation and can induce endoderm progenitor identity. Duplication of ancestral sox17 in the teleost lineage produced the paralogues sox32 and sox17 in zebrafish. Sox32 is required for specification of endoderm and progenitors of the left-right organiser (Kupffer's Vesicle, KV), with Sox17 a downstream target of Sox32 that is implicated in further KV development. Phenotypic evidence therefore suggests functional similarities between zebrafish Sox32 and Sox17 and mammalian SOX17. Here, we directly compare these orthologues and paralogues, using the early zebrafish embryo as a biological platform for functional testing. Our results indicate that, unlike Sox32, human SOX17 cannot induce endoderm specification in zebrafish. Furthermore, using hybrid protein functional analyses, we show that Sox32 specificity for the endoderm gene regulatory network is linked to evolutionary divergence in its DNA-binding HMG domain from its paralogue Sox17. Additionally, changes in the C-terminal regions of Sox32 and Sox17 underpin their differing target specificities. Finally, we establish that specific conserved peptides in the C-terminal domain are essential for the role of Sox17 in establishing correct organ asymmetry. Overall, our results illuminate the molecular basis for functional divergence of Sox32 and Sox17 in vertebrate endoderm development and left-right patterning, and the evolution of SoxF transcription factor function.
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2
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Rüegg AB, van der Weijden VA, de Sousa JA, von Meyenn F, Pausch H, Ulbrich SE. Developmental progression continues during embryonic diapause in the roe deer. Commun Biol 2024; 7:270. [PMID: 38443549 PMCID: PMC10914810 DOI: 10.1038/s42003-024-05944-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/21/2024] [Indexed: 03/07/2024] Open
Abstract
Embryonic diapause in mammals is a temporary developmental delay occurring at the blastocyst stage. In contrast to other diapausing species displaying a full arrest, the blastocyst of the European roe deer (Capreolus capreolus) proliferates continuously and displays considerable morphological changes in the inner cell mass. We hypothesised that developmental progression also continues during this period. Here we evaluate the mRNA abundance of developmental marker genes in embryos during diapause and elongation. Our results show that morphological rearrangements of the epiblast during diapause correlate with gene expression patterns and changes in cell polarity. Immunohistochemical staining further supports these findings. Primitive endoderm formation occurs during diapause in embryos composed of around 3,000 cells. Gastrulation coincides with elongation and thus takes place after embryo reactivation. The slow developmental progression makes the roe deer an interesting model for unravelling the link between proliferation and differentiation and requirements for embryo survival.
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Affiliation(s)
- Anna B Rüegg
- ETH Zurich, Animal Physiology, Institute of Agricultural Sciences, Zurich, Switzerland
| | - Vera A van der Weijden
- ETH Zurich, Animal Physiology, Institute of Agricultural Sciences, Zurich, Switzerland
- Max-Planck Institute for Molecular Genetics, Berlin, Germany
| | - João Agostinho de Sousa
- ETH Zurich, Laboratory of Nutrition and Metabolic Epigenetics, Institute of Food, Nutrition and Health, Zurich, Switzerland
| | - Ferdinand von Meyenn
- ETH Zurich, Laboratory of Nutrition and Metabolic Epigenetics, Institute of Food, Nutrition and Health, Zurich, Switzerland
| | - Hubert Pausch
- ETH Zurich, Animal Genomics, Institute of Agricultural Sciences, Zurich, Switzerland
| | - Susanne E Ulbrich
- ETH Zurich, Animal Physiology, Institute of Agricultural Sciences, Zurich, Switzerland.
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3
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Bellchambers HM, Phatak AR, Nenni MJ, Padua MB, Gao H, Liu Y, Ware SM. Single cell RNA analysis of the left-right organizer transcriptome reveals potential novel heterotaxy genes. Sci Rep 2023; 13:10688. [PMID: 37393374 PMCID: PMC10314903 DOI: 10.1038/s41598-023-36862-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 06/13/2023] [Indexed: 07/03/2023] Open
Abstract
The establishment of left-right patterning in mice occurs at a transient structure called the embryonic node or left-right organizer (LRO). Previous analysis of the LRO has proven challenging due to the small cell number and transient nature of this structure. Here, we seek to overcome these difficulties to define the transcriptome of the LRO. Specifically, we used single cell RNA sequencing of 0-1 somite embryos to identify LRO enriched genes which were compared to bulk RNA sequencing of LRO cells isolated by fluorescent activated cell sorting. Gene ontology analysis indicated an enrichment of genes associated with cilia and laterality terms. Furthermore, comparison to previously identified LRO genes identified 127 novel LRO genes, including Ttll3, Syne1 and Sparcl1, for which the expression patterns were validated using whole mount in situ hybridization. This list of novel LRO genes will be a useful resource for further studies on LRO morphogenesis, the establishment of laterality and the genetic causes of heterotaxy.
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Affiliation(s)
- Helen M Bellchambers
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, 1044 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - Amruta R Phatak
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, 1044 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - Mardi J Nenni
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Maria B Padua
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, 1044 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - Hongyu Gao
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yunlong Liu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Stephanie M Ware
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, 1044 W. Walnut Street, Indianapolis, IN, 46202, USA.
