1
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Zhang L, Xue G, Zhou X, Huang J, Li Z. A mathematical framework for understanding the spontaneous emergence of complexity applicable to growing multicellular systems. PLoS Comput Biol 2024; 20:e1011882. [PMID: 38838038 PMCID: PMC11182560 DOI: 10.1371/journal.pcbi.1011882] [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: 02/02/2024] [Revised: 06/17/2024] [Accepted: 05/20/2024] [Indexed: 06/07/2024] Open
Abstract
In embryonic development and organogenesis, cells sharing identical genetic codes acquire diverse gene expression states in a highly reproducible spatial distribution, crucial for multicellular formation and quantifiable through positional information. To understand the spontaneous growth of complexity, we constructed a one-dimensional division-decision model, simulating the growth of cells with identical genetic networks from a single cell. Our findings highlight the pivotal role of cell division in providing positional cues, escorting the system toward states rich in information. Moreover, we pinpointed lateral inhibition as a critical mechanism translating spatial contacts into gene expression. Our model demonstrates that the spatial arrangement resulting from cell division, combined with cell lineages, imparts positional information, specifying multiple cell states with increased complexity-illustrated through examples in C.elegans. This study constitutes a foundational step in comprehending developmental intricacies, paving the way for future quantitative formulations to construct synthetic multicellular patterns.
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Affiliation(s)
- Lu Zhang
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Gang Xue
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xiaolin Zhou
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Jiandong Huang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Chinese Academy of Sciences (CAS) Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Zhiyuan Li
- Center for Quantitative Biology, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
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2
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Kingsley EP, Hager ER, Lassance JM, Turner KM, Harringmeyer OS, Kirby C, Neugeboren BI, Hoekstra HE. Adaptive tail-length evolution in deer mice is associated with differential Hoxd13 expression in early development. Nat Ecol Evol 2024; 8:791-805. [PMID: 38378804 PMCID: PMC11009118 DOI: 10.1038/s41559-024-02346-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 01/25/2024] [Indexed: 02/22/2024]
Abstract
Variation in the size and number of axial segments underlies much of the diversity in animal body plans. Here we investigate the evolutionary, genetic and developmental mechanisms driving tail-length differences between forest and prairie ecotypes of deer mice (Peromyscus maniculatus). We first show that long-tailed forest mice perform better in an arboreal locomotion assay, consistent with tails being important for balance during climbing. We then identify six genomic regions that contribute to differences in tail length, three of which associate with caudal vertebra length and the other three with vertebra number. For all six loci, the forest allele increases tail length, indicative of the cumulative effect of natural selection. Two of the genomic regions associated with variation in vertebra number contain Hox gene clusters. Of those, we find an allele-specific decrease in Hoxd13 expression in the embryonic tail bud of long-tailed forest mice, consistent with its role in axial elongation. Additionally, we find that forest embryos have more presomitic mesoderm than prairie embryos and that this correlates with an increase in the number of neuromesodermal progenitors, which are modulated by Hox13 paralogues. Together, these results suggest a role for Hoxd13 in the development of natural variation in adaptive morphology on a microevolutionary timescale.
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Affiliation(s)
- Evan P Kingsley
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
- Department of Genetics, Harvard Medical School, Boston, MA, USA.
| | - Emily R Hager
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Jean-Marc Lassance
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
- GIGA Institute, University of Liège, Liège, Belgium
| | - Kyle M Turner
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
- Centre for Teaching Support & Innovation, University of Toronto, Toronto, Ontario, Canada
| | - Olivia S Harringmeyer
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Christopher Kirby
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Beverly I Neugeboren
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
- Environmental Health and Safety, Harvard University, Cambridge, MA, USA
| | - Hopi E Hoekstra
- Department of Organismic & Evolutionary Biology, Department of Molecular & Cellular Biology, Museum of Comparative Zoology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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3
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Coen E, Prusinkiewicz P. Developmental timing in plants. Nat Commun 2024; 15:2674. [PMID: 38531864 PMCID: PMC10965974 DOI: 10.1038/s41467-024-46941-1] [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: 10/31/2023] [Accepted: 03/13/2024] [Indexed: 03/28/2024] Open
Abstract
Plants exhibit reproducible timing of developmental events at multiple scales, from switches in cell identity to maturation of the whole plant. Control of developmental timing likely evolved for similar reasons that humans invented clocks: to coordinate events. However, whereas clocks are designed to run independently of conditions, plant developmental timing is strongly dependent on growth and environment. Using simplified models to convey key concepts, we review how growth-dependent and inherent timing mechanisms interact with the environment to control cyclical and progressive developmental transitions in plants.
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Affiliation(s)
- Enrico Coen
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Colney Lane, Norwich, NR4 7UH, UK.
| | - Przemyslaw Prusinkiewicz
- Department of Computer Science, University of Calgary, 2500 University Dr. N.W., Calgary, AB, T2N 1N4, Canada.
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4
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Tingle JL, Garner KL, Astley HC. Functional diversity of snake locomotor behaviors: A review of the biological literature for bioinspiration. Ann N Y Acad Sci 2024; 1533:16-37. [PMID: 38367220 DOI: 10.1111/nyas.15109] [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] [Indexed: 02/19/2024]
Abstract
Organismal solutions to natural challenges can spark creative engineering applications. However, most engineers are not experts in organismal biology, creating a potential barrier to maximally effective bioinspired design. In this review, we aim to reduce that barrier with respect to a group of organisms that hold particular promise for a variety of applications: snakes. Representing >10% of tetrapod vertebrates, snakes inhabit nearly every imaginable terrestrial environment, moving with ease under many conditions that would thwart other animals. To do so, they employ over a dozen different types of locomotion (perhaps well over). Lacking limbs, they have evolved axial musculoskeletal features that enable their vast functional diversity, which can vary across species. Different species also have various skin features that provide numerous functional benefits, including frictional anisotropy or isotropy (as their locomotor habits demand), waterproofing, dirt shedding, antimicrobial properties, structural colors, and wear resistance. Snakes clearly have much to offer to the fields of robotics and materials science. We aim for this review to increase knowledge of snake functional diversity by facilitating access to the relevant literature.
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Affiliation(s)
| | - Kelsey L Garner
- Department of Biology, University of Akron, Akron, Ohio, USA
| | - Henry C Astley
- Department of Biology, University of Akron, Akron, Ohio, USA
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5
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Miao Y, Pourquié O. Cellular and molecular control of vertebrate somitogenesis. Nat Rev Mol Cell Biol 2024:10.1038/s41580-024-00709-z. [PMID: 38418851 DOI: 10.1038/s41580-024-00709-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 03/02/2024]
Abstract
Segmentation is a fundamental feature of the vertebrate body plan. This metameric organization is first implemented by somitogenesis in the early embryo, when paired epithelial blocks called somites are rhythmically formed to flank the neural tube. Recent advances in in vitro models have offered new opportunities to elucidate the mechanisms that underlie somitogenesis. Notably, models derived from human pluripotent stem cells introduced an efficient proxy for studying this process during human development. In this Review, we summarize the current understanding of somitogenesis gained from both in vivo studies and in vitro studies. We deconstruct the spatiotemporal dynamics of somitogenesis into four distinct modules: dynamic events in the presomitic mesoderm, segmental determination, somite anteroposterior polarity patterning, and epithelial morphogenesis. We first focus on the segmentation clock, as well as signalling and metabolic gradients along the tissue, before discussing the clock and wavefront and other models that account for segmental determination. We then detail the molecular and cellular mechanisms of anteroposterior polarity patterning and somite epithelialization.
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Affiliation(s)
- Yuchuan Miao
- Department of Genetics, Harvard Medical School, Boston, MA, USA.
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
| | - Olivier Pourquié
- Department of Genetics, Harvard Medical School, Boston, MA, USA.
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA, USA.
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6
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Filippopoulou K, Konstantinides N. Evolution of patterning. FEBS J 2024; 291:663-671. [PMID: 37943156 DOI: 10.1111/febs.16995] [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: 06/19/2023] [Revised: 09/28/2023] [Accepted: 11/07/2023] [Indexed: 11/10/2023]
Abstract
Developing tissues are patterned in space and time; this enables them to differentiate their cell types and form complex structures to support different body plans. Although space and time are two independent entities, there are many examples of spatial patterns that originate from temporal ones. The most prominent example is the expression of the genes hunchback, Krüppel, pdm, and castor, which are expressed temporally in the neural stem cells of the Drosophila ventral nerve cord and spatially along the anteroposterior axis of the blastoderm stage embryo. In this Viewpoint, we investigate the relationship between space and time in specific examples of spatial and temporal patterns with the aim of gaining insight into the evolutionary history of patterning.
