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Miao Y, Djeffal Y, De Simone A, Zhu K, Lee JG, Lu Z, Silberfeld A, Rao J, Tarazona OA, Mongera A, Rigoni P, Diaz-Cuadros M, Song LMS, Di Talia S, Pourquié O. Reconstruction and deconstruction of human somitogenesis in vitro. Nature 2023; 614:500-508. [PMID: 36543321 PMCID: PMC10018515 DOI: 10.1038/s41586-022-05655-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
The vertebrate body displays a segmental organization that is most conspicuous in the periodic organization of the vertebral column and peripheral nerves. This metameric organization is first implemented when somites, which contain the precursors of skeletal muscles and vertebrae, are rhythmically generated from the presomitic mesoderm. Somites then become subdivided into anterior and posterior compartments that are essential for vertebral formation and segmental patterning of the peripheral nervous system1-4. How this key somitic subdivision is established remains poorly understood. Here we introduce three-dimensional culture systems of human pluripotent stem cells called somitoids and segmentoids, which recapitulate the formation of somite-like structures with anteroposterior identity. We identify a key function of the segmentation clock in converting temporal rhythmicity into the spatial regularity of anterior and posterior somitic compartments. We show that an initial 'salt and pepper' expression of the segmentation gene MESP2 in the newly formed segment is transformed into compartments of anterior and posterior identity through an active cell-sorting mechanism. Our research demonstrates that the major patterning modules that are involved in somitogenesis, including the clock and wavefront, anteroposterior polarity patterning and somite epithelialization, can be dissociated and operate independently in our in vitro systems. Together, we define a framework for the symmetry-breaking process that initiates somite polarity patterning. Our work provides a platform for decoding general principles of somitogenesis and advancing knowledge of human development.
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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
| | - Yannis Djeffal
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | | | - Kongju Zhu
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Jong Gwan Lee
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Ziqi Lu
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA
| | - Andrew Silberfeld
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Jyoti Rao
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Oscar A Tarazona
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Alessandro Mongera
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Pietro Rigoni
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Margarete Diaz-Cuadros
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Laura Min Sook Song
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA
| | - Stefano Di Talia
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 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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Wang Y, Troutwine BR, Zhang H, Gray RS. The axonemal dynein heavy chain 10 gene is essential for monocilia motility and spine alignment in zebrafish. Dev Biol 2022; 482:82-90. [PMID: 34915022 PMCID: PMC8792996 DOI: 10.1016/j.ydbio.2021.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 02/07/2023]
Abstract
Adolescent idiopathic scoliosis (AIS) is a common pediatric musculoskeletal disorder worldwide, characterized by atypical spine curvatures in otherwise healthy children. Human genetic studies have identified candidate genes associated with AIS, however, only a few of these have been shown to recapitulate adult-viable scoliosis in animal models. Using an F0 CRISPR screening approach in zebrafish, we demonstrate that disruption of the dynein axonemal heavy chain 10 (dnah10) gene results in recessive adult-viable scoliosis in zebrafish. Using a stably segregating dnah10 mutant zebrafish, we showed that the ependymal monocilia lining the hindbrain and spinal canal displayed reduced beat frequency, which was correlated with the disassembly of the Reissner fiber and the onset of body curvatures. Taken together, these results suggest that monocilia function in larval zebrafish contributes to the polymerization of the Reissner fiber and straightening of the body axis.
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Affiliation(s)
- Yunjia Wang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China; Department of Nutritional Sciences, 200 W 24th Street, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Benjamin R Troutwine
- Department of Nutritional Sciences, 200 W 24th Street, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Hongqi Zhang
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
| | - Ryan S Gray
- Department of Nutritional Sciences, 200 W 24th Street, The University of Texas at Austin, Austin, TX, 78712, USA.
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Kokudo Y, Arakawa T, Takahashi H, Kobara H, Kamada M, Deguchi K, Touge T, Masaki T, Yamamoto T. Ascending spinal tract formation in chick embryo originating from different spinal regions. Brain Res 2021; 1768:147595. [PMID: 34332964 DOI: 10.1016/j.brainres.2021.147595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 11/18/2022]
Abstract
The present study aimed to assess spinal tract formation in neurons originating from cervical (C7), brachial (C14), and thoracic (T4) regions, with the lumbar (LS2) region as a reference, in a chick embryo. For the assessment of the spinal tracts, we introduced a vector expressing human placental alkaline phosphatase into progenitor cells generated after neural tube closure and belonging to the above segments, using in ovo electroporation. The ascending axons took primarily similar paths: dorsal commissural, ventral commissural, and dorsal non-commissural paths, with some variance depending on their originating segments. Some populations of non-commissural neurons later extended their axons following a ventral path. The elongation rates of these axons are primarily constant and tended to increase over time; however, some variations depending on the originating segments were also observed. Some of the dorsally ascending axons entered into the developing cerebellum, and spinocerebellar neurons originating from T4 projected their axons into the cortex of the cerebellum differently from those from LS2. These results unveil an overall picture of early ascending spinal tract formation.
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Affiliation(s)
- Yohei Kokudo
- Department of Neurological Intractable Disease Research, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Takahiro Arakawa
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, 761-0793, Japan
| | - Hiroo Takahashi
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, 761-0793, Japan
| | - Hideki Kobara
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Masaki Kamada
- Department of Neurological Intractable Disease Research, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Kazushi Deguchi
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Tetsuo Touge
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Tsutomu Masaki
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
| | - Tohru Yamamoto
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, 761-0793, Japan.
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Guo SS, Au TYK, Wynn S, Aszodi A, Chan D, Fässler R, Cheah KSE. β1 Integrin regulates convergent extension in mouse notogenesis, ensures notochord integrity and the morphogenesis of vertebrae and intervertebral discs. Development 2020; 147:dev192724. [PMID: 33051257 DOI: 10.1242/dev.192724] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/01/2020] [Indexed: 12/17/2022]
Abstract
The notochord drives longitudinal growth of the body axis by convergent extension, a highly conserved developmental process that depends on non-canonical Wnt/planar cell polarity (PCP) signaling. However, the role of cell-matrix interactions mediated by integrins in the development of the notochord is unclear. We developed transgenic Cre mice, in which the β1 integrin gene (Itgb1) is ablated at E8.0 in the notochord only or in the notochord and tail bud. These Itgb1 conditional mutants display misaligned, malformed vertebral bodies, hemi-vertebrae and truncated tails. From early somite stages, the notochord was interrupted and displaced in these mutants. Convergent extension of the notochord was impaired with defective cell movement. Treatment of E7.25 wild-type embryos with anti-β1 integrin blocking antibodies, to target node pit cells, disrupted asymmetric localization of VANGL2. Our study implicates pivotal roles of β1 integrin for the establishment of PCP and convergent extension of the developing notochord, its structural integrity and positioning, thereby ensuring development of the nucleus pulposus and the proper alignment of vertebral bodies and intervertebral discs. Failure of this control may contribute to human congenital spine malformations.