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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4
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Antony D, Gulec Yilmaz E, Gezdirici A, Slagter L, Bakey Z, Bornaun H, Tanidir IC, Van Dinh T, Brunner HG, Walentek P, Arnold SJ, Backofen R, Schmidts M. Spectrum of Genetic Variants in a Cohort of 37 Laterality Defect Cases. Front Genet 2022; 13:861236. [PMID: 35547246 PMCID: PMC9083912 DOI: 10.3389/fgene.2022.861236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Laterality defects are defined by the perturbed left–right arrangement of organs in the body, occurring in a syndromal or isolated fashion. In humans, primary ciliary dyskinesia (PCD) is a frequent underlying condition of defective left–right patterning, where ciliary motility defects also result in reduced airway clearance, frequent respiratory infections, and infertility. Non-motile cilia dysfunction and dysfunction of non-ciliary genes can also result in disturbances of the left–right body axis. Despite long-lasting genetic research, identification of gene mutations responsible for left–right patterning has remained surprisingly low. Here, we used whole-exome sequencing with Copy Number Variation (CNV) analysis to delineate the underlying molecular cause in 35 mainly consanguineous families with laterality defects. We identified causative gene variants in 14 families with a majority of mutations detected in genes previously associated with PCD, including two small homozygous CNVs. None of the patients were previously clinically diagnosed with PCD, underlining the importance of genetic diagnostics for PCD diagnosis and adequate clinical management. Identified variants in non-PCD-associated genes included variants in PKD1L1 and PIFO, suggesting that dysfunction of these genes results in laterality defects in humans. Furthermore, we detected candidate variants in GJA1 and ACVR2B possibly associated with situs inversus. The low mutation detection rate of this study, in line with other previously published studies, points toward the possibility of non-coding genetic variants, putative genetic mosaicism, epigenetic, or environmental effects promoting laterality defects.
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Affiliation(s)
- Dinu Antony
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, Netherlands
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Elif Gulec Yilmaz
- Department of Medical Genetics, University of Health Sciences, Istanbul Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Alper Gezdirici
- Department of Medical Genetics, University of Health Sciences, Istanbul Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Lennart Slagter
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, Netherlands
| | - Zeineb Bakey
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, Netherlands
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Helen Bornaun
- Department of Pediatric Cardiology, University of Health Sciences, Istanbul Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | | | - Tran Van Dinh
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
| | - Han G. Brunner
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, Netherlands
- Maastricht University Medical Center and GROW School of Oncology and Development, Maastricht University, Maastricht, Netherlands
| | - Peter Walentek
- Renal Division, Department of Medicine, University Hospital Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS- Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Sebastian J. Arnold
- CIBSS- Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- CIBSS- Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Miriam Schmidts
- Genome Research Division, Human Genetics Department, Radboud University Medical Center and Radboud Institute for Molecular Life Sciences, Nijmegen, Netherlands
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Faculty of Medicine, Freiburg, Germany
- CIBSS- Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- *Correspondence: Miriam Schmidts,
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5
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Little RB, Norris DP. Right, left and cilia: How asymmetry is established. Semin Cell Dev Biol 2021; 110:11-18. [PMID: 32571625 DOI: 10.1016/j.semcdb.2020.06.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 12/13/2022]
Abstract
The initial breaking of left-right (L-R) symmetry in the embryo is controlled by a motile-cilia-driven leftward fluid flow in the left-right organiser (LRO), resulting in L-R asymmetric gene expression flanking the LRO. Ultimately this results in left- but not right-sided activation of the Nodal-Pitx2 pathway in more lateral tissues. While aspects of the initial breaking event clearly vary between vertebrates, events in the Lateral Plate Mesoderm (LPM) are conserved through the vertebrate lineage. Evidence from model systems and humans highlights the role of cilia both in the initial symmetry breaking and in the ability of more lateral tissues to exhibit asymmetric gene expression. In this review we concentrate on the process of L-R determination in mouse and humans.
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Affiliation(s)
- Rosie B Little
- MRC Harwell Institute, Harwell Campus, Oxfordshire, OX11 0RD, UK
| | - Dominic P Norris
- MRC Harwell Institute, Harwell Campus, Oxfordshire, OX11 0RD, UK.
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6
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Igarashi H, Uemura M, Hiramatsu R, Hiramatsu R, Segami S, Pattarapanawan M, Hirate Y, Yoshimura Y, Hashimoto H, Higashiyama H, Sumitomo H, Kurohmaru M, Saijoh Y, Suemizu H, Kanai-Azuma M, Kanai Y. Sox17 is essential for proper formation of the marginal zone of extraembryonic endoderm adjacent to a developing mouse placental disk. Biol Reprod 2019; 99:578-589. [PMID: 29635272 DOI: 10.1093/biolre/ioy079] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/03/2018] [Indexed: 02/01/2023] Open
Abstract
In mouse conceptus, two yolk-sac membranes, the parietal endoderm (PE) and visceral endoderm (VE), are involved in protecting and nourishing early-somite-stage embryos prior to the establishment of placental circulation. Both PE and VE membranes are tightly anchored to the marginal edge of the developing placental disk, in which the extraembryonic endoderm (marginal zone endoderm: ME) shows the typical flat epithelial morphology intermediate between those of PE and VE in vivo. However, the molecular characteristics and functions of the ME in mouse placentation remain unclear. Here, we show that SOX17, not SOX7, is continuously expressed in the ME cells, whereas both SOX17 and SOX7 are coexpressed in PE cells, by at least 10.5 days postconception. The Sox17-null conceptus, but not the Sox7-null one, showed the ectopic appearance of squamous VE-like epithelial cells in the presumptive ME region, together with reduced cell density and aberrant morphology of PE cells. Such aberrant ME formation in the Sox17-null extraembryonic endoderm was not rescued by the chimeric embryo replaced with the wild-type gut endoderm by the injection of wild-type ES cells into the Sox17-null blastocyst, suggesting the cell autonomous defects in the extraembryonic endoderm of Sox17-null concepti. These findings provide direct evidence of the crucial roles of SOX17 in proper formation and maintenance of the ME region, highlighting a novel entry point to understand the in vivo VE-to-PE transition in the marginal edge of developing placenta.
