1
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Hongo I, Yamaguchi C, Okamoto H. Brain enlargement with rostral bias in larvae from a spontaneously occurring female variant line of Xenopus; role of aberrant embryonic Wnt/β-catenin signaling. Cells Dev 2024; 179:203918. [PMID: 38574816 DOI: 10.1016/j.cdev.2024.203918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/11/2024] [Accepted: 03/29/2024] [Indexed: 04/06/2024]
Abstract
Increased brain size and its rostral bias are hallmarks of vertebrate evolution, but the underlying developmental and genetic basis remains poorly understood. To provide clues to understanding vertebrate brain evolution, we investigated the developmental mechanisms of brain enlargement observed in the offspring of a previously unrecognized, spontaneously occurring female variant line of Xenopus that appears to reflect a genetic variation. Brain enlargement in larvae from this line showed a pronounced rostral bias that could be traced back to the neural plate, the primordium of the brain. At the gastrula stage, the Spemann organizer, which is known to induce the neural plate from the adjacent dorsal ectoderm and give it the initial rostrocaudal patterning, was expanded from dorsal to ventral in a large proportion of the offspring of variant females. Consistently, siamois expression, which is required for Spemann organizer formation, was expanded laterally from dorsal to ventral at the blastula stage in variant offspring. This implies that the active region of the Wnt/β-catenin signaling pathway was similarly expanded in advance on the dorsal side, as siamois is a target gene of this pathway. Notably, the earliest detectable change in variant offspring was in fertilized eggs, in which maternal wnt11b mRNA, a candidate dorsalizing factor responsible for activating Wnt/β-catenin signaling in the dorsal embryonic region, had a wider distribution in the vegetal cortical cytoplasm. Since lateral spreading of wnt11b mRNA, and possibly that of other potential maternal dorsalizing factors in these eggs, is expected to facilitate lateral expansion of the active region of the Wnt/β-catenin pathway during subsequent embryonic stages, we concluded that aberrant Wnt/β-catenin signaling could cause rostral-biased brain enlargement via expansion of siamois expression and consequent expansion of the Spemann organizer in Xenopus. Our studies of spontaneously occurring variations in brain development in Xenopus would provide hints for uncovering genetic mutations that drive analogous morphogenetic variations during vertebrate brain evolution.
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Affiliation(s)
- Ikuko Hongo
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Chihiro Yamaguchi
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Harumasa Okamoto
- Department of Life Science, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan.
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2
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Kruger RE, Frum T, Brumm AS, Hickey SL, Niakan KK, Aziz F, Shammami MA, Roberts JG, Ralston A. Smad4 is essential for epiblast scaling and morphogenesis after implantation, but nonessential before implantation. Development 2024; 151:dev202377. [PMID: 38752427 PMCID: PMC11190579 DOI: 10.1242/dev.202377] [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: 10/05/2023] [Accepted: 05/03/2024] [Indexed: 05/28/2024]
Abstract
Bone morphogenic protein (BMP) signaling plays an essential and highly conserved role in embryo axial patterning in animal species. However, in mammalian embryos, which develop inside the mother, early development includes a preimplantation stage, which does not occur in externally developing embryos. During preimplantation, the epiblast is segregated from extra-embryonic lineages that enable implantation and development in utero. Yet, the requirement for BMP signaling is imprecisely defined in mouse early embryos. Here, we show that, in contrast to previous reports, BMP signaling (SMAD1/5/9 phosphorylation) is not detectable until implantation when it is detected in the primitive endoderm - an extra-embryonic lineage. Moreover, preimplantation development appears to be normal following deletion of maternal and zygotic Smad4, an essential effector of canonical BMP signaling. In fact, mice lacking maternal Smad4 are viable. Finally, we uncover a new requirement for zygotic Smad4 in epiblast scaling and cavitation immediately after implantation, via a mechanism involving FGFR/ERK attenuation. Altogether, our results demonstrate no role for BMP4/SMAD4 in the first lineage decisions during mouse development. Rather, multi-pathway signaling among embryonic and extra-embryonic cell types drives epiblast morphogenesis postimplantation.
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Affiliation(s)
- Robin E. Kruger
- Cell and Molecular Biology Ph.D. Program, Michigan State University, East Lansing, MI 48824, USA
- Reproductive and Developmental Sciences Training Program, Michigan State University, East Lansing, MI 48824, USA
| | - Tristan Frum
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - A. Sophie Brumm
- Human Embryo and Stem Cell Laboratory, The Francis Crick Institute,London NW1 1AT, UK
| | - Stephanie L. Hickey
- Research Technology Support Facility, Michigan State University, East Lansing, MI 48824, USA
| | - Kathy K. Niakan
- Human Embryo and Stem Cell Laboratory, The Francis Crick Institute,London NW1 1AT, UK
- The Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
- Wellcome Trust – Medical Research Council Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge CB2 0AW, UK
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | - Farina Aziz
- Cell and Molecular Biology Ph.D. Program, Michigan State University, East Lansing, MI 48824, USA
| | - Marcelio A. Shammami
- Reproductive and Developmental Sciences Training Program, Michigan State University, East Lansing, MI 48824, USA
- Genetics and Genome Sciences Ph.D. Program, Michigan State University, East Lansing, MI 48824, USA
| | - Jada G. Roberts
- Molecular, Cellular, and Integrative Physiology Ph.D. Program, Michigan State University, East Lansing, MI 48824, USA
| | - Amy Ralston
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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Lin J, Zhang M, Liang F, Ni Y, Zhang J, Shi H, Hong M, Ding L. Morphological and transcriptomic analyses of embryonic development of red-eared slider Trachemys scripta elegans. Anim Reprod Sci 2024; 261:107395. [PMID: 38104500 DOI: 10.1016/j.anireprosci.2023.107395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023]
Abstract
Embryology provides an understanding of individual's origin and developmental patterns. Turtles are among the oldest living reptiles and have unique body structure. However, the morphogenesis and mechanisms of turtles are not fully understood. In this study, we focused on the embryonic development of red-eared slider (Trachemys scripta elegans) which widely distributes in the world. At an incubation temperature of 28 °C, the turtle eggs had a 61-day incubation cycle, and the entire embryonic development process was divided into 27 stages and 3 phases according to variations in age, body size, and morphological characteristics. The early phase of embryonic development (the first 12 stages) were characterized by embryo growth, and the appearance of internal organ precursors. The middle phase (stages 13-20) involved prominent heart division at stage 13 and the appearance of carapace and plastron at stages 14 and 17, respectively. In the later phase (stages 21-27), the hatchlings formed, and the carapace and plastron thickened. Transcriptome analysis of embryos showed enrichment of the differential genes in pathways related to development, metabolism, disease, and cellular processes. The Kyoto Encyclopedia of Genes and Genomes enrichment (KEGG) analysis implied the crucial regulatory role of the axon guidance pathway. Real-time fluorescence quantitative PCR indicated upregulated expression of wnt5a and bmp7 in stages 7 and 16 compared to that in stage 12. This study revealed the development process of red-eared slider embryo and the dynamics of the signaling pathway affecting its development, which supplemented the theory of embryo development, and provided new ideas for the molecular mechanism of turtle embryo development.
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Affiliation(s)
- Jing Lin
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Miaomiao Zhang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Fangbin Liang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Yunfang Ni
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Jiani Zhang
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Haitao Shi
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China
| | - Meiling Hong
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China.
| | - Li Ding
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, China.
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4
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Kruger RE, Frum T, Brumm AS, Hickey SL, Niakan KK, Aziz F, Shammami MA, Roberts JG, Ralston A. Smad4 is essential for epiblast scaling and morphogenesis after implantation, but nonessential prior to implantation in the mouse. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.23.576717. [PMID: 38328075 PMCID: PMC10849569 DOI: 10.1101/2024.01.23.576717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Bone Morphogenic Protein (BMP) signaling plays an essential and highly conserved role in axial patterning in embryos of many externally developing animal species. However, in mammalian embryos, which develop inside the mother, early development includes an additional stage known as preimplantation. During preimplantation, the epiblast lineage is segregated from the extraembryonic lineages that enable implantation and development in utero. Yet, the requirement for BMP signaling in mouse preimplantation is imprecisely defined. We show that, in contrast to prior reports, BMP signaling (as reported by SMAD1/5/9 phosphorylation) is not detectable until implantation, when it is detected in the primitive endoderm - an extraembryonic lineage. Moreover, preimplantation development appears normal following deletion of maternal and zygotic Smad4, an essential effector of BMP signaling. In fact, mice lacking maternal Smad4 are viable. Finally, we uncover a new requirement for zygotic Smad4 in epiblast scaling and cavitation immediately after implantation, via a mechanism involving FGFR/ERK attenuation. Altogether, our results demonstrate no role for BMP4/SMAD4 in the first lineage decisions during mouse development. Rather, multi-pathway signaling among embryonic and extraembryonic cell types drives epiblast morphogenesis post-implantation.
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Affiliation(s)
- Robin E. Kruger
- Cell and Molecular Biology Ph.D. Program, Michigan State University, East Lansing, MI, 48824, USA
- Reproductive and Developmental Sciences Training Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Tristan Frum
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Current address: Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - A. Sophie Brumm
- Human Embryo and Stem Cell Laboratory, The Francis Crick Institute; London, NW1 1AT, UK
| | - Stephanie L. Hickey
- Research Technology Support Facility, Michigan State University, East Lansing, MI, 48824, USA
| | - Kathy K. Niakan
- Human Embryo and Stem Cell Laboratory, The Francis Crick Institute; London, NW1 1AT, UK
- The Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3EG, UK
- Wellcome Trust – Medical Research Council Stem Cell Institute, University of Cambridge, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, CB2 0AW, UK
- Epigenetics Programme, Babraham Institute, Cambridge, CB22 3AT, UK
| | - Farina Aziz
- Cell and Molecular Biology Ph.D. Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Marcelio A. Shammami
- Reproductive and Developmental Sciences Training Program, Michigan State University, East Lansing, MI, 48824, USA
- Genetics and Genome Sciences Ph.D. Program, Michigan State University, East Lansing, MI 48824, USA
| | - Jada G. Roberts
- Molecular, Cellular, and Integrative Physiology Ph.D. Program, Michigan State University, East Lansing, MI 48824, USA
| | - Amy Ralston
- Reproductive and Developmental Sciences Training Program, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
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5
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Lawson-Keister E, Zhang T, Nazari F, Fagotto F, Manning ML. Differences in boundary behavior in the 3D vertex and Voronoi models. PLoS Comput Biol 2024; 20:e1011724. [PMID: 38181065 PMCID: PMC10796063 DOI: 10.1371/journal.pcbi.1011724] [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] [Received: 06/05/2023] [Revised: 01/18/2024] [Accepted: 11/30/2023] [Indexed: 01/07/2024] Open
Abstract
An important open question in the modeling of biological tissues is how to identify the right scale for coarse-graining, or equivalently, the right number of degrees of freedom. For confluent biological tissues, both vertex and Voronoi models, which differ only in their representation of the degrees of freedom, have effectively been used to predict behavior, including fluid-solid transitions and cell tissue compartmentalization, which are important for biological function. However, recent work in 2D has hinted that there may be differences between the two models in systems with heterotypic interfaces between two tissue types, and there is a burgeoning interest in 3D tissue models. Therefore, we compare the geometric structure and dynamic sorting behavior in mixtures of two cell types in both 3D vertex and Voronoi models. We find that while the cell shape indices exhibit similar trends in both models, the registration between cell centers and cell orientation at the boundary are significantly different between the two models. We demonstrate that these macroscopic differences are caused by changes to the cusp-like restoring forces introduced by the different representations of the degrees of freedom at the boundary, and that the Voronoi model is more strongly constrained by forces that are an artifact of the way the degrees of freedom are represented. This suggests that vertex models may be more appropriate for 3D simulations of tissues with heterotypic contacts.