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7
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Harper M, Hu Y, Donahue J, Acosta B, Dievenich Braes F, Nguyen S, Zeng J, Barbaro J, Lee H, Bui H, McMenamin SK. Thyroid hormone regulates proximodistal patterning in fin rays. Proc Natl Acad Sci U S A 2023; 120:e2219770120. [PMID: 37186843 PMCID: PMC10214145 DOI: 10.1073/pnas.2219770120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 03/26/2023] [Indexed: 05/17/2023] Open
Abstract
Processes that regulate size and patterning along an axis must be highly integrated to generate robust shapes; relative changes in these processes underlie both congenital disease and evolutionary change. Fin length mutants in zebrafish have provided considerable insight into the pathways regulating fin size, yet signals underlying patterning have remained less clear. The bony rays of the fins possess distinct patterning along the proximodistal axis, reflected in the location of ray bifurcations and the lengths of ray segments, which show progressive shortening along the axis. Here, we show that thyroid hormone (TH) regulates aspects of proximodistal patterning of the caudal fin rays, regardless of fin size. TH promotes distal gene expression patterns, coordinating ray bifurcations and segment shortening with skeletal outgrowth along the proximodistal axis. This distalizing role for TH is conserved between development and regeneration, in all fins (paired and medial), and between Danio species as well as distantly related medaka. During regenerative outgrowth, TH acutely induces Shh-mediated skeletal bifurcation. Zebrafish have multiple nuclear TH receptors, and we found that unliganded Thrab-but not Thraa or Thrb-inhibits the formation of distal features. Broadly, these results demonstrate that proximodistal morphology is regulated independently from size-instructive signals. Modulating proximodistal patterning relative to size-either through changes to TH metabolism or other hormone-independent pathways-can shift skeletal patterning in ways that recapitulate aspects of fin ray diversity found in nature.
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Affiliation(s)
- Melody Harper
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Yinan Hu
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Joan Donahue
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Benjamin Acosta
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Flora Dievenich Braes
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Stacy Nguyen
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Jenny Zeng
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Julianna Barbaro
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Hyungwoo Lee
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Hoa Bui
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
| | - Sarah K. McMenamin
- Biology Department, Morrissey College of Arts and Sciences, Boston College, Chestnut Hill, MA02467
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8
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Sherratt E, Nash-Hahn T, Nankivell JH, Rasmussen AR, Hampton PM, Sanders KL. Macroevolution in axial morphospace: innovations accompanying the transition to marine environments in elapid snakes. ROYAL SOCIETY OPEN SCIENCE 2022; 9:221087. [PMID: 36569233 PMCID: PMC9768463 DOI: 10.1098/rsos.221087] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Sea snakes in the Hydrophis-Microcephalophis clade (Elapidae) show exceptional body shape variation along a continuum from similar forebody and hindbody girths, to dramatically reduced girths of the forebody relative to hindbody. The latter is associated with specializations on burrowing prey. This variation underpins high sympatric diversity and species richness and is not shared by other marine (or terrestrial) snakes. Here, we examined a hypothesis that macroevolutionary changes in axial development contribute to the propensity, at clade level, for body shape change. We quantified variation in the number and size of vertebrae in two body regions (pre- and post-apex of the heart) for approximately 94 terrestrial and marine elapids. We found Hydrophis-Microcephalophis exhibit increased rates of vertebral evolution in the pre- versus post-apex regions compared to all other Australasian elapids. Unlike other marine and terrestrial elapids, axial elongation in Hydrophis-Microcephalophis occurs via the preferential addition of vertebrae pre-heart apex, which is the region that undergoes concomitant shifts in vertebral number and size during transitions along the relative fore- to hindbody girth axis. We suggest that this macroevolutionary developmental change has potentially acted as a key innovation in Hydrophis-Microcephalophis by facilitating novel (especially burrowing) prey specializations that are not shared with other marine snakes.
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Affiliation(s)
- Emma Sherratt
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
- South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
| | - Tamika Nash-Hahn
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - James H. Nankivell
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
- South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
| | - Arne R. Rasmussen
- The Royal Danish Academy, Institute of Conservation, 1435 Copenhagen, Denmark
| | - Paul M. Hampton
- Department of Biology, Colorado Mesa University, Grand Junction, CO 81501, USA
| | - Kate L. Sanders
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
- South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
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9
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Pechriggl E, Blumer M, Tubbs RS, Olewnik Ł, Konschake M, Fortélny R, Stofferin H, Honis HR, Quinones S, Maranillo E, Sanudo J. Embryology of the Abdominal Wall and Associated Malformations—A Review. Front Surg 2022; 9:891896. [PMID: 35874129 PMCID: PMC9300894 DOI: 10.3389/fsurg.2022.891896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/10/2022] [Indexed: 12/12/2022] Open
Abstract
In humans, the incidence of congenital defects of the intraembryonic celom and its associated structures has increased over recent decades. Surgical treatment of abdominal and diaphragmatic malformations resulting in congenital hernia requires deep knowledge of ventral body closure and the separation of the primary body cavities during embryogenesis. The correct development of both structures requires the coordinated and fine-tuned synergy of different anlagen, including a set of molecules governing those processes. They have mainly been investigated in a range of vertebrate species (e.g., mouse, birds, and fish), but studies of embryogenesis in humans are rather rare because samples are seldom available. Therefore, we have to deal with a large body of conflicting data concerning the formation of the abdominal wall and the etiology of diaphragmatic defects. This review summarizes the current state of knowledge and focuses on the histological and molecular events leading to the establishment of the abdominal and thoracic cavities in several vertebrate species. In chronological order, we start with the onset of gastrulation, continue with the establishment of the three-dimensional body shape, and end with the partition of body cavities. We also discuss well-known human etiologies.
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Affiliation(s)
- Elisabeth Pechriggl
- Institute of Clinical and Functional Anatomy, Medical University of Innsbruck (MUI), Innsbruck, Austria
| | - Michael Blumer
- Institute of Clinical and Functional Anatomy, Medical University of Innsbruck (MUI), Innsbruck, Austria
| | - R. Shane Tubbs
- Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Neurology, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Anatomical Sciences, St. George’s University, St. George’s, Grenada, West Indies
- Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Surgery, Tulane University School of Medicine, New Orleans, LA, United States
- Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, LA, United States
- University of Queensland, Brisbane, Australia
| | - Łukasz Olewnik
- Department of Anatomical Dissection and Donation, Medical University of Lodz, Lodz, Poland
| | - Marko Konschake
- Institute of Clinical and Functional Anatomy, Medical University of Innsbruck (MUI), Innsbruck, Austria
- Correspondence: Marko Konschake
| | - René Fortélny
- Department of General, Visceral, and Oncological Surgery, Wilhelminenspital, Vienna, Austria
| | - Hannes Stofferin
- Institute of Clinical and Functional Anatomy, Medical University of Innsbruck (MUI), Innsbruck, Austria
| | - Hanne Rose Honis
- Institute of Clinical and Functional Anatomy, Medical University of Innsbruck (MUI), Innsbruck, Austria
| | - Sara Quinones
- Department of Anatomy and Embryology, School of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Eva Maranillo
- Department of Anatomy and Embryology, School of Medicine, Complutense University of Madrid, Madrid, Spain
| | - José Sanudo
- Department of Anatomy and Embryology, School of Medicine, Complutense University of Madrid, Madrid, Spain
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10
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Pourquié O. A brief history of the segmentation clock. Dev Biol 2022; 485:24-36. [DOI: 10.1016/j.ydbio.2022.02.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 02/23/2022] [Indexed: 11/16/2022]
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11
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Thomson L, Muresan L, Steventon B. The zebrafish presomitic mesoderm elongates through compaction-extension. Cells Dev 2021. [PMID: 34597846 DOI: 10.1101/2021.03.11.434927] [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] [Indexed: 05/07/2023]
Abstract
In vertebrate embryos the presomitic mesoderm becomes progressively segmented into somites at the anterior end while extending along the anterior-posterior axis. A commonly adopted model to explain how this tissue elongates is that of posterior growth, driven in part by the addition of new cells from uncommitted progenitor populations in the tailbud. However, in zebrafish, much of somitogenesis is associated with an absence of overall volume increase, and posterior progenitors do not contribute new cells until the final stages of somitogenesis. Here, we perform a comprehensive 3D morphometric analysis of the paraxial mesoderm and reveal that extension is linked to a volumetric decrease and an increase in cell density. We also find that individual cells decrease in volume over successive somite stages. Live cell tracking confirms that much of this tissue deformation occurs within the presomitic mesoderm progenitor zone and is associated with non-directional rearrangement. Taken together, we propose a compaction-extension mechanism of tissue elongation that highlights the need to better understand the role tissue intrinsic and extrinsic forces in regulating morphogenesis.
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Affiliation(s)
- Lewis Thomson
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
| | - Leila Muresan
- Cambridge Advanced Imaging Centre, University of Cambridge, Cambridge, UK
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12
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Linde-Medina M, Smit TH. Molecular and Mechanical Cues for Somite Periodicity. Front Cell Dev Biol 2021; 9:753446. [PMID: 34901002 PMCID: PMC8663771 DOI: 10.3389/fcell.2021.753446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 10/14/2021] [Indexed: 11/13/2022] Open
Abstract
Somitogenesis refers to the segmentation of the paraxial mesoderm, a tissue located on the back of the embryo, into regularly spaced and sized pieces, i.e., the somites. This periodicity is important to assure, for example, the formation of a functional vertebral column. Prevailing models of somitogenesis are based on the existence of a gene regulatory network capable of generating a striped pattern of gene expression, which is subsequently translated into periodic tissue boundaries. An alternative view is that the pre-pattern that guides somitogenesis is not chemical, but of a mechanical origin. A striped pattern of mechanical strain can be formed in physically connected tissues expanding at different rates, as it occurs in the embryo. Here we argue that both molecular and mechanical cues could drive somite periodicity and suggest how they could be integrated.