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Affiliation(s)
- Hitomi Igarashi
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Mami Uemura
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.,Department of Experimental Animal Model for Human Disease, Center for Experimental Animals, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Ryuji Hiramatsu
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Ryuto Hiramatsu
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Saki Segami
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | | | - Yoshikazu Hirate
- Department of Experimental Animal Model for Human Disease, Center for Experimental Animals, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Yuki Yoshimura
- Central Institute for Experimental Animals, Kawasaki-ku, Kawasaki, Kanagawa, Japan
| | - Haruo Hashimoto
- Central Institute for Experimental Animals, Kawasaki-ku, Kawasaki, Kanagawa, Japan
| | - Hiroki Higashiyama
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Hiroyuki Sumitomo
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Masamichi Kurohmaru
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yukio Saijoh
- Department of Neurobiology and Anatomy, The University of Utah, Salt Lake City, Utah, USA
| | - Hiroshi Suemizu
- Central Institute for Experimental Animals, Kawasaki-ku, Kawasaki, Kanagawa, Japan
| | - Masami Kanai-Azuma
- Department of Experimental Animal Model for Human Disease, Center for Experimental Animals, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Yoshiakira Kanai
- Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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7
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Abstract
The adult gastrointestinal tract (GI) is a series of connected organs (esophagus, stomach, small intestine, colon) that develop via progressive regional specification of a continuous tubular embryonic organ anlage. This chapter focuses on organogenesis of the small intestine. The intestine arises by folding of a flat sheet of endodermal cells into a tube of highly proliferative pseudostratified cells. Dramatic elongation of this tube is driven by rapid epithelial proliferation. Then, epithelial-mesenchymal crosstalk and physical forces drive a stepwise cascade that results in convolution of the tubular surface into finger-like projections called villi. Concomitant with villus formation, a sharp epithelial transcriptional boundary is defined between stomach and intestine. Finally, flask-like depressions called crypts are established to house the intestinal stem cells needed throughout life for epithelial renewal. New insights into these events are being provided by in vitro organoid systems, which hold promise for future regenerative engineering of the small intestine.
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Affiliation(s)
- Sha Wang
- University of Michigan, Cell and Developmental Biology Department, Ann Arbor, MI, United States
| | - Katherine D Walton
- University of Michigan, Cell and Developmental Biology Department, Ann Arbor, MI, United States.
| | - Deborah L Gumucio
- University of Michigan, Cell and Developmental Biology Department, Ann Arbor, MI, United States
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8
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Abstract
TGF-β family ligands function in inducing and patterning many tissues of the early vertebrate embryonic body plan. Nodal signaling is essential for the specification of mesendodermal tissues and the concurrent cellular movements of gastrulation. Bone morphogenetic protein (BMP) signaling patterns tissues along the dorsal-ventral axis and simultaneously directs the cell movements of convergence and extension. After gastrulation, a second wave of Nodal signaling breaks the symmetry between the left and right sides of the embryo. During these processes, elaborate regulatory feedback between TGF-β ligands and their antagonists direct the proper specification and patterning of embryonic tissues. In this review, we summarize the current knowledge of the function and regulation of TGF-β family signaling in these processes. Although we cover principles that are involved in the development of all vertebrate embryos, we focus specifically on three popular model organisms: the mouse Mus musculus, the African clawed frog of the genus Xenopus, and the zebrafish Danio rerio, highlighting the similarities and differences between these species.
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Affiliation(s)
- Joseph Zinski
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Benjamin Tajer
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
| | - Mary C Mullins
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6058
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9
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Burdine RD, Grimes DT. Antagonistic interactions in the zebrafish midline prior to the emergence of asymmetric gene expression are important for left-right patterning. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0402. [PMID: 27821532 DOI: 10.1098/rstb.2015.0402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2016] [Indexed: 12/16/2022] Open
Abstract
Left-right (L-R) asymmetry of the internal organs of vertebrates is presaged by domains of asymmetric gene expression in the lateral plate mesoderm (LPM) during somitogenesis. Ciliated L-R coordinators (LRCs) are critical for biasing the initiation of asymmetrically expressed genes, such as nodal and pitx2, to the left LPM. Other midline structures, including the notochord and floorplate, are then required to maintain these asymmetries. Here we report an unexpected role for the zebrafish EGF-CFC gene one-eyed pinhead (oep) in the midline to promote pitx2 expression in the LPM. Late zygotic oep (LZoep) mutants have strongly reduced or absent pitx2 expression in the LPM, but this expression can be rescued to strong levels by restoring oep in midline structures only. Furthermore, removing midline structures from LZoep embryos can rescue pitx2 expression in the LPM, suggesting the midline is a source of an LPM pitx2 repressor that is itself inhibited by oep Reducing lefty1 activity in LZoep embryos mimics removal of the midline, implicating lefty1 in the midline-derived repression. Together, this suggests a model where Oep in the midline functions to overcome a midline-derived repressor, involving lefty1, to allow for the expression of left side-specific genes in the LPM.This article is part of the themed issue 'Provocative questions in left-right asymmetry'.