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Affiliation(s)
- Shiny Shengzhen Guo
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Max Planck Institute of Biochemistry, Department of Molecular Medicine, 82152 Martinsried, Germany
| | - Tiffany Y K Au
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Sarah Wynn
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Attila Aszodi
- Department of General, Trauma and Reconstructive Surgery, Munich University Hospital, Ludwig-Maximilians-University, Fraunhoferstraβe 20, 82152 Planegg-Martinsried, Germany
| | - Danny Chan
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Reinhard Fässler
- Max Planck Institute of Biochemistry, Department of Molecular Medicine, 82152 Martinsried, Germany
| | - Kathryn S E Cheah
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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Bao Q, Liberman G, Solomon E, Frydman L. High-resolution diffusion MRI studies of development in pregnant mice visualized by novel spatiotemporal encoding schemes. NMR Biomed 2020; 33:e4208. [PMID: 31809554 DOI: 10.1002/nbm.4208] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 10/08/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
This study introduces an MRI approach to map diffusion of water in vivo with high resolution under challenging conditions; the approach's potential is then used in diffusivity characterizations of embryos and fetoplacental units in pregnant mice, as well as of newborn mice in their initial postnatal period. The method relies on performing self-referenced spatiotemporal encoded MRI acquisitions, which can achieve the motional and susceptibility immunities needed to target challenging regions such as a mouse's abdominal cavity in a single shot. When suitably combined with zooming-in and novel interleaving procedures, these scans can overcome the inhomogeneity and sensitivity challenges arising upon targeting ≈100 μm in-plane resolutions, and thereby enable longitudinal development studies of abdominal organs that have hitherto eluded in vivo diffusion-weighted imaging. This is employed here to follow processes related to embryonic implantation and placentation, including the final stages of mouse gastrulation, the development of white matter in fetal brains, the maturation of fetal spines, and the evolution of the different layers making up mouse hemochorial placentas. The protocol's ability to extract diffusivity information in challenging regions as a function of embryonic mouse development is thus demonstrated, and its usefulness as a tool for visualizing pregnancy-related developmental changes in rodents is discussed.
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Affiliation(s)
- Qingjia Bao
- Department of Chemical and Biological Physics, Weizmann Institute, Rehovot, Israel
| | - Gilad Liberman
- Department of Chemical and Biological Physics, Weizmann Institute, Rehovot, Israel
| | - Eddy Solomon
- Department of Chemical and Biological Physics, Weizmann Institute, Rehovot, Israel
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute, Rehovot, Israel
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Kamel R, Youssef A. How reliable is fetal occiput and spine position assessment prior to induction of labor? Ultrasound Obstet Gynecol 2019; 53:535-540. [PMID: 29947161 DOI: 10.1002/uog.19169] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 05/16/2018] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
OBJECTIVES To assess the reliability of fetal occiput and spine position determination in nulliparous women prior to induction of labor (IOL), and to evaluate identification of fetal occiput and spine positions prior to IOL in the prediction of labor outcome. METHODS A series of 136 nulliparous women were recruited prospectively, immediately after the decision to perform IOL was made. Transabdominal ultrasound was performed to determine fetal head and spine positions. After at least 1 h, and prior to IOL, fetal occiput and spine positions were reassessed. Fetal occiput and spine positions were then compared between women who underwent vaginal delivery and those who delivered by Cesarean section. RESULTS On the first and second assessments, respectively, fetal occiput position was anterior in 55 (40.4%) and 62 (45.6%) women, transverse in 52 (38.2%) and 49 (36.0%) women, and posterior in 29 (21.3%) and 25 (18.4%) women, while fetal spine position was anterior in 58 (42.6%) and 52 (38.2%) women, transverse in 42 (30.9%) and 50 (36.8%) women, and posterior in 36 (26.5%) and 34 (25.0%) women. Discordance between the first and second assessments of fetal occiput position was identified in 34 (25.0%) women, whereas discordance of fetal spine position was observed in 40 (29.4%) women. The incidence of fetal occiput posterior position in women undergoing Cesarean section was comparable to that in the vaginal-delivery group (19 (18.8%) vs 6 (17.1%); P = 0.826), which was similarly the case for fetal posterior spine position (27 (26.7%) vs 7 (20%); P = 0.428). Women with fetal occiput posterior position had a longer induction-to-delivery interval in comparison to those with non-occiput posterior fetal position (1786 ± 805 vs 1347 ± 784 min; P = 0.013). CONCLUSIONS Fetal occiput and spine positions are dynamic in a considerable proportion of women undergoing IOL, and their assessment does not seem to correlate with mode of delivery. Occiput and spine position assessment in women prior to IOL is unlikely to be clinically useful. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
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Affiliation(s)
- R Kamel
- Department of Obstetrics and Gynecology, Kasr Al-Ainy University Hospital, Cairo University, Cairo, Egypt
| | - A Youssef
- Department of Obstetrics and Gynecology, Sant'Orsola-Malpighi University Hospital, University of Bologna, Bologna, Italy
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Genest D, Puybareau E, Léonard M, Cousty J, De Crozé N, Talbot H. High throughput automated detection of axial malformations in Medaka embryo. Comput Biol Med 2019; 105:157-168. [PMID: 30654166 DOI: 10.1016/j.compbiomed.2018.12.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 12/18/2018] [Accepted: 12/29/2018] [Indexed: 11/18/2022]
Abstract
Fish embryo models are widely used as screening tools to assess the efficacy and/or toxicity of chemicals. This assessment involves the analysis of embryo morphological abnormalities. In this article, we propose a multi-scale pipeline to allow automated classification of fish embryos (Medaka: Oryzias latipes) based on the presence or absence of spine malformations. The proposed pipeline relies on the acquisition of fish embryo 2D images, on feature extraction based on mathematical morphology operators and on machine learning classification. After image acquisition, segmentation tools are used to detect the embryo before analysing several morphological features. An approach based on machine learning is then applied to these features to automatically classify embryos according to the presence of axial malformations. We built and validated our learning model on 1459 images with a 10-fold cross-validation by comparison with the gold standard of 3D observations performed under a microscope by a trained operator. Our pipeline results in correct classification in 85% of the cases included in the database. This percentage is similar to the percentage of success of a trained human operator working on 2D images. The key benefit of our approach is the low computational cost of our image analysis pipeline, which guarantees optimal throughput analysis.