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Affiliation(s)
- Elizabeth Lawson-Keister
- Department of Physics and BioInspired Syracuse, Syracuse University, Syracuse, New York, United States of America
| | - Tao Zhang
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Fatemeh Nazari
- School of Biomedical Engineering, Ecole Centrale de Lille, Villeneuve-d’Ascq, France
- Centre de Recherche en Biologie cellulaire de Montpellier, University of Montpellier and CNRS, Montpellier, France
| | - François Fagotto
- Centre de Recherche en Biologie cellulaire de Montpellier, University of Montpellier and CNRS, Montpellier, France
| | - M. Lisa Manning
- Department of Physics and BioInspired Syracuse, Syracuse University, Syracuse, New York, United States of America
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6
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Sato Y, Narasaki I, Kunimoto T, Moriyama Y, Hashimoto C. The complete dorsal structure is formed from only the blastocoel roof of Xenopus blastula: insight into the gastrulation movement evolutionarily conserved among chordates. Dev Genes Evol 2023:10.1007/s00427-023-00701-1. [PMID: 36933042 DOI: 10.1007/s00427-023-00701-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/12/2023] [Indexed: 03/19/2023]
Abstract
Gastrulation is a critical event whose molecular mechanisms are thought to be conserved among vertebrates. However, the morphological movement during gastrulation appears to be divergent across species, making it difficult to discuss the evolution of the process. Previously, we proposed a novel amphibian gastrulation model, the "subduction and zippering (S&Z) model". In this model, the organizer and the prospective neuroectoderm are originally localized in the blastula's blastocoel roof, and these embryonic regions move downward to make physical contact of their inner surfaces with each other at the dorsal marginal zone. The developmental stage when contact between the head organizer and the anterior-most neuroectoderm is established is called "anterior contact establishment (ACE)." After ACE, the A-P body axis elongates posteriorly. According to this model, the body axis is derived from limited regions of the dorsal marginal zone at ACE. To investigate this possibility, we conducted stepwise tissue deletions using Xenopus laevis embryos and revealed that the dorsal one-third of the marginal zone had the ability to form the complete dorsal structure by itself. Furthermore, a blastocoel roof explant of the blastula, which should contain the organizer and the prospective neuroectoderm in the S&Z model, autonomously underwent gastrulation and formed the complete dorsal structure. Collectively, these results are consistent with the S&Z gastrulation model and identify the embryonic region sufficient for construction of the complete dorsal structure. Finally, by comparing amphibian gastrulation to gastrulation of protochordates and amniotes, we discuss the gastrulation movement evolutionarily conserved among chordates.
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Affiliation(s)
- Yuki Sato
- JT Biohistory Research Hall, 1-1 Murasaki-Cho, Takatsuki Osaka, 569-1125, Japan
| | - Izumi Narasaki
- JT Biohistory Research Hall, 1-1 Murasaki-Cho, Takatsuki Osaka, 569-1125, Japan.,Department of Biology, Graduate School of Science, Osaka University, Suita, Japan
| | - Takuya Kunimoto
- JT Biohistory Research Hall, 1-1 Murasaki-Cho, Takatsuki Osaka, 569-1125, Japan.,Department of Biology, Graduate School of Science, Osaka University, Suita, Japan
| | - Yuki Moriyama
- Faculty of Science and Engineering, Chuo University, Hachioji, Japan
| | - Chikara Hashimoto
- JT Biohistory Research Hall, 1-1 Murasaki-Cho, Takatsuki Osaka, 569-1125, Japan. .,Department of Biology, Graduate School of Science, Osaka University, Suita, Japan.
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7
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Favarolo MB, Revinski DR, Garavaglia MJ, López SL. Nodal and churchill1 position the expression of a notch ligand during Xenopus germ layer segregation. Life Sci Alliance 2022; 5:5/12/e202201693. [PMID: 36180230 PMCID: PMC9604498 DOI: 10.26508/lsa.202201693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/24/2022] Open
Abstract
Churchill and Nodal signaling, which participate in vertebrates’ germ layer induction, position a domain of Delta/Notch activity, which refines germ layer boundaries during frog gastrulation. In vertebrates, Nodal signaling plays a major role in endomesoderm induction, but germ layer delimitation is poorly understood. In avian embryos, the neural/mesoderm boundary is controlled by the transcription factor CHURCHILL1, presumably through the repressor ZEB2, but there is scarce knowledge about its role in other vertebrates. During amphibian gastrulation, Delta/Notch signaling refines germ layer boundaries in the marginal zone, but it is unknown the place this pathway occupies in the network comprising Churchill1 and Nodal. Here, we show that Xenopus churchill1 is expressed in the presumptive neuroectoderm at mid-blastula transition and during gastrulation, upregulates zeb2, prevents dll1 expression in the neuroectoderm, and favors neuroectoderm over endomesoderm development. Nodal signaling prevents dll1 expression in the endoderm but induces it in the presumptive mesoderm, from where it activates Notch1 and its target gene hes4 in the non-involuting marginal zone. We propose a model where Nodal and Churchill1 position Dll1/Notch1/Hes4 domains in the marginal zone, ensuring the delimitation between mesoderm and neuroectoderm.
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Affiliation(s)
- María Belén Favarolo
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular e Histología/1° U.A. Departamento de Histología, Embriología, Biología Celular y Genética, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN), Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires, Argentina
| | - Diego R Revinski
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular e Histología/1° U.A. Departamento de Histología, Embriología, Biología Celular y Genética, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN), Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires, Argentina
| | - Matías J Garavaglia
- Laboratorio de Bioinsumos, Instituto de Biotecnología, Universidad Nacional de Hurlingham, Buenos Aires, Argentina
| | - Silvia L López
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Biología Celular e Histología/1° U.A. Departamento de Histología, Embriología, Biología Celular y Genética, Buenos Aires, Argentina .,CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN), Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires, Argentina
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Ducos B, Bensimon D, Scerbo P. Vertebrate Cell Differentiation, Evolution, and Diseases: The Vertebrate-Specific Developmental Potential Guardians VENTX/ NANOG and POU5/ OCT4 Enter the Stage. Cells 2022; 11:cells11152299. [PMID: 35892595 PMCID: PMC9331430 DOI: 10.3390/cells11152299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/09/2022] [Accepted: 07/13/2022] [Indexed: 01/02/2023] Open
Abstract
During vertebrate development, embryonic cells pass through a continuum of transitory pluripotent states that precede multi-lineage commitment and morphogenesis. Such states are referred to as “refractory/naïve” and “competent/formative” pluripotency. The molecular mechanisms maintaining refractory pluripotency or driving the transition to competent pluripotency, as well as the cues regulating multi-lineage commitment, are evolutionarily conserved. Vertebrate-specific “Developmental Potential Guardians” (vsDPGs; i.e., VENTX/NANOG, POU5/OCT4), together with MEK1 (MAP2K1), coordinate the pluripotency continuum, competence for multi-lineage commitment and morphogenesis in vivo. During neurulation, vsDPGs empower ectodermal cells of the neuro-epithelial border (NEB) with multipotency and ectomesenchyme potential through an “endogenous reprogramming” process, giving rise to the neural crest cells (NCCs). Furthermore, vsDPGs are expressed in undifferentiated-bipotent neuro-mesodermal progenitor cells (NMPs), which participate in posterior axis elongation and growth. Finally, vsDPGs are involved in carcinogenesis, whereby they confer selective advantage to cancer stem cells (CSCs) and therapeutic resistance. Intriguingly, the heterogenous distribution of vsDPGs in these cell types impact on cellular potential and features. Here, we summarize the findings about the role of vsDPGs during vertebrate development and their selective advantage in evolution. Our aim to present a holistic view regarding vsDPGs as facilitators of both cell plasticity/adaptability and morphological innovation/variation. Moreover, vsDPGs may also be at the heart of carcinogenesis by allowing malignant cells to escape from physiological constraints and surveillance mechanisms.
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Affiliation(s)
- Bertrand Ducos
- LPENS, PSL, CNRS, 24 rue Lhomond, 75005 Paris, France
- IBENS, PSL, CNRS, 46 rue d’Ulm, 75005 Paris, France
- High Throughput qPCR Core Facility, ENS, PSL, 46 rue d’Ulm, 75005 Paris, France
- Correspondence: (B.D.); (D.B.); (P.S.)
| | - David Bensimon
- LPENS, PSL, CNRS, 24 rue Lhomond, 75005 Paris, France
- IBENS, PSL, CNRS, 46 rue d’Ulm, 75005 Paris, France
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90094, USA
- Correspondence: (B.D.); (D.B.); (P.S.)
| | - Pierluigi Scerbo
- LPENS, PSL, CNRS, 24 rue Lhomond, 75005 Paris, France
- IBENS, PSL, CNRS, 46 rue d’Ulm, 75005 Paris, France
- Correspondence: (B.D.); (D.B.); (P.S.)
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9
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Hongo I, Okamoto H. FGF/MAPK/Ets signaling in Xenopus ectoderm contributes to neural induction and patterning in an autonomous and paracrine manner, respectively. Cells Dev 2022; 170:203769. [DOI: 10.1016/j.cdev.2022.203769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 01/16/2022] [Accepted: 02/15/2022] [Indexed: 10/19/2022]
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10
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Kumar V, Park S, Lee U, Kim J. The Organizer and Its Signaling in Embryonic Development. J Dev Biol 2021; 9:jdb9040047. [PMID: 34842722 PMCID: PMC8628936 DOI: 10.3390/jdb9040047] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/20/2021] [Accepted: 10/29/2021] [Indexed: 12/25/2022] Open
Abstract
Germ layer specification and axis formation are crucial events in embryonic development. The Spemann organizer regulates the early developmental processes by multiple regulatory mechanisms. This review focuses on the responsive signaling in organizer formation and how the organizer orchestrates the germ layer specification in vertebrates. Accumulated evidence indicates that the organizer influences embryonic development by dual signaling. Two parallel processes, the migration of the organizer’s cells, followed by the transcriptional activation/deactivation of target genes, and the diffusion of secreting molecules, collectively direct the early development. Finally, we take an in-depth look at active signaling that originates from the organizer and involves germ layer specification and patterning.
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Affiliation(s)
- Vijay Kumar
- Department of Biochemistry, Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 24252, Korea;
| | - Soochul Park
- Department of Biological Sciences, Sookmyung Women’s University, Seoul 04310, Korea;
| | - Unjoo Lee
- Department of Electrical Engineering, Hallym University, Chuncheon 24252, Korea
- Correspondence: (U.L.); (J.K.); Tel.: +82-33-248-2544 (J.K.); Fax: +82-33-244-8425 (J.K.)
| | - Jaebong Kim
- Department of Biochemistry, Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 24252, Korea;
- Correspondence: (U.L.); (J.K.); Tel.: +82-33-248-2544 (J.K.); Fax: +82-33-244-8425 (J.K.)