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Affiliation(s)
- Rebecca D Burdine
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Daniel T Grimes
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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10
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Turner DA, Girgin M, Alonso-Crisostomo L, Trivedi V, Baillie-Johnson P, Glodowski CR, Hayward PC, Collignon J, Gustavsen C, Serup P, Steventon B, P Lutolf M, Arias AM. Anteroposterior polarity and elongation in the absence of extra-embryonic tissues and of spatially localised signalling in gastruloids: mammalian embryonic organoids. Development 2017; 144:3894-3906. [PMID: 28951435 PMCID: PMC5702072 DOI: 10.1242/dev.150391] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 09/08/2017] [Indexed: 12/14/2022]
Abstract
The establishment of the anteroposterior (AP) axis is a crucial step during animal embryo development. In mammals, genetic studies have shown that this process relies on signals spatiotemporally deployed in the extra-embryonic tissues that locate the position of the head and the onset of gastrulation, marked by T/Brachyury (T/Bra) at the posterior of the embryo. Here, we use gastruloids, mESC-based organoids, as a model system with which to study this process. We find that gastruloids localise T/Bra expression to one end and undergo elongation similar to the posterior region of the embryo, suggesting that they develop an AP axis. This process relies on precisely timed interactions between Wnt/β-catenin and Nodal signalling, whereas BMP signalling is dispensable. Additionally, polarised T/Bra expression occurs in the absence of extra-embryonic tissues or localised sources of signals. We suggest that the role of extra-embryonic tissues in the mammalian embryo might not be to induce the axes but to bias an intrinsic ability of the embryo to initially break symmetry. Furthermore, we suggest that Wnt signalling has a separable activity involved in the elongation of the axis.
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Affiliation(s)
- David A Turner
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Mehmet Girgin
- Laboratory of Stem Cell Bioengineering, Institute of Bioengineering, School of Life Sciences and School of Engineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Luz Alonso-Crisostomo
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Vikas Trivedi
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Peter Baillie-Johnson
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Cherise R Glodowski
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Penelope C Hayward
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Jérôme Collignon
- Université Paris-Diderot, CNRS, Institut Jacques Monod, 75013 Paris, France
| | - Carsten Gustavsen
- Danish Stem Cell Center, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Palle Serup
- Danish Stem Cell Center, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Benjamin Steventon
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Matthias P Lutolf
- Laboratory of Stem Cell Bioengineering, Institute of Bioengineering, School of Life Sciences and School of Engineering, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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11
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Grimes DT, Burdine RD. Left-Right Patterning: Breaking Symmetry to Asymmetric Morphogenesis. Trends Genet 2017; 33:616-628. [PMID: 28720483 DOI: 10.1016/j.tig.2017.06.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 06/15/2017] [Accepted: 06/20/2017] [Indexed: 10/19/2022]
Abstract
Vertebrates exhibit striking left-right (L-R) asymmetries in the structure and position of the internal organs. Symmetry is broken by motile cilia-generated asymmetric fluid flow, resulting in a signaling cascade - the Nodal-Pitx2 pathway - being robustly established within mesodermal tissue on the left side only. This pathway impinges upon various organ primordia to instruct their side-specific development. Recently, progress has been made in understanding both the breaking of embryonic L-R symmetry and how the Nodal-Pitx2 pathway controls lateralized cell differentiation, migration, and other aspects of cell behavior, as well as tissue-level mechanisms, that drive asymmetries in organ formation. Proper execution of asymmetric organogenesis is critical to health, making furthering our understanding of L-R development an important concern.
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Affiliation(s)
- Daniel T Grimes
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
| | - Rebecca D Burdine
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
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12
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Maes M, Cogliati B, Crespo Yanguas S, Willebrords J, Vinken M. Roles of connexins and pannexins in digestive homeostasis. Cell Mol Life Sci 2015; 72:2809-21. [PMID: 26084872 DOI: 10.1007/s00018-015-1961-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 12/21/2022]
Abstract
Connexin proteins are abundantly present in the digestive system. They primarily form gap junctions, which control the intercellular exchange of critical homeostasis regulators. By doing so, gap junctions drive a plethora of gastrointestinal and hepatic functional features, including gastric and gut motility, gastric acid secretion, intestinal innate immune defense, xenobiotic biotransformation, glycogenolysis, bile secretion, ammonia detoxification and plasma protein synthesis. In the last decade, it has become clear that connexin hemichannels, which are the structural precursors of gap junctions, also provide a pathway for cellular communication, namely between the cytosol and the extracellular environment. Although merely pathological functions have been described, some physiological roles have been attributed to connexin hemichannels, in particular in the modulation of colonic motility. This equally holds true for cellular channels composed of pannexins, connexin-like proteins recently identified in the intestine and the liver, which have become acknowledged key players in inflammatory processes and that have been proposed to control colonic motility, secretion and blood flow.