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Affiliation(s)
- Diane Genest
- Université Paris-Est, LIGM (UMR 8049), CNRS, ENPC, ESIEE, UPEM, 2 Boulevard Blaise Pascal, 93162, Noisy-le Grand, France; L'OREAL Research & Innovation, 1 avenue Eugène Schueller, 93600, Aulnay sous Bois, France.
| | - Elodie Puybareau
- Université Paris-Est, LIGM (UMR 8049), CNRS, ENPC, ESIEE, UPEM, 2 Boulevard Blaise Pascal, 93162, Noisy-le Grand, France; EPITA Research and Development Laboratory (LRDE), 14-16 rue Voltaire, 94270, Le Kremlin-Bicêtre, France.
| | - Marc Léonard
- L'OREAL Research & Innovation, 1 avenue Eugène Schueller, 93600, Aulnay sous Bois, France
| | - Jean Cousty
- Université Paris-Est, LIGM (UMR 8049), CNRS, ENPC, ESIEE, UPEM, 2 Boulevard Blaise Pascal, 93162, Noisy-le Grand, France
| | - Noémie De Crozé
- L'OREAL Research & Innovation, 1 avenue Eugène Schueller, 93600, Aulnay sous Bois, France
| | - Hugues Talbot
- Université Paris-Est, LIGM (UMR 8049), CNRS, ENPC, ESIEE, UPEM, 2 Boulevard Blaise Pascal, 93162, Noisy-le Grand, France
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Blecher R, Heinemann-Yerushalmi L, Assaraf E, Konstantin N, Chapman JR, Cope TC, Bewick GS, Banks RW, Zelzer E. New functions for the proprioceptive system in skeletal biology. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170327. [PMID: 30249776 PMCID: PMC6158198 DOI: 10.1098/rstb.2017.0327] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2018] [Indexed: 01/13/2023] Open
Abstract
Muscle spindles and Golgi tendon organs (GTOs) are two types of sensory receptors that respond to changes in length or tension of skeletal muscles. These mechanosensors have long been known to participate in both proprioception and stretch reflex. Here, we present recent findings implicating these organs in maintenance of spine alignment as well as in realignment of fractured bones. These discoveries have been made in several mouse lines lacking functional mechanosensors in part or completely. In both studies, the absence of functional spindles and GTOs produced a more severe phenotype than that of spindles alone. Interestingly, the spinal curve phenotype, which appeared during peripubertal development, bears resemblance to the human condition adolescent idiopathic scoliosis. This similarity may contribute to the study of the disease by offering both an animal model and a clue as to its aetiology. Moreover, it raises the possibility that impaired proprioceptive signalling may be involved in the aetiology of other conditions. Overall, these new findings expand considerably the scope of involvement of proprioception in musculoskeletal development and function.This article is part of the Theo Murphy meeting issue 'Mechanics of development'.
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Affiliation(s)
- Ronen Blecher
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
- Department of Orthopedic Surgery, Assaf HaRofeh Medical Center, Zerrifin 70300, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- Swedish Neuroscience Institute, Seattle, WA 98122, USA
| | | | - Eran Assaraf
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
- Department of Orthopedic Surgery, Assaf HaRofeh Medical Center, Zerrifin 70300, Israel, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nitzan Konstantin
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | | | - Timothy C Cope
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA 30332, USA
| | - Guy S Bewick
- Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Robert W Banks
- Department of Biosciences, Durham University, Durham DH1 3LE, UK
| | - Elazar Zelzer
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
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Abstract
The availability of a collection of fetal and embryonic spines made possible a review of the involution of the notochord. Results of this histological, histochemical and immunohistochemical study are in accord with the dominant view in the literature that the notochord does not contribute materially to the adult nucleus pulposus. It is also consonant with the expectation that, normally, all chordal cells have disappeared during early childhood, but is not sufficiently detailed to assess the possibility of occasional survivors.
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Masturzo B, Farina A, Attamante L, Piazzese A, Rolfo A, Gaglioti P, Todros T. Sonographic evaluation of the fetal spine position and success rate of manual rotation of the fetus in occiput posterior position: A randomized controlled trial. J Clin Ultrasound 2017; 45:472-476. [PMID: 28369942 DOI: 10.1002/jcu.22477] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND To evaluate whether sonographic (US) diagnosis of the fetal spine position could increase the success rate of manual rotation of the fetal occiput (MRFO) in second-stage arrest in persistent occiput posterior position (OPP). METHODS In this randomized controlled parallel single-center trial, 58 nulliparous in second-stage arrest of labor with fetus in cephalic presentation and OPP diagnosed by US were randomly assigned to group A where the fetal spine position was not known by the operator or to group B where the operator knew it. The main outcome was the success of MRFO in the two groups. Secondary outcomes were perineal injuries, blood loss, duration of expulsive period, and neonatal APGAR at 5 minutes. RESULTS A priori knowledge of the spine position improves the success of the MRFO (41.4% group A versus 82.8% group B, p value < 0.001), the percentage of spontaneous deliveries (27.6% group A versus 69% group B, p value = 0.01), and maternal outcome (intact perineum and blood loss). No differences were detected on the neonatal side. CONCLUSIONS MRFO is a safe and useful procedure that should be performed in second-stage arrest in OPP. A better performance was observed when supported by the US knowledge of the spine position. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:472-476, 2017.
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Affiliation(s)
- Bianca Masturzo
- Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Via Ventimiglia 3, 10126, Turin, Italy
| | - Antonio Farina
- Department of Medicine and Surgery (DIMEC), Division of Prenatal Medicine, Sant'Orsola Malpighi Hospital; University of Bologna, Bologna, Italy
| | - Lorenza Attamante
- Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Via Ventimiglia 3, 10126, Turin, Italy
| | - Annalisa Piazzese
- Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Via Ventimiglia 3, 10126, Turin, Italy
| | - Alessandro Rolfo
- Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Via Ventimiglia 3, 10126, Turin, Italy
| | - Pietro Gaglioti
- Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Via Ventimiglia 3, 10126, Turin, Italy
| | - Tullia Todros
- Department of Surgical Sciences, Sant'Anna Hospital, University of Turin, Via Ventimiglia 3, 10126, Turin, Italy
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Wren TAL, Ponrartana S, Gilsanz V. Vertebral cross-sectional area: an orphan phenotype with potential implications for female spinal health. Osteoporos Int 2017; 28:1179-1189. [PMID: 27975301 DOI: 10.1007/s00198-016-3832-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 11/02/2016] [Indexed: 12/23/2022]
Abstract
A high priority in imaging-based research is the identification of the structural basis that confers greater risk for spinal disorders. New evidence indicates that factors related to sex influence the fetal development of the axial skeleton. Girls are born with smaller vertebral cross-sectional area compared to boys-a sexual dimorphism that is present throughout life and independent of body size. The smaller female vertebra is associated with greater flexibility of the spine that could represent the human adaptation to fetal load. It also likely contributes to the higher prevalence of spinal deformities, such as exaggerated lordosis and progressive scoliosis in adolescent girls when compared to boys, and to the greater susceptibility for spinal osteoporosis and vertebral fractures in elderly women than men.
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Affiliation(s)
- T A L Wren
- Department of Orthopaedic Surgery, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - S Ponrartana
- Department of Radiology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - V Gilsanz
- Department of Orthopaedic Surgery, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
- Department of Radiology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
- Department of Radiology, Children's Hospital Los Angeles, MS no. 81, 4650 Sunset Boulevard, Los Angeles, CA, 90027, USA.
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Miyamoto A, Wake H, Ishikawa AW, Eto K, Shibata K, Murakoshi H, Koizumi S, Moorhouse AJ, Yoshimura Y, Nabekura J. Microglia contact induces synapse formation in developing somatosensory cortex. Nat Commun 2016; 7:12540. [PMID: 27558646 PMCID: PMC5007295 DOI: 10.1038/ncomms12540] [Citation(s) in RCA: 416] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 07/12/2016] [Indexed: 01/17/2023] Open
Abstract
Microglia are the immune cells of the central nervous system that play important roles in brain pathologies. Microglia also help shape neuronal circuits during development, via phagocytosing weak synapses and regulating neurogenesis. Using in vivo multiphoton imaging of layer 2/3 pyramidal neurons in the developing somatosensory cortex, we demonstrate here that microglial contact with dendrites directly induces filopodia formation. This filopodia formation occurs only around postnatal day 8-10, a period of intense synaptogenesis and when microglia have an activated phenotype. Filopodia formation is preceded by contact-induced Ca(2+) transients and actin accumulation. Inhibition of microglia by genetic ablation decreases subsequent spine density, functional excitatory synapses and reduces the relative connectivity from layer 4 neurons. Our data provide the direct demonstration of microglial-induced spine formation and provide further insights into immune system regulation of neuronal circuit development, with potential implications for developmental disorders of immune and brain dysfunction.