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11
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Abou Azar F, Lim GE. Metabolic Contributions of Wnt Signaling: More Than Controlling Flight. Front Cell Dev Biol 2021; 9:709823. [PMID: 34568323 PMCID: PMC8458764 DOI: 10.3389/fcell.2021.709823] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/16/2021] [Indexed: 12/12/2022] Open
Abstract
The canonical Wnt signaling pathway is ubiquitous throughout the body and influences a diverse array of physiological processes. Following the initial discovery of the Wnt signaling pathway during wing development in Drosophila melanogaster, it is now widely appreciated that active Wnt signaling in mammals is necessary for the development and growth of various tissues involved in whole-body metabolism, such as brain, liver, pancreas, muscle, and adipose. Moreover, elegant gain- and loss-of-function studies have dissected the tissue-specific roles of various downstream effector molecules in the regulation of energy homeostasis. This review attempts to highlight and summarize the contributions of the Wnt signaling pathway and its downstream effectors on whole-body metabolism and their influence on the development of metabolic diseases, such as diabetes and obesity. A better understanding of the Wnt signaling pathway in these tissues may aid in guiding the development of future therapeutics to treat metabolic diseases.
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Affiliation(s)
- Frederic Abou Azar
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.,Cardiometabolic Axis, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - Gareth E Lim
- Department of Medicine, Université de Montréal, Montreal, QC, Canada.,Cardiometabolic Axis, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
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12
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Itoh K, Ossipova O, Sokol SY. Pinhead antagonizes Admp to promote notochord formation. iScience 2021; 24:102520. [PMID: 34142034 PMCID: PMC8188501 DOI: 10.1016/j.isci.2021.102520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 03/18/2021] [Accepted: 05/05/2021] [Indexed: 12/05/2022] Open
Abstract
Dorsoventral patterning of a vertebrate embryo critically depends on the activity of Smad1 that mediates signaling by BMP proteins, anti-dorsalizing morphogenetic protein (Admp), and their antagonists. Pinhead (Pnhd), a cystine-knot-containing secreted protein, is expressed in the ventrolateral mesoderm during Xenopus gastrulation; however, its molecular targets and signaling mechanisms have not been fully elucidated. Our mass spectrometry-based screen of the gastrula secretome identified Admp as Pnhd-associated protein. We show that Pnhd binds Admp and inhibits its ventralizing activity by reducing Smad1 phosphorylation and its transcriptional targets. Importantly, Pnhd depletion further increased phospho-Smad1 levels in the presence of Admp. Furthermore, Pnhd synergized with Chordin and a truncated BMP4 receptor in the induction of notochord markers in ectoderm cells, and Pnhd-depleted embryos displayed notochord defects. Our findings suggest that Pnhd binds and inactivates Admp to promote notochord development. We propose that the interaction between Admp and Pnhd refines Smad1 activity gradients during vertebrate gastrulation.
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Affiliation(s)
- Keiji Itoh
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Olga Ossipova
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Sergei Y. Sokol
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, USA
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13
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Abstract
The fertilized frog egg contains all the materials needed to initiate development of a new organism, including stored RNAs and proteins deposited during oogenesis, thus the earliest stages of development do not require transcription. The onset of transcription from the zygotic genome marks the first genetic switch activating the gene regulatory network that programs embryonic development. Zygotic genome activation occurs after an initial phase of transcriptional quiescence that continues until the midblastula stage, a period called the midblastula transition, which was first identified in Xenopus. Activation of transcription is programmed by maternally supplied factors and is regulated at multiple levels. A similar switch exists in most animals and is of great interest both to developmental biologists and to those interested in understanding nuclear reprogramming. Here we review in detail our knowledge on this major switch in transcription in Xenopus and place recent discoveries in the context of a decades old problem.
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Affiliation(s)
- Ira L Blitz
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States.
| | - Ken W Y Cho
- Department of Developmental and Cell Biology, University of California, Irvine, CA, United States.
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14
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Castro Colabianchi AM, Tavella MB, Boyadjián López LE, Rubinstein M, Franchini LF, López SL. Segregation of brain and organizer precursors is differentially regulated by Nodal signaling at blastula stage. Biol Open 2021; 10:bio.051797. [PMID: 33563608 PMCID: PMC7928228 DOI: 10.1242/bio.051797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The blastula Chordin- and Noggin-expressing (BCNE) center comprises animal-dorsal and marginal-dorsal cells of the amphibian blastula and contains the precursors of the brain and the gastrula organizer. Previous findings suggested that the BCNE behaves as a homogeneous cell population that only depends on nuclear β-catenin activity but does not require Nodal and later segregates into its descendants during gastrulation. In contrast to previous findings, in this work, we show that the BCNE does not behave as a homogeneous cell population in response to Nodal antagonists. In fact, we found that chordin.1 expression in a marginal subpopulation of notochordal precursors indeed requires Nodal input. We also establish that an animal BCNE subpopulation of cells that express both, chordin.1 and sox2 (a marker of pluripotent neuroectodermal cells), and gives rise to most of the brain, persisted at blastula stage after blocking Nodal. Therefore, Nodal signaling is required to define a population of chordin.1+ cells and to restrict the recruitment of brain precursors within the BCNE as early as at blastula stage. We discuss our findings in Xenopus in comparison to other vertebrate models, uncovering similitudes in early brain induction and delimitation through Nodal signaling. This article has an associated First Person interview with the first author of the paper. Summary: Nodal signaling is involved in the delimitation of the blastula cell populations that give rise to the brain and axial mesoderm in Xenopus.
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Affiliation(s)
- Aitana M Castro Colabianchi
- Universidad de Buenos Aires. Facultad de Medicina, Departamento de Biología Celular e Histología / 1° U.A. Departamento de Histología, Embriología, Biología Celular y Genética, Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires 1121, Argentina.,CONICET - Universidad de Buenos Aires. Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN), Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - María B Tavella
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI) "Dr. Héctor N. Torres", Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1428, Argentina
| | - Laura E Boyadjián López
- Universidad de Buenos Aires. Facultad de Medicina, Departamento de Biología Celular e Histología / 1° U.A. Departamento de Histología, Embriología, Biología Celular y Genética, Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires 1121, Argentina.,CONICET - Universidad de Buenos Aires. Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN), Universidad de Buenos Aires, Buenos Aires 1121, Argentina
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI) "Dr. Héctor N. Torres", Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1428, Argentina.,Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Lucía F Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI) "Dr. Héctor N. Torres", Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1428, Argentina
| | - Silvia L López
- Universidad de Buenos Aires. Facultad de Medicina, Departamento de Biología Celular e Histología / 1° U.A. Departamento de Histología, Embriología, Biología Celular y Genética, Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires 1121, Argentina .,CONICET - Universidad de Buenos Aires. Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN), Universidad de Buenos Aires, Buenos Aires 1121, Argentina
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15
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Ossipova O, Itoh K, Radu A, Ezan J, Sokol SY. Pinhead signaling regulates mesoderm heterogeneity via the FGF receptor-dependent pathway. Development 2020; 147:dev188094. [PMID: 32859582 PMCID: PMC7502591 DOI: 10.1242/dev.188094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 08/04/2020] [Indexed: 12/29/2022]
Abstract
Among the three embryonic germ layers, the mesoderm plays a central role in the establishment of the vertebrate body plan. The mesoderm is specified by secreted signaling proteins from the FGF, Nodal, BMP and Wnt families. No new classes of extracellular mesoderm-inducing factors have been identified in more than two decades. Here, we show that the pinhead (pnhd) gene encodes a secreted protein that is essential for the activation of a subset of mesodermal markers in the Xenopus embryo. RNA sequencing revealed that many transcriptional targets of Pnhd are shared with those of the FGF pathway. Pnhd activity was accompanied by Erk phosphorylation and required FGF and Nodal but not Wnt signaling. We propose that during gastrulation Pnhd acts in the marginal zone to contribute to mesoderm heterogeneity via an FGF receptor-dependent positive feedback mechanism.
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Affiliation(s)
- Olga Ossipova
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Keiji Itoh
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Aurelian Radu
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jerome Ezan
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sergei Y Sokol
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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16
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Esmaeili M, Blythe SA, Tobias JW, Zhang K, Yang J, Klein PS. Chromatin accessibility and histone acetylation in the regulation of competence in early development. Dev Biol 2020; 462:20-35. [PMID: 32119833 PMCID: PMC7225061 DOI: 10.1016/j.ydbio.2020.02.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/29/2020] [Accepted: 02/25/2020] [Indexed: 02/06/2023]
Abstract
As development proceeds, inductive cues are interpreted by competent tissues in a spatially and temporally restricted manner. While key inductive signaling pathways within competent cells are well-described at a molecular level, the mechanisms by which tissues lose responsiveness to inductive signals are not well understood. Localized activation of Wnt signaling before zygotic gene activation in Xenopus laevis leads to dorsal development, but competence to induce dorsal genes in response to Wnts is lost by the late blastula stage. We hypothesize that loss of competence is mediated by changes in histone modifications leading to a loss of chromatin accessibility at the promoters of Wnt target genes. We use ATAC-seq to evaluate genome-wide changes in chromatin accessibility across several developmental stages. Based on overlap with p300 binding, we identify thousands of putative cis-regulatory elements at the gastrula stage, including sites that lose accessibility by the end of gastrulation and are enriched for pluripotency factor binding motifs. Dorsal Wnt target gene promoters are not accessible after the loss of competence in the early gastrula while genes involved in mesoderm and neural crest development maintain accessibility at their promoters. Inhibition of histone deacetylases increases acetylation at the promoters of dorsal Wnt target genes and extends competence for dorsal gene induction by Wnt signaling. Histone deacetylase inhibition, however, is not sufficient to extend competence for mesoderm or neural crest induction. These data suggest that chromatin state regulates the loss of competence to inductive signals in a context-dependent manner.
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Affiliation(s)
- Melody Esmaeili
- Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Shelby A Blythe
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - John W Tobias
- Penn Genomic Analysis Core and Abramson Cancer Center, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Kai Zhang
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jing Yang
- Department of Comparative Biosciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Peter S Klein
- Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Departments of Medicine (Hematology-Oncology) and Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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17
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Britton G, Heemskerk I, Hodge R, Qutub AA, Warmflash A. A novel self-organizing embryonic stem cell system reveals signaling logic underlying the patterning of human ectoderm. Development 2019; 146:dev.179093. [PMID: 31519692 DOI: 10.1242/dev.179093] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/06/2019] [Indexed: 12/20/2022]
Abstract
During development, the ectoderm is patterned by a combination of BMP and WNT signaling. Research in model organisms has provided substantial insight into this process; however, there are currently no systems in which to study ectodermal patterning in humans. Further, the complexity of neural plate border specification has made it difficult to transition from discovering the genes involved to deeper mechanistic understanding. Here, we develop an in vitro model of human ectodermal patterning, in which human embryonic stem cells self-organize to form robust and quantitatively reproducible patterns corresponding to the complete medial-lateral axis of the embryonic ectoderm. Using this platform, we show that the duration of endogenous WNT signaling is a crucial control parameter, and that cells sense relative levels of BMP and WNT signaling in making fate decisions. These insights allowed us to develop an improved protocol for placodal differentiation. Thus, our platform is a powerful tool for studying human ectoderm patterning and for improving directed differentiation protocols.This article has an associated 'The people behind the papers' interview.
