1
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Zhang J, Larschan E, Bigness J, Singh R. scNODE : generative model for temporal single cell transcriptomic data prediction. Bioinformatics 2024; 40:ii146-ii154. [PMID: 39230694 PMCID: PMC11373355 DOI: 10.1093/bioinformatics/btae393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024] Open
Abstract
SUMMARY Measurement of single-cell gene expression at different timepoints enables the study of cell development. However, due to the resource constraints and technical challenges associated with the single-cell experiments, researchers can only profile gene expression at discrete and sparsely sampled timepoints. This missing timepoint information impedes downstream cell developmental analyses. We propose scNODE, an end-to-end deep learning model that can predict in silico single-cell gene expression at unobserved timepoints. scNODE integrates a variational autoencoder with neural ordinary differential equations to predict gene expression using a continuous and nonlinear latent space. Importantly, we incorporate a dynamic regularization term to learn a latent space that is robust against distribution shifts when predicting single-cell gene expression at unobserved timepoints. Our evaluations on three real-world scRNA-seq datasets show that scNODE achieves higher predictive performance than state-of-the-art methods. We further demonstrate that scNODE's predictions help cell trajectory inference under the missing timepoint paradigm and the learned latent space is useful for in silico perturbation analysis of relevant genes along a developmental cell path. AVAILABILITY AND IMPLEMENTATION The data and code are publicly available at https://github.com/rsinghlab/scNODE.
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Affiliation(s)
- Jiaqi Zhang
- Department of Computer Science, Brown University, Providence, RI 02906, United States
| | - Erica Larschan
- Center for Computational Molecular Biology, Brown University, Providence, RI 02912, United States
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, United States
| | - Jeremy Bigness
- Center for Computational Molecular Biology, Brown University, Providence, RI 02912, United States
| | - Ritambhara Singh
- Department of Computer Science, Brown University, Providence, RI 02906, United States
- Center for Computational Molecular Biology, Brown University, Providence, RI 02912, United States
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2
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Shi M, McCracken KW, Patel AB, Zhang W, Ester L, Valerius MT, Bonventre JV. Human ureteric bud organoids recapitulate branching morphogenesis and differentiate into functional collecting duct cell types. Nat Biotechnol 2023; 41:252-261. [PMID: 36038632 PMCID: PMC9957856 DOI: 10.1038/s41587-022-01429-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 07/13/2022] [Indexed: 12/29/2022]
Abstract
Directed differentiation of human pluripotent stem cells (hPSCs) into functional ureteric and collecting duct (CD) epithelia is essential to kidney regenerative medicine. Here we describe highly efficient, serum-free differentiation of hPSCs into ureteric bud (UB) organoids and functional CD cells. The hPSCs are first induced into pronephric progenitor cells at 90% efficiency and then aggregated into spheres with a molecular signature similar to the nephric duct. In a three-dimensional matrix, the spheres form UB organoids that exhibit branching morphogenesis similar to the fetal UB and correct distal tip localization of RET expression. Organoid-derived cells incorporate into the UB tips of the progenitor niche in chimeric fetal kidney explant culture. At later stages, the UB organoids differentiate into CD organoids, which contain >95% CD cell types as estimated by single-cell RNA sequencing. The CD epithelia demonstrate renal electrophysiologic functions, with ENaC-mediated vectorial sodium transport by principal cells and V-type ATPase proton pump activity by FOXI1-induced intercalated cells.
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Affiliation(s)
- Min Shi
- Division of Renal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Division of Nephrology, Kidney Research Institute, West China Hospital of Sichuan University, Chengdu, China
| | - Kyle W McCracken
- Division of Renal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. .,Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA. .,Division of Nephrology, Center for Stem Cell and Organoid Medicine (CuSTOM), Cincinnati Children's Hospital Medical Center, Cincinnati, USA.