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Affiliation(s)
- Akiko Miyamoto
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
| | - Hiroaki Wake
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 102-0076, Japan
| | - Ayako Wendy Ishikawa
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
- Division of Visual Information Processing, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Kei Eto
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
| | - Keisuke Shibata
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Pharmacology, Graduated School of Medical and Engineering, Yamanashi University, Chuo 409-3898, Japan
| | - Hideji Murakoshi
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama 102-0076, Japan
- Section of Multiphoton Neuroimaging, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Schuichi Koizumi
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Pharmacology, Graduated School of Medical and Engineering, Yamanashi University, Chuo 409-3898, Japan
| | - Andrew J. Moorhouse
- School of Medical Sciences, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Yumiko Yoshimura
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
- Division of Visual Information Processing, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan
- Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama 240-0193, Japan
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13
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Dall'Asta A, Paramasivam G, Lees CC. Crystal Vue technique for imaging fetal spine and ribs. Ultrasound Obstet Gynecol 2016; 47:383-384. [PMID: 26511656 DOI: 10.1002/uog.15800] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 10/23/2015] [Indexed: 06/05/2023]
Affiliation(s)
- A Dall'Asta
- Centre for Fetal Care, Imperial College Healthcare NHS Trust, London, UK
- Department of Obstetrics and Gynaecology, University of Parma, Parma, Italy
| | - G Paramasivam
- Centre for Fetal Care, Imperial College Healthcare NHS Trust, London, UK
| | - C C Lees
- Centre for Fetal Care, Imperial College Healthcare NHS Trust, London, UK
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, London, UK
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
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14
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Bae JY, Cha HH, Seong WJ. Fetal Spinal Deformity Caused by Uterine Synechiae Mimicking Severe Scoliosis: A Case Report. J Reprod Med 2016; 61:171-174. [PMID: 27172642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND A severely deformed vertebra is a matter of concern, particularly when it develops before 24 weeks of gestation, which may lead to compromised pulmonary function and neurological development. CASE A 39-year-old, nulliparous woman presented at 19 weeks of gestation. Her uterus was snowman shaped due to uterine synechiae, and the fetus was confined in the upper section, where amniotic fluid was scanty. The fetal spine was flexed at the upper thoracic level at an angle greater than 90°, with the head flexed and touching the right shoulder throughout pregnancy. Cesarean section was performed at 29+3 weeks of gestation due to preterm labor. A radiograph acquired immediately postpartum showed only a mild degree of spinal flexion, and during the course of hospitalization for respiratory support the infant's spine straightened completely. The infant was discharged without any complications. CONCLUSION Here, we report an unusual case of severe fetal spinal deformity observed in early fetal life, and the subsequent positive outcome. We therefore advise caution, following a careful evaluation and consultation, before arriving at a decision of termination.
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Basude S, McDermott L, Newell S, Wreyford B, Denbow M, Hutchinson J, Abdel-Fattah S. Fetal hemivertebra: associations and perinatal outcome. Ultrasound Obstet Gynecol 2015; 45:434-438. [PMID: 24789522 DOI: 10.1002/uog.13401] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/11/2014] [Accepted: 04/22/2014] [Indexed: 06/03/2023]
Abstract
OBJECTIVES To assess the accuracy of antenatal diagnosis of hemivertebra, to quantify the association with coexisting anomalies and to determine the perinatal outcome. METHOD This was a retrospective observational study of all cases of suspected fetal or neonatal hemivertebra identified via the UK Southwest Congenital Anomaly Register (SWCAR) between 2002 and 2012. RESULTS From a total of 88 cases of hemivertebra identified during the study period, data were obtained for 67 of them: 45 (10 isolated and 35 with coexisting anomalies) cases were suspected antenatally and 22 (10 isolated and 12 with coexisting anomalies) were diagnosed postnatally. Of the cases detected postnatally, five (four with coexisting anomalies) were unsuspected and diagnosed at postmortem examination. The most commonly associated anomalies included additional skeletal abnormalities (n = 16), genitourinary abnormalities (n = 10), VATER/VACTERL association (n = 5), cardiac abnormalities (n = 4) and central nervous system abnormalities (n = 4). In cases with coexisting anomalies there was a 48% fetal/neonatal loss, compared to 19% in cases with isolated hemivertebra. CONCLUSIONS Although antenatal diagnosis of hemivertebra was accurate, a third of the cases were diagnosed only postnatally. These data suggest a difficulty in antenatal diagnosis of the condition. The majority of cases of hemivertebra had coexisting anomalies, and in these cases the rate of perinatal loss was high. These data should be useful in providing additional information for counseling when a diagnosis of hemivertebra is made.
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Affiliation(s)
- S Basude
- Department of Obstetrics and Fetal Medicine, St Michael's Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
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16
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Rodríguez-Ibarra LE, Abdo-de la Parra MI, Aguilar-Zárate G, Valasco-Blanco G, Ibarra-Castro L. [Osteological development of the vertebral column and caudal complex of Lujanus guttatus (Perciformes: Lutjanidae) larvae under rearing conditions]. REV BIOL TROP 2015; 63:155-164. [PMID: 26299121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
The spotted rose snapper (Lutjanus guttatus) is an important commercial species in Mexico with good culture potential. The osteological study at early stages in this species is an important tool to confirm normal bone structure and for the detection of malformations that may occur during early development. This study was carried out in order to evaluate and describe the normal osteological development of the vertebral column and caudal complex of this species grown under controlled conditions. For this, a total of 540 larvae of L. guttatus, between 2.1 and 17.5 mm of total length (TL), were cultured during 36 days; culture conditions were 28 degrees C, 5.74 mg/L oxygen and 32.2 ups salinity with standard feeding rates. To detect growth changes, a sample of 15 organisms was daily taken from day one until day 36 of post-hatch (DPH). Samples were processed following standard techniques of clearing, and cartilage (alcian blue) and bone staining (alizarin red). Results showed that the vertebral column is composed of ten vertebrae in the abdominal region, and 14 vertebrae including the urostyle in the caudal region. The development of the axial skeleton starts with the neural arches and haemal arches at 3.8 mm TL. Caudal elements such as the hypurals and parahypural began to develop at 4.1 mm TL. Pre-flexion and flexion of the notochord and the formation of all hypurals were observed between 5.3 and 5.8 mm TL. Ossification of the vertebrae in the abdominal region and in some neural arches initiated at 9.5mm TL. In the caudal region, all the neural and haemal arches ossified at 10.2 mm TL. All the abdominal vertebrae and their respective neural arches and parapophyses ossified at 11.2 mm TL, while the elements of the caudal complex that ossified were the hypurals, parahypurals and modified haemal spines. All caudal fm rays, 12 neural spines and 3 haemal arches were ossified by 15.5 mm. The complete ossification process of this specie under laboratory culture conditions was observed when larvae reached 17.3 mm TL on 36 DPH. Detailed analysis of the osteological structures will allow a reference description to evaluate and detect malformations that may occur during the larval culture of the spotted rose snapper.