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Affiliation(s)
- George Britton
- Systems Synthetic and Physical Biology Program, Rice University Houston, Houston, TX 77005, USA
| | - Idse Heemskerk
- Department of Biosciences, Rice University Houston, Houston, TX 77005, USA
| | - Rachel Hodge
- Department of Biosciences, Rice University Houston, Houston, TX 77005, USA
| | - Amina A Qutub
- Department of Bioengineering, Rice University Houston, Houston, TX 77005, USA
| | - Aryeh Warmflash
- Department of Biosciences, Rice University Houston, Houston, TX 77005, USA .,Department of Bioengineering, Rice University Houston, Houston, TX 77005, USA
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18
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Gentsch GE, Spruce T, Owens NDL, Smith JC. Maternal pluripotency factors initiate extensive chromatin remodelling to predefine first response to inductive signals. Nat Commun 2019; 10:4269. [PMID: 31537794 PMCID: PMC6753111 DOI: 10.1038/s41467-019-12263-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 08/30/2019] [Indexed: 12/14/2022] Open
Abstract
Embryonic development yields many different cell types in response to just a few families of inductive signals. The property of signal-receiving cells that determines how they respond to inductive signals is known as competence, and it differs in different cell types. Here, we explore the ways in which maternal factors modify chromatin to specify initial competence in the frog Xenopus tropicalis. We identify early-engaged regulatory DNA sequences, and infer from them critical activators of the zygotic genome. Of these, we show that the pioneering activity of the maternal pluripotency factors Pou5f3 and Sox3 determines competence for germ layer formation by extensively remodelling compacted chromatin before the onset of inductive signalling. This remodelling includes the opening and marking of thousands of regulatory elements, extensive chromatin looping, and the co-recruitment of signal-mediating transcription factors. Our work identifies significant developmental principles that inform our understanding of how pluripotent stem cells interpret inductive signals.
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Affiliation(s)
- George E Gentsch
- Developmental Biology Laboratory, The Francis Crick Institute, London, NW1 1AT, UK.
| | - Thomas Spruce
- Centre for Genomic Regulation, Barcelona Institute for Science and Technology, 08003, Barcelona, Spain
| | - Nick D L Owens
- Department of Stem Cell and Developmental Biology, Pasteur Institute, 75015, Paris, France
| | - James C Smith
- Developmental Biology Laboratory, The Francis Crick Institute, London, NW1 1AT, UK.
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19
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Gentsch GE, Owens NDL, Smith JC. The Spatiotemporal Control of Zygotic Genome Activation. iScience 2019; 16:485-498. [PMID: 31229896 PMCID: PMC6593175 DOI: 10.1016/j.isci.2019.06.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/07/2019] [Accepted: 06/06/2019] [Indexed: 11/16/2022] Open
Abstract
One of the earliest and most significant events in embryonic development is zygotic genome activation (ZGA). In several species, bulk transcription begins at the midblastula transition (MBT) when, after a certain number of cleavages, the embryo attains a particular nuclear-to-cytoplasmic (N/C) ratio, maternal repressors become sufficiently diluted, and the cell cycle slows down. Here we resolve the frog ZGA in time and space by profiling RNA polymerase II (RNAPII) engagement and its transcriptional readout. We detect a gradual increase in both the quantity and the length of RNAPII elongation before the MBT, revealing that >1,000 zygotic genes disregard the N/C timer for their activation and that the sizes of newly transcribed genes are not necessarily constrained by cell cycle duration. We also find that Wnt, Nodal, and BMP signaling together generate most of the spatiotemporal dynamics of regional ZGA, directing the formation of orthogonal body axes and proportionate germ layers.
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Affiliation(s)
- George E Gentsch
- Developmental Biology Laboratory, Francis Crick Institute, London NW1 1AT, UK.
| | - Nick D L Owens
- Department of Stem Cell and Developmental Biology, Pasteur Institute, Paris 75015, France
| | - James C Smith
- Developmental Biology Laboratory, Francis Crick Institute, London NW1 1AT, UK.
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20
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Polevoy H, Gutkovich YE, Michaelov A, Volovik Y, Elkouby YM, Frank D. New roles for Wnt and BMP signaling in neural anteroposterior patterning. EMBO Rep 2019; 20:embr.201845842. [PMID: 30936121 DOI: 10.15252/embr.201845842] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/04/2019] [Accepted: 03/07/2019] [Indexed: 01/19/2023] Open
Abstract
During amphibian development, neural patterning occurs via a two-step process. Spemann's organizer secretes BMP antagonists that induce anterior neural tissue. A subsequent caudalizing step re-specifies anterior fated cells to posterior fates such as hindbrain and spinal cord. The neural patterning paradigm suggests that a canonical Wnt-signaling gradient acts along the anteroposterior axis to pattern the nervous system. Wnt activity is highest in the posterior, inducing spinal cord, at intermediate levels in the trunk, inducing hindbrain, and is lowest in anterior fated forebrain, while BMP-antagonist levels are constant along the axis. Our results in Xenopus laevis challenge this paradigm. We find that inhibition of canonical Wnt signaling or its downstream transcription factors eliminates hindbrain, but not spinal cord fates, an observation not compatible with a simple high-to-low Wnt gradient specifying all fates along the neural anteroposterior axis. Additionally, we find that BMP activity promotes posterior spinal cord cell fate formation in an FGF-dependent manner, while inhibiting hindbrain fates. These results suggest a need to re-evaluate the paradigms of neural anteroposterior pattern formation during vertebrate development.
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Affiliation(s)
- Hanna Polevoy
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Yoni E Gutkovich
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ariel Michaelov
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Yael Volovik
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Yaniv M Elkouby
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Dale Frank
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
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21
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Onai T. Canonical Wnt/β-catenin and Notch signaling regulate animal/vegetal axial patterning in the cephalochordate amphioxus. Evol Dev 2018; 21:31-43. [PMID: 30288919 DOI: 10.1111/ede.12273] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In bilaterians, animal/vegetal axial (A/V) patterning is a fundamental early developmental event for establishment of animal/vegetal polarity and following specification of the germ layers (ectoderm, mesoderm, endoderm), of which the evolutionary origin is enigmatic. Understanding A/V axial patterning in a basal animal from each phylum would help to reconstruct the ancestral state of germ layer specification in bilaterians and thus, the evolution of mesoderm, the third intermediate cell layer. Herein, data show that the canonical Wnt/β-catenin (cWnt) and Notch signaling pathways control mesoderm specification from the early endomesoderm in the basal chordate amphioxus. Amphioxus belongs to the deuterostome, one of the main superphyla in Bilateria. In the present study, genes (tcf, dsh, axin, gsk3β) encoding cWnt components were expressed in the endomesoderm during the gastrula stages. Excess cWnt signaling by BIO, a GSK3 inhibitor, expanded the expression domains of outer endomesodermal genes that include future mesodermal ones and suppressed inner endomesodermal and ectodermal genes. Interfering Notch signaling by DAPT, a γ-secretase inhibitor, resulted in decreased expression of ectodermal and endomesodermal markers. These results suggest that cWnt and Notch have important roles in mesoderm specification in amphioxus embryos. The evolution of the mesoderm is also discussed.
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Affiliation(s)
- Takayuki Onai
- Department of Anatomy, University of Fukui, School of Medical Sciences, Fukui, Japan.,Life Science Innovation Center, University of Fukui, Fukui, Japan
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22
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Abstract
One challenge in biology is to make sense of the complexity of biological networks. A good system to approach this is signaling pathways, whose well-characterized molecular details allow us to relate the internal processes of each pathway to their input-output behavior. In this study, we analyzed mathematical models of three metazoan signaling pathways: the canonical Wnt, MAPK/ERK, and Tgfβ pathways. We find an unexpected convergence: the three pathways behave in some physiological contexts as linear signal transmitters. Testing the results experimentally, we present direct measurements of linear input-output behavior in the Wnt and ERK pathways. Analytics from each model further reveal that linearity arises through different means in each pathway, which we tested experimentally in the Wnt and ERK pathways. Linearity is a desired property in engineering where it facilitates fidelity and superposition in signal transmission. Our findings illustrate how cells tune different complex networks to converge on the same behavior.
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Affiliation(s)
- Harry Nunns
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaUnited States
| | - Lea Goentoro
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaUnited States
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23
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Castro Colabianchi AM, Revinski DR, Encinas PI, Baez MV, Monti RJ, Rodríguez Abinal M, Kodjabachian L, Franchini LF, López SL. Notch1 is asymmetrically distributed from the beginning of embryogenesis and controls the ventral center. Development 2018; 145:dev.159368. [PMID: 29866901 DOI: 10.1242/dev.159368] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 05/25/2018] [Indexed: 12/14/2022]
Abstract
Based on functional evidence, we have previously demonstrated that early ventral Notch1 activity restricts dorsoanterior development in Xenopus We found that Notch1 has ventralizing properties and abolishes the dorsalizing activity of β-catenin by reducing its steady state levels, in a process that does not require β-catenin phosphorylation by glycogen synthase kinase 3β. In the present work, we demonstrate that Notch1 mRNA and protein are enriched in the ventral region from the beginning of embryogenesis in Xenopus This is the earliest sign of ventral development, preceding the localized expression of wnt8a, bmp4 and Ventx genes in the ventral center and the dorsal accumulation of nuclear β-catenin. Knockdown experiments indicate that Notch1 is necessary for the normal expression of genes essential for ventral-posterior development. These results indicate that during early embryogenesis ventrally located Notch1 promotes the development of the ventral center. Together with our previous evidence, these results suggest that ventral enrichment of Notch1 underlies the process by which Notch1 participates in restricting nuclear accumulation of β-catenin to the dorsal side.
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Affiliation(s)
- Aitana M Castro Colabianchi
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias 'Prof. E. De Robertis' (IBCN), Facultad de Medicina. Laboratorio de Embriología Molecular 'Prof. Dr. Andrés E. Carrasco', C1121ABG Buenos Aires, Argentina
| | - Diego R Revinski
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias 'Prof. E. De Robertis' (IBCN), Facultad de Medicina. Laboratorio de Embriología Molecular 'Prof. Dr. Andrés E. Carrasco', C1121ABG Buenos Aires, Argentina.,Aix Marseille Université, CNRS, IBDM, 13288 Marseille, France
| | - Paula I Encinas
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias 'Prof. E. De Robertis' (IBCN), Facultad de Medicina. Laboratorio de Embriología Molecular 'Prof. Dr. Andrés E. Carrasco', C1121ABG Buenos Aires, Argentina
| | - María Verónica Baez
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias 'Prof. E. De Robertis' (IBCN), Facultad de Medicina. Laboratorio de Embriología Molecular 'Prof. Dr. Andrés E. Carrasco', C1121ABG Buenos Aires, Argentina
| | - Renato J Monti
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias 'Prof. E. De Robertis' (IBCN), Facultad de Medicina. Laboratorio de Embriología Molecular 'Prof. Dr. Andrés E. Carrasco', C1121ABG Buenos Aires, Argentina
| | - Mateo Rodríguez Abinal
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias 'Prof. E. De Robertis' (IBCN), Facultad de Medicina. Laboratorio de Embriología Molecular 'Prof. Dr. Andrés E. Carrasco', C1121ABG Buenos Aires, Argentina
| | | | - Lucía F Franchini
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1428ADN Buenos Aires, Argentina
| | - Silvia L López
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias 'Prof. E. De Robertis' (IBCN), Facultad de Medicina. Laboratorio de Embriología Molecular 'Prof. Dr. Andrés E. Carrasco', C1121ABG Buenos Aires, Argentina
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24
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Favarolo MB, López SL. Notch signaling in the division of germ layers in bilaterian embryos. Mech Dev 2018; 154:122-144. [PMID: 29940277 DOI: 10.1016/j.mod.2018.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/08/2018] [Accepted: 06/18/2018] [Indexed: 01/09/2023]
Abstract
Bilaterian embryos are triploblastic organisms which develop three complete germ layers (ectoderm, mesoderm, and endoderm). While the ectoderm develops mainly from the animal hemisphere, there is diversity in the location from where the endoderm and the mesoderm arise in relation to the animal-vegetal axis, ranging from endoderm being specified between the ectoderm and mesoderm in echinoderms, and the mesoderm being specified between the ectoderm and the endoderm in vertebrates. A common feature is that part of the mesoderm segregates from an ancient bipotential endomesodermal domain. The process of segregation is noisy during the initial steps but it is gradually refined. In this review, we discuss the role of the Notch pathway in the establishment and refinement of boundaries between germ layers in bilaterians, with special focus on its interaction with the Wnt/β-catenin pathway.
