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Abstract
During gastrulation, early embryos specify and reorganise the topology of their germ layers. Surprisingly, this fundamental and early process does not appear to be rigidly constrained by evolutionary pressures; instead, the morphology of gastrulation is highly variable throughout the animal kingdom. Recent experimental results demonstrate that it is possible to generate different alternative gastrulation modes in single organisms, such as in early cnidarian, arthropod and vertebrate embryos. Here, we review the mechanisms that underlie the plasticity of vertebrate gastrulation both when experimentally manipulated and during evolution. Using the insights obtained from these experiments we discuss the effects of the increase in yolk volume on the morphology of gastrulation and provide new insights into two crucial innovations during amniote gastrulation: the transition from a ring-shaped mesoderm domain in anamniotes to a crescent-shaped domain in amniotes, and the evolution of the reptilian blastoporal plate/canal into the avian primitive streak.
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Affiliation(s)
| | - Cornelis J. Weijer
- School of Life Sciences Research Complex, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
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2
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Williams MK, Arur S. In preprints: buckling under pressure during gastrulation. Development 2022; 149:275338. [DOI: 10.1242/dev.200792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Margot Kossmann Williams
- Center for Precision Environmental Health and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Swathi Arur
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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3
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Sheng G, Martinez Arias A, Sutherland A. The primitive streak and cellular principles of building an amniote body through gastrulation. Science 2021; 374:abg1727. [PMID: 34855481 DOI: 10.1126/science.abg1727] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Guojun Sheng
- International Research Center for Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Alfonso Martinez Arias
- Systems Bioengineering, DCEXS, Universidad Pompeu Fabra, Doctor Aiguader, 88 ICREA, Pag Lluis Companys 23, Barcelona, Spain
| | - Ann Sutherland
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, USA
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4
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Steventon B, Busby L, Arias AM. Establishment of the vertebrate body plan: Rethinking gastrulation through stem cell models of early embryogenesis. Dev Cell 2021; 56:2405-2418. [PMID: 34520764 DOI: 10.1016/j.devcel.2021.08.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 07/20/2021] [Accepted: 08/14/2021] [Indexed: 12/28/2022]
Abstract
A striking property of vertebrate embryos is the emergence of a conserved body plan across a wide range of organisms through the process of gastrulation. As the body plan unfolds, gene regulatory networks (GRNs) and multicellular interactions (cell regulatory networks, CRNs) combine to generate a conserved set of morphogenetic events that lead to the phylotypic stage. Interrogation of these multilevel interactions requires manipulation of the mechanical environment, which is difficult in vivo. We review recent studies of stem cell models of early embryogenesis from different species showing that, independent of species origin, cells in culture form similar structures. The main difference between embryos and in vitro models is the boundary conditions of the multicellular ensembles. We discuss these observations and suggest that the mechanical and geometric boundary conditions of different embryos before gastrulation hide a morphogenetic ground state that is revealed in the stem-cell-based models of embryo development.
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Affiliation(s)
| | - Lara Busby
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Alfonso Martinez Arias
- Systems Bioengineering, DCEXS, Universidad Pompeu Fabra, Doctor Aiguader, 88 ICREA, Pag Lluis Companys 23, Barcelona, Spain.
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5
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Gorfinkiel N, Martinez Arias A. The cell in the age of the genomic revolution: Cell Regulatory Networks. Cells Dev 2021; 168:203720. [PMID: 34252599 DOI: 10.1016/j.cdev.2021.203720] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 12/30/2022]
Abstract
Over the last few years an intense activity in the areas of advanced microscopy and quantitative cell biology has put the focus on the morphogenetic events that shape embryos. The interest in these processes is taking place against the backdrop of genomic studies, particularly of global patterns of gene expression at the level of single cells, which cannot fully account for the way cells build tissues and organs. Here we discuss the need to integrate the activity of genes with that of cells and propose the need to develop a framework, based on cellular processes and cell interactions, that parallels that which has been created for gene activity in the form of Gene Regulatory Networks (GRNs). We begin to do this by suggesting elements for building Cell Regulatory Networks (CRNs). In the same manner that GRNs create schedules of gene expression that result in the emergence of cell fates over time, CRNs create tissues and organs i.e. space. We also suggest how GRNs and CRNs might interact in the building of embryos through feedback loops involving mechanics and tissue tectonics.