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17
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Doberentz E, Madea B, Müller AM. Coronal clefts in infants - rare differential diagnosis of traumatic injuries of vertebral bodies in battered children. Leg Med (Tokyo) 2014; 16:333-6. [PMID: 25082734 DOI: 10.1016/j.legalmed.2014.06.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 05/28/2014] [Accepted: 06/27/2014] [Indexed: 11/18/2022]
Abstract
Accidental and nonaccidental spinal injuries are generally rarely seen in infants. If affected, vertebral bodies usually present compression fractures due to forced hyperflexion or hypertension. Radiographic examination of the infantile skeleton can reveal a radiolucent band running through a vertebral body. These so called vertebral clefts are mainly visualized in the lateral spinal radiograph. Usually they can be found in the 1st year of life. Radiological appearance of coronal clefts was compared to that of a traumatic vertebral compression fracture. Clefts were mostly localized in the lumbar spine and had a completely different radiological appearance comparing to a traumatic compression fracture. As coronal clefts can be seen as a result from a retarded ossification of the vertebral bodies in fetal development they are a physiological variant. Due to this different etiology they have to be distinguished from spinal signs of child abuse.
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Affiliation(s)
- E Doberentz
- Institute of Legal Medicine, University of Bonn, Stiftsplatz 12, 53111 Bonn, Germany.
| | - B Madea
- Institute of Legal Medicine, University of Bonn, Stiftsplatz 12, 53111 Bonn, Germany
| | - A M Müller
- Department of Pediatric Pathology, University of Bonn, Sigmund-Freud-Str. 25, 53105 Bonn, Germany
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18
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Beck-Cormier S, Escande M, Souilhol C, Vandormael-Pournin S, Sourice S, Pilet P, Babinet C, Cohen-Tannoudji M. Notchless is required for axial skeleton formation in mice. PLoS One 2014; 9:e98507. [PMID: 24875805 PMCID: PMC4038589 DOI: 10.1371/journal.pone.0098507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 05/03/2014] [Indexed: 01/19/2023] Open
Abstract
Maintenance of cell survival is essential for proper embryonic development. In the mouse, Notchless homolog 1 (Drosophila) (Nle1) is instrumental for survival of cells of the inner cell mass upon implantation. Here, we analyze the function of Nle1 after implantation using the Meox2tm1(cre)Sor mouse that expresses the Cre recombinase specifically in the epiblast at E5.5. First, we find that NLE1 function is required in epiblast cells, as Nle1-deficient cells are rapidly eliminated. In this report, we also show that the Meox2Cre transgene is active in specific tissues during organogenesis. In particular, we detect high Cre expression in the vertebral column, ribs, limbs and tailbud. We took advantage of this dynamic expression profile to analyze the effects of inducing mosaic deletion of Nle1 in the embryo. We show that Nle1 deletion in this context, results in severe developmental anomalies leading to lethality at birth. Mutant embryos display multiple developmental defects in particular during axial skeletal formation. We also provide evidence that axial defects are due to an increase in apoptotic cell death in the somite at E9.5. These data demonstrate an essential role for Nle1 during organogenesis and in particular during axial development.
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Affiliation(s)
- Sarah Beck-Cormier
- Mouse Functional Genetics, Department of Developmental & Stem Cell Biology, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique, URA 2578, Institut Pasteur, Paris, France
- * E-mail:
| | - Marie Escande
- Mouse Functional Genetics, Department of Developmental & Stem Cell Biology, Institut Pasteur, Paris, France
| | - Céline Souilhol
- Mouse Functional Genetics, Department of Developmental & Stem Cell Biology, Institut Pasteur, Paris, France
| | - Sandrine Vandormael-Pournin
- Mouse Functional Genetics, Department of Developmental & Stem Cell Biology, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique, URA 2578, Institut Pasteur, Paris, France
| | - Sophie Sourice
- Institut National de la Santé et de la recherche Médicale, U791, LIOAD, STEP group “Skeletal Tissue Engineering and Physiopathology”, Nantes, France
| | - Paul Pilet
- Institut National de la Santé et de la recherche Médicale, U791, LIOAD, STEP group “Skeletal Tissue Engineering and Physiopathology”, Nantes, France
| | - Charles Babinet
- Mouse Functional Genetics, Department of Developmental & Stem Cell Biology, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique, URA 2578, Institut Pasteur, Paris, France
| | - Michel Cohen-Tannoudji
- Mouse Functional Genetics, Department of Developmental & Stem Cell Biology, Institut Pasteur, Paris, France
- Centre National de la Recherche Scientifique, URA 2578, Institut Pasteur, Paris, France
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19
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Takahashi Y, Yasuhiko Y, Takahashi J, Takada S, Johnson RL, Saga Y, Kanno J. Metameric pattern of intervertebral disc/vertebral body is generated independently of Mesp2/Ripply-mediated rostro-caudal patterning of somites in the mouse embryo. Dev Biol 2013; 380:172-84. [PMID: 23727513 DOI: 10.1016/j.ydbio.2013.05.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 02/03/2023]
Abstract
The vertebrae are derived from the sclerotome of somites. Formation of the vertebral body involves a process called resegmentation, by which the caudal half of a sclerotome is combined with the rostral half of the next sclerotome. To elucidate the relationship between resegmentation and rostro-caudal patterning of somite, we used the Uncx4.1-LacZ transgene to characterize the resegmentation process. Our observations suggested that in the thoracic and lumbar vertebrae, the Uncx4.1-expressing caudal sclerotome gave rise to the intervertebral disc (IVD) and rostral portion of the vertebral body (VB). In the cervical vertebrae, the Uncx4.1-expressing caudal sclerotome appeared to contribute to the IVD and both caudal and rostral ends of the VB. This finding suggests that the rostro-caudal gene expression boundary does not necessarily coincide with the resegmentation boundary. This conclusion was supported by analyses of Mesp2 KO and Ripply1/2 double KO embryos lacking rostral and caudal properties, respectively. Resegmentation was not observed in Mesp2 KO embryos, but both the IVD and whole VB were formed from the caudalized sclerotome. Expression analysis of IVD marker genes including Pax1 in the wild-type, Mesp2 KO, and Ripply1/2 DKO embryos also supported the idea that a metameric pattern of IVD/VB is generated independently of Mesp2/Ripply-mediated rostro-caudal patterning of somite. However, in the lumbar region, IVD differentiation appeared to be stimulated by the caudal property and suppressed by the rostral property. Therefore, we propose that rostro-caudal patterning of somites is not a prerequisite for metameric patterning of the IVD and VB, but instead required to stimulate IVD differentiation in the caudal half of the sclerotome.
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Affiliation(s)
- Yu Takahashi
- Cellular & Molecular Toxicology Division, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagayaku, Tokyo 158-8501, Japan.