| | - Ankit B Patel
- Division of Renal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Weitao Zhang
- Division of Renal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Lioba Ester
- Division of Renal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Department II of Internal Medicine, University of Cologne, Faculty of Medicine, and University Hospital Cologne, Cologne, Germany
| | - M Todd Valerius
- Division of Renal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Harvard Stem Cell Institute, Cambridge and Boston, Boston, MA, USA
| | - Joseph V Bonventre
- Division of Renal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. .,Harvard Stem Cell Institute, Cambridge and Boston, Boston, MA, USA. .,Division of Engineering in Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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3
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Au SKW, Portelli IV, DeWitte-Orr SJ. Using long, sequence-specific dsRNA to knockdown inducible protein expression and virus production via an RNAi-like mechanism. FISH & SHELLFISH IMMUNOLOGY 2022; 131:945-957. [PMID: 36351544 DOI: 10.1016/j.fsi.2022.10.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
RNA interference (RNAi) is a powerful innate immune mechanism to knock down translation of specific proteins whose machinery is conserved from plants to mammals. The template used to determine which mRNA's translation is inhibited is dsRNA, whose origin can range from viruses (long dsRNA, ∼100-1000s bp) to host (micro(mi)RNA, ∼20mers). While miRNA-mediated RNAi is well described in vertebrates, the ability of long dsRNA to guide RNAi-mediated translation inhibition in vertebrates is controversial. Indeed, as long dsRNA is so effective at inducing type I interferons (IFNs), and IFNs down-regulate RNAi machinery, it is believed that IFN-competent cells are not capable of using long dsRNA for RNAi. In the present study the ability of long, sequence specific dsRNA to knock down both host protein expression and viral replication is investigated in IFN-competent rainbow trout cells. Before exploring RNAi effects, the optimal dsRNA concentration that would funnel into RNAi without triggering the IFN response was determined. After which, the ability of sequence specific long dsRNA to target knockdown via RNAi was evaluated in: (1) uninfected host cells using inducible luciferase gene expression and (2) host cells infected with chum salmon reovirus (CSV), frog virus 3 (FV3) or viral hemorrhagic septicemia virus genotype IVa (VHSV-IVa). Induced expression studies utilized RTG-P1, a luciferase reporter cell line, and dsRNA containing luciferase sequence (dsRNA-Luc) or a mis-matched sequence (dsRNA-GFP), and subsequent luminescence intensity was measured. Anti-CSV studies used dsRNA-CSVseg7 and dsRNA-CSVseg10 to target CSV segment 7 and CSV segment 10 respectively. Inhibition of virus replication was measured by viral titration and RT-qPCR. Taking advantage of the fact that long dsRNA can accommodate more sequences than miRNAs, the antiviral capability of dsRNA molecules containing both CSV segment 7 and segment 10 simultaneously was also measured. Target sequence appears important, as dsRNA-FV3MCP did not knock down FV3 titres, and while dsRNA-VHSV-N knocked down VHSV-IVa, dsRNA-VHSV-G and dsRNA-VHSV-M did not. This is the first study in fish to provide evidence that sequence specific long dsRNA induces potent gene expression silencing and antiviral responses in vitro via an RNAi-like mechanism instead of an IFN-dependent response.
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Affiliation(s)
- Sarah K W Au
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada; Department of Health Sciences, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Iliana V Portelli
- Department of Health Sciences, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Stephanie J DeWitte-Orr
- Department of Biology, Wilfrid Laurier University, Waterloo, ON, Canada; Department of Health Sciences, Wilfrid Laurier University, Waterloo, ON, Canada.
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4
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Talbot CD, Walsh MD, Cutty SJ, Elsayed R, Vlachaki E, Bruce AEE, Wardle FC, Nelson AC. Eomes function is conserved between zebrafish and mouse and controls left-right organiser progenitor gene expression via interlocking feedforward loops. Front Cell Dev Biol 2022; 10:982477. [PMID: 36133924 PMCID: PMC9483813 DOI: 10.3389/fcell.2022.982477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
The T-box family transcription factor Eomesodermin (Eomes) is present in all vertebrates, with many key roles in the developing mammalian embryo and immune system. Homozygous Eomes mutant mouse embryos exhibit early lethality due to defects in both the embryonic mesendoderm and the extraembryonic trophoblast cell lineage. In contrast, zebrafish lacking the predominant Eomes homologue A (Eomesa) do not suffer complete lethality and can be maintained. This suggests fundamental differences in either the molecular function of Eomes orthologues or the molecular configuration of processes in which they participate. To explore these hypotheses we initially analysed the expression of distinct Eomes isoforms in various mouse cell types. Next we compared the functional capabilities of these murine isoforms to zebrafish Eomesa. These experiments provided no evidence for functional divergence. Next we examined the functions of zebrafish Eomesa and other T-box family members expressed in early development, as well as its paralogue Eomesb. Though Eomes is a member of the Tbr1 subfamily we found evidence for functional redundancy with the Tbx6 subfamily member Tbx16, known to be absent from eutherians. However, Tbx16 does not appear to synergise with Eomesa cofactors Mixl1 and Gata5. Finally, we analysed the ability of Eomesa and other T-box factors to induce zebrafish left-right organiser progenitors (known as dorsal forerunner cells) known to be positively regulated by vgll4l, a gene we had previously shown to be repressed by Eomesa. Here we demonstrate that Eomesa indirectly upregulates vgll4l expression via interlocking feedforward loops, suggesting a role in establishment of left-right asymmetry. Conversely, other T-box factors could not similarly induce left-right organiser progenitors. Overall these findings demonstrate conservation of Eomes molecular function and participation in similar processes, but differential requirements across evolution due to additional co-expressed T-box factors in teleosts, albeit with markedly different molecular capabilities. Our analyses also provide insights into the role of Eomesa in left-right organiser formation in zebrafish.