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Affiliation(s)
| | - Theodoor H. Smit
- Department of Orthopaedic Surgery, Amsterdam Movement Sciences, Amsterdam University Medical Centres, Amsterdam, Netherlands
- Department of Medical Biology, Amsterdam University Medical Centres, Amsterdam, Netherlands
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13
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The zebrafish presomitic mesoderm elongates through compaction-extension. Cells Dev 2021; 168:203748. [PMID: 34597846 PMCID: PMC7612712 DOI: 10.1016/j.cdev.2021.203748] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 09/21/2021] [Accepted: 09/21/2021] [Indexed: 11/21/2022]
Abstract
In vertebrate embryos the presomitic mesoderm becomes progressively segmented into somites at the anterior end while extending along the anterior-posterior axis. A commonly adopted model to explain how this tissue elongates is that of posterior growth, driven in part by the addition of new cells from uncommitted progenitor populations in the tailbud. However, in zebrafish, much of somitogenesis is associated with an absence of overall volume increase, and posterior progenitors do not contribute new cells until the final stages of somitogenesis. Here, we perform a comprehensive 3D morphometric analysis of the paraxial mesoderm and reveal that extension is linked to a volumetric decrease and an increase in cell density. We also find that individual cells decrease in volume over successive somite stages. Live cell tracking confirms that much of this tissue deformation occurs within the presomitic mesoderm progenitor zone and is associated with non-directional rearrangement. Taken together, we propose a compaction-extension mechanism of tissue elongation that highlights the need to better understand the role tissue intrinsic and extrinsic forces in regulating morphogenesis.
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14
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Boareto M, Tomka T, Iber D. Positional information encoded in the dynamic differences between neighboring oscillators during vertebrate segmentation. Cells Dev 2021; 168:203737. [PMID: 34481980 DOI: 10.1016/j.cdev.2021.203737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 07/28/2021] [Accepted: 08/20/2021] [Indexed: 01/24/2023]
Abstract
A central problem in developmental biology is to understand how cells interpret their positional information to give rise to spatial patterns, such as the process of periodic segmentation of the vertebrate embryo into somites. For decades, somite formation has been interpreted according to the clock-and-wavefront model. In this conceptual framework, molecular oscillators set the frequency of somite formation while the positional information is encoded in signaling gradients. Recent experiments using ex vivo explants have challenged this interpretation, suggesting that positional information is encoded in the properties of the oscillators, independent of long-range modulations such as signaling gradients. Here, we propose that positional information is encoded in the difference in the levels of neighboring oscillators. The differences gradually increase because both the amplitude and the period of the oscillators increase with time. When this difference exceeds a certain threshold, the segmentation program starts. Using this framework, we quantitatively fit experimental data from in vivo and ex vivo mouse segmentation, and propose mechanisms of somite scaling. Our results suggest a novel mechanism of spatial pattern formation based on the local interactions between dynamic molecular oscillators.
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Affiliation(s)
- Marcelo Boareto
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland; Swiss Institute of Bioinformatics, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Tomas Tomka
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Dagmar Iber
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zurich, Mattenstrasse 26, 4058 Basel, Switzerland; Swiss Institute of Bioinformatics, Mattenstrasse 26, 4058 Basel, Switzerland.
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15
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Giraud G, Paul R, Duffraisse M, Khan S, Shashidhara LS, Merabet S. Developmental Robustness: The Haltere Case in Drosophila. Front Cell Dev Biol 2021; 9:713282. [PMID: 34368162 PMCID: PMC8343187 DOI: 10.3389/fcell.2021.713282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 06/30/2021] [Indexed: 11/24/2022] Open
Abstract
Developmental processes have to be robust but also flexible enough to respond to genetic and environmental variations. Different mechanisms have been described to explain the apparent antagonistic nature of developmental robustness and plasticity. Here, we present a “self-sufficient” molecular model to explain the development of a particular flight organ that is under the control of the Hox gene Ultrabithorax (Ubx) in the fruit fly Drosophila melanogaster. Our model is based on a candidate RNAi screen and additional genetic analyses that all converge to an autonomous and cofactor-independent mode of action for Ubx. We postulate that this self-sufficient molecular mechanism is possible due to an unusually high expression level of the Hox protein. We propose that high dosage could constitute a so far poorly investigated molecular strategy for allowing Hox proteins to both innovate and stabilize new forms during evolution.
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Affiliation(s)
| | | | | | - Soumen Khan
- Indian Institute of Science Education and Research (IISER), Pune, India
| | - L S Shashidhara
- Indian Institute of Science Education and Research (IISER), Pune, India.,Ashoka University, Sonipat, India
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16
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Williams SA, Pilbeam D. Homeotic change in segment identity derives the human vertebral formula from a chimpanzee-like one. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 176:283-294. [PMID: 34227681 DOI: 10.1002/ajpa.24356] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/12/2021] [Accepted: 06/07/2021] [Indexed: 01/10/2023]
Abstract
OBJECTIVES One of the most contentious issues in paleoanthropology is the nature of the last common ancestor of humans and our closest living relatives, chimpanzees and bonobos (panins). The numerical composition of the vertebral column has featured prominently, with multiple models predicting distinct patterns of evolution and contexts from which bipedalism evolved. Here, we study total numbers of vertebrae from a large sample of hominoids to quantify variation in and patterns of regional and total numbers of vertebrae in hominoids. MATERIALS AND METHODS We compile and study a large sample (N = 893) of hominoid vertebral formulae (numbers of cervical, thoracic, lumbar, sacral, caudal segments in each specimen) and analyze full vertebral formulae, total numbers of vertebrae, and super-regional numbers of vertebrae: presacral (cervical, thoracic, lumbar) vertebrae and sacrococcygeal vertebrae. We quantify within- and between-taxon variation using heterogeneity and similarity measures derived from population genetics. RESULTS We find that humans are most similar to African apes in total and super-regional numbers of vertebrae. Additionally, our analyses demonstrate that selection for bipedalism reduced variation in numbers of vertebrae relative to other hominoids. DISCUSSION The only proposed ancestral vertebral configuration for the last common ancestor of hominins and panins that is consistent with our results is the modal formula demonstrated by chimpanzees and bonobos (7 cervical-13 thoracic-4 lumbar-6 sacral-3 coccygeal). Hox gene expression boundaries suggest that a rostral shift in Hox10/Hox11-mediated complexes could produce the human modal formula from the proposal ancestral and panin modal formula.
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Affiliation(s)
- Scott A Williams
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, USA.,New York Consortium in Evolutionary Primatology, New York, USA
| | - David Pilbeam
- Department of Human Evolutionary Biology, Harvard University, Cambridge, USA
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17
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Boareto M. Patterning via local cell-cell interactions in developing systems. Dev Biol 2019; 460:77-85. [PMID: 31866513 DOI: 10.1016/j.ydbio.2019.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 01/26/2023]
Abstract
Spatial patterning during embryonic development emerges from the differentiation of progenitor cells that share the same genetic program. One of the main challenges in systems biology is to understand the relationship between gene network and patterning, especially how the cells communicate to coordinate their differentiation. This review aims to describe the principles of pattern formation from local cell-cell interactions mediated by the Notch signalling pathway. Notch mediates signalling via direct cell-cell contact and regulates cell fate decisions in many tissues during embryonic development. Here, I will describe the patterning mechanisms via different Notch ligands and the critical role of Notch oscillations during the segmentation of the vertebrate body, brain development, and blood vessel formation.
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Affiliation(s)
- Marcelo Boareto
- Department of Biosystems Science and Engineering (D-BSSE), ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland; Swiss Institute of Bioinformatics, Mattenstrasse 26, 4058, Basel, Switzerland.
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18
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Grall E, Tschopp P. A sense of place, many times over ‐ pattern formation and evolution of repetitive morphological structures. Dev Dyn 2019; 249:313-327. [DOI: 10.1002/dvdy.131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 10/30/2019] [Accepted: 11/04/2019] [Indexed: 12/14/2022] Open
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19
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Sherratt E, Sanders KL. Patterns of intracolumnar size variation inform the heterochronic mechanisms underlying extreme body shape divergence in microcephalic sea snakes. Evol Dev 2019; 22:283-290. [PMID: 31730744 DOI: 10.1111/ede.12328] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sea snakes (Hydrophiinae) that specialize on burrowing eel prey have repeatedly evolved tiny heads and reduced forebody relative to hindbody girths. Previous research has found that these "microcephalic" forms have higher counts of precaudal vertebrae, and postnatal ontogenetic changes cause their hindbodies to reach greater girths relative to their forebodies. We examine variation in vertebral size along the precaudal axis of neonates and adults of three species. In the nonmicrocephalic Hydrophis curtus, these intracolumnar patterns take the form of symmetrical curved profiles, with longer vertebrae in the midbody (50% of body length) relative to distal regions. In contrast, intracolumnar profiles in the microcephalic H. macdowelli and H. obscurus are strongly asymmetrical curves (negative skewness) due to the presence of numerous, smaller-sized vertebrate in the forebody (anterior to the heart). Neonate and adult H. macdowelli and H. obscurus specimens all exhibit this pattern, implying an onset of fore- versus hindbody decoupling in the embryo stage. Based on this, we suggest plausible developmental mechanisms involving the presence and positioning of Hox boundaries and heterochronic changes in segmentation. Tests of our hypotheses would give new insights into the drivers of rapid convergent shifts in evolution, but will ultimately require studies of gene expression in the embryos of relevant taxa.