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Affiliation(s)
- Nicole Gorfinkiel
- Departamento de Genética, Fisiología y Microbiología, Facultad de CC Biológicas, Universidad Complutense, José Antonio Nováis 12, Madrid, Spain.
| | - Alfonso Martinez Arias
- Systems Bioengineering, DCEXS, Universidad Pompeu Fabra, ICREA (Institució Catalana de Recerca i Estudis Avançats), Doctor Aiguader 88, Pg. Lluís Companys 23, Barcelona, Spain.
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6
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How to build a larval body with less than a hundred cells? Insights from the early development of a stalked jellyfish (Staurozoa, Cnidaria). ORG DIVERS EVOL 2020. [DOI: 10.1007/s13127-020-00459-8] [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]
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7
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Fagotto F. Tissue segregation in the early vertebrate embryo. Semin Cell Dev Biol 2020; 107:130-146. [DOI: 10.1016/j.semcdb.2020.05.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 11/30/2022]
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8
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Popov IK, Ray HJ, Skoglund P, Keller R, Chang C. The RhoGEF protein Plekhg5 regulates apical constriction of bottle cells during gastrulation. Development 2018; 145:dev168922. [PMID: 30446627 PMCID: PMC6307888 DOI: 10.1242/dev.168922] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 11/07/2018] [Indexed: 12/12/2022]
Abstract
Apical constriction regulates epithelial morphogenesis during embryonic development, but how this process is controlled is not understood completely. Here, we identify a Rho guanine nucleotide exchange factor (GEF) gene plekhg5 as an essential regulator of apical constriction of bottle cells during Xenopus gastrulation. plekhg5 is expressed in the blastopore lip and its expression is sufficient to induce ectopic bottle cells in epithelia of different germ layers in a Rho-dependent manner. This activity is not shared by arhgef3, which encodes another organizer-specific RhoGEF. Plekhg5 protein is localized in the apical cell cortex via its pleckstrin homology domain, and the GEF activity enhances its apical recruitment. Plekhg5 induces apical actomyosin accumulation and cell elongation. Knockdown of plekhg5 inhibits activin-induced bottle cell formation and endogenous blastopore lip formation in gastrulating frog embryos. Apical accumulation of actomyosin, apical constriction and bottle cell formation fail to occur in these embryos. Taken together, our data indicate that transcriptional regulation of plekhg5 expression at the blastopore lip determines bottle cell morphology via local polarized activation of Rho by Plekhg5, which stimulates apical actomyosin activity to induce apical constriction.
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Affiliation(s)
- Ivan K Popov
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Heather J Ray
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Paul Skoglund
- Biology Department, University of Virginia, Charlottesville, VA 22903, USA
| | - Ray Keller
- Biology Department, University of Virginia, Charlottesville, VA 22903, USA
| | - Chenbei Chang
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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9
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Ossipova O, Kim K, Sokol SY. Planar polarization of Vangl2 in the vertebrate neural plate is controlled by Wnt and Myosin II signaling. Biol Open 2015; 4:722-30. [PMID: 25910938 PMCID: PMC4467192 DOI: 10.1242/bio.201511676] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The vertebrate neural tube forms as a result of complex morphogenetic movements, which require the functions of several core planar cell polarity (PCP) proteins, including Vangl2 and Prickle. Despite the importance of these proteins for neurulation, their subcellular localization and the mode of action have remained largely unknown. Here we describe the anteroposterior planar cell polarity (AP-PCP) of the cells in the Xenopus neural plate. At the neural midline, the Vangl2 protein is enriched at anterior cell edges and that this localization is directed by Prickle, a Vangl2-interacting protein. Our further analysis is consistent with the model, in which Vangl2 AP-PCP is established in the neural plate as a consequence of Wnt-dependent phosphorylation. Additionally, we uncover feedback regulation of Vangl2 polarity by Myosin II, reiterating a role for mechanical forces in PCP. These observations indicate that both Wnt signaling and Myosin II activity regulate cell polarity and cell behaviors during vertebrate neurulation.