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Affiliation(s)
- Conor D. Talbot
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
| | - Mark D. Walsh
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
| | - Stephen J. Cutty
- Randall Centre for Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London, United Kingdom
| | - Randa Elsayed
- Warwick Medical School, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
| | - Eirini Vlachaki
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
| | - Ashley E. E. Bruce
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Fiona C. Wardle
- Randall Centre for Cell and Molecular Biophysics, New Hunt’s House, Guy’s Campus, King’s College London, London, United Kingdom
| | - Andrew C. Nelson
- School of Life Sciences, Gibbet Hill Campus, University of Warwick, Coventry, United Kingdom
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5
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Germano G, Porazzi P, Felix C. Leukemia‐associated transcription factor
mllt3
is important for primitive erythroid development in zebrafish embryogenesis. Dev Dyn 2022; 251:1728-1740. [DOI: 10.1002/dvdy.477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 03/15/2022] [Accepted: 04/06/2022] [Indexed: 11/11/2022] Open
Affiliation(s)
- Giuseppe Germano
- Division of Hematology/Oncology Institute of Pediatric Research Città Della Speranza Padova Italy
| | - Patrizia Porazzi
- Department of Cancer Biology, Sidney Kimmel Cancer Center Thomas Jefferson University Philadelphia Pennsylvania USA
| | - Carolyn Felix
- Division of Oncology, Department of Pediatrics The Children's Hospital of Philadelphia Philadelphia Pennsylvania USA
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6
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Darrah K, Wesalo J, Lukasak B, Tsang M, Chen JK, Deiters A. Small Molecule Control of Morpholino Antisense Oligonucleotide Function through Staudinger Reduction. J Am Chem Soc 2021; 143:18665-18671. [PMID: 34705461 DOI: 10.1021/jacs.1c08723] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conditionally activated, caged morpholino antisense agents (cMOs) are tools that enable the temporal and spatial investigation of gene expression, regulation, and function during embryonic development. Cyclic MOs are conformationally gated oligonucleotide analogs that do not block gene expression until they are linearized through the application of an external trigger, such as light or enzyme activity. Here, we describe the first examples of small molecule-responsive cMOs, which undergo rapid and efficient decaging via a Staudinger reduction. This is enabled by a highly flexible linker design that offers opportunities for the installation of chemically activated, self-immolative motifs. We synthesized cyclic cMOs against two distinct, developmentally relevant genes and demonstrated phosphine-triggered knockdown of gene expression in zebrafish embryos. This represents the first report of a small molecule-triggered antisense agent for gene knockdown, adding another bioorthogonal entry to the growing arsenal of gene knockdown tools.
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Affiliation(s)
- Kristie Darrah
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Joshua Wesalo
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Bradley Lukasak
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Michael Tsang
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - James K Chen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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7
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Klingbeil K, Nguyen TQ, Fahrner A, Guthmann C, Wang H, Schoels M, Lilienkamp M, Franz H, Eckert P, Walz G, Yakulov TA. Corpuscles of Stannius development requires FGF signaling. Dev Biol 2021; 481:160-171. [PMID: 34666023 DOI: 10.1016/j.ydbio.2021.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/06/2021] [Accepted: 10/11/2021] [Indexed: 01/02/2023]
Abstract
The corpuscles of Stannius (CS) represent a unique endocrine organ of teleostean fish that secrets stanniocalcin-1 (Stc1) to maintain calcium homeostasis. Appearing at 20-25 somite stage in the distal zebrafish pronephros, stc1-expressing cells undergo apical constriction, and are subsequently extruded to form a distinct gland on top of the distal pronephric tubules at 50 h post fertilization (hpf). Several transcription factors (e.g. Hnf1b, Irx3b, Tbx2a/b) and signaling pathways (e.g. Notch) control CS development. We report now that Fgf signaling is required to commit tubular epithelial cells to differentiate into stc1-expressing CS cells. Inhibition of Fgf signaling by SU5402, dominant-negative Fgfr1, or depletion of fgf8a prevented CS formation and stc1 expression. Ablation experiments revealed that CS have the ability to partially regenerate via active cell migration involving extensive filopodia and lamellipodia formation. Activation of Wnt signaling curtailed stc1 expression, but had no effect on CS formation. Thus, our observations identify Fgf signaling as a crucial component of CS cell fate commitment.
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Affiliation(s)
- Konstantin Klingbeil
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Thanh Quang Nguyen
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Andreas Fahrner
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Clara Guthmann
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Hui Wang
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Maximilian Schoels
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Miriam Lilienkamp
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Henriette Franz
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Priska Eckert
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany; Signaling Research Centers BIOSS and CIBSS, University of Freiburg, Albertstrasse 19, 79104, Freiburg, Germany
| | - Toma Antonov Yakulov
- Renal Division, Department of Medicine, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany.
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8
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Yuikawa T, Ikeda M, Tsuda S, Saito S, Yamasu K. Involvement of Oct4-type transcription factor Pou5f3 in posterior spinal cord formation in zebrafish embryos. Dev Growth Differ 2021; 63:306-322. [PMID: 34331767 DOI: 10.1111/dgd.12742] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/13/2021] [Accepted: 07/27/2021] [Indexed: 12/21/2022]
Abstract
In vertebrate embryogenesis, elongation of the posterior body is driven by de novo production of the axial and paraxial mesoderm as well as the neural tube at the posterior end. This process is presumed to depend on the stem cell-like population in the tail bud region, but the details of the gene regulatory network involved are unknown. Previous studies suggested the involvement of pou5f3, an Oct4-type POU gene in zebrafish, in axial elongation. In the present study, we first found that pou5f3 is expressed mainly in the dorsal region of the tail bud immediately after gastrulation, and that this expression is restricted to the posterior-most region of the elongating neural tube during somitogenesis. This pou5f3 expression was complementary to the broad expression of sox3 in the neural tube, and formed a sharp boundary with specific expression of tbxta (orthologue of mammalian T/Brachyury) in the tail bud, implicating pou5f3 in the specification of tail bud-derived cells toward neural differentiation in the spinal cord. When pou5f3 was functionally impaired after gastrulation by induction of a dominant-interfering pou5f3 mutant gene (en-pou5f3), trunk and tail elongation were markedly disturbed at distinct positions along the axis depending on the stage. This finding showed involvement of pou5f3 in de novo generation of the body from the tail bud. Conditional functional abrogation also showed that pou5f3 downregulates mesoderm-forming genes but promotes neural development by activating neurogenesis genes around the tail bud. These results suggest that pou5f3 is involved in formation of the posterior spinal cord.