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Affiliation(s)
- Emma Sherratt
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Kate L Sanders
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
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20
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Hampton PM. Foraging ecology influences the number of vertebrae in hydrophiine sea snakes. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
The number of vertebrae in snakes is highly variable both within and among species. Across ophidian taxa, the number of vertebrae has been linked to many aspects of ecology and performance. Herein, I test the hypothesis that variation in the number of vertebrae and the length of the anterior region of sea snakes are associated with foraging ecology. I predicted that sea snakes that invade burrows and crevices for prey would have relatively longer anterior regions as a result of a greater number of vertebrae. Using radiographs, I counted the number of vertebrae between the head and atria and between the atria and cloaca for 22 species of hydrophiine sea snakes. The length between the cranium and atria was positively associated with the frequency of burrowing prey consumed. The number of vertebrae in the pre-atrial region showed a positive association with diet, although the analysis only approached statistical significance. No association was observed between diet and the number of vertebrae between the atria and cloaca, indicating that heart position is constrained with respect to the cloaca. These data indicate that sea snakes specializing on burrowing prey have adapted elongated, anterior regions of the body through an increased number of vertebrae.
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Affiliation(s)
- Paul M Hampton
- Department of Biology, Colorado Mesa University, Grand Junction, CO, USA
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21
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Reyes Corral WD, Aguirre WE. Effects of temperature and water turbulence on vertebral number and body shape in Astyanax mexicanus (Teleostei: Characidae). PLoS One 2019; 14:e0219677. [PMID: 31356643 PMCID: PMC6663064 DOI: 10.1371/journal.pone.0219677] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 06/29/2019] [Indexed: 11/22/2022] Open
Abstract
Environmental changes can modify the phenotypic characteristics of populations, which in turn can influence their evolutionary trajectories. In ectotherms like fishes, temperature is a particularly important environmental variable that is known to have significant impacts on the phenotype. Here, we raised specimens of the surface ecomorph of Astyanax mexicanus at temperatures of 20°C, 23°C, 25°C, and 28°C to examine how temperature influenced vertebral number and body shape. To increase biological realism, specimens were also subjected to two water turbulence regimes. Vertebral number was counted from x-rays and body shape variation was analysed using geometric morphometric methods. Temperature significantly impacted mean total vertebral number, which increased at the lowest and highest temperatures. Fish reared at lower temperatures had relatively more precaudal vertebrae while fish reared at higher temperatures had relatively more caudal vertebrae. Vertebral anomalies, especially vertebral fusions, were most frequent at the extreme temperature treatments. Temperature significantly impacted body shape as well, with fish reared at 20°C being particularly divergent. Water turbulence also impacted body shape in a generally predictable manner, with specimens reared in high turbulence environments being more streamlined and having extended dorsal and anal fin bases. Variation in environmental variables thus resulted in significant changes in morphological traits known to impact fish fitness, indicating that A. mexicanus has the capacity to exhibit a range of phenotypic plasticity when challenged by environmental change. Understanding the biochemical mechanisms underlying this plasticity and whether adaptive plasticity has influenced the evolutionary radiation of the Characidae, are major directions for future research.
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Affiliation(s)
| | - Windsor E. Aguirre
- Department of Biological Sciences, DePaul University, Chicago, Illinois, United States of America
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22
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Carrieri FA, Murray PJ, Ditsova D, Ferris MA, Davies P, Dale JK. CDK1 and CDK2 regulate NICD1 turnover and the periodicity of the segmentation clock. EMBO Rep 2019; 20:e46436. [PMID: 31267714 PMCID: PMC6607002 DOI: 10.15252/embr.201846436] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 03/11/2019] [Accepted: 03/26/2019] [Indexed: 12/14/2022] Open
Abstract
All vertebrates share a segmented body axis. Segments form from the rostral end of the presomitic mesoderm (PSM) with a periodicity that is regulated by the segmentation clock. The segmentation clock is a molecular oscillator that exhibits dynamic clock gene expression across the PSM with a periodicity that matches somite formation. Notch signalling is crucial to this process. Altering Notch intracellular domain (NICD) stability affects both the clock period and somite size. However, the mechanism by which NICD stability is regulated in this context is unclear. We identified a highly conserved site crucial for NICD recognition by the SCF E3 ligase, which targets NICD for degradation. We demonstrate both CDK1 and CDK2 can phosphorylate NICD in the domain where this crucial residue lies and that NICD levels vary in a cell cycle-dependent manner. Inhibiting CDK1 or CDK2 activity increases NICD levels both in vitro and in vivo, leading to a delay of clock gene oscillations and an increase in somite size.
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Affiliation(s)
- Francesca Anna Carrieri
- Division of Cell and Developmental BiologySchool of Life SciencesUniversity of DundeeDundeeUK
| | | | - Dimitrinka Ditsova
- Division of Cell and Developmental BiologySchool of Life SciencesUniversity of DundeeDundeeUK
| | | | - Paul Davies
- Medical Research Council Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
| | - Jacqueline Kim Dale
- Division of Cell and Developmental BiologySchool of Life SciencesUniversity of DundeeDundeeUK
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23
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Sherratt E, Coutts FJ, Rasmussen AR, Sanders KL. Vertebral evolution and ontogenetic allometry: The developmental basis of extreme body shape divergence in microcephalic sea snakes. Evol Dev 2019; 21:135-144. [DOI: 10.1111/ede.12284] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 02/04/2019] [Accepted: 02/05/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Emma Sherratt
- Department of Ecology and Evolutionary Biology School of Biological Sciences, The University of Adelaide Adelaide South Australia Australia
| | - Felicity J. Coutts
- Department of Ecology and Evolutionary Biology School of Biological Sciences, The University of Adelaide Adelaide South Australia Australia
- Earth Sciences Section, South Australian Museum Adelaide South Australia Australia
| | - Arne R. Rasmussen
- The Royal Danish Academy of Fine Arts, Schools of Architecture, Design and Conservation Copenhagen Denmark
| | - Kate L. Sanders
- Department of Ecology and Evolutionary Biology School of Biological Sciences, The University of Adelaide Adelaide South Australia Australia
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24
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Smith KK, Keyte AL. Adaptations of the Marsupial Newborn: Birth as an Extreme Environment. Anat Rec (Hoboken) 2019; 303:235-249. [DOI: 10.1002/ar.24049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/07/2018] [Accepted: 05/28/2018] [Indexed: 12/15/2022]
Affiliation(s)
| | - Anna L. Keyte
- Laboratory of Neurogenetics of LanguageRockefeller University New York New York
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25
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Brocal J, De Decker S, José-López R, Manzanilla EG, Penderis J, Stalin C, Bertram S, Schoenebeck JJ, Rusbridge C, Fitzpatrick N, Gutierrez-Quintana R. C7 vertebra homeotic transformation in domestic dogs - are Pug dogs breaking mammalian evolutionary constraints? J Anat 2018; 233:255-265. [PMID: 29761492 DOI: 10.1111/joa.12822] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2018] [Indexed: 12/20/2022] Open
Abstract
The number of cervical vertebrae in mammals is almost constant at seven, regardless of their neck length, implying that there is selection against variation in this number. Homebox (Hox) genes are involved in this evolutionary mammalian conservation, and homeotic transformation of cervical into thoracic vertebrae (cervical ribs) is a common phenotypic abnormality when Hox gene expression is altered. This relatively benign phenotypic change can be associated with fatal traits in humans. Mutations in genes upstream of Hox, inbreeding and stressors during organogenesis can also cause cervical ribs. The aim of this study was to describe the prevalence of cervical ribs in a large group of domestic dogs of different breeds, and explore a possible relation with other congenital vertebral malformations (CVMs) in the breed with the highest prevalence of cervical ribs. By phenotyping we hoped to give clues as to the underlying genetic causes. Twenty computed tomography studies from at least two breeds belonging to each of the nine groups recognized by the Federation Cynologique Internationale, including all the brachycephalic 'screw-tailed' breeds that are known to be overrepresented for CVMs, were reviewed. The Pug dog was more affected by cervical ribs than any other breed (46%; P < 0.001), and was selected for further analysis. No association was found between the presence of cervical ribs and vertebral body formation defect, bifid spinous process, caudal articular process hypoplasia/aplasia and an abnormal sacrum, which may infer they have a different aetiopathogenesis. However, Pug dogs with cervical ribs were more likely to have a transitional thoraco-lumbar vertebra (P = 0.041) and a pre-sacral vertebral count of 26 (P < 0.001). Higher C7/T1 dorsal spinous processes ratios were associated with the presence of cervical ribs (P < 0.001), supporting this is a true homeotic transformation. Relaxation of the stabilizing selection has likely occurred, and the Pug dog appears to be a good naturally occurring model to further investigate the aetiology of cervical ribs, other congenital vertebral anomalies and numerical alterations.