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Affiliation(s)
- Michaël Maes
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
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13
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Claudin-10 is required for relay of left-right patterning cues from Hensen's node to the lateral plate mesoderm. Dev Biol 2015; 401:236-48. [PMID: 25744724 DOI: 10.1016/j.ydbio.2015.02.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 02/19/2015] [Accepted: 02/23/2015] [Indexed: 01/22/2023]
Abstract
Species-specific symmetry-breaking events at the left-right organizer (LRO) drive an evolutionarily-conserved cascade of gene expression in the lateral plate mesoderm that is required for the asymmetric positioning of organs within the body cavity. The mechanisms underlying the transfer of the left and right laterality information from the LRO to the lateral plate mesoderm are poorly understood. Here, we investigate the role of Claudin-10, a tight junction protein, in facilitating the transfer of left-right identity from the LRO to the lateral plate mesoderm. Claudin-10 is asymmetrically expressed on the right side of the chick LRO, Hensen's node. Gain- and loss-of-function studies demonstrated that right-sided expression of Claudin-10 is essential for normal rightward heart tube looping, the first morphological asymmetry during organogenesis. Manipulation of Claudin-10 expression did not perturb asymmetric gene expression at Hensen's node, but did disrupt asymmetric gene expression in the lateral plate mesoderm. Bilateral expression of Claudin-10 at Hensen's node prevented expression of Nodal, Lefty-2 and Pitx2c in the left lateral plate mesoderm, while morpholino knockdown of Claudin-10 inhibited expression of Snail1 in the right lateral plate mesoderm. We also determined that amino acids that are predicted to affect ion selectivity and protein interactions that bridge Claudin-10 to the actin cytoskeleton were essential for its left-right patterning function. Collectively, our data demonstrate a novel role for Claudin-10 during the transmission of laterality information from Hensen's node to both the left and right sides of the embryo and demonstrate that tight junctions have a critical role during the relay of left-right patterning cues from Hensen's node to the lateral plate mesoderm.
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14
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Uemura M, Igarashi H, Ozawa A, Tsunekawa N, Kurohmaru M, Kanai-Azuma M, Kanai Y. Fate mapping of gallbladder progenitors in posteroventral foregut endoderm of mouse early somite-stage embryos. J Vet Med Sci 2015; 77:587-91. [PMID: 25648459 PMCID: PMC4478739 DOI: 10.1292/jvms.14-0635] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In early embryogenesis, the posteroventral foregut endoderm gives rise to the
budding endodermal organs including the liver, ventral pancreas and gallbladder during
early somitogenesis. Despite the detailed fate maps of the liver and pancreatic
progenitors in the mouse foregut endoderm, the exact location of the gallbladder
progenitors remains unclear. In this study, we performed a DiI fate-mapping analysis using
whole-embryo cultures of mouse early somite-stage embryos. Here, we show that the majority
of gallbladder progenitors in 9–11-somite-stage embryos are located in the lateral-most
domain of the foregut endoderm at the first intersomite junction level along the
anteroposterior axis. This definition of their location highlights a novel entry point to
understanding of the molecular mechanisms of initial specification of the gallbladder.
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Affiliation(s)
- Mami Uemura
- Department of Veterinary Anatomy, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
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15
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Hamada H, Tam PP. Mechanisms of left-right asymmetry and patterning: driver, mediator and responder. F1000PRIME REPORTS 2014; 6:110. [PMID: 25580264 PMCID: PMC4275019 DOI: 10.12703/p6-110] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The establishment of a left-right (LR) organizer in the form of the ventral node is an absolute prerequisite for patterning the tissues on contralateral sides of the body of the mouse embryo. The experimental findings to date are consistent with a mechanistic paradigm that the laterality information, which is generated in the ventral node, elicits asymmetric molecular activity and cellular behaviour in the perinodal tissues. This information is then relayed to the cells in the lateral plate mesoderm (LPM) when the left-specific signal is processed and translated into LR body asymmetry. Here, we reflect on our current knowledge and speculate on the following: (a) what are the requisite anatomical and functional attributes of an LR organizer, (b) what asymmetric information is emanated from this organizer, and (c) how this information is transferred across the paraxial tissue compartment and elicits a molecular response specifically in the LPM.
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Affiliation(s)
- Hiroshi Hamada
- Developmental Genetics Group, Graduate School of Frontier Bioscience, Osaka UniversityJapan
| | - Patrick P.L. Tam
- Embryology Unit, Children's Medical Research Institute and Sydney Medical School, University of SydneyNew South WalesAustralia
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16
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Lauriol J, Jaffré F, Kontaridis MI. The role of the protein tyrosine phosphatase SHP2 in cardiac development and disease. Semin Cell Dev Biol 2014; 37:73-81. [PMID: 25256404 DOI: 10.1016/j.semcdb.2014.09.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 09/09/2014] [Accepted: 09/15/2014] [Indexed: 02/06/2023]
Abstract
Congenital heart disease is the most common human developmental disorder, affecting ∼1:100 newborns, and is the primary cause of birth-defect related deaths worldwide. As a major regulator of receptor tyrosine kinase (RTK), cytokine and G-protein coupled receptor signaling, the non-receptor protein tyrosine phosphatase SHP2 plays a critical role in normal cardiac development and function. Indeed, SHP2 participates in a wide variety of cellular functions, including proliferation, survival, differentiation, migration, and cell-cell communication. Moreover, human activating and inactivating mutations of SHP2 are responsible for two related developmental disorders called Noonan and LEOPARD Syndromes, respectively, which are both characterized, in part, by congenital heart defects. Structural, enzymologic, biochemical, and SHP2 mouse model studies have together greatly enriched our knowledge of SHP2 and, as such, have also uncovered the diverse roles for SHP2 in cardiac development, including its contribution to progenitor cell specification, cardiac morphogenesis, and maturation of cardiac valves and myocardial chambers. By delineating the precise mechanisms by which SHP2 is involved in regulating these processes, we can begin to better understand the pathogenesis of cardiac disease and find more strategic and effective therapies for treatment of patients with congenital heart disorders.