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20
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Gizzo S, Saccardi C, Di Gangi S, Dalla Toffola A, D'Antona D, Nardelli GB, Saccardi C, Patrelli TS. Ultrasound investigation during labour of consensual or nonconsensual fetal spine in an occiput posterior cephalic presentation can improve the management of delivery? Ultrasound Med Biol 2013; 39:550-551. [PMID: 22975031 DOI: 10.1016/j.ultrasmedbio.2012.07.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 07/21/2012] [Indexed: 06/01/2023]
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21
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Lambi AG, Pankratz TL, Mundy C, Gannon M, Barbe MF, Richtsmeier JT, Popoff SN. The skeletal site-specific role of connective tissue growth factor in prenatal osteogenesis. Dev Dyn 2012; 241:1944-59. [PMID: 23073844 PMCID: PMC3752831 DOI: 10.1002/dvdy.23888] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2012] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Connective tissue growth factor (CTGF/CCN2) is a matricellular protein that is highly expressed during bone development. Mice with global CTGF ablation (knockout, KO) have multiple skeletal dysmorphisms and perinatal lethality. A quantitative analysis of the bone phenotype has not been conducted. RESULTS We demonstrated skeletal site-specific changes in growth plate organization, bone microarchitecture, and shape and gene expression levels in CTGF KO compared with wild-type mice. Growth plate malformations included reduced proliferation zone and increased hypertrophic zone lengths. Appendicular skeletal sites demonstrated decreased metaphyseal trabecular bone, while having increased mid-diaphyseal bone and osteogenic expression markers. Axial skeletal analysis showed decreased bone in caudal vertebral bodies, mandibles, and parietal bones in CTGF KO mice, with decreased expression of osteogenic markers. Analysis of skull phenotypes demonstrated global and regional differences in CTGF KO skull shape resulting from allometric (size-based) and nonallometric shape changes. Localized differences in skull morphology included increased skull width and decreased skull length. Dysregulation of the transforming growth factor-β-CTGF axis coupled with unique morphologic traits provides a potential mechanistic explanation for the skull phenotype. CONCLUSIONS We present novel data on a skeletal phenotype in CTGF KO mice, in which ablation of CTGF causes site-specific aberrations in bone formation.
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Affiliation(s)
- Alex G. Lambi
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Talia L. Pankratz
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Christina Mundy
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Maureen Gannon
- Department of Molecular Physiology and Biophysics, Division of Diabetes, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Mary F. Barbe
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Joan T. Richtsmeier
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Steven N. Popoff
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania
- Department of Orthopaedic Surgery, Temple University School of Medicine, Philadelphia, Pennsylvania
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22
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Bautista-Gómez E, Morales-García V, Galván Espinosa H, Flores-Romero AL, Vásquez Santiago E, Pizarro Osorno N. [Mayer-Rokitansky-Küster-Hauser syndrome. A report of two cases]. Ginecol Obstet Mex 2012; 80:663-667. [PMID: 23240231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The Mayer-Rokitansky-Kuster-Hauser is a rare congenital anomaly characterized by lack of vaginal and uterine development variable and normal ovaries. It results from agenesis or hypoplasia Müller duct system. Cervicovaginal agenesis as part of the complex syndrome, is even rarer. We report two cases: adolescent patient with primary amenorrhea, cervicovaginal agenesis and chronic pelvic pain, and a 28-year-old patient with primary amenorrhea, congenital absence of uterus and vagina.
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23
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Abstract
We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline.
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Affiliation(s)
- Biruntha Senthinathan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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24
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Tong XH, Liu QH, Xu SH, Ma DY, Xiao ZZ, Xiao YS, Li J. Skeletal development and abnormalities of the vertebral column and of the fins in hatchery-reared turbot Scophthalmus maximus. J Fish Biol 2012; 80:486-502. [PMID: 22380549 DOI: 10.1111/j.1095-8649.2011.03173.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
To describe the skeletal development and abnormalities in turbot Scophthalmus maximus, samples were collected every day from hatching to 60 days after hatching (DAH). A whole-mount cartilage and bone-staining technique was used. Vertebral ontogeny started with the formation of anterior haemal arches at 5·1 mm standard length (L(S) ) c. 11 DAH, and was completed by the full attainment of parapophyses at 16·9 mm L(S) c. 31 DAH. Vertebral centra started to develop at 6·3 mm L(S) c. 16 DAH and ossification in all centra was visible at 11·0 mm L(S) c. 25 DAH. The caudal fin appeared at 5·1 mm L(S) c. 11 DAH and ossification was visible at 20·6 mm L(S) c. 37 DAH. The onset of dorsal and anal fin elements appeared at 5·8 mm L(S) c. 15 DAH and 6·3 mm L(S) c. 16 DAH, respectively. Ossifications of both dorsal fin and anal fin were visible at 20·6 mm L(S) c. 37 DAH. The pectorals were the only fins present before first feeding, their ossifications were completed at 23·5 mm L(S) c. 48 DAH. Pelvic fins began forming at 7·2 mm L(S) c. 19 DAH and calcification of the whole structure was visible at 19·8 mm L(S) c. 36 DAH. In the present study, 24 types of skeletal abnormalities were observed. About 51% of individuals presented skeletal abnormalities, and the highest occurrence was found in the haemal region of the vertebral column. As for each developmental stage, the most common abnormalities were in the dorsal fin during early metamorphic period (stage 2), vertebral fusion during climax metamorphosis (stage 3) and caudal fin abnormality during both late-metamorphic period (stage 4) and post-metamorphic period (stage 5). Such research will be useful for early detection of skeletal malformations during different growth periods of reared S. maximus.
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Affiliation(s)
- X H Tong
- Center of Biotechnology R&D, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China
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25
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Patten SA, Jacobs-McDaniels NL, Zaouter C, Drapeau P, Albertson RC, Moldovan F. Role of Chd7 in zebrafish: a model for CHARGE syndrome. PLoS One 2012; 7:e31650. [PMID: 22363697 PMCID: PMC3282775 DOI: 10.1371/journal.pone.0031650] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 01/10/2012] [Indexed: 11/19/2022] Open
Abstract
CHARGE syndrome is caused by mutations in the CHD7 gene. Several organ systems including the retina, cranial nerves, inner ear and heart are affected in CHARGE syndrome. However, the mechanistic link between mutations in CHD7 and many of the organ systems dysfunction remains elusive. Here, we show that Chd7 is required for the organization of the neural retina in zebrafish. We observe an abnormal expression or a complete absence of molecular markers for the retinal ganglion cells and photoreceptors, indicating that Chd7 regulates the differentiation of retinal cells and plays an essential role in retinal cell development. In addition, zebrafish with reduced Chd7 display an abnormal organization and clustering of cranial motor neurons. We also note a pronounced reduction in the facial branchiomotor neurons and the vagal motor neurons display aberrant positioning. Further, these fish exhibit a severe loss of the facial nerves. Knock-down of Chd7 results in a curvature of the long body axis and these fish develop irregular shaped vertebrae and have a reduction in bone mineralization. Chd7 knockdown also results in a loss of proper segment polarity illustrated by flawed efnb2a and ttna expression, which is associated with later vascular segmentation defects. These critical roles for Chd7 in retinal and vertebral development were previously unrecognized and our results provide new insights into the role of Chd7 during development and in CHARGE syndrome pathogenesis.