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Affiliation(s)
- J Brocal
- School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - S De Decker
- Department of Veterinary Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hertfordshire, UK
| | - R José-López
- School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - E G Manzanilla
- Teagasc Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland
| | - J Penderis
- Vet-Extra Neurology, Broadleys Veterinary Hospital, Stirling, UK
| | - C Stalin
- School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - S Bertram
- Department of Veterinary Clinical Science and Services, The Royal Veterinary College, University of London, North Mymms, Hertfordshire, UK
| | - J J Schoenebeck
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, UK
| | - C Rusbridge
- Fitzpatrick Referrals, Eashing, Surrey, UK.,School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | | | - R Gutierrez-Quintana
- School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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26
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Powell GL, Russell AP, Sutey J. Patterns of growth in the presacral vertebral column of the leopard gecko (Eublepharis macularius). J Morphol 2018; 279:1088-1103. [PMID: 29732599 DOI: 10.1002/jmor.20833] [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: 11/28/2017] [Revised: 03/06/2018] [Accepted: 04/08/2018] [Indexed: 11/10/2022]
Abstract
Postnatal growth patterns within the vertebral column may be informative about body proportions and regionalization. We measured femur length, lengths of all pre-sacral vertebrae, and lengths of intervertebral spaces, from radiographs of a series of 21 Eublepharis macularius, raised under standard conditions and covering most of the ontogenetic body size range. Vertebrae were grouped into cervical, sternal, and dorsal compartments, and lengths of adjacent pairs of vertebrae were summed before analysis. Femur length was included as an index of body size. Principal component analysis of the variance-covariance matrix of these data was used to investigate scaling among them. PC1 explained 94.19% of total variance, interpreted as the variance due to body size. PC1 differed significantly from the hypothetical isometric vector, indicating overall allometry. The atlas and axis vertebrae displayed strong negative allometry; the remainder of the vertebral pairs exhibited weak negative allometry, isometry or positive allometry. PC1 explained a markedly smaller amount of variance for the vertebral pairs of the cervical compartment than for the remainder of the vertebral pairs, with the exception of the final pair. The relative standard deviations of the eigenvalues from the PCAs of the three vertebral compartments indicated that the vertebrae of the cervical compartment were less strongly integrated by scaling than were the sternal or dorsal vertebrae, which did not differ greatly between themselves in their strong integration, suggesting that the growth of the cervical vertebrae is constrained by the mechanical requirements of the head. Regionalization of the remainder of the vertebral column is less clearly defined but may be associated with wave form propagation incident upon locomotion, and by locomotory changes occasioned by tail autotomy and regeneration. Femur length exhibits negative allometry relative to individual vertebral pairs and to vertebral column length, suggesting a change in locomotor requirements over the ontogenetic size range.
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Affiliation(s)
| | - Anthony P Russell
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Jennifer Sutey
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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27
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Abstract
Collinear regulation of Hox genes in space and time has been an outstanding question ever since the initial work of Ed Lewis in 1978. Here we discuss recent advances in our understanding of this phenomenon in relation to novel concepts associated with large-scale regulation and chromatin structure during the development of both axial and limb patterns. We further discuss how this sequential transcriptional activation marks embryonic stem cell-like axial progenitors in mammals and, consequently, how a temporal genetic system is further translated into spatial coordinates via the fate of these progenitors. In this context, we argue the benefit and necessity of implementing this unique mechanism as well as the difficulty in evolving an alternative strategy to deliver this critical positional information.
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Affiliation(s)
- Jacqueline Deschamps
- Hubrecht Institute, University Medical Center Utrecht, 3584 CT Utrecht, the Netherlands
| | - Denis Duboule
- School of Life Sciences, Ecole Polytechnique Fédérale, Lausanne, 1015 Lausanne, Switzerland.,Department of Genetics and Evolution, University of Geneva, 1211 Geneva 4, Switzerland
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28
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Slijepčević MD, Ukropina M, Filipović B, Ivanović A. Ossification and development of vertebrae in the Balkan crested newt Triturus ivanbureschi (Salamandridae, Caudata). ZOOLOGY 2017; 126:164-171. [PMID: 29113765 DOI: 10.1016/j.zool.2017.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 10/01/2017] [Accepted: 10/01/2017] [Indexed: 11/30/2022]
Abstract
Vertebral morphology, development, and evolution have been investigated for many decades, especially in the recent evo-devo era. Nevertheless, comparative data on development and ossification modes within the major tetrapod groups are scarce and frequently suffer from the use of a simplistic approach, resulting in simplistic generalizations about the formation of tetrapod vertebrae. Here, we describe the development and ossification of trunk vertebrae in Triturus ivanbureschi (Salamandridae, Caudata) and compare the results with published data on other related taxa. In so doing, we focus on the modes of ossification and development of the centrum and neural arches by analysing three developmental stages defined by the degree of limb development: stages 47, 52, and 62 according to Glücksohn (1932). Our examination of histological sections through trunk vertebrae enabled us to identify three modes of ossification within single trunk vertebrae: (i) perichordal (direct ossification of the connective tissue surrounding the notochord); (ii) perichondrial (direct ossification of the perichondrium, consisting of cartilage-covering connective tissue), and (iii) endochondral (ossification within the preformed cartilage template). We also noted the presence of intravertebral or notochordal cartilage. Although our results indicate that this cartilage develops within the notochord surrounded by the continuous notochordal sheath, more detailed further studies could shed light on its origin and development.
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Affiliation(s)
- Maja D Slijepčević
- University of Belgrade, Institute for Biological Research "Siniša Stanković", 11000 Belgrade, Serbia.
| | - Mirela Ukropina
- University of Belgrade, Institute of Zoology, Faculty of Biology, 11000 Belgrade, Serbia
| | - Branko Filipović
- University of Belgrade, Institute for Biological Research "Siniša Stanković", 11000 Belgrade, Serbia
| | - Ana Ivanović
- University of Belgrade, Institute of Zoology, Faculty of Biology, 11000 Belgrade, Serbia
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29
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Leal F, Cohn MJ. Developmental, genetic, and genomic insights into the evolutionary loss of limbs in snakes. Genesis 2017; 56. [DOI: 10.1002/dvg.23077] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 09/29/2017] [Accepted: 10/06/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Francisca Leal
- Howard Hughes Medical Institute, UF Genetics Institute, University of Florida; Gainesville FL 32610
- Department of Biology; University of Florida; Gainesville FL 32610
| | - Martin J. Cohn
- Department of Biology; University of Florida; Gainesville FL 32610
- Department of Molecular Genetics and Microbiology; University of Florida; Gainesville FL 32610
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30
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De Clercq A, Perrott MR, Davie PS, Preece MA, Wybourne B, Ruff N, Huysseune A, Witten PE. Vertebral column regionalisation in Chinook salmon, Oncorhynchus tshawytscha. J Anat 2017; 231:500-514. [PMID: 28762509 PMCID: PMC5603787 DOI: 10.1111/joa.12655] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2017] [Indexed: 02/05/2023] Open
Abstract
Teleost vertebral centra are often similar in size and shape, but vertebral-associated elements, i.e. neural arches, haemal arches and ribs, show regional differences. Here we examine how the presence, absence and specific anatomical and histological characters of vertebral centra-associated elements can be used to define vertebral column regions in juvenile Chinook salmon (Oncorhynchus tshawytscha). To investigate if the presence of regions within the vertebral column is independent of temperature, animals raised at 8 and 12 °C were studied at 1400 and 1530 degreedays, in the freshwater phase of the life cycle. Anatomy and composition of the skeletal tissues of the vertebral column were analysed using Alizarin red S whole-mount staining and histological sections. Six regions, termed I-VI, are recognised in the vertebral column of specimens of both temperature groups. Postcranial vertebrae (region I) carry neural arches and parapophyses but lack ribs. Abdominal vertebrae (region II) carry neural arches and ribs that articulate with parapophyses. Elastic- and fibrohyaline cartilage and Sharpey's fibres connect the bone of the parapophyses to the bone of the ribs. In the transitional region (III) vertebrae carry neural arches and parapophyses change stepwise into haemal arches. Ribs decrease in size, anterior to posterior. Vestigial ribs remain attached to the haemal arches with Sharpey's fibres. Caudal vertebrae (region IV) carry neural and haemal arches and spines. Basidorsals and basiventrals are small and surrounded by cancellous bone. Preural vertebrae (region V) carry neural and haemal arches with modified neural and haemal spines to support the caudal fin. Ural vertebrae (region VI) carry hypurals and epurals that represent modified haemal and neural arches and spines, respectively. The postcranial and transitional vertebrae and their respective characters are usually recognised, but should be considered as regions within the vertebral column of teleosts because of their distinctive morphological characters. While the number of vertebrae within each region can vary, each of the six regions is recognised in specimens of both temperature groups. This refined identification of regionalisation in the vertebral column of Chinook salmon can help to address evolutionary developmental and functional questions, and to support applied research into this farmed species.