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Affiliation(s)
- Tatsuya Yuikawa
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Masaaki Ikeda
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Sachiko Tsuda
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Shinji Saito
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
| | - Kyo Yamasu
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Japan
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9
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Naganathan S, Oates A. Patterning and mechanics of somite boundaries in zebrafish embryos. Semin Cell Dev Biol 2020; 107:170-178. [DOI: 10.1016/j.semcdb.2020.04.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/12/2020] [Accepted: 04/19/2020] [Indexed: 12/12/2022]
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10
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Osborn DPS, Li K, Cutty SJ, Nelson AC, Wardle FC, Hinits Y, Hughes SM. Fgf-driven Tbx protein activities directly induce myf5 and myod to initiate zebrafish myogenesis. Development 2020; 147:147/8/dev184689. [PMID: 32345657 PMCID: PMC7197714 DOI: 10.1242/dev.184689] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 02/14/2020] [Indexed: 01/02/2023]
Abstract
Skeletal muscle derives from dorsal mesoderm formed during vertebrate gastrulation. Fibroblast growth factor (Fgf) signalling cooperates with Tbx transcription factors to promote dorsal mesoderm formation, but their role in myogenesis has been unclear. Using zebrafish, we show that dorsally derived Fgf signals act through Tbx16 and Tbxta to induce slow and fast trunk muscle precursors at distinct dorsoventral positions. Tbx16 binds to and directly activates the myf5 and myod genes, which are required for commitment to myogenesis. Tbx16 activity depends on Fgf signalling from the organiser. In contrast, Tbxta is not required for myf5 expression, but binds a specific site upstream of myod that is not bound by Tbx16 and drives (dependent on Fgf signals) myod expression in adaxial slow precursors, thereby initiating trunk myogenesis. After gastrulation, when similar muscle cell populations in the post-anal tail are generated from tailbud, declining Fgf signalling is less effective at initiating adaxial myogenesis, which is instead initiated by Hedgehog signalling from the notochord. Our findings suggest a hypothesis for ancestral vertebrate trunk myogenic patterning and how it was co-opted during tail evolution to generate similar muscle by new mechanisms. This article has an associated ‘The people behind the papers’ interview. Highlighted Article: Tbx16 and Tbxta activate myf5 and myod directly during the earliest myogenesis in zebrafish, and Fgf signalling acts through Tbx16 to drive myogenesis in trunk but not tail.
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Affiliation(s)
- Daniel P S Osborn
- Randall Centre for Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, SE1 1UL, UK
| | - Kuoyu Li
- Randall Centre for Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, SE1 1UL, UK
| | - Stephen J Cutty
- Randall Centre for Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, SE1 1UL, UK
| | - Andrew C Nelson
- Randall Centre for Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, SE1 1UL, UK
| | - Fiona C Wardle
- Randall Centre for Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, SE1 1UL, UK
| | - Yaniv Hinits
- Randall Centre for Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, SE1 1UL, UK
| | - Simon M Hughes
- Randall Centre for Cell and Molecular Biophysics, New Hunt's House, Guy's Campus, King's College London, SE1 1UL, UK
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11
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Leerberg DM, Hopton RE, Draper BW. Fibroblast Growth Factor Receptors Function Redundantly During Zebrafish Embryonic Development. Genetics 2019; 212:1301-1319. [PMID: 31175226 PMCID: PMC6707458 DOI: 10.1534/genetics.119.302345] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 05/29/2019] [Indexed: 01/08/2023] Open
Abstract
Fibroblast growth factor (Fgf) signaling regulates many processes during development. In most cases, one tissue layer secretes an Fgf ligand that binds and activates an Fgf receptor (Fgfr) expressed by a neighboring tissue. Although studies have identified the roles of specific Fgf ligands during development, less is known about the requirements for the receptors. We have generated null mutations in each of the five fgfr genes in zebrafish. Considering the diverse requirements for Fgf signaling throughout development, and that null mutations in the mouse Fgfr1 and Fgfr2 genes are embryonic lethal, it was surprising that all zebrafish homozygous mutants are viable and fertile, with no discernable embryonic defect. Instead, we find that multiple receptors are involved in coordinating most Fgf-dependent developmental processes. For example, mutations in the ligand fgf8a cause loss of the midbrain-hindbrain boundary, whereas, in the fgfr mutants, this phenotype is seen only in embryos that are triple mutant for fgfr1a;fgfr1b;fgfr2, but not in any single or double mutant combinations. We show that this apparent fgfr redundancy is also seen during the development of several other tissues, including posterior mesoderm, pectoral fins, viscerocranium, and neurocranium. These data are an essential step toward defining the specific Fgfrs that function with particular Fgf ligands to regulate important developmental processes in zebrafish.