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Affiliation(s)
- Jessica Lauriol
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Fabrice Jaffré
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Maria I Kontaridis
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, United States.
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17
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Hou J, Wei W, Saund RS, Xiang P, Cunningham TJ, Yi Y, Alder O, Lu DYD, Savory JGA, Krentz NAJ, Montpetit R, Cullum R, Hofs N, Lohnes D, Humphries RK, Yamanaka Y, Duester G, Saijoh Y, Hoodless PA. A regulatory network controls nephrocan expression and midgut patterning. Development 2014; 141:3772-81. [PMID: 25209250 DOI: 10.1242/dev.108274] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although many regulatory networks involved in defining definitive endoderm have been identified, the mechanisms through which these networks interact to pattern the endoderm are less well understood. To explore the mechanisms involved in midgut patterning, we dissected the transcriptional regulatory elements of nephrocan (Nepn), the earliest known midgut specific gene in mice. We observed that Nepn expression is dramatically reduced in Sox17(-/-) and Raldh2(-/-) embryos compared with wild-type embryos. We further show that Nepn is directly regulated by Sox17 and the retinoic acid (RA) receptor via two enhancer elements located upstream of the gene. Moreover, Nepn expression is modulated by Activin signaling, with high levels inhibiting and low levels enhancing RA-dependent expression. In Foxh1(-/-) embryos in which Nodal signaling is reduced, the Nepn expression domain is expanded into the anterior gut region, confirming that Nodal signaling can modulate its expression in vivo. Together, Sox17 is required for Nepn expression in the definitive endoderm, while RA signaling restricts expression to the midgut region. A balance of Nodal/Activin signaling regulates the anterior boundary of the midgut expression domain.
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Affiliation(s)
- Juan Hou
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Wei Wei
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Ranajeet S Saund
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132-3401, USA
| | - Ping Xiang
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Thomas J Cunningham
- Development, Aging and Regeneration Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Yuyin Yi
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada Cell and Developmental Biology Program, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Olivia Alder
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Daphne Y D Lu
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Joanne G A Savory
- Cellular and Molecular Medicine, University of Ottawa, Ottawa K1H 8M5, Canada
| | - Nicole A J Krentz
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Rachel Montpetit
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Rebecca Cullum
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Nicole Hofs
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - David Lohnes
- Cellular and Molecular Medicine, University of Ottawa, Ottawa K1H 8M5, Canada
| | - R Keith Humphries
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada Experimental Medicine, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Yojiro Yamanaka
- Goodman Cancer Research Centre, Department of Human Genetics, McGill University, Montreal, Quebec H2W 1S6, Canada
| | - Gregg Duester
- Development, Aging and Regeneration Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Yukio Saijoh
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132-3401, USA
| | - Pamela A Hoodless
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada Cell and Developmental Biology Program, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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18
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Blum M, Feistel K, Thumberger T, Schweickert A. The evolution and conservation of left-right patterning mechanisms. Development 2014; 141:1603-13. [PMID: 24715452 DOI: 10.1242/dev.100560] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Morphological asymmetry is a common feature of animal body plans, from shell coiling in snails to organ placement in humans. The signaling protein Nodal is key for determining this laterality. Many vertebrates, including humans, use cilia for breaking symmetry during embryonic development: rotating cilia produce a leftward flow of extracellular fluids that induces the asymmetric expression of Nodal. By contrast, Nodal asymmetry can be induced flow-independently in invertebrates. Here, we ask when and why flow evolved. We propose that flow was present at the base of the deuterostomes and that it is required to maintain organ asymmetry in otherwise perfectly bilaterally symmetrical vertebrates.
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Affiliation(s)
- Martin Blum
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany
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19
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Saijoh Y, Viotti M, Hadjantonakis AK. Follow your gut: relaying information from the site of left-right symmetry breaking in the mouse. Genesis 2014; 52:503-14. [PMID: 24753065 DOI: 10.1002/dvg.22783] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/08/2014] [Accepted: 04/08/2014] [Indexed: 12/19/2022]
Abstract
A central unresolved question in the molecular cascade that drives establishment of left-right (LR) asymmetry in vertebrates are the mechanisms deployed to relay information between the midline site of symmetry-breaking and the tissues which will execute a program of asymmetric morphogenesis. The cells located between these two distant locations must provide the medium for signal relay. Of these, the gut endoderm is an attractive candidate tissue for signal transmission since it comprises the epithelium that lies between the node, where asymmetry originates, and the lateral plate, where asymmetry can first be detected. Here, focusing on the mouse as a model, we review our current understanding and entertain open questions concerning the relay of LR information from its origin.