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Affiliation(s)
- A. De Clercq
- Institute of Veterinary, Animal and Biomedical SciencesMassey UniversityPalmerston NorthNew Zealand
- Evolutionary Developmental BiologyGhent UniversityGhentBelgium
| | - M. R. Perrott
- Institute of Veterinary, Animal and Biomedical SciencesMassey UniversityPalmerston NorthNew Zealand
| | - P. S. Davie
- Institute of Veterinary, Animal and Biomedical SciencesMassey UniversityPalmerston NorthNew Zealand
| | | | - B. Wybourne
- Skretting AustraliaRosny ParkTasmaniaAustralia
| | - N. Ruff
- Skretting AustraliaRosny ParkTasmaniaAustralia
| | - A. Huysseune
- Evolutionary Developmental BiologyGhent UniversityGhentBelgium
| | - P. E. Witten
- Institute of Veterinary, Animal and Biomedical SciencesMassey UniversityPalmerston NorthNew Zealand
- Evolutionary Developmental BiologyGhent UniversityGhentBelgium
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31
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The effect of temperature on the initial development of Brycon amazonicus Spix & Agassiz, 1829 as tool for micromanipulation of embryos. ZYGOTE 2017; 25:637-651. [DOI: 10.1017/s096719941700051x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummaryPrimordial germ cell (PGC) transplant is a promising tool in aquaculture; however, successful use of this technique requires in depth knowledge of the early stages of embryo and larval development. The aim of this study was to analyse the effect of different temperatures (22, 26, and 30°C) on the early development of B. amazonicus. The newly fertilized eggs were distributed into tanks with controlled temperature and oxygenation. Samples were collected at pre-established times and analysed under light and fluorescence microscopy. Temperature influenced the speed and duration of each stage of early development, including hatching time. The highest pronuclei fusion rate was observed 8 min post-fertilization (mpf) at 22 and 26°C, and 6 mpf at 30°C. The duration of the 512–1000 blastomeres phase during in the blastocyst stage was 1 h 30 min at 22°C, and 25 min at 26 and 30°C. Hatching occurred at 24 h 30 mpf at 22°C, 16 h post-fertilization (hpf) at 26°C, and 11 h 30 mpf at 30°C. The rate of morphologically normal larvae was 88.34% at 22°C, 90.49% at 26°C, and 73% at 30°C. Malformations of the head, yolk sac, heart, and tail were observed in all temperatures. Nevertheless, B. amazonicus embryos were able to develop satisfactory in all three temperatures tested. These results enable embryo manipulation at different temperatures to optimize the micromanipulation time of embryos and larvae for biotechnological studies.
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Govedarica P, Cvijanović M, Slijepčević M, Ivanović A. Trunk elongation and ontogenetic changes in the axial skeleton ofTriturusnewts. J Morphol 2017; 278:1577-1585. [DOI: 10.1002/jmor.20733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/05/2017] [Accepted: 07/01/2017] [Indexed: 01/11/2023]
Affiliation(s)
- Petar Govedarica
- University of Belgrade, Faculty of Biology; Institute of Zoology, Studentski trg 16; 11000 Belgrade Serbia
| | - Milena Cvijanović
- University of Belgrade; Institute for Biological Research “Siniša Stanković”, Department of Evolutionary Biology, Bul. Despota Stefana 142; 11060 Belgrade Serbia
| | - Maja Slijepčević
- University of Belgrade; Institute for Biological Research “Siniša Stanković”, Department of Evolutionary Biology, Bul. Despota Stefana 142; 11060 Belgrade Serbia
| | - Ana Ivanović
- University of Belgrade, Faculty of Biology; Institute of Zoology, Studentski trg 16; 11000 Belgrade Serbia
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Elements of biological oscillations in time and space. Nat Struct Mol Biol 2017; 23:1030-1034. [PMID: 27922613 DOI: 10.1038/nsmb.3320] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/13/2016] [Indexed: 12/16/2022]
Abstract
Oscillations in time and space are ubiquitous in nature and play critical roles in dynamic cellular processes. Although the molecular mechanisms underlying the generation of the dynamics are diverse, several distinct regulatory elements have been recognized as being critical in producing and modulating oscillatory dynamics. These include negative and positive feedback, time delay, nonlinearity in regulation, and random fluctuations ('noise'). Here we discuss the specific roles of these five elements in promoting or attenuating oscillatory dynamics, by drawing on insights from quantitative analyses of natural or synthetic biological networks.
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Liao BK, Oates AC. Delta-Notch signalling in segmentation. ARTHROPOD STRUCTURE & DEVELOPMENT 2017; 46:429-447. [PMID: 27888167 PMCID: PMC5446262 DOI: 10.1016/j.asd.2016.11.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 11/20/2016] [Accepted: 11/21/2016] [Indexed: 06/06/2023]
Abstract
Modular body organization is found widely across multicellular organisms, and some of them form repetitive modular structures via the process of segmentation. It's vastly interesting to understand how these regularly repeated structures are robustly generated from the underlying noise in biomolecular interactions. Recent studies from arthropods reveal similarities in segmentation mechanisms with vertebrates, and raise the possibility that the three phylogenetic clades, annelids, arthropods and chordates, might share homology in this process from a bilaterian ancestor. Here, we discuss vertebrate segmentation with particular emphasis on the role of the Notch intercellular signalling pathway. We introduce vertebrate segmentation and Notch signalling, pointing out historical milestones, then describe existing models for the Notch pathway in the synchronization of noisy neighbouring oscillators, and a new role in the modulation of gene expression wave patterns. We ask what functions Notch signalling may have in arthropod segmentation and explore the relationship between Notch-mediated lateral inhibition and synchronization. Finally, we propose open questions and technical challenges to guide future investigations into Notch signalling in segmentation.
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Affiliation(s)
- Bo-Kai Liao
- Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK
| | - Andrew C Oates
- Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London NW7 1AA, UK; Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
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35
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Soul LC, Benson RBJ. Developmental mechanisms of macroevolutionary change in the tetrapod axis: A case study of Sauropterygia. Evolution 2017; 71:1164-1177. [PMID: 28240769 PMCID: PMC5485078 DOI: 10.1111/evo.13217] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 02/05/2017] [Accepted: 02/19/2017] [Indexed: 01/29/2023]
Abstract
Understanding how developmental processes change on macroevolutionary timescales to generate body plan disparity is fundamental to the study of vertebrate evolution. Adult morphology of the vertebral column directly reflects the mechanisms that generate vertebral counts (somitogenesis) and their regionalisation (homeotic effects) during embryonic development. Sauropterygians were a group of Mesozoic marine reptiles that exhibited an extremely high disparity of presacral vertebral/somite counts. Using phylogenetic comparative methods, we demonstrate that somitogenesis and homeotic effects evolved in a co-ordinated way among sauropterygians, contrasting with the wider pattern in tetrapods, in which somitogenetic and homeotic shifts are uncorrelated. Changes in sauropterygian body proportions were primarily enabled by homeotic shifts, with a lesser, but important, contribution from differences in postpatterning growth among somites. High body plan plasticity was present in Triassic sauropterygians and was maintained among their Jurassic and Cretaceous descendants. The extreme disparity in the body plan of plesiosaurian sauropterygians did not result from accelerated rates of evolutionary change in neck length, but instead reflect this ancestral versatility of sauropterygian axial development. Our results highlight variation in modes of axial development among tetrapods, and show that heterogeneous statistical models can uncover novel macroevolutionary patterns for animal body plans and the developmental mechanisms that control them.
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Affiliation(s)
- Laura C. Soul
- Department of Paleobiology, National Museum of Natural HistorySmithsonian InstitutionWashingtonDistrict of Columbia20013
- Department of Earth SciencesUniversity of Oxford,OX1 3ANUnited Kingdom
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36
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Abstract
In the developing vertebrate embryo, segmentation initiates through the formation of repeated segments, or somites, on either side of the posterior neural tube along the anterior to posterior axis. The periodicity of somitogenesis is regulated by a molecular oscillator, the segmentation clock, driving cyclic gene expression in the unsegmented paraxial mesoderm, from which somites derive. Three signaling pathways underlie the molecular mechanism of the oscillator: Wnt, FGF, and Notch. In particular, Notch has been demonstrated to be an essential piece in the intricate somitogenesis regulation puzzle. Notch is required to synchronize oscillations between neighboring cells, and is moreover necessary for somite formation and clock gene oscillations. Following ligand activation, the Notch receptor is cleaved to liberate the active intracellular domain (NICD) and during somitogenesis NICD itself is produced and degraded in a cyclical manner, requiring tightly regulated, and coordinated turnover. It was recently shown that the pace of the segmentation clock is exquisitely sensitive to levels/stability of NICD. In this review, we focus on what is known about the mechanisms regulating NICD turnover, crucial to the activity of the pathway in all developmental contexts. To date, the regulation of NICD stability has been attributed to phosphorylation of the PEST domain which serves to recruit the SCF/Sel10/FBXW7 E3 ubiquitin ligase complex involved in NICD turnover. We will describe the pathophysiological relevance of NICD-FBXW7 interaction, whose defects have been linked to leukemia and a variety of solid cancers.
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Affiliation(s)
- Francesca A Carrieri
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee Dundee, UK
| | - Jacqueline Kim Dale
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee Dundee, UK
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37
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Yoshida H, Okada M, Takebayashi-Suzuki K, Ueno N, Suzuki A. Involvement of JunB Proto-Oncogene in Tail Formation During Early Xenopus Embryogenesis. Zoolog Sci 2016; 33:282-9. [PMID: 27268982 DOI: 10.2108/zs150136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Integration of signaling pathways is important for the establishment of the body plan during embryogenesis. However, little is known about how the multiple signals interact to regulate morphogenesis. Here, we show that junb is expressed in the posterior neural plate and the caudal fin during Xenopus embryogenesis and that overexpression of wild-type JunB induces small head phenotypes and ectopic tail-like structures. A mutant form of JunB that lacked GSK3 and MAPK phosphorylation sites showed stronger tail-like structure-inducing activity than wild-type JunB. Moreover, the mutant JunB induced expression of tailbud and neural marker genes, but not somite and chordoneural hinge (CNH) marker genes in ectopic tail-like structures. In ectodermal explants of Xenopus embryos, overexpression of JunB increased the expression of tailbud and posterior marker genes including fgf3, xbra (t) and wnt8. These results indicate that JunB is capable of inducing the ectopic formation of tissues similar to the tailbud, and that the tailbud-inducing activity of JunB is likely to be regulated by FGF and Wnt pathways. Overall, our results suggest that JunB is a regulator of tail organization possibly through integration of several morphogen signaling pathways.