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Affiliation(s)
- Dena M Leerberg
- Department of Molecular and Cellular Biology, University of California, Davis, California 95616
| | - Rachel E Hopton
- Department of Molecular and Cellular Biology, University of California, Davis, California 95616
| | - Bruce W Draper
- Department of Molecular and Cellular Biology, University of California, Davis, California 95616
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12
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Davidson AJ, Lewis P, Przepiorski A, Sander V. Turning mesoderm into kidney. Semin Cell Dev Biol 2018; 91:86-93. [PMID: 30172050 DOI: 10.1016/j.semcdb.2018.08.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 08/24/2018] [Accepted: 08/28/2018] [Indexed: 02/07/2023]
Abstract
The intermediate mesoderm is located between the somites and the lateral plate mesoderm and gives rise to renal progenitors that contribute to the three mammalian kidney types (pronephros, mesonephros and metanephros). In this review, focusing largely on murine kidney development, we examine how the intermediate mesoderm forms during gastrulation/axis elongation and how it progressively gives rise to distinct renal progenitors along the rostro-caudal axis. We highlight some of the potential signalling cues and core transcription factor circuits that direct these processes, up to the point of early metanephric kidney formation.
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Affiliation(s)
- Alan J Davidson
- Department of Molecular Medicine & Pathology, School of Medical Sciences, Faculty of Medical & Health Sciences, The University of Auckland, Private Bag 921019, Auckland 1142, New Zealand.
| | - Paula Lewis
- Department of Molecular Medicine & Pathology, School of Medical Sciences, Faculty of Medical & Health Sciences, The University of Auckland, Private Bag 921019, Auckland 1142, New Zealand
| | - Aneta Przepiorski
- Department of Molecular Medicine & Pathology, School of Medical Sciences, Faculty of Medical & Health Sciences, The University of Auckland, Private Bag 921019, Auckland 1142, New Zealand
| | - Veronika Sander
- Department of Molecular Medicine & Pathology, School of Medical Sciences, Faculty of Medical & Health Sciences, The University of Auckland, Private Bag 921019, Auckland 1142, New Zealand
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13
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Nelson AC, Cutty SJ, Gasiunas SN, Deplae I, Stemple DL, Wardle FC. In Vivo Regulation of the Zebrafish Endoderm Progenitor Niche by T-Box Transcription Factors. Cell Rep 2018; 19:2782-2795. [PMID: 28658625 PMCID: PMC5494305 DOI: 10.1016/j.celrep.2017.06.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 04/28/2017] [Accepted: 05/31/2017] [Indexed: 01/15/2023] Open
Abstract
T-box transcription factors T/Brachyury homolog A (Ta) and Tbx16 are essential for correct mesoderm development in zebrafish. The downstream transcriptional networks guiding their functional activities are poorly understood. Additionally, important contributions elsewhere are likely masked due to redundancy. Here, we exploit functional genomic strategies to identify Ta and Tbx16 targets in early embryogenesis. Surprisingly, we discovered they not only activate mesodermal gene expression but also redundantly regulate key endodermal determinants, leading to substantial loss of endoderm in double mutants. To further explore the gene regulatory networks (GRNs) governing endoderm formation, we identified targets of Ta/Tbx16-regulated homeodomain transcription factor Mixl1, which is absolutely required in zebrafish for endoderm formation. Interestingly, we find many endodermal determinants coordinately regulated through common genomic occupancy by Mixl1, Eomesa, Smad2, Nanog, Mxtx2, and Pou5f3. Collectively, these findings augment the endoderm GRN and reveal a panel of target genes underlying the Ta, Tbx16, and Mixl1 mutant phenotypes.
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Affiliation(s)
- Andrew C Nelson
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK; Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK; School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK.
| | - Stephen J Cutty
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Saule N Gasiunas
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Isabella Deplae
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK
| | - Derek L Stemple
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Fiona C Wardle
- Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, UK.
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14
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Kindt LM, Coughlin AR, Perosino TR, Ersfeld HN, Hampton M, Liang JO. Identification of transcripts potentially involved in neural tube closure using RNA sequencing. Genesis 2018; 56:e23096. [PMID: 29488319 DOI: 10.1002/dvg.23096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 02/02/2018] [Accepted: 02/19/2018] [Indexed: 01/08/2023]
Abstract
Anencephaly is a fatal human neural tube defect (NTD) in which the anterior neural tube remains open. Zebrafish embryos with reduced Nodal signaling display an open anterior neural tube phenotype that is analogous to anencephaly. Previous work from our laboratory suggests that Nodal signaling acts through induction of the head mesendoderm and mesoderm. Head mesendoderm/mesoderm then, through an unknown mechanism, promotes formation of the polarized neuroepithelium that is capable of undergoing the movements required for closure. We compared the transcriptome of embryos treated with a Nodal signaling inhibitor at sphere stage, which causes NTDs, to embryos treated at 30% epiboly, which does not cause NTDs. This screen identified over 3,000 transcripts with potential roles in anterior neurulation. Expression of several genes encoding components of tight and adherens junctions was significantly reduced, supporting the model that Nodal signaling regulates formation of the neuroepithelium. mRNAs involved in Wnt, FGF, and BMP signaling were also differentially expressed, suggesting these pathways might regulate anterior neurulation. In support of this, we found that pharmacological inhibition of FGF-receptor function causes an open anterior NTD as well as loss of mesodermal derivatives. This suggests that Nodal and FGF signaling both promote anterior neurulation through induction of head mesoderm.