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Affiliation(s)
- María Belén Favarolo
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Facultad de Medicina, Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires, Argentina
| | - Silvia L López
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis" (IBCN), Facultad de Medicina, Laboratorio de Embriología Molecular "Prof. Dr. Andrés E. Carrasco", Buenos Aires, Argentina.
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25
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Huang Y, Winklbauer R. Cell migration in the Xenopus gastrula. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2018; 7:e325. [PMID: 29944210 DOI: 10.1002/wdev.325] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 05/22/2018] [Accepted: 05/30/2018] [Indexed: 12/17/2022]
Abstract
Xenopus gastrulation movements are in large part based on the rearrangement of cells by differential cell-on-cell migration within multilayered tissues. Different patterns of migration-based cell intercalation drive endoderm and mesoderm internalization and their positioning along their prospective body axes. C-cadherin, fibronectin, integrins, and focal contact components are expressed in all gastrula cells and play putative roles in cell-on-cell migration, but their actual functions in this respect are not yet understood. The gastrula can be subdivided into two motility domains, and in the vegetal, migratory domain, two modes of cell migration are discerned. Vegetal endoderm cells show ingression-type migration, a variant of amoeboid migration characterized by the lack of locomotory protrusions and by macropinocytosis as a mechanism of trailing edge resorption. Mesendoderm and prechordal mesoderm cells use lamellipodia in a mesenchymal mode of migration. Gastrula cell motility can be dissected into traits, such as cell polarity, adhesion, mobility, or protrusive activity, which are controlled separately yet in complex, combinatorial ways. Cells can instantaneously switch between different combinations of traits, showing plasticity as they respond to substratum properties. This article is categorized under: Early Embryonic Development > Gastrulation and Neurulation.
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Affiliation(s)
- Yunyun Huang
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Rudolf Winklbauer
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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26
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Abstract
Understanding cell fate patterning and morphogenesis in the mammalian embryo remains a formidable challenge. Recently, in vivo models based on embryonic stem cells (ESCs) have emerged as complementary methods to quantitatively dissect the physical and molecular processes that shape the embryo. Here we review recent developments in using ESCs to create both two- and three-dimensional culture models that shed light on mammalian gastrulation.
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Affiliation(s)
- Eric D Siggia
- Center for Studies in Physics and Biology, The Rockefeller University, New York, NY, United States.
| | - Aryeh Warmflash
- Departments of Biosciences and Bioengineering, Rice University, Houston, TX, United States.
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27
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Sokpor G, Castro-Hernandez R, Rosenbusch J, Staiger JF, Tuoc T. ATP-Dependent Chromatin Remodeling During Cortical Neurogenesis. Front Neurosci 2018; 12:226. [PMID: 29686607 PMCID: PMC5900035 DOI: 10.3389/fnins.2018.00226] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/22/2018] [Indexed: 12/20/2022] Open
Abstract
The generation of individual neurons (neurogenesis) during cortical development occurs in discrete steps that are subtly regulated and orchestrated to ensure normal histogenesis and function of the cortex. Notably, various gene expression programs are known to critically drive many facets of neurogenesis with a high level of specificity during brain development. Typically, precise regulation of gene expression patterns ensures that key events like proliferation and differentiation of neural progenitors, specification of neuronal subtypes, as well as migration and maturation of neurons in the developing cortex occur properly. ATP-dependent chromatin remodeling complexes regulate gene expression through utilization of energy from ATP hydrolysis to reorganize chromatin structure. These chromatin remodeling complexes are characteristically multimeric, with some capable of adopting functionally distinct conformations via subunit reconstitution to perform specific roles in major aspects of cortical neurogenesis. In this review, we highlight the functions of such chromatin remodelers during cortical development. We also bring together various proposed mechanisms by which ATP-dependent chromatin remodelers function individually or in concert, to specifically modulate vital steps in cortical neurogenesis.
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Affiliation(s)
- Godwin Sokpor
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany
| | - Ricardo Castro-Hernandez
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany
| | - Joachim Rosenbusch
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany
| | - Jochen F Staiger
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany.,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Goettingen, Germany
| | - Tran Tuoc
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Goettingen, Goettingen, Germany.,DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Goettingen, Germany
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28
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Zhang H, Huang X, Shi Y, Liu W, He M. Identification and analysis of an MKK4 homologue in response to the nucleus grafting operation and antigens in the pearl oyster, Pinctada fucata. FISH & SHELLFISH IMMUNOLOGY 2018; 73:279-287. [PMID: 29269289 DOI: 10.1016/j.fsi.2017.12.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/04/2017] [Accepted: 12/16/2017] [Indexed: 06/07/2023]
Abstract
The mitogen-activated protein kinase kinase 4 (MKK4) is a key component of the c-Jun N-terminal kinase (JNK) signaling pathway and regulates multiple cellular activities. However, little is known about the roles of this kinase in pearl oyster. In this study, we identified an MKK4 homologue in Pinctada fucata by using a transcriptome database. Sequence analysis and protein structure prediction showed that PfMKK4 is highly conserved to MKK4 from other vertebrate and invertebrate species. Phylogenetic analysis revealed that PfMKK4 has the closest relationship with that from Crassostrea gigas. QPCR was used to investigate expression profiles in different healthy adult tissues and developmental stages of P. fucata. We found that PfMKK4 was ubiquitously expressed in all tissues and developmental stages examined except for in D-shaped larvae. Gene expression analysis suggested that PfMKK4 is involved in the response to the nucleus insertion operation. Lipopolysaccharide (LPS) and polyinosinic:polycytidylic acid [poly(I:C)] stimulation in vivo reduced PfMKK4 mRNA expression at 6 h, 48 h and 48 h, 72 h, respectively. LPS and poly(I:C) induced PfMKK4 phosphorylation in a primary mantle cell culture. These results contribute to better understanding of the potential role played by PfMKK4 in protecting the pearl oyster from injury caused by grafting or disease.
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Affiliation(s)
- Hua Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiande Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Yu Shi
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Wenguang Liu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Maoxian He
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
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29
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Brafman D, Willert K. Wnt/β-catenin signaling during early vertebrate neural development. Dev Neurobiol 2017; 77:1239-1259. [PMID: 28799266 DOI: 10.1002/dneu.22517] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/24/2017] [Accepted: 08/09/2017] [Indexed: 12/29/2022]
Abstract
The vertebrate central nervous system (CNS) is comprised of vast number of distinct cell types arranged in a highly organized manner. This high degree of complexity is achieved by cellular communication, including direct cell-cell contact, cell-matrix interactions, and cell-growth factor signaling. Among the several developmental signals controlling the development of the CNS, Wnt proteins have emerged as particularly critical and, hence, have captivated the attention of many researchers. With Wnts' evolutionarily conserved function as primordial symmetry breaking signals, these proteins and their downstream effects are responsible for simultaneously establishing cellular diversity and tissue organization. With their expansive repertoire of secreted agonists and antagonists, cell surface receptors, signaling cascades and downstream biological effects, Wnts are ideally suited to control the complex processes underlying vertebrate neural development. In this review, we will describe the mechanisms by which Wnts exert their potent effects on cells and tissues and highlight the many roles of Wnt signaling during neural development, starting from the initial induction of the neural plate, the subsequent patterning along the embryonic axes, to the intricately organized structure of the CNS. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1239-1259, 2017.
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Affiliation(s)
- David Brafman
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona, 85287
| | - Karl Willert
- Department of Cellular & Molecular Medicine, University of California San Diego, La Jolla, CA, 92093-0695
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30
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Canty L, Zarour E, Kashkooli L, François P, Fagotto F. Sorting at embryonic boundaries requires high heterotypic interfacial tension. Nat Commun 2017; 8:157. [PMID: 28761157 PMCID: PMC5537356 DOI: 10.1038/s41467-017-00146-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 06/02/2017] [Indexed: 11/22/2022] Open
Abstract
The establishment of sharp boundaries is essential for segregation of embryonic tissues during development, but the underlying mechanism of cell sorting has remained unclear. Opposing hypotheses have been proposed, either based on global tissue adhesive or contractile properties or on local signalling through cell contact cues. Here we use ectoderm-mesoderm separation in Xenopus to directly evaluate the role of these various parameters. We find that ephrin-Eph-based repulsion is very effective at inducing and maintaining separation, whereas differences in adhesion or contractility have surprisingly little impact. Computer simulations support and generalise our experimental results, showing that a high heterotypic interfacial tension between tissues is key to their segregation. We propose a unifying model, in which conditions of sorting previously considered as driven by differential adhesion/tension should be viewed as suboptimal cases of heterotypic interfacial tension.The mechanisms that cause different cells to segregate into distinct tissues are unclear. Here the authors show in Xenopus that formation of a boundary between two tissues is driven by local tension along the interface rather than by global differences in adhesion or cortical contractility.
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Affiliation(s)
- Laura Canty
- Dept. of Biology, McGill University, Montreal, QC, Canada, H3A1B1
| | - Eleyine Zarour
- Dept. of Biology, McGill University, Montreal, QC, Canada, H3A1B1
| | - Leily Kashkooli
- Dept. of Biology, McGill University, Montreal, QC, Canada, H3A1B1
- CRBM, CNRS, Montpellier, 34293, France
| | - Paul François
- Dept. of Biology, McGill University, Montreal, QC, Canada, H3A1B1
- Dept. of Physics, McGill University, Montreal, QC, Canada, H3A2T8
| | - François Fagotto
- Dept. of Biology, McGill University, Montreal, QC, Canada, H3A1B1.
- CRBM, CNRS, Montpellier, 34293, France.
- Dept. of Biology, University of Montpellier, Montpellier, 34095, France.