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Affiliation(s)
- Hitoshi Yoshida
- 1 Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Maya Okada
- 1 Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Kimiko Takebayashi-Suzuki
- 1 Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Naoto Ueno
- 2 Division of Morphogenesis, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki, Aichi 444-8585, Japan.,3 Department of Basic Biology, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193, Japan
| | - Atsushi Suzuki
- 1 Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
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38
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Böhmer C, Rauhut OWM, Wörheide G. New insights into the vertebral Hox code of archosaurs. Evol Dev 2016; 17:258-69. [PMID: 26372060 DOI: 10.1111/ede.12136] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Variation in axial formulae (i.e., number and identity of vertebrae) is an important feature in the evolution of vertebrates. Vertebrae at different axial positions exhibit a region-specific morphology. Key determinants for the establishment of particular vertebral shapes are the highly conserved Hox genes. Here, we analyzed Hox gene expression in the presacral vertebral column in the Nile crocodile in order to complement and extend a previous examination in the alligator and thus establish a Hox code for the axial skeleton of crocodilians in general. The newly determined expression of HoxA-4, C-5, B-7, and B-8 all revealed a crocodilian-specific pattern. HoxA-4 and HoxC-5 characterize cervical morphologies and the latter furthermore is associated with the position of the forelimb relative to the axial skeleton. HoxB-7 and HoxB-8 map exclusively to the dorsal vertebral region. The resulting expression patterns of these two Hox genes is the first description of their exact expression in the archosaurian embryo. Our comparative analyses of the Hox code in several amniote taxa provide new evidence that evolutionary differences in the axial skeleton correspond to changes in Hox gene expression domains. We detect two general processes: (i) expansion of a Hox gene's expression domain as well as (ii) a shift of gene expression. We infer that the ancestral archosaur Hox code may have resembled that of the crocodile. In association with the evolution of morphological traits, it may have been modified to patterns that can be observed in birds.
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Affiliation(s)
- Christine Böhmer
- Department für Geo- und Umweltwissenschaften & GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany.,SNSB - Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 München, Germany
| | - Oliver W M Rauhut
- Department für Geo- und Umweltwissenschaften & GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany.,SNSB - Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 München, Germany
| | - Gert Wörheide
- Department für Geo- und Umweltwissenschaften & GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333 München, Germany.,SNSB - Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Str. 10, 80333 München, Germany
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39
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The many roles of Notch signaling during vertebrate somitogenesis. Semin Cell Dev Biol 2016; 49:68-75. [DOI: 10.1016/j.semcdb.2014.11.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 11/23/2014] [Accepted: 11/26/2014] [Indexed: 02/06/2023]
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40
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Early development of the vertebral column. Semin Cell Dev Biol 2016; 49:83-91. [DOI: 10.1016/j.semcdb.2015.11.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 11/05/2015] [Indexed: 11/20/2022]
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41
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Slijepčević M, Galis F, Arntzen JW, Ivanović A. Homeotic transformations and number changes in the vertebral column of Triturus newts. PeerJ 2015; 3:e1397. [PMID: 26587355 PMCID: PMC4647568 DOI: 10.7717/peerj.1397] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/20/2015] [Indexed: 01/23/2023] Open
Abstract
We explored intraspecific variation in vertebral formulae, more specifically the variation in the number of thoracic vertebrae and frequencies of transitional sacral vertebrae in Triturus newts (Caudata: Salamandridae). Within salamandrid salamanders this monophyletic group shows the highest disparity in the number of thoracic vertebrae and considerable intraspecific variation in the number of thoracic vertebrae. Triturus species also differ in their ecological preferences, from predominantly terrestrial to largely aquatic. Following Geoffroy St. Hilaire's and Darwin's rule which states that structures with a large number of serially homologous repetitive elements are more variable than structures with smaller numbers, we hypothesized that the variation in vertebral formulae increases in more elongated species with a larger number of thoracic vertebrae. We furthermore hypothesized that the frequency of transitional vertebrae will be correlated with the variation in the number of thoracic vertebrae within the species. We also investigated potential effects of species hybridization on the vertebral formula. The proportion of individuals with a number of thoracic vertebrae different from the modal number and the range of variation in number of vertebrae significantly increased in species with a larger number of thoracic vertebrae. Contrary to our expectation, the frequencies of transitional vertebrae were not correlated with frequencies of change in the complete vertebrae number. The frequency of transitional sacral vertebra in hybrids did not significantly differ from that of the parental species. Such a pattern could be a result of selection pressure against transitional vertebrae and/or a bias towards the development of full vertebrae numbers. Although our data indicate relaxed selection for vertebral count changes in more elongated, aquatic species, more data on different selective pressures in species with different numbers of vertebrae in the two contrasting, terrestrial and aquatic environments are needed to test for causality.
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Affiliation(s)
- Maja Slijepčević
- Institute for Biological Research “Siniša Stanković”, University of Belgrade, Belgrade, Serbia
| | | | | | - Ana Ivanović
- Naturalis Biodiversity Center, Leiden, The Netherlands
- Institute of Zoology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
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42
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Böhmer C, Rauhut OWM, Wörheide G. Correlation between Hox code and vertebral morphology in archosaurs. Proc Biol Sci 2015; 282:20150077. [PMID: 26085583 PMCID: PMC4590465 DOI: 10.1098/rspb.2015.0077] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/19/2015] [Indexed: 12/30/2022] Open
Abstract
The relationship between developmental genes and phenotypic variation is of central interest in evolutionary biology. An excellent example is the role of Hox genes in the anteroposterior regionalization of the vertebral column in vertebrates. Archosaurs (crocodiles, dinosaurs including birds) are highly variable both in vertebral morphology and number. Nevertheless, functionally equivalent Hox genes are active in the axial skeleton during embryonic development, indicating that the morphological variation across taxa is likely owing to modifications in the pattern of Hox gene expression. By using geometric morphometrics, we demonstrate a correlation between vertebral Hox code and quantifiable vertebral morphology in modern archosaurs, in which the boundaries between morphological subgroups of vertebrae can be linked to anterior Hox gene expression boundaries. Our findings reveal homologous units of cervical vertebrae in modern archosaurs, each with their specific Hox gene pattern, enabling us to trace these homologies in the extinct sauropodomorph dinosaurs, a group with highly variable vertebral counts. Based on the quantifiable vertebral morphology, this allows us to infer the underlying genetic mechanisms in vertebral evolution in fossils, which represents not only an important case study, but will lead to a better understanding of the origin of morphological disparity in recent archosaur vertebral columns.
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Affiliation(s)
- Christine Böhmer
- Department für Geo- und Umweltwissenschaften und GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Strasse 10, München 80333, Deutschland SNSB - Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Strasse 10, München 80333, Deutschland
| | - Oliver W M Rauhut
- Department für Geo- und Umweltwissenschaften und GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Strasse 10, München 80333, Deutschland SNSB - Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Strasse 10, München 80333, Deutschland
| | - Gert Wörheide
- Department für Geo- und Umweltwissenschaften und GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Strasse 10, München 80333, Deutschland SNSB - Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Strasse 10, München 80333, Deutschland
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Denans N, Iimura T, Pourquié O. Hox genes control vertebrate body elongation by collinear Wnt repression. eLife 2015; 4. [PMID: 25719209 PMCID: PMC4384752 DOI: 10.7554/elife.04379] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 02/20/2015] [Indexed: 12/23/2022] Open
Abstract
In vertebrates, the total number of vertebrae is precisely defined. Vertebrae derive
from embryonic somites that are continuously produced posteriorly from the presomitic
mesoderm (PSM) during body formation. We show that in the chicken embryo, activation
of posterior Hox genes (paralogs 9–13) in the tail-bud
correlates with the slowing down of axis elongation. Our data indicate that a subset
of progressively more posterior Hox genes, which are collinearly
activated in vertebral precursors, repress Wnt activity with increasing strength.