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Affiliation(s)
- Lexy M Kindt
- Department of Biology, University of Minnesota Duluth, Duluth.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth
| | - Alicia R Coughlin
- Department of Biology, University of Minnesota Duluth, Duluth.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth
| | | | - Haley N Ersfeld
- Department of Biology, University of Minnesota Duluth, Duluth
| | - Marshall Hampton
- Integrated Biosciences Graduate Program, University of Minnesota, Duluth.,Department of Mathematics and Statistics, University of Minnesota Duluth, Duluth
| | - Jennifer O Liang
- Department of Biology, University of Minnesota Duluth, Duluth.,Integrated Biosciences Graduate Program, University of Minnesota, Duluth
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15
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Dasgupta S, Vliet SM, Kupsco A, Leet JK, Altomare D, Volz DC. Tris(1,3-dichloro-2-propyl) phosphate disrupts dorsoventral patterning in zebrafish embryos. PeerJ 2017; 5:e4156. [PMID: 29259843 PMCID: PMC5733366 DOI: 10.7717/peerj.4156] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 11/21/2017] [Indexed: 12/02/2022] Open
Abstract
Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a high-production volume organophosphate flame retardant widely used within the United States. Within zebrafish, initiation of TDCIPP exposure at 0.75 h post-fertilization (hpf) results in genome-wide alterations in methylation during cleavage (2 hpf) as well as epiboly delay or arrest (at higher concentrations) during late-blastula and early-gastrula (4–6 hpf). To determine whether these TDCIPP-induced effects were associated with impacts on the transcriptome, embryos were exposed to vehicle (0.1% DMSO) or 2 µM TDCIPP from 0.75 hpf to 6 hpf, and total RNA was extracted from triplicate embryo pools per treatment and hybridized onto duplicate Affymetrix Zebrafish Gene 1.0 ST Arrays per RNA sample. Based on transcriptome-wide profiling, TDCIPP resulted in a significant impact on biological processes involved in dorsoventral patterning and bone morphogenetic protein (BMP) signaling. Consistent with these responses, TDCIPP exposure also resulted in strongly dorsalized embryos by 24 hpf—a phenotype that mimicked the effects of dorsomorphin, a potent and selective BMP inhibitor. Moreover, the majority of dorsalized embryos were preceded by epiboly arrest at 6 hpf. Our microarray data also revealed that the expression of sizzled (szl)—a gene encoding a secreted Frizzled-related protein that limits BMP signaling—was significantly decreased by nearly 4-fold at 6 hpf. Therefore, we used a splice-blocking morpholino to test the hypothesis that knockdown of szl phenocopies TDCIPP-induced delays in epiboly progression. Interestingly, contrary to our hypothesis, injection of szl MOs did not affect epiboly progression but, similar to chordin (chd) morphants, resulted in mildly ventralized embryos by 24 hpf. Overall, our findings suggest that TDCIPP-induced epiboly delay may not be driven by decreased szl expression, and that TDCIPP-induced dorsalization may—similar to dorsomorphin—be due to interference with BMP signaling during early zebrafish development.
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Affiliation(s)
- Subham Dasgupta
- Department of Environmental Sciences, University of California, Riverside, CA, United States of America
| | - Sara M Vliet
- Department of Environmental Sciences, University of California, Riverside, CA, United States of America.,Environmental Toxicology Graduate Program, University of California, Riverside, CA, United States of America
| | - Allison Kupsco
- Department of Environmental Sciences, University of California, Riverside, CA, United States of America
| | - Jessica K Leet
- University of South Carolina, Columbia, SC, United States of America
| | - Diego Altomare
- University of South Carolina, Columbia, SC, United States of America
| | - David C Volz
- Department of Environmental Sciences, University of California, Riverside, CA, United States of America
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16
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Morrow ZT, Maxwell AM, Hoshijima K, Talbot JC, Grunwald DJ, Amacher SL. tbx6l and tbx16 are redundantly required for posterior paraxial mesoderm formation during zebrafish embryogenesis. Dev Dyn 2017; 246:759-769. [PMID: 28691257 DOI: 10.1002/dvdy.24547] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 05/19/2017] [Accepted: 07/04/2017] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND T-box genes encode a large transcription factor family implicated in many aspects of development. We are focusing on two related zebrafish T-box genes, tbx6l and tbx16, that are expressed in highly overlapping patterns in embryonic paraxial mesoderm. tbx16 mutants are deficient in trunk, but not tail, somites; we explored whether presence of tail somites in tbx16 mutants was due to compensatory function provided by the tbx6l gene. RESULTS We generated two zebrafish tbx6l mutant alleles. Loss of tbx6l has no apparent effect on embryonic development, nor does tbx6l loss enhance the phenotype of two other T-box gene mutants, ta and tbx6, or of the mesp family gene mutant msgn1. In contrast, loss of tbx6l function dramatically enhances the paraxial mesoderm deficiency of tbx16 mutants. CONCLUSIONS These data demonstrate that tbx6l and tbx16 genes function redundantly to direct tail somite development. tbx6l single mutants develop normally because tbx16 fully compensates for loss of tbx6l function. However, tbx6l only partially compensates for loss of tbx16 function. These results resolve the question of why loss of function of tbx16 gene, which is expressed throughout the ventral and paraxial mesoderm, profoundly affects somite development in the trunk but not the tail. Developmental Dynamics 246:759-769, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Zachary T Morrow