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Affiliation(s)
- Shunmoogum A. Patten
- Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada
- Faculty of Dentistry, University of Montreal, Montreal, Quebec, Canada
| | | | | | - Pierre Drapeau
- Department of Pathology and Cell Biology, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
| | - R. Craig Albertson
- Department of Biology, Syracuse University, Syracuse, New York, USA
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Florina Moldovan
- Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada
- Faculty of Dentistry, University of Montreal, Montreal, Quebec, Canada
- * E-mail:
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Fadel RA, Sequeira RP, Abu-Hijleh MF, Obeidat M, Salem AHA. Effect of prenatal administration of therapeutic doses of topiramate on ossification of ribs and vertebrae in rat fetuses. Rom J Morphol Embryol 2012; 53:321-327. [PMID: 22732801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
There are few studies that have addressed the effects of prenatal exposure of topiramate on ossification of the bones derived from the paraxial mesoderm. This study aimed to evaluate skeletal ossification of ribs and vertebrae in 20-day-old rat fetuses after maternal exposure to two therapeutic doses of topiramate. Three groups of Sprague-Dawley pregnant rats were used: control, topiramate 50 mg/kg/day and topiramate 100 mg/kg/day treated groups. Topiramate was administered by gavage from day 6-19 of gestation. Fetuses were collected on day 20 by caesarean section. Fetal bones were stained with alizarin red and ossification was assessed. Results showed significant delayed ossification of ribs and vertebrae in topiramate-exposed fetuses at both doses and the effects were not dose dependent. In all examined groups, there was a direct correlation between the fetal weight and the number of complete ossified vertebral centers. Also, there were significant increases in skeletal abnormalities, particularly in ribs in both treated groups when compared to the control group. In conclusion, therapeutic doses of topiramate should be taken cautiously during pregnancy as they lead to fetal growth restriction and increases abnormalities of axial skeleton in rat fetuses.
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Affiliation(s)
- R A Fadel
- Department of Anatomy, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain.
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Egle D, Strobl I, Weiskopf-Schwendinger V, Grubinger E, Kraxner F, Mutz-Dehbalaie IS, Strasak A, Scheier M. Appearance of the fetal posterior fossa at 11 + 3 to 13 + 6 gestational weeks on transabdominal ultrasound examination. Ultrasound Obstet Gynecol 2011; 38:620-624. [PMID: 21308843 DOI: 10.1002/uog.8957] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/24/2011] [Indexed: 05/30/2023]
Abstract
OBJECTIVES To describe the sonographic appearance of the structures of the posterior cranial fossa in fetuses at 11 + 3 to 13 + 6 weeks of pregnancy and to determine whether abnormal findings of the brain and spine can be detected by sonography at this time. METHODS This was a prospective study including 692 fetuses whose mothers attended Innsbruck Medical University Hospital for first-trimester sonography. In 3% (n = 21) of cases, measurement was prevented by fetal position. Of the remaining 671 cases, in 604 there was either a normal anomaly scan at 20 weeks or delivery of a healthy child and in these cases the transcerebellar diameter (TCD) and the anteroposterior diameter of the cisterna magna (CM), measured at 11 + 3 to 13 + 6 weeks, were analyzed. In 502 fetuses, the anteroposterior diameter of the fourth ventricle (4V) was also measured. In 25 fetuses, intra- and interobserver repeatability was calculated. RESULTS We observed a linear correlation between crown-rump length (CRL) and CM (CM = 0.0536 × CRL - 1.4701; R2 = 0.688), TCD (TCD = 0.1482 × CRL - 1.2083; R2 = 0.701) and 4V (4V = 0.0181 × CRL + 0.9186; R2 = 0.118). In three patients with posterior fossa cysts, measurements significantly exceeded the reference values. One fetus with spina bifida had an obliterated CM and the posterior border of the 4V could not be visualized. CONCLUSIONS Transabdominal sonographic assessment of the posterior fossa is feasible in the first trimester. Measurements of the 4V, the CM and the TCD performed at this time are reliable. The established reference values assist in detecting fetal anomalies. However, findings must be interpreted carefully, as some supposed malformations might be merely delayed development of brain structures.
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Affiliation(s)
- D Egle
- Department of Gynaecology and Obstetrics, Innsbruck Medical University, Innsbruck, Austria
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Maruyama T. [Development of the skeletal system in utero]. Clin Calcium 2011; 21:1299-1305. [PMID: 21881191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The skeletal system develops from mesenchyme originated from the mesodermal germ layer and neural crest. In view of developmental bone biology, the skeletal system can be divided into four parts : skull, limbs, vertebrae/the ventral column, and ribs/sternum. Bone formation takes place in two ways. In most bones including axial (vertebral column and ribs) and appendicular (limbs) skeletons, a cartilage model first forms and is finally replaced with bone, which is called endochondral ossification. In contrast, most flat bones, such as the majority of bones of the skull, form directly from mesenchymal cells without the prior formation of cartilage ; this type of osteogenesis is called intramembranous ossification. I here discuss development of the skeletal system focusing on its time line in utero.
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Affiliation(s)
- Tetsuo Maruyama
- Department of Obstetrics and Gynecology, Keio University, Japan
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Abstract
One of the most striking features of the human vertebral column is its periodic organization along the anterior-posterior axis. This pattern is established when segments of vertebrates, called somites, bud off at a defined pace from the anterior tip of the embryo's presomitic mesoderm (PSM). To trigger this rhythmic production of somites, three major signaling pathways--Notch, Wnt/β-catenin, and fibroblast growth factor (FGF)--integrate into a molecular network that generates a traveling wave of gene expression along the embryonic axis, called the "segmentation clock." Recent systems approaches have begun identifying specific signaling circuits within the network that set the pace of the oscillations, synchronize gene expression cycles in neighboring cells, and contribute to the robustness and bilateral symmetry of somite formation. These findings establish a new model for vertebrate segmentation and provide a conceptual framework to explain human diseases of the spine, such as congenital scoliosis.
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Affiliation(s)
- Olivier Pourquié
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS (UMR 7104), Inserm U964, Université de Strasbourg, Illkirch F-67400, France
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Yap SP, Xing X, Kraus P, Sivakamasundari V, Chan HY, Lufkin T. Generation of mice with a novel conditional null allele of the Sox9 gene. Biotechnol Lett 2011; 33:1551-8. [PMID: 21484342 DOI: 10.1007/s10529-011-0608-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 03/29/2011] [Indexed: 11/26/2022]
Abstract
Sox9 is expressed in multiple tissues during mouse development and adulthood. Mutations in the Sox9 gene or changes in expression levels can be attributed to many congenital diseases. Heterozygous loss-of-function mutations in the human SOX9 gene cause Campomelic dysplasia, a semi-lethal skeletal malformation syndrome. Disruption of Sox9 by conventional gene targeting leads to perinatal lethality in heterozygous mice, hence hampering the feasibility to obtain the homozygous Sox9 null mice for in vivo functional studies. In this study, we generated a conditional allele of Sox9 (Sox9 ( tm4.Tlu )) by flanking exon 1 with loxP sites. Homozygous mice for the Sox9 ( tm4.Tlu ) allele (Sox9 ( flox/flox )) are viable, fertile and indistinguishable from wildtype (WT) mice, indicating that the Sox9 ( tm4.Tlu ) allele is a fully functional Sox9 allele. Furthermore, we demonstrated that Cre-mediated recombination using a Col2a1-Cre line resulted in specific ablation of Sox9 activity in cartilage tissues.