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31
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Kim K, Cho J, Hilzinger TS, Nunns H, Liu A, Ryba BE, Goentoro L. Two-Element Transcriptional Regulation in the Canonical Wnt Pathway. Curr Biol 2017; 27:2357-2364.e5. [PMID: 28756947 DOI: 10.1016/j.cub.2017.06.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/02/2017] [Accepted: 06/14/2017] [Indexed: 12/25/2022]
Abstract
The canonical Wnt pathway regulates numerous fundamental processes throughout development and adult physiology and is often disrupted in diseases [1-4]. Signal in the pathway is transduced by β-catenin, which in complex with Tcf/Lef regulates transcription. Despite the many processes that the Wnt pathway governs, β-catenin acts primarily on a single cis element in the DNA, the Wnt-responsive element (WRE), at times potentiated by a nearby Helper site. In this study, working with Xenopus, mouse, and human systems, we identified a cis element, distinct from WRE, upon which β-catenin and Tcf act. The element is 11 bp long, hundreds of bases apart from the WRE, and exhibits a suppressive effect. In Xenopus patterning, loss of the 11-bp negative regulatory elements (11-bp NREs) broadened dorsal expression of siamois. In mouse embryonic stem cells, genomic deletion of the 11-bp NREs in the promoter elevated Brachyury expression. This reveals a previously unappreciated mechanism within the Wnt pathway, where gene response is not only driven by WREs but also tuned by 11-bp NREs. Using electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP), we found evidence for the NREs binding to β-catenin and Tcf-suggesting a dual action by β-catenin as a signal and a feedforward sensor. Analyzing β-catenin ChIP sequencing in human cells, we found the 11-bp NREs co-localizing with the WRE in 45%-71% of the peaks, suggesting a widespread role for the mechanism. This study presents an example of a more complex cis regulation by a signaling pathway, where a signal is processed through two distinct cis elements in a gene circuitry.
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Affiliation(s)
- Kibeom Kim
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jaehyoung Cho
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Thomas S Hilzinger
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Harry Nunns
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Andrew Liu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Bryan E Ryba
- Department of Physics and Department of Molecular Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lea Goentoro
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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32
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Controlling the Messenger: Regulated Translation of Maternal mRNAs in Xenopus laevis Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:49-82. [PMID: 27975270 DOI: 10.1007/978-3-319-46095-6_2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The selective translation of maternal mRNAs encoding cell-fate determinants drives the earliest decisions of embryogenesis that establish the vertebrate body plan. This chapter will discuss studies in Xenopus laevis that provide insights into mechanisms underlying this translational control. Xenopus has been a powerful model organism for many discoveries relevant to the translational control of maternal mRNAs because of the large size of its oocytes and eggs that allow for microinjection of molecules and the relative ease of manipulating the oocyte to egg transition (maturation) and fertilization in culture. Consequently, many key studies have focused on the expression of maternal mRNAs during the oocyte to egg transition (the meiotic cell cycle) and the rapid cell divisions immediately following fertilization. This research has made seminal contributions to our understanding of translational regulatory mechanisms, but while some of the mRNAs under consideration at these stages encode cell-fate determinants, many encode cell cycle regulatory proteins that drive these early cell cycles. In contrast, while maternal mRNAs encoding key developmental (i.e., cell-fate) regulators that function after the first cleavage stages may exploit aspects of these foundational mechanisms, studies reveal that these mRNAs must also rely on distinct and, as of yet, incompletely understood mechanisms. These findings are logical because the functions of such developmental regulatory proteins have requirements distinct from cell cycle regulators, including becoming relevant only after fertilization and then only in specific cells of the embryo. Indeed, key maternal cell-fate determinants must be made available in exquisitely precise amounts (usually low), only at specific times and in specific cells during embryogenesis. To provide an appreciation for the regulation of maternal cell-fate determinant expression, an overview of the maternal phase of Xenopus embryogenesis will be presented. This section will be followed by a review of translational mechanisms operating in oocytes, eggs, and early cleavage-stage embryos and conclude with a discussion of how the regulation of key maternal cell-fate determinants at the level of translation functions in Xenopus embryogenesis. A key theme is that the molecular asymmetries critical for forming the body axes are established and further elaborated upon by the selective temporal and spatial regulation of maternal mRNA translation.
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Nakamura Y, Hoppler S. Genome-wide analysis of canonical Wnt target gene regulation in Xenopus tropicalis challenges β-catenin paradigm. Genesis 2017; 55. [PMID: 28095618 PMCID: PMC5299483 DOI: 10.1002/dvg.22991] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 10/30/2016] [Indexed: 12/20/2022]
Abstract
Wnt/β‐catenin signaling is an important cell‐to‐cell signaling mechanism that controls gene expression during embryonic development and is critically implicated in human diseases. Developmental, cellular, and transcriptional responses to Wnt signaling are remarkably context‐specific in different biological processes. While nuclear localization of β‐catenin is the key to activation of the Wnt/β‐catenin pathway and target gene expression, the molecular mechanisms of how the same Wnt/β‐catenin signaling pathway induces specific responses remain undetermined. Recent advances in high‐throughput sequencing technologies and the availability of genome information for Xenopus tropicalis have enabled us to uncover a genome‐wide view of Wnt/β‐catenin signaling in early vertebrate embryos, which challenges previous concepts about molecular mechanisms of Wnt target gene regulation. In this review, we summarize our experimental approaches, introduce the technologies we employed and focus on recent findings about Wnt target gene regulation from Xenopus research. We will also discuss potential functions of widespread β‐catenin binding in the genome that we discovered in this species.
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Affiliation(s)
- Yukio Nakamura
- Institute of Medical Sciences, Foresterhill Health Campus, University of Aberdeen, Aberdeen, AB25 2ZD, United Kingdom
| | - Stefan Hoppler
- Institute of Medical Sciences, Foresterhill Health Campus, University of Aberdeen, Aberdeen, AB25 2ZD, United Kingdom
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34
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Schille C, Schambony A. Signaling pathways and tissue interactions in neural plate border formation. NEUROGENESIS 2017; 4:e1292783. [PMID: 28352644 DOI: 10.1080/23262133.2017.1292783] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 02/04/2023]
Abstract
The neural crest is a transient cell population that gives rise to various cell types of multiple tissues and organs in the vertebrate embryo. Neural crest cells arise from the neural plate border, a region localized at the lateral borders of the prospective neural plate. Temporally and spatially coordinated interaction with the adjacent tissues, the non-neural ectoderm, the neural plate and the prospective dorsolateral mesoderm, is required for neural plate border specification. Signaling molecules, namely BMP, Wnt and FGF ligands and corresponding antagonists are derived from these tissues and interact to induce the expression of neural plate border specific genes. The present mini-review focuses on the current understanding of how the NPB territory is formed and accentuates the need for coordinated interaction of BMP and Wnt signaling pathways and precise tissue communication that are required for the definition of the prospective NC in the competent ectoderm.
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Affiliation(s)
- Carolin Schille
- Biology Department, Developmental Biology, Friedrich-Alexander University Erlangen-Nuremberg , Erlangen, Germany
| | - Alexandra Schambony
- Biology Department, Developmental Biology, Friedrich-Alexander University Erlangen-Nuremberg , Erlangen, Germany
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35
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Stevens ML, Chaturvedi P, Rankin SA, Macdonald M, Jagannathan S, Yukawa M, Barski A, Zorn AM. Genomic integration of Wnt/β-catenin and BMP/Smad1 signaling coordinates foregut and hindgut transcriptional programs. Development 2017; 144:1283-1295. [PMID: 28219948 DOI: 10.1242/dev.145789] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/03/2017] [Indexed: 12/16/2022]
Abstract
Digestive system development is orchestrated by combinatorial signaling interactions between endoderm and mesoderm, but how these signals are interpreted in the genome is poorly understood. Here we identified the transcriptomes of Xenopus foregut and hindgut progenitors, which are conserved with mammals. Using RNA-seq and ChIP-seq we show that BMP/Smad1 regulates dorsal-ventral gene expression in both the endoderm and mesoderm, whereas Wnt/β-catenin acts as a genome-wide toggle between foregut and hindgut programs. Unexpectedly, β-catenin and Smad1 binding were associated with both transcriptional activation and repression, with Wnt-repressed genes often lacking canonical Tcf DNA binding motifs, suggesting a novel mode of direct repression. Combinatorial Wnt and BMP signaling was mediated by Smad1 and β-catenin co-occupying hundreds of cis-regulatory DNA elements, and by a crosstalk whereby Wnt negatively regulates BMP ligand expression in the foregut. These results extend our understanding of gastrointestinal organogenesis and of how Wnt and BMP might coordinate genomic responses in other contexts.
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Affiliation(s)
- Mariana L Stevens
- Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Praneet Chaturvedi
- Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Scott A Rankin
- Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Melissa Macdonald
- Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Sajjeev Jagannathan
- Division of Allergy & Immunology and Human Genetics, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Masashi Yukawa
- Division of Allergy & Immunology and Human Genetics, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Artem Barski
- Division of Allergy & Immunology and Human Genetics, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Aaron M Zorn
- Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Research Foundation and Department of Pediatrics College of Medicine, University of Cincinnati, Cincinnati, OH 45229, USA
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36
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Abstract
Cytokines of the transforming growth factor β (TGF-β) family, including TGF-βs, bone morphogenic proteins (BMPs), activins, and Nodal, play crucial roles in embryonic development and adult tissue homeostasis by regulating cell proliferation, survival, and differentiation, as well as stem-cell self-renewal and lineage-specific differentiation. Smad proteins are critical downstream mediators of these signaling activities. In addition to regulating the transcription of direct target genes of TGF-β, BMP, activin, or Nodal, Smad proteins also participate in extensive cross talk with other signaling pathways, often in a cell-type- or developmental stage-specific manner. These combinatorial signals often produce context-, time-, and location-dependent biological outcomes that are critical for development. This review discusses recent progress in our understanding of the cross talk between Smad proteins and signaling pathways of Wnt, Notch, Hippo, Hedgehog (Hh), mitogen-activated protein (MAP), kinase, phosphoinositide 3-kinase (PI3K)-Akt, nuclear factor κB (NF-κB), and Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathways.
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Affiliation(s)
- Kunxin Luo
- Department of Molecular and Cell Biology, University of California, Berkeley, and Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720
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37
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Zhang M, Skirkanich J, Lampson MA, Klein PS. Cell Cycle Remodeling and Zygotic Gene Activation at the Midblastula Transition. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:441-487. [DOI: 10.1007/978-3-319-46095-6_9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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38
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Houston DW. Vertebrate Axial Patterning: From Egg to Asymmetry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:209-306. [PMID: 27975274 PMCID: PMC6550305 DOI: 10.1007/978-3-319-46095-6_6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The emergence of the bilateral embryonic body axis from a symmetrical egg has been a long-standing question in developmental biology. Historical and modern experiments point to an initial symmetry-breaking event leading to localized Wnt and Nodal growth factor signaling and subsequent induction and formation of a self-regulating dorsal "organizer." This organizer forms at the site of notochord cell internalization and expresses primarily Bone Morphogenetic Protein (BMP) growth factor antagonists that establish a spatiotemporal gradient of BMP signaling across the embryo, directing initial cell differentiation and morphogenesis. Although the basics of this model have been known for some time, many of the molecular and cellular details have only recently been elucidated and the extent that these events remain conserved throughout vertebrate evolution remains unclear. This chapter summarizes historical perspectives as well as recent molecular and genetic advances regarding: (1) the mechanisms that regulate symmetry-breaking in the vertebrate egg and early embryo, (2) the pathways that are activated by these events, in particular the Wnt pathway, and the role of these pathways in the formation and function of the organizer, and (3) how these pathways also mediate anteroposterior patterning and axial morphogenesis. Emphasis is placed on comparative aspects of the egg-to-embryo transition across vertebrates and their evolution. The future prospects for work regarding self-organization and gene regulatory networks in the context of early axis formation are also discussed.
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Affiliation(s)
- Douglas W Houston
- Department of Biology, The University of Iowa, 257 BB, Iowa City, IA, 52242, USA.