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Affiliation(s)
- Olga Ossipova
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kyeongmi Kim
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sergei Y Sokol
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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10
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The interplay between cell signalling and mechanics in developmental processes. Nat Rev Genet 2013; 14:733-44. [PMID: 24045690 DOI: 10.1038/nrg3513] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Force production and the propagation of stress and strain within embryos and organisms are crucial physical processes that direct morphogenesis. In addition, there is mounting evidence that biomechanical cues created by these processes guide cell behaviours and cell fates. In this Review we discuss key roles for biomechanics during development to directly shape tissues, to provide positional information for cell fate decisions and to enable robust programmes of development. Several recently identified molecular mechanisms suggest how cells and tissues might coordinate their responses to biomechanical cues. Finally, we outline long-term challenges in integrating biomechanics with genetic analysis of developing embryos.
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11
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Kaneda T, Motoki JYD. Gastrulation and pre-gastrulation morphogenesis, inductions, and gene expression: Similarities and dissimilarities between urodelean and anuran embryos. Dev Biol 2012; 369:1-18. [DOI: 10.1016/j.ydbio.2012.05.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 05/14/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
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12
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Abstract
Morphogenesis takes place against a background of organism-to-organism and environmental variation. Therefore, fundamental questions in the study of morphogenesis include: How are the mechanical processes of tissue movement and deformation affected by that variability, and in turn, how do the mechanic of the system modulate phenotypic variation? We highlight a few key factors, including environmental temperature, embryo size and environmental chemistry that might perturb the mechanics of morphogenesis in natural populations. Then we discuss several ways in which mechanics-including feedback from mechanical cues-might influence intra-specific variation in morphogenesis. To understand morphogenesis it will be necessary to consider whole-organism, environment and evolutionary scales because these larger scales present the challenges that developmental mechanisms have evolved to cope with. Studying the variation organisms express and the variation organisms experience will aid in deciphering the causes of birth defects.
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Affiliation(s)
- Michelangelo von Dassow
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave, 5059-BST3, Pittsburgh, PA 15213, USA.
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13
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Abstract
During the development of multicellular organisms, cell fate specification is followed by the sorting of different cell types into distinct domains from where the different tissues and organs are formed. Cell sorting involves both the segregation of a mixed population of cells with different fates and properties into distinct domains, and the active maintenance of their segregated state. Because of its biological importance and apparent resemblance to fluid segregation in physics, cell sorting was extensively studied by both biologists and physicists over the last decades. Different theories were developed that try to explain cell sorting on the basis of the physical properties of the constituent cells. However, only recently the molecular and cellular mechanisms that control the physical properties driving cell sorting, have begun to be unraveled. In this review, we will provide an overview of different cell-sorting processes in development and discuss how these processes can be explained by the different sorting theories, and how these theories in turn can be connected to the molecular and cellular mechanisms driving these processes.
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Affiliation(s)
- S F Gabby Krens
- Institute of Science and Technology Austria, Klosterneuburg, Austria
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14
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Collazo A, Keller R. Early development of Ensatina eschscholtzii: an amphibian with a large, yolky egg. EvoDevo 2010; 1:6. [PMID: 20849648 PMCID: PMC2938725 DOI: 10.1186/2041-9139-1-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2010] [Accepted: 08/03/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Comparative analyses between amphibians, concentrating on the cellular mechanisms of morphogenesis, reveal a large variability in the early developmental processes that were thought to be conserved during evolution. Increased egg size is one factor that could have a strong effect on early developmental processes such as cleavage pattern and gastrulation. Salamanders of the family Plethodontidae are particularly appropriate for such comparative studies because the species have eggs of varying size, including very large yolky eggs. RESULTS In this paper, we describe for the first time the early development (from fertilization through neurulation) of the plethodontid salamander Ensatina eschscholtzii. This species has one of the largest eggs known for an amphibian, with a mean ± SD diameter of 6 ± 0.43 mm (range 5.3-6.9; n = 17 eggs). Cleavage is meroblastic until approximately the 16-cell stage (fourth or fifth cleavage). At the beginning of gastrulation, the blastocoel roof is one cell thick, and the dorsal lip of the blastopore forms below the equator of the embryo. The ventral lip of the blastopore forms closer to the vegetal pole, and relatively little involution occurs during gastrulation. Cell migration is visible through the transparent blastocoel roof of the gastrula. At the end of gastrulation, a small archenteron spreading dorsally from the blastopore represents the relatively small and superficial area of the egg where early embryonic axis formation occurs. The resulting pattern is similar to the embryonic disk described for one species of anuran. CONCLUSIONS Comparisons with the early development of other species of amphibians suggest that an evolutionary increase in egg size can result in predictable changes in the patterns and rate of early development, but mainly within an evolutionary lineage.