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Affiliation(s)
- Yukio Saijoh
- Department of Neurobiology and Anatomy, The University of Utah, Salt Lake City, Utah
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20
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Abstract
Many aspects of heart development are determined by the left right axis and as a result several congenital diseases have their origins in aberrant left-right patterning. Establishment of this axis occurs early in embryogenesis before formation of the linear heart tube yet impacts upon much later morphogenetic events. In this review I discuss the differing mechanisms by which left-right polarity is achieved in the mouse and chick embryos and comment on the evolution of this system. I then discus three major classes of cardiovascular defect associated with aberrant left-right patterning seen in mouse mutants and human disease. I describe phenotypes associated with the determination of atrial identity and venous connections, looping morphogenesis of the heart tube and finally the asymmetric remodelling of the embryonic branchial arch arterial system to form the leftward looped arch of aorta and associated great arteries. Where appropriate, I consider left right patterning defects from an evolutionary perspective, demonstrating how developmental processes have been modified in species over time and illustrating how comparative embryology can aide in our understanding of congenital heart disease.
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Affiliation(s)
- Iain M Dykes
- Department of Cardiovascular Medicine and Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Headington, Oxford, OX3 7BN, UK
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21
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Collins MM, Ryan AK. Are there conserved roles for the extracellular matrix, cilia, and junctional complexes in left-right patterning? Genesis 2014; 52:488-502. [PMID: 24668924 DOI: 10.1002/dvg.22774] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 03/19/2014] [Indexed: 01/11/2023]
Abstract
Many different types of molecules have essential roles in patterning the left-right axis and directing asymmetric morphogenesis. In particular, the relationship between signaling molecules and transcription factors has been explored extensively. Another group of proteins implicated in left-right patterning are components of the extracellular matrix, apical junctions, and cilia. These structural molecules have the potential to participate in the conversion of morphogenetic cues from the extracellular environment into morphogenetic patterning via their interactions with the actin cytoskeleton. Although it has been relatively easy to temporally position these proteins within the hierarchy of the left-right patterning pathway, it has been more difficult to define how they mechanistically fit into these pathways. Consequently, our understanding of how these factors impart patterning information to influence the establishment of the left-right axis remains limited. In this review, we will discuss those structural molecules that have been implicated in early phases of left-right axis development.
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Affiliation(s)
- Michelle M Collins
- Department of Human Genetics, McGill University, Montréal, Québec, Canada
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22
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Tingler M, Ott T, Tözser J, Kurz S, Getwan M, Tisler M, Schweickert A, Blum M. Symmetry breakage in the frog Xenopus
: Role of Rab11 and the ventral-right blastomere. Genesis 2014; 52:588-99. [DOI: 10.1002/dvg.22766] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/12/2014] [Accepted: 02/25/2014] [Indexed: 02/04/2023]
Affiliation(s)
- Melanie Tingler
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Tim Ott
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Janos Tözser
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Sabrina Kurz
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Maike Getwan
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Matthias Tisler
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Axel Schweickert
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
| | - Martin Blum
- Institute of Zoology, University of Hohenheim; Stuttgart D-70593 Germany
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23
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Abstract
Many internal organs develop distinct left and right sides that are essential for their functions. In several vertebrate embryos, motile cilia generate an asymmetric fluid flow that plays an important role in establishing left-right (LR) signaling cascades. These ‘LR cilia’ are found in the ventral node and posterior notochordal plate in mammals, the gastrocoel roof plate in amphibians and Kupffer’s vesicle in teleost fish. I consider these transient ciliated structures as the ‘organ of asymmetry’ that directs LR patterning of the developing embryo. Variations in size and morphology of the organ of asymmetry in different vertebrate species have raised questions regarding the fundamental features that are required for LR determination. Here, I review current models for how LR asymmetry is established in vertebrates, discuss the cellular architecture of the ciliated organ of asymmetry and then propose key features of this organ that are critical for orienting the LR body axis.
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Affiliation(s)
- Jeffrey D Amack
- Department of Cell and Developmental Biology; State University of New York; Upstate Medical University; Syracuse, NY USA
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24
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Roles of cilia, fluid flow, and Ca2+ signaling in breaking of left-right symmetry. Trends Genet 2013; 30:10-7. [PMID: 24091059 DOI: 10.1016/j.tig.2013.09.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/18/2013] [Accepted: 09/03/2013] [Indexed: 11/23/2022]
Abstract
The emergence of left-right (L-R) asymmetry during embryogenesis is a classic problem in developmental biology. It is only since the 1990s, however, that substantial insight into this problem has been achieved by molecular and genetic approaches. Various genes required for L-R asymmetric morphogenesis in vertebrates have now been identified, and many of these genes are required for the formation and motility of cilia. Breaking of L-R symmetry in the mouse embryo occurs in the ventral node, where two types of cilia are present. Whereas centrally located motile cilia generate a leftward fluid flow, peripherally located immotile cilia sense a flow-dependent signal, which is either chemical or mechanical in nature. Although Ca2+ signaling is implicated in flow sensing, the precise mechanism remains unknown. Here we summarize current knowledge of L-R symmetry breaking in vertebrates (focusing on the mouse), with a special emphasis on the roles of cilia, fluid flow, and Ca2+ signaling.