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Gillis WQ, Kirmizitas A, Iwasaki Y, Ki DH, Wyrick JM, Thomsen GH. Gtpbp2 is a positive regulator of Wnt signaling and maintains low levels of the Wnt negative regulator Axin. Cell Commun Signal 2016; 14:15. [PMID: 27484226 PMCID: PMC4969687 DOI: 10.1186/s12964-016-0138-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/29/2016] [Indexed: 12/29/2022] Open
Abstract
Background Canonical Wnt signals, transduced by stabilized β-catenin, play similar roles across animals in maintaining stem cell pluripotency, regulating cell differentiation, and instructing normal embryonic development. Dysregulated Wnt/β-catenin signaling causes diseases and birth defects, and a variety of regulatory processes control this pathway to ensure its proper function and integration with other signaling systems. We previously identified GTP-binding protein 2 (Gtpbp2) as a novel regulator of BMP signaling, however further exploration revealed that Gtpbp2 can also affect Wnt signaling, which is a novel finding reported here. Results Knockdown of Gtpbp2 in Xenopus embryos causes severe axial defects and reduces expression of Spemann-Mangold organizer genes. Gtpbp2 knockdown blocks responses to ectopic Wnt8 ligand, such as organizer gene induction in ectodermal tissue explants and induction of secondary axes in whole embryos. However, organizer gene induction by ectopic Nodal2 is unaffected by Gtpbp2 knockdown. Epistasis tests, conducted by activating Wnt signal transduction at sequential points in the canonical pathway, demonstrate that Gtpbp2 is required downstream of Dishevelled and Gsk3β but upstream of β-catenin, which is similar to the previously reported effects of Axin1 overexpression in Xenopus embryos. Focusing on Axin in Xenopus embryos, we find that knockdown of Gtpbp2 elevates endogenous or exogenous Axin protein levels. Furthermore, Gtpbp2 fusion proteins co-localize with Dishevelled and co-immunoprecipitate with Axin and Gsk3b. Conclusions We conclude that Gtpbp2 is required for canonical Wnt/β-catenin signaling in Xenopus embryos. Our data suggest a model in which Gtpbp2 suppresses the accumulation of Axin protein, a rate-limiting component of the β-catenin destruction complex, such that Axin protein levels negatively correlate with Gtpbp2 levels. This model is supported by the similarity of our Gtpbp2-Wnt epistasis results and previously reported effects of Axin overexpression, the physical interactions of Gtpbp2 with Axin, and the correlation between elevated Axin protein levels and lost Wnt responsiveness upon Gtpbp2 knockdown. A wide variety of cancer-causing Wnt pathway mutations require low Axin levels, so development of Gtpbp2 inhibitors may provide a new therapeutic strategy to elevate Axin and suppress aberrant β-catenin signaling in cancer and other Wnt-related diseases. Electronic supplementary material The online version of this article (doi:10.1186/s12964-016-0138-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- William Q Gillis
- Department of Biochemistry and Cell Biology, Graduate Program in Molecular and Cellular Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794-5215, USA.,Present Address: Department of Biological Sciences, State University of New York, College at Old Westbury, Old Westbury, NY, 11568, USA
| | - Arif Kirmizitas
- Department of Biochemistry and Cell Biology, Graduate Program in Molecular and Cellular Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794-5215, USA.,Present Address: The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK
| | - Yasuno Iwasaki
- Department of Biochemistry and Cell Biology, Graduate Program in Molecular and Cellular Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794-5215, USA
| | - Dong-Hyuk Ki
- Department of Biochemistry and Cell Biology, Graduate Program in Molecular and Cellular Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794-5215, USA.,Present Address: Department of Pediatric Oncology, Dana-Farber Cancer Institute, Division of Hematology/Oncology, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA
| | - Jonathan M Wyrick
- Department of Biochemistry and Cell Biology, Graduate Program in Molecular and Cellular Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794-5215, USA
| | - Gerald H Thomsen
- Department of Biochemistry and Cell Biology, Graduate Program in Molecular and Cellular Biology, Center for Developmental Genetics, Stony Brook University, Stony Brook, NY, 11794-5215, USA.
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Nakamura Y, de Paiva Alves E, Veenstra GJC, Hoppler S. Tissue- and stage-specific Wnt target gene expression is controlled subsequent to β-catenin recruitment to cis-regulatory modules. Development 2016; 143:1914-25. [PMID: 27068107 PMCID: PMC4920159 DOI: 10.1242/dev.131664] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 03/31/2016] [Indexed: 12/20/2022]
Abstract
Key signalling pathways, such as canonical Wnt/β-catenin signalling, operate repeatedly to regulate tissue- and stage-specific transcriptional responses during development. Although recruitment of nuclear β-catenin to target genomic loci serves as the hallmark of canonical Wnt signalling, mechanisms controlling stage- or tissue-specific transcriptional responses remain elusive. Here, a direct comparison of genome-wide occupancy of β-catenin with a stage-matched Wnt-regulated transcriptome reveals that only a subset of β-catenin-bound genomic loci are transcriptionally regulated by Wnt signalling. We demonstrate that Wnt signalling regulates β-catenin binding to Wnt target genes not only when they are transcriptionally regulated, but also in contexts in which their transcription remains unaffected. The transcriptional response to Wnt signalling depends on additional mechanisms, such as BMP or FGF signalling for the particular genes we investigated, which do not influence β-catenin recruitment. Our findings suggest a more general paradigm for Wnt-regulated transcriptional mechanisms, which is relevant for tissue-specific functions of Wnt/β-catenin signalling in embryonic development but also for stem cell-mediated homeostasis and cancer. Chromatin association of β-catenin, even to functional Wnt-response elements, can no longer be considered a proxy for identifying transcriptionally Wnt-regulated genes. Context-dependent mechanisms are crucial for transcriptional activation of Wnt/β-catenin target genes subsequent to β-catenin recruitment. Our conclusions therefore also imply that Wnt-regulated β-catenin binding in one context can mark Wnt-regulated transcriptional target genes for different contexts. Highlighted article: Dual ChIP-seq and RNA-seq in vivo experiments show that the context-specific events that occur subsequent to β-catenin binding enable gene-specific regulation, rather than β-catenin recruitment per se.
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Affiliation(s)
- Yukio Nakamura
- Institute of Medical Sciences, Foresterhill Health Campus, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Eduardo de Paiva Alves
- Centre for Genome-Enabled Biology and Medicine, University of Aberdeen, Aberdeen AB24 3RY, UK
| | - Gert Jan C Veenstra
- Radboud University, Department of Molecular Developmental Biology, Faculty of Science, Radboud Institute for Molecular Life Sciences, 6500 HB Nijmegen, The Netherlands
| | - Stefan Hoppler
- Institute of Medical Sciences, Foresterhill Health Campus, University of Aberdeen, Aberdeen AB25 2ZD, UK
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41
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Multicellular Mathematical Modelling of Mesendoderm Formation in Amphibians. Bull Math Biol 2016; 78:436-67. [PMID: 26934886 DOI: 10.1007/s11538-016-0150-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 01/04/2016] [Indexed: 10/22/2022]
Abstract
The earliest cell fate decisions in a developing embryo are those associated with establishing the germ layers. The specification of the mesoderm and endoderm is of particular interest as the mesoderm is induced from the endoderm, potentially from an underlying bipotential group of cells, the mesendoderm. Mesendoderm formation has been well studied in an amphibian model frog, Xenopus laevis, and its formation is driven by a gene regulatory network (GRN) induced by maternal factors deposited in the egg. We have recently demonstrated that the axolotl, a urodele amphibian, utilises a different topology in its GRN to specify the mesendoderm. In this paper, we develop spatially structured mathematical models of the GRNs governing mesendoderm formation in a line of cells. We explore several versions of the model of mesendoderm formation in both Xenopus and the axolotl, incorporating the key differences between these two systems. Model simulations are able to reproduce known experimental data, such as Nodal expression domains in Xenopus, and also make predictions about how the positional information derived from maternal factors may be interpreted to drive cell fate decisions. We find that whilst cell-cell signalling plays a minor role in Xenopus, it is crucial for correct patterning domains in axolotl.
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42
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Kiecker C, Bates T, Bell E. Molecular specification of germ layers in vertebrate embryos. Cell Mol Life Sci 2016; 73:923-47. [PMID: 26667903 PMCID: PMC4744249 DOI: 10.1007/s00018-015-2092-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 10/11/2015] [Accepted: 11/09/2015] [Indexed: 11/17/2022]
Abstract
In order to generate the tissues and organs of a multicellular organism, different cell types have to be generated during embryonic development. The first step in this process of cellular diversification is the formation of the three germ layers: ectoderm, endoderm and mesoderm. The ectoderm gives rise to the nervous system, epidermis and various neural crest-derived tissues, the endoderm goes on to form the gastrointestinal, respiratory and urinary systems as well as many endocrine glands, and the mesoderm will form the notochord, axial skeleton, cartilage, connective tissue, trunk muscles, kidneys and blood. Classic experiments in amphibian embryos revealed the tissue interactions involved in germ layer formation and provided the groundwork for the identification of secreted and intracellular factors involved in this process. We will begin this review by summarising the key findings of those studies. We will then evaluate them in the light of more recent genetic studies that helped clarify which of the previously identified factors are required for germ layer formation in vivo, and to what extent the mechanisms identified in amphibians are conserved across other vertebrate species. Collectively, these studies have started to reveal the gene regulatory network (GRN) underlying vertebrate germ layer specification and we will conclude our review by providing examples how our understanding of this GRN can be employed to differentiate stem cells in a targeted fashion for therapeutic purposes.
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Affiliation(s)
- Clemens Kiecker
- MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK
| | - Thomas Bates
- MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK
- Leibniz Institute on Aging, Fritz Lipmann Institute, Jena, Germany
| | - Esther Bell
- MRC Centre for Developmental Neurobiology, King's College London, Guy's Campus, London, UK.
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Atlas Toolkit: Fast registration of 3D morphological datasets in the absence of landmarks. Sci Rep 2016; 6:20732. [PMID: 26864723 PMCID: PMC4749973 DOI: 10.1038/srep20732] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/31/2015] [Indexed: 11/09/2022] Open
Abstract
Image registration is a gateway technology for Developmental Systems Biology, enabling computational analysis of related datasets within a shared coordinate system. Many registration tools rely on landmarks to ensure that datasets are correctly aligned; yet suitable landmarks are not present in many datasets. Atlas Toolkit is a Fiji/ImageJ plugin collection offering elastic group-wise registration of 3D morphological datasets, guided by segmentation of the interesting morphology. We demonstrate the method by combinatorial mapping of cell signalling events in the developing eyes of chick embryos, and use the integrated datasets to predictively enumerate Gene Regulatory Network states.