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Affiliation(s)
- Andres Collazo
- Division of Cell Biology and Genetics, House Ear Institute, 2100 West Third Street, Los Angeles, CA 90057, USA
- University of Southern California, Neuroscience Graduate Program, Hedco Neurosciences Bldg. RM 120E, 3641 Watt Way, Los Angeles, CA. 90089-2520, USA
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, CA, USA
- Department of Otolaryngology, Keck School of Medicine, University of Southern California, CA, USA
| | - Ray Keller
- Department of Biology, University of Virginia, P.O. Box 400328, Charlottesville, VA 22904-4328, USA
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15
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Salazar-Ciudad I. Morphological evolution and embryonic developmental diversity in metazoa. Development 2010; 137:531-9. [PMID: 20110318 DOI: 10.1242/dev.045229] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Most studies of pattern formation and morphogenesis in metazoans focus on a small number of model species, despite the fact that information about a wide range of species and developmental stages has accumulated in recent years. By contrast, this article attempts to use this broad knowledge base to arrive at a classification of developmental types through which metazoan body plans are generated. This classification scheme pays particular attention to the diverse ways by which cell signalling and morphogenetic movements depend on each other, and leads to several testable hypotheses regarding morphological variation within and between species, as well as metazoan evolution.
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Affiliation(s)
- Isaac Salazar-Ciudad
- Grup de Genòmica, Bioinformàtica i Evolució, Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Cerdanyola del Valles, Spain.
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16
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Salazar-Ciudad I. Looking at the origin of phenotypic variation from pattern formation gene networks. J Biosci 2010; 34:573-87. [PMID: 19920342 DOI: 10.1007/s12038-009-0075-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This article critically reviews some widespread views about the overall functioning of development. Special attention is devoted to views in developmental genetics about the superstructure of developmental gene networks. According to these views gene networks are hierarchic and multilayered. The highest layers partition the embryo in large coarse areas and control downstream genes that subsequently subdivide the embryo into smaller and smaller areas. These views are criticized on the bases of developmental and evolutionary arguments. First, these views, although detailed at the level of gene identities, do not incorporate morphogenetic mechanisms nor do they try to explain how morphology changes during development. Often, they assume that morphogenetic mechanisms are subordinate to cell signaling events. This is in contradiction to the evidence reviewed herein. Experimental evidence on pattern formation also contradicts the view that developmental gene networks are hierarchically multilayered and that their functioning is decodable from promoter analysis. Simple evolutionary arguments suggest that, indeed, developmental gene networks tend to be non-hierarchic. Re-use leads to extensive modularity in gene networks while developmental drift blurs this modularity. Evolutionary opportunism makes developmental gene networks very dependent on epigenetic factors.
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Affiliation(s)
- Isaac Salazar-Ciudad
- Developmental Biology Program, Institute of Biotechnology, FIN-00014, University of Helsinki, Helsinki, Finland.
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Kaneda T, Iwamoto Y, Motoki JYD. Origin of the prechordal plate and patterning of the anteroposterior regional specificity of the involuting and extending archenteron roof of a urodele, Cynops pyrrhogaster. Dev Biol 2009; 334:84-96. [DOI: 10.1016/j.ydbio.2009.07.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 06/12/2009] [Accepted: 07/09/2009] [Indexed: 11/28/2022]
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18
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Shook DR, Keller R. Epithelial type, ingression, blastopore architecture and the evolution of chordate mesoderm morphogenesis. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2008; 310:85-110. [PMID: 18041055 DOI: 10.1002/jez.b.21198] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chordate embryos show an evolutionary trend in the mechanisms they use to internalize presumptive mesoderm, relying predominantly on invagination in the basal chordates, varying combinations of involution and ingression in the anamniote vertebrates and reptiles, and predominantly on ingression in birds and mammals. This trend is associated with variations in epithelial type and changes in embryonic architecture as well as variations in the type of blastopore formed by an embryo. We also note the surprising conservation of the involution, during gastrulation, of at least a subset of the notochordal cells throughout the chordates, and suggest that this indicates a constraint on morphogenic evolution based on a functional linkage between architecture and patterning. Finally, we propose a model for the evolutionary transitions from gastrulation through a urodele amphibian-type blastopore to gastrulation through a primitive streak, as in chick or mouse.
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Affiliation(s)
- David R Shook
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904-4328, USA.
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