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio
| | - Adrienne M Maxwell
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio
| | - Kazuyuki Hoshijima
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Jared C Talbot
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio.,Department of Biological Chemistry and Pharmacology, The Ohio State University School of Medicine, Columbus, Ohio.,Center for Muscle Health and Neuromuscular Disorders, The Ohio State University and Nationwide Children's Hospital, Columbus, Ohio
| | - David J Grunwald
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Sharon L Amacher
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio.,Department of Biological Chemistry and Pharmacology, The Ohio State University School of Medicine, Columbus, Ohio.,Center for Muscle Health and Neuromuscular Disorders, The Ohio State University and Nationwide Children's Hospital, Columbus, Ohio.,Center for RNA Biology, The Ohio State University, Columbus, Ohio
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17
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Naylor RW, Han HI, Hukriede NA, Davidson AJ. Wnt8a expands the pool of embryonic kidney progenitors in zebrafish. Dev Biol 2017; 425:130-141. [PMID: 28359809 DOI: 10.1016/j.ydbio.2017.03.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 03/24/2017] [Accepted: 03/25/2017] [Indexed: 01/15/2023]
Abstract
During zebrafish embryogenesis the pronephric kidney arises from a small population of posterior mesoderm cells that then undergo expansion during early stages of renal organogenesis. While wnt8 is required for posterior mesoderm formation during gastrulation, it is also transiently expressed in the post-gastrula embryo in the intermediate mesoderm, the precursor to the pronephros and some blood/vascular lineages. Here, we show that knockdown of wnt8a, using a low dose of morpholino that does not disrupt early mesoderm patterning, reduces the number of kidney and blood cells. For the kidney, wnt8a deficiency decreases renal progenitor growth during early somitogenesis, as detected by EdU incorporation, but has no effect on apoptosis. The depletion of the renal progenitor pool in wnt8a knockdown embryos leads to cellular deficits in the pronephros at 24 hpf that are characterised by a shortened distal-most segment and stretched proximal tubule cells. A pulse of the canonical Wnt pathway agonist BIO during early somitogenesis is sufficient to rescue the size of the renal progenitor pool while longer treatment expands the number of kidney cells. Taken together, these observations indicate that Wnt8, in addition to its well-established role in posterior mesoderm patterning, also plays a later role as a factor that expands the renal progenitor pool prior to kidney morphogenesis.
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Affiliation(s)
- Richard W Naylor
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland 1142, New Zealand.
| | - Hwa In Han
- Department of Developmental Biology, Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| | - Neil A Hukriede
- Department of Developmental Biology, Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| | - Alan J Davidson
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland 1142, New Zealand.
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18
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Abstract
The pronephros is the first kidney type to form in vertebrate embryos. The first step of pronephrogenesis in the zebrafish is the formation of the intermediate mesoderm during gastrulation, which occurs in response to secreted morphogens such as BMPs and Nodals. Patterning of the intermediate mesoderm into proximal and distal cell fates is induced by retinoic acid signaling with downstream transcription factors including wt1a, pax2a, pax8, hnf1b, sim1a, mecom, and irx3b. In the anterior intermediate mesoderm, progenitors of the glomerular blood filter migrate and fuse at the midline and recruit a blood supply. More posteriorly localized tubule progenitors undergo epithelialization and fuse with the cloaca. The Notch signaling pathway regulates the formation of multi-ciliated cells in the tubules and these cells help propel the filtrate to the cloaca. The lumenal sheer stress caused by flow down the tubule activates anterior collective migration of the proximal tubules and induces stretching and proliferation of the more distal segments. Ultimately these processes create a simple two-nephron kidney that is capable of reabsorbing and secreting solutes and expelling excess water-processes that are critical to the homeostasis of the body fluids. The zebrafish pronephric kidney provides a simple, yet powerful, model system to better understand the conserved molecular and cellular progresses that drive nephron formation, structure, and function.