This leads to a graded repression of the Brachyury/T transcription
factor, reducing mesoderm ingression and slowing down the elongation process. Due to
the continuation of somite formation, this mechanism leads to the progressive
reduction of PSM size. This ultimately brings the retinoic acid (RA)-producing
segmented region in close vicinity to the tail bud, potentially accounting for the
termination of segmentation and axis elongation. DOI:http://dx.doi.org/10.7554/eLife.04379.001 In humans and other vertebrates, the number of bones (vertebrae) in the spine is
determined early in development. The vertebrae form from blocks of tissue called
somites that make segments along the body axis—a virtual line running from the
head to the tail-end—of the embryo. The somites form as the embryo increases
in length, with new somites forming periodically at the back near the embryo's
tail-end. A family of genes called the Hox genes are involved in controlling
the formation of the somites. However, it is not known whether they directly control
the number of somites that form, or whether they control the length of the body of
the embryo. Denans et al. studied the Hox genes in chicken embryos. The
experiments suggest that the activation of some of the Hox genes in
a structure called the tail-bud, which is found at the tail-end of the embryo, slow
down the elongation of the body. The Hox genes achieve this by
repressing the activity of a signaling pathway called Wnt so that Wnt activity in the
tail-bud progressively decreases as the embryo develops. The elongation of the body stops when the levels of a molecule called retinoic acid
increase in the tail-bud, which causes the loss of the stem cells that are needed to
make the somites. Denans et al.'s findings suggest that Hox
genes influence the timing of the halt in elongation, which in turn is important for
determining the total number of somites that form. Understanding how
Hox genes control the formation of the cells that will make up
the somites and influence Wnt signaling is a major challenge for the future. DOI:http://dx.doi.org/10.7554/eLife.04379.002
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Affiliation(s)
- Nicolas Denans
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, University of Strasbourg, Illkirch, France
| | - Tadahiro Iimura
- Stowers Institute for Medical Research, Kansas City, United States
| | - Olivier Pourquié
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, University of Strasbourg, Illkirch, France
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44
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Beck CW. Development of the vertebrate tailbud. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2014; 4:33-44. [DOI: 10.1002/wdev.163] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/29/2014] [Accepted: 10/05/2014] [Indexed: 01/09/2023]
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Buchholtz EA, Wayrynen KL, Lin IW. Breaking constraint: axial patterning in Trichechus (Mammalia: Sirenia). Evol Dev 2014; 16:382-93. [PMID: 25339599 DOI: 10.1111/ede.12103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Meristic variation is often limited in serially homologous systems with high internal differentiation and high developmental modularity. The mammalian neck, an extreme example, has a fixed (at seven) count of diversely specialized segments. Imposition of the mammalian cervical constraint has been tentatively linked to the origin of the diaphragm, which is muscularized by cells that migrate from cervical somites during development. With six cervical vertebrae, the genus Trichechus (manatee) has apparently broken this constraint, although the mechanism of constraint escape is unknown. Hypotheses for the developmental origin of Trichechus cervical morphology include cervical rib 7 repatterning, a primaxial/abaxial patterning shift, and local homeosis at the cervical/thoracic boundary. We tested predictions of these hypotheses by documenting vertebral morphology, axial ossification patterns, regionalization of the postcranial skeleton, and the relationship of thoracic ribs to sternal subunits in a large data set of fetal and adult Trichechus and Dugong specimens. These observations forced rejection of all three hypotheses. We propose alternatively that a global slowing of the rate of somitogenesis reduced somite count and disrupted alignment of Hox-generated anatomical markers relative to somite (and vertebral) boundaries throughout the Trichechus column. This hypothesis is consistent with observations of the full range of traditional cervical morphologies in the six cervical vertebrae, conserved postcranial proportions, and column-wide reduction in count relative to its sister taxon, Dugong. It also suggests that the origin of the mammalian cervical constraint lies in patterning, not in count, and that Trichechus and the tree sloths have broken the constraint using different developmental mechanisms.
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Affiliation(s)
- Emily A Buchholtz
- Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA
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46
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Aguirre WE, Walker K, Gideon S. Tinkering with the axial skeleton: vertebral number variation in ecologically divergent threespine stickleback populations. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12316] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Windsor E. Aguirre
- Department of Biological Sciences; DePaul University; Chicago IL 60614-3207 USA
| | - Kendal Walker
- Department of Biological Sciences; DePaul University; Chicago IL 60614-3207 USA
| | - Shawn Gideon
- Department of Biological Sciences; DePaul University; Chicago IL 60614-3207 USA
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47
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Keyte AL, Smith KK. Heterochrony and developmental timing mechanisms: changing ontogenies in evolution. Semin Cell Dev Biol 2014; 34:99-107. [PMID: 24994599 DOI: 10.1016/j.semcdb.2014.06.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/14/2014] [Accepted: 06/23/2014] [Indexed: 01/20/2023]
Abstract
Heterochrony, or a change in developmental timing, is an important mechanism of evolutionary change. Historically the concept of heterochrony has focused alternatively on changes in size and shape or changes in developmental sequence, but most have focused on the pattern of change. Few studies have examined changes in the mechanisms that embryos use to actually measure time during development. Recently, evolutionary studies focused on changes in distinct timekeeping mechanisms have appeared, and this review examines two such case studies: the evolution of increased segment number in snakes and the extreme rostral to caudal gradient of developmental maturation in marsupials. In both examples, heterochronic modifications of the somite clock have been important drivers of evolutionary change.
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Affiliation(s)
- Anna L Keyte
- Department of Pediatrics, Duke University Medical Center, Durham, NC, United States
| | - Kathleen K Smith
- Department of Biology, Duke University, Durham, NC, United States.
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Janesick A, Nguyen TTL, Aisaki KI, Igarashi K, Kitajima S, Chandraratna RAS, Kanno J, Blumberg B. Active repression by RARγ signaling is required for vertebrate axial elongation. Development 2014; 141:2260-70. [PMID: 24821986 DOI: 10.1242/dev.103705] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Retinoic acid receptor gamma 2 (RARγ2) is the major RAR isoform expressed throughout the caudal axial progenitor domain in vertebrates. During a microarray screen to identify RAR targets, we identified a subset of genes that pattern caudal structures or promote axial elongation and are upregulated by increased RAR-mediated repression. Previous studies have suggested that RAR is present in the caudal domain, but is quiescent until its activation in late stage embryos terminates axial elongation. By contrast, we show here that RARγ2 is engaged in all stages of axial elongation, not solely as a terminator of axial growth. In the absence of RA, RARγ2 represses transcriptional activity in vivo and maintains the pool of caudal progenitor cells and presomitic mesoderm. In the presence of RA, RARγ2 serves as an activator, facilitating somite differentiation. Treatment with an RARγ-selective inverse agonist (NRX205099) or overexpression of dominant-negative RARγ increases the expression of posterior Hox genes and that of marker genes for presomitic mesoderm and the chordoneural hinge. Conversely, when RAR-mediated repression is reduced by overexpressing a dominant-negative co-repressor (c-SMRT), a constitutively active RAR (VP16-RARγ2), or by treatment with an RARγ-selective agonist (NRX204647), expression of caudal genes is diminished and extension of the body axis is prematurely terminated. Hence, gene repression mediated by the unliganded RARγ2-co-repressor complex constitutes a novel mechanism to regulate and facilitate the correct expression levels and spatial restriction of key genes that maintain the caudal progenitor pool during axial elongation in Xenopus embryos.
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Affiliation(s)
- Amanda Janesick
- Department of Developmental and Cell Biology, 2011 Biological Sciences 3, University of California, Irvine, CA 92697-2300, USA
| | - Tuyen T L Nguyen
- Department of Developmental and Cell Biology, 2011 Biological Sciences 3, University of California, Irvine, CA 92697-2300, USA
| | - Ken-ichi Aisaki
- Division of Cellular and Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Katsuhide Igarashi
- Division of Cellular and Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Satoshi Kitajima
- Division of Cellular and Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | | | - Jun Kanno
- Division of Cellular and Molecular Toxicology, Biological Safety Research Center, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Bruce Blumberg
- Department of Developmental and Cell Biology, 2011 Biological Sciences 3, University of California, Irvine, CA 92697-2300, USA Department of Pharmaceutical Sciences, University of California, Irvine, CA 92697-2300, USA
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Differential occupation of axial morphospace. ZOOLOGY 2014; 117:70-6. [DOI: 10.1016/j.zool.2013.10.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 10/07/2013] [Accepted: 10/09/2013] [Indexed: 01/12/2023]
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50
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Hiraga T, Sakamoto H, Nishikawa S, Muneuchi I, Ueda H, Inoue M, Shimura R, Uebayashi A, Yasuda N, Momose K, Masatomi H, Teraoka H. Vertebral formula in red-crowned crane (Grus japonensis) and hooded crane (Grus monacha). J Vet Med Sci 2013; 76:503-8. [PMID: 24334828 PMCID: PMC4064133 DOI: 10.1292/jvms.13-0295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Red-crowned cranes (Grus japonensis) are distributed
separately in the east Eurasian Continent (continental population) and in Hokkaido, Japan
(island population). The island population is sedentary in eastern Hokkaido and has
increased from a very small number of cranes to over 1,300, thus giving rise to the
problem of poor genetic diversity. While, Hooded cranes (Grus monacha),
which migrate from the east Eurasian Continent and winter mainly in Izumi, Kagoshima
Prefecture, Japan, are about eight-time larger than the island population of Red-crowned
cranes. We collected whole bodies of these two species, found dead or moribund in eastern
Hokkaido and in Izumi, and observed skeletons with focus on vertebral formula. Numbers of
cervical vertebrae (Cs), thoracic vertebrae (Ts), vertebrae composing the synsacrum (Sa)
and free coccygeal vertebrae (free Cos) in 22 Red-crowned cranes were 17 or 18, 9–11, 13
or 14 and 7 or 8, respectively. Total number of vertebrae was 47, 48 or 49, and the
vertebral formula was divided into three types including 9 sub-types. Numbers of Cs, Ts,
vertebrae composing the Sa and free Cos in 25 Hooded cranes were 17 or 18, 9 or 10, 12–14
and 6–8, respectively. Total number of vertebrae was 46, 47, 48 or 49, and the vertebral
formula was divided into four types including 14 sub-types. Our findings clearly showed
various numerical vertebral patterns in both crane species; however, these variations in
the vertebral formula may be unrelated to the genetic diversity.
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Affiliation(s)
- Takeo Hiraga
- School of Veterinary Medicine, Rakuno Gakuen University, 582 Midori-machi, Ebetsu, Hokkaido 069-8501, Japan
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