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25
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Uemura M, Ozawa A, Nagata T, Kurasawa K, Tsunekawa N, Nobuhisa I, Taga T, Hara K, Kudo A, Kawakami H, Saijoh Y, Kurohmaru M, Kanai-Azuma M, Kanai Y. Sox17 haploinsufficiency results in perinatal biliary atresia and hepatitis in C57BL/6 background mice. Development 2013; 140:639-48. [PMID: 23293295 DOI: 10.1242/dev.086702] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Congenital biliary atresia is an incurable disease of newborn infants, of unknown genetic causes, that results in congenital deformation of the gallbladder and biliary duct system. Here, we show that during mouse organogenesis, insufficient SOX17 expression in the gallbladder and bile duct epithelia results in congenital biliary atresia and subsequent acute 'embryonic hepatitis', leading to perinatal death in ~95% of the Sox17 heterozygote neonates in C57BL/6 (B6) background mice. During gallbladder and bile duct development, Sox17 was expressed at the distal edge of the gallbladder primordium. In the Sox17(+/-) B6 embryos, gallbladder epithelia were hypoplastic, and some were detached from the luminal wall, leading to bile duct stenosis or atresia. The shredding of the gallbladder epithelia is probably caused by cell-autonomous defects in proliferation and maintenance of the Sox17(+/-) gallbladder/bile duct epithelia. Our results suggest that Sox17 plays a dosage-dependent function in the morphogenesis and maturation of gallbladder and bile duct epithelia during the late-organogenic stages, highlighting a novel entry point to the understanding of the etiology and pathogenesis of human congenital biliary atresia.
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Affiliation(s)
- Mami Uemura
- Department of Veterinary Anatomy, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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26
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Takao D, Nemoto T, Abe T, Kiyonari H, Kajiura-Kobayashi H, Shiratori H, Nonaka S. Asymmetric distribution of dynamic calcium signals in the node of mouse embryo during left-right axis formation. Dev Biol 2013; 376:23-30. [PMID: 23357539 DOI: 10.1016/j.ydbio.2013.01.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 01/15/2013] [Accepted: 01/17/2013] [Indexed: 11/27/2022]
Abstract
In the node of mouse embryo, rotational movements of cilia generate an external liquid flow known as nodal flow, which determines left-right asymmetric gene expression. How nodal flow is converted into asymmetric gene expression is still controversial, but the increase of Ca(2+) levels in endodermal cells to the left of the node has been proposed to play a role. However, Ca(2+) signals inside the node itself have not yet been described. By our optimized Ca(2+) imaging method, we were able to observe dynamic Ca(2+) signals in the node in live mouse embryos. Pharmacological disruption of Ca(2+) signals did not affect ciliary movements or nodal flow, but did alter the expression patterns of the Nodal and Cerl-2 genes. Quantitative analyses of Ca(2+) signal frequencies and distributions showed that during left-right axis establishment, formerly symmetric Ca(2+) signals became biased to the left side. In iv/iv mutant embryos that showed randomized laterality due to ciliary immotility, Ca(2+) signals were found to be variously left-sided, right-sided, or bilateral, and thus symmetric on average. In Pkd2 mutant embryos, which lacked polycystin-2, a Ca(2+)-permeable cation channel necessary for left-right axis formation, the Ca(2+) signal frequency was lower than in wild-type embryos. Our data support a model in which dynamic Ca(2+) signals in the node are involved in left-right patterning.
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Affiliation(s)
- Daisuke Takao
- Laboratory for Spatiotemporal Regulations, National Institute for Basic Biology, Japan
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27
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Nilsson M, Fagman H. Mechanisms of thyroid development and dysgenesis: an analysis based on developmental stages and concurrent embryonic anatomy. Curr Top Dev Biol 2013; 106:123-70. [PMID: 24290349 DOI: 10.1016/b978-0-12-416021-7.00004-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Thyroid dysgenesis is the most common cause of congenital hypothyroidism that affects 1 in 3000 newborns. Although a number of pathogenetic mutations in thyroid developmental genes have been identified, the molecular mechanism of disease is unknown in most cases. This chapter summarizes the current knowledge of normal thyroid development and puts the different developmental stages in perspective, from the time of foregut endoderm patterning to the final shaping of pharyngeal anatomy, for understanding how specific malformations may arise. At the cellular level, we will also discuss fate determination of follicular and C-cell progenitors and their subsequent embryonic growth, migration, and differentiation as the different thyroid primordia evolve and merge to establish the final size and shape of the gland.
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Affiliation(s)
- Mikael Nilsson
- Sahlgrenska Cancer Center, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden.
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28
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Norris DP. Cilia, calcium and the basis of left-right asymmetry. BMC Biol 2012; 10:102. [PMID: 23256866 PMCID: PMC3527145 DOI: 10.1186/1741-7007-10-102] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 12/14/2012] [Indexed: 01/09/2023] Open
Abstract
The clockwise rotation of cilia in the developing mammalian embryo drives a leftward flow of liquid; this genetically regulated biophysical force specifies left-right asymmetry of the mammalian body. How leftward flow is interpreted and information propagated to other tissues is the subject of debate. Four recent papers have shed fresh light on the possible mechanisms.
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Affiliation(s)
- Dominic P Norris
- Mammalian Genetics Unit, MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire, OX11 0RD, UK.
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