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44
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Zou J, Wang R, Li R, Kong Y, Wang J, Ning X, Zhang L, Wang S, Hu X, Bao Z. The genome-wide identification of mitogen-activated protein kinase kinase (MKK) genes in Yesso scallop Patinopecten yessoensis and their expression responses to bacteria challenges. FISH & SHELLFISH IMMUNOLOGY 2015; 45:901-911. [PMID: 26067168 DOI: 10.1016/j.fsi.2015.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/02/2015] [Accepted: 06/07/2015] [Indexed: 06/04/2023]
Abstract
Mitogen-activated protein kinase kinases (MKK) are the essential components of the evolutionarily conserved MAPK signaling cascade, which regulates a variety of cellular activities and innate immune responses. Although MKK genes have been extensively studied in various vertebrate and invertebrate species, they have not been systematically characterized in bivalves. In this study, we identified and characterized five MKK genes (PyMKK1/2, PyMKK4, PyMKK5, PyMKK3/6 and PyMKK7) in the Yesso scallop (Patinopecten yessoensis). Phylogenetic and protein structural analyses were conducted to determine their identities and evolutionary relationships. To gain insights into the possible roles of MKK genes during scallop innate immune responses, quantitative real-time PCR (qRT-PCR) was used to investigate their expression profiles during different developmental stages in samples taken from healthy adult tissues and hemocytes after Micrococcus luteus and Vibrio anguillarum bacterial infections. The Yesso scallop MKKs (PyMKKs) were found to have highly conserved structural features compared to the MKK genes from other invertebrate species. Using qRT-PCR analysis, three distinct expression patterns were detected among the PyMKKs over the course of ten different developmental stages. In adult scallops, the majority of the PyMKKs were highly expressed in mantle, gill, muscle and hemocytes. The differential expression patterns of the five PyMKKs after M. luteus (Gram-positive) and V. anguillarum (Gram-negative) bacterial infections suggested their possible involvement in the innate immune response and provide the foundation and resource for the further study on innate immune response of MAPK signal pathway in mollusk.
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Affiliation(s)
- Jiajun Zou
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Ruijia Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
| | - Ruojiao Li
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Yifan Kong
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Jing Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Xianhui Ning
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Lingling Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Shi Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Xiaoli Hu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
| | - Zhenmin Bao
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
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45
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Cibois M, Luxardi G, Chevalier B, Thomé V, Mercey O, Zaragosi LE, Barbry P, Pasini A, Marcet B, Kodjabachian L. BMP signalling controls the construction of vertebrate mucociliary epithelia. Development 2015; 142:2352-63. [PMID: 26092849 DOI: 10.1242/dev.118679] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 05/13/2015] [Indexed: 01/14/2023]
Abstract
Despite the importance of mucociliary epithelia in animal physiology, the mechanisms controlling their establishment are poorly understood. Using the developing Xenopus epidermis and regenerating human upper airways, we reveal the importance of BMP signalling for the construction of vertebrate mucociliary epithelia. In Xenopus, attenuation of BMP activity is necessary for the specification of multiciliated cells (MCCs), ionocytes and small secretory cells (SSCs). Conversely, BMP activity is required for the proper differentiation of goblet cells. Our data suggest that the BMP and Notch pathways interact to control fate choices in the developing epidermis. Unexpectedly, BMP activity is also necessary for the insertion of MCCs, ionocytes and SSCs into the surface epithelium. In human, BMP inhibition also strongly stimulates the formation of MCCs in normal and pathological (cystic fibrosis) airway samples, whereas BMP overactivation has the opposite effect. This work identifies the BMP pathway as a key regulator of vertebrate mucociliary epithelium differentiation and morphogenesis.
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Affiliation(s)
- Marie Cibois
- Aix-Marseille Université, CNRS, IBDM, Marseille 13288, France
| | | | | | - Virginie Thomé
- Aix-Marseille Université, CNRS, IBDM, Marseille 13288, France
| | - Olivier Mercey
- CNRS, IPMC, Sophia-Antipolis 06560, France University of Nice Sophia Antipolis (UNS), IPMC, Sophia-Antipolis 06560, France
| | - Laure-Emmanuelle Zaragosi
- CNRS, IPMC, Sophia-Antipolis 06560, France University of Nice Sophia Antipolis (UNS), IPMC, Sophia-Antipolis 06560, France
| | | | - Andrea Pasini
- Aix-Marseille Université, CNRS, IBDM, Marseille 13288, France
| | - Brice Marcet
- CNRS, IPMC, Sophia-Antipolis 06560, France University of Nice Sophia Antipolis (UNS), IPMC, Sophia-Antipolis 06560, France
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46
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Katz Imberman S, Kolpakova A, Keren A, Bengal E. Myocyte enhancer factor 2D regulates ectoderm specification and adhesion properties of animal cap cells in the early Xenopus embryo. FEBS J 2015; 282:2930-47. [PMID: 26038288 DOI: 10.1111/febs.13331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/21/2015] [Accepted: 05/29/2015] [Indexed: 11/28/2022]
Abstract
In Xenopus, animal cap (AC) cells give rise to ectoderm and its derivatives: epidermis and the central nervous system. Ectoderm has long been considered a default pathway of embryonic development, with cells that are not under the influence of vegetal Nodal signaling adopting an ectodermal program of gene expression. In the present study, we describe the involvement of the animally-localized maternal transcription factor myocyte enhancer factor (Mef) 2D in regulating the identity of AC cells. We find that Mef2D is required for the formation of both ectodermal lineages: neural and epidermis. Gain and loss of function experiments indicate that Mef2D regulates early gastrula expression of key ectodermal/epidermal genes in the animal region. Mef2D controls the activity of zygotic bone morphogenetic protein (BMP) signaling known to dictate the epidermal differentiation program. Exogenous expression of Mef2D in vegetal blastomeres was sufficient to induce ectopic expression of ectoderm/epidermal genes in the vegetal half of the embryo, when Nodal signaling was inhibited. Depletion of Mef2D caused a loss of AC cell adhesion that was rescued by the expression of E-cadherin or bone morphogenetic protein 4. In addition, expression of Mef2D in the prospective endoderm caused unusual aggregation of vegetal cells with animal cells in vitro and inappropriate segregation to other germ layers in vivo. Mef2D cooperates with another animally-expressed transcription factor, FoxI1e. Together, they regulate the expression of genes encoding signaling proteins and the transcription factors that control the regional identity of animal cells. Therefore, we describe a new role for the animally-localized Mef2D protein in early ectoderm specification, which is similar to that of the vegetally-localized VegT in endoderm and mesoderm formation.
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Affiliation(s)
- Sandra Katz Imberman
- Department of Biochemistry, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Alina Kolpakova
- Department of Biochemistry, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Aviad Keren
- Department of Biochemistry, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Eyal Bengal
- Department of Biochemistry, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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47
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Tuazon FB, Mullins MC. Temporally coordinated signals progressively pattern the anteroposterior and dorsoventral body axes. Semin Cell Dev Biol 2015; 42:118-33. [PMID: 26123688 PMCID: PMC4562868 DOI: 10.1016/j.semcdb.2015.06.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 06/16/2015] [Indexed: 10/23/2022]
Abstract
The vertebrate body plan is established through the precise spatiotemporal coordination of morphogen signaling pathways that pattern the anteroposterior (AP) and dorsoventral (DV) axes. Patterning along the AP axis is directed by posteriorizing signals Wnt, fibroblast growth factor (FGF), Nodal, and retinoic acid (RA), while patterning along the DV axis is directed by bone morphogenetic proteins (BMP) ventralizing signals. This review addresses the current understanding of how Wnt, FGF, RA and BMP pattern distinct AP and DV cell fates during early development and how their signaling mechanisms are coordinated to concomitantly pattern AP and DV tissues.
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Affiliation(s)
- Francesca B Tuazon
- Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, 1152 BRBII/III, 421 Curie Boulevard, Philadelphia, PA 19104-6058, United States
| | - Mary C Mullins
- Department of Cell and Developmental Biology, University of Pennsylvania, Perelman School of Medicine, 1152 BRBII/III, 421 Curie Boulevard, Philadelphia, PA 19104-6058, United States.
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48
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Sun G, Hu Z, Min Z, Yan X, Guan Z, Su H, Fu Y, Ma X, Chen YG, Zhang MQ, Tao Q, Wu W. Small C-terminal Domain Phosphatase 3 Dephosphorylates the Linker Sites of Receptor-regulated Smads (R-Smads) to Ensure Transforming Growth Factor β (TGFβ)-mediated Germ Layer Induction in Xenopus Embryos. J Biol Chem 2015; 290:17239-49. [PMID: 26013826 DOI: 10.1074/jbc.m115.655605] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Indexed: 01/27/2023] Open
Abstract
Germ layer induction is one of the earliest events shortly after fertilization that initiates body formation of vertebrate embryos. In Xenopus, the maternally deposited transcriptional factor VegT promotes the expression of zygotic Nodal/Activin ligands that further form a morphogen gradient along the vegetal-animal axis and trigger the induction of the three germ layers. Here we found that SCP3 (small C-terminal domain phosphatase 3) is maternally expressed and vegetally enriched in Xenopus embryos and is essential for the timely induction of germ layers. SCP3 is required for the full activation of Nodal/Activin and bone morphogenetic protein signals and functions via dephosphorylation in the linker regions of receptor-regulated Smads. Consistently, the linker regions of receptor-regulated Smads are heavily phosphorylated in fertilized eggs, and this phosphorylation is gradually removed when embryos approach the midblastula transition. Knockdown of maternal SCP3 attenuates these dephosphorylation events and the activation of Nodal/Activin and bone morphogenetic protein signals after midblastula transition. This study thus suggested that the maternal SCP3 serves as a vegetally enriched, intrinsic factor to ensure a prepared status of Smads for their activation by the upcoming ligands during germ layer induction of Xenopus embryos.
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Affiliation(s)
- Guanni Sun
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhirui Hu
- the Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST, Tsinghua University, Beijing 100084, China
| | - Zheying Min
- the School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaohua Yan
- the State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China, and
| | - Zhenpo Guan
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Hanxia Su
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yu Fu
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaopeng Ma
- the Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST, Tsinghua University, Beijing 100084, China
| | - Ye-Guang Chen
- the State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China, and
| | - Michael Q Zhang
- the Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST, Tsinghua University, Beijing 100084, China, the Department of Biological Sciences, Center for Systems Biology, University of Texas at Dallas, Richardson, Texas 75080
| | - Qinghua Tao
- the School of Life Sciences, Tsinghua University, Beijing 100084, China,
| | - Wei Wu
- From the MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing 100084, China,
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49
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Ro H, Hur TL, Rhee M. Ubiquitin conjugation system for body axes specification in vertebrates. Anim Cells Syst (Seoul) 2015. [DOI: 10.1080/19768354.2015.1026399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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50
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Zhang S, Li J, Lea R, Vleminckx K, Amaya E. Fezf2 promotes neuronal differentiation through localised activation of Wnt/β-catenin signalling during forebrain development. Development 2015; 141:4794-805. [PMID: 25468942 PMCID: PMC4299278 DOI: 10.1242/dev.115691] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Brain regionalisation, neuronal subtype diversification and circuit connectivity are crucial events in the establishment of higher cognitive functions. Here we report the requirement for the transcriptional repressor Fezf2 for proper differentiation of neural progenitor cells during the development of the Xenopus forebrain. Depletion of Fezf2 induces apoptosis in postmitotic neural progenitors, with concomitant reduction in forebrain size and neuronal differentiation. Mechanistically, we found that Fezf2 stimulates neuronal differentiation by promoting Wnt/β-catenin signalling in the developing forebrain. In addition, we show that Fezf2 promotes activation of Wnt/β-catenin signalling by repressing the expression of two negative regulators of Wnt signalling, namely lhx2 and lhx9. Our findings suggest that Fezf2 plays an essential role in controlling when and where neuronal differentiation occurs within the developing forebrain and that it does so by promoting local Wnt/β-catenin signalling via a double-repressor model.
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Affiliation(s)
- Siwei Zhang
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Jingjing Li
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Robert Lea
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Kris Vleminckx
- Department for Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Enrique Amaya
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
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