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Affiliation(s)
- Richard W Naylor
- Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Sarah S Qubisi
- Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Alan J Davidson
- Department of Molecular Medicine and Pathology, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
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19
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Warga RM, Wicklund A, Webster SE, Kane DA. Progressive loss of RacGAP1/ ogre activity has sequential effects on cytokinesis and zebrafish development. Dev Biol 2016; 418:307-22. [PMID: 27339293 DOI: 10.1016/j.ydbio.2016.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/27/2016] [Accepted: 06/16/2016] [Indexed: 12/20/2022]
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20
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Tbx16 regulates hox gene activation in mesodermal progenitor cells. Nat Chem Biol 2016; 12:694-701. [PMID: 27376691 PMCID: PMC4990471 DOI: 10.1038/nchembio.2124] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 04/12/2016] [Indexed: 12/14/2022]
Abstract
The transcription factor T-box 16 (Tbx16/Spadetail) is an essential regulator of paraxial mesoderm development in zebrafish (Danio rerio). Mesodermal progenitor cells (MPCs) fail to differentiate into trunk somites in tbx16 mutants and instead accumulate within the tailbud in an immature state. The mechanisms by which Tbx16 controls mesoderm patterning have remained enigmatic, and we describe here the application of photoactivatable morpholino oligonucleotides to determine the Tbx16 transcriptome in MPCs. We identify 124 Tbx16-regulated genes that are expressed in zebrafish gastrulae, including several developmental signaling proteins and regulators of gastrulation, myogenesis, and somitogenesis. Unexpectedly, we observe that loss of Tbx16 function precociously activates posterior hox genes in MPCs, and overexpression of a single posterior hox gene is sufficient to disrupt MPC migration. Our studies support a model in which Tbx16 regulates the timing of collinear hox gene activation to coordinate the anterior-posterior fates and positions of paraxial MPCs.
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21
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Manning AJ, Kimelman D. Tbx16 and Msgn1 are required to establish directional cell migration of zebrafish mesodermal progenitors. Dev Biol 2015; 406:172-85. [PMID: 26368502 DOI: 10.1016/j.ydbio.2015.09.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/26/2015] [Accepted: 09/01/2015] [Indexed: 01/08/2023]
Abstract
The epithelial to mesenchymal transition (EMT) is an essential process that occurs repeatedly during embryogenesis whereby stably adherent cells convert to an actively migrating state. While much is known about the factors and events that initiate the EMT, the steps that cells undergo to become directionally migratory are far less well understood. Zebrafish embryos lacking the transcription factors Tbx16/Spadetail and Mesogenin1 (Msgn1) are a valuable system for investigating the EMT. Mesodermal cells in these embryos are unable to perform the EMT necessary to leave the most posterior end of the body (the tailbud) and join the pre-somitic mesoderm, a process that is conserved in all vertebrates. It has previously been very difficult to study this EMT in vertebrates because of the multiple cell types in the tailbud and the morphogenetic changes the whole embryo undergoes. Here, we describe a novel tissue explant system for imaging the mesodermal cell EMT in vivo that allows us to investigate the requirements for cells to acquire migratory properties during the EMT with high spatio-temporal resolution. This method revealed that, despite the inability of tbx16;msgn1-deficient cells to leave the tailbud, actin-based protrusions form surprisingly normally in these cells and they become highly motile. However, tbx16;msgn1-deficient cells have specific cell-autonomous defects in the persistence and anterior direction of migration because the lamellipodia they form are not productive in driving anteriorward migration. Additionally, we show that mesoderm morphogenesis and differentiation are separable and that there is a migratory cue that directs mesodermal cell migration that is independent of Tbx16 and Msgn1. This work defines changes that cells undergo as they complete the EMT and provides new insight into the mechanisms required in vivo for cells to become mesenchymal.
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Affiliation(s)
- Alyssa J Manning
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - David Kimelman
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA.
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22
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Payumo AY, Walker WJ, McQuade LE, Yamazoe S, Chen JK. Optochemical dissection of T-box gene-dependent medial floor plate development. ACS Chem Biol 2015; 10:1466-75. [PMID: 25781211 DOI: 10.1021/cb5010178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In addition to their cell-autonomous roles in mesoderm development, the zebrafish T-box transcription factors no tail a (ntla) and spadetail (spt/tbx16) are required for medial floor plate (MFP) formation. Posterior MFP cells are completely absent in zebrafish embryos lacking both Ntla and Spt function, and genetic mosaic analyses have shown that the two T-box genes promote MFP development in a non-cell-autonomous manner. On the basis of these observations, it has been proposed that Ntla/Spt-dependent mesoderm-derived signals are required for the induction of posterior but not anterior MFP cells. To investigate the mechanisms by which Ntla and Spt regulate MFP development, we have used photoactivatable caged morpholinos (cMOs) to silence these T-box genes with spatiotemporal control. We find that posterior MFP formation requires Ntla or Spt activity during early gastrulation, specifically in lateral margin-derived cells that converge toward the midline during epiboly and somitogenesis. Nodal signaling-dependent MFP specification is maintained in the absence of Ntla and Spt function; however, midline cells in ntla;spt morphants exhibit aberrant morphogenetic movements, resulting in their anterior mislocalization. Our findings indicate that Ntla and Spt do not differentially regulate MFP induction along the anterior-posterior axis; rather, the T-box genes act redundantly within margin-derived cells to promote the posterior extension of MFP progenitors.
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Affiliation(s)
- Alexander Y. Payumo
- Department of Chemical and Systems Biology, ‡Department of Developmental
Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Whitney J. Walker
- Department of Chemical and Systems Biology, ‡Department of Developmental
Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Lindsey E. McQuade
- Department of Chemical and Systems Biology, ‡Department of Developmental
Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Sayumi Yamazoe
- Department of Chemical and Systems Biology, ‡Department of Developmental
Biology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - James K. Chen
- Department of Chemical and Systems Biology, ‡Department of Developmental
Biology, Stanford University School of Medicine, Stanford, California 94305, United States
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