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Affiliation(s)
- Sook Peng Yap
- Stem Cell and Developmental Biology, Genome Institute of Singapore, 60 Biopolis Street, Singapore.
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Lee YJ, McPherron A, Choe S, Sakai Y, Chandraratna RA, Lee SJ, Oh SP. Growth differentiation factor 11 signaling controls retinoic acid activity for axial vertebral development. Dev Biol 2010; 347:195-203. [PMID: 20801112 DOI: 10.1016/j.ydbio.2010.08.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2010] [Revised: 08/20/2010] [Accepted: 08/20/2010] [Indexed: 11/17/2022]
Abstract
Mice deficient in growth differentiation factor 11 (GDF11) signaling display anterior transformation of axial vertebrae and truncation of caudal vertebrae. However, the in vivo molecular mechanisms by which GDF11 signaling regulates the development of the vertebral column have yet to be determined. We found that Gdf11 and Acvr2b mutants are sensitive to exogenous RA treatment on vertebral specification and caudal vertebral development. We show that diminished expression of Cyp26a1, a retinoic acid inactivating enzyme, and concomitant elevation of retinoic acid activity in the caudal region of Gdf11(-/-) embryos may account for this phenomenon. Reduced expression or function of Cyp26a1 enhanced anterior transformation of axial vertebrae in wild-type and Acvr2b mutants. Furthermore, a pan retinoic acid receptor antagonist (AGN193109) could lessen the anterior transformation phenotype and rescue the tail truncation phenotype of Gdf11(-/-) mice. Taken together, these results suggest that GDF11 signaling regulates development of caudal vertebrae and is involved in specification of axial vertebrae in part by maintaining Cyp26a1 expression, which represses retinoic acid activity in the caudal region of embryos during the somitogenesis stage.
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Affiliation(s)
- Young Jae Lee
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
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Cheng PJ, Huang SY, Shaw SW, Chueh HY, Soong YK. Evaluation of fetal spine biometry between 11 and 14 weeks of gestation. Ultrasound Med Biol 2010; 36:1060-1065. [PMID: 20620693 DOI: 10.1016/j.ultrasmedbio.2010.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 01/31/2010] [Accepted: 04/12/2010] [Indexed: 05/29/2023]
Abstract
This study was designed to establish a fetal spine nomogram for age 11 through 14 weeks of gestation and to document relations among fetal spine length, distance and angle. These parameters were prospectively measured during the first trimester of singleton pregnancies, along with nuchal translucency, over a 3-year period. A total of 430 fetuses were included in the study. The regression equations among fetal spine parameters and gestational age were as follows: Spine length (mm) = 1.116 x gestational age (days) - 59.169; spine distance (mm) = 1.079 x gestational age (days) - 59.038; head-spine angle = 0.740 x gestational age (days) + 4.735; spine length:spine distance ratio = -0.002 x gestational age (days) + 1.234. Prenatal age-specific reference intervals for fetal spine biometry between 11 and 14 weeks of gestation may assist in evaluation of fetuses investigated for genetic abnormalities that can be expressed by deviation in spine length, distance, or angle.
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Affiliation(s)
- Po-Jen Cheng
- Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Linkou Medical Center, Taoyuan, Taiwan.
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Blasi I, D'Amico R, Fenu V, Volpe A, Fuchs I, Henrich W, Mazza V. Sonographic assessment of fetal spine and head position during the first and second stages of labor for the diagnosis of persistent occiput posterior position: a pilot study. Ultrasound Obstet Gynecol 2010; 35:210-215. [PMID: 20101635 DOI: 10.1002/uog.7504] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVES The aim of this pilot study was to perform a preliminary investigation into the predictive values of the position of the fetal spine and of the occiput measured during the first and second stages of labor by intrapartum ultrasound for persistent occiput posterior (OP) position. METHODS This was a prospective, cohort study, in which 100 women with singleton pregnancies were enrolled during the first or second stage of labor. The women underwent intrapartum transabdominal sonography and the positions of the fetal head and spine were recorded. The women were followed up until delivery and occiput position at birth was assessed. RESULTS Eighty-four pregnancies were evaluated in the second stage of labor, with 74 of these also evaluated in the first stage. Fifty-one percent of fetuses were found to be in an OP position during the first stage of labor, but the majority of these rotated to an anterior position before delivery. There were six cases of OP at delivery, and all of these were among the 23 fetuses that were found to be in an OP position on ultrasound evaluation during the second stage of labor. All six were also found to have a posterior spine position during the second stage of labor, with this finding observed in only one fetus with occiput anterior position at delivery. CONCLUSIONS The results of this study suggest that the position of the head and spine during the second stage of labor could be useful indicators for predicting the OP position at delivery. The results also suggest that the OP position at delivery results from a failure of rotation from the OP position, rather than a malrotation from the anterior position. Studies with larger sample sizes are needed to confirm these results.
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Affiliation(s)
- I Blasi
- Prenatal Medicine Unit, Department of Obstetrics and Gynaecology, Modena and Reggio Emilia University, Modena, Italy.
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Purdie EL, Samsudin S, Eddy FB, Codd GA. Effects of the cyanobacterial neurotoxin beta-N-methylamino-L-alanine on the early-life stage development of zebrafish (Danio rerio). Aquat Toxicol 2009; 95:279-284. [PMID: 19297033 DOI: 10.1016/j.aquatox.2009.02.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 02/06/2009] [Accepted: 02/16/2009] [Indexed: 05/27/2023]
Abstract
beta-N-Methylamino-L-alanine (BMAA), a neurotoxic amino acid, is produced by members of all known groups of cyanobacteria. In the presence of added carbonate, BMAA generates an analogue of glutamate which has been associated with motor neuron (MN) diseases via a mechanism of motor neurone specific excitotoxicity. The toxicity of BMAA has been established in various mammalian test models, but the widespread aquatic production of BMAA raises questions of BMAA toxicity to aquatic organisms. Zebrafish (Danio rerio) embryos were exposed to varying concentrations of BMAA (5-50,000 microgl(-1)) with and without added carbonate. BMAA exposure induced a range of neuro-muscular and developmental abnormalities in D. rerio, which can be directly related to disruptions to glutamatergic signalling pathways. When exposed to BMAA plus added carbonate, the incidence of pericardial oedema increased by up to 21% in test subjects, correlating with a reduction in heart rate. Increased incidence of abnormal spinal axis formation was seen in all D. rerio larvae exposed to BMAA concentrations of >or=50microgl(-1), with a further 10% increase from >or=500 microgl(-1) BMAA when carbonate species were present. A dose-dependent increase in clonus-like convulsions was observable in embryos exposed to >or=5 microgl(-1) BMAA+/-added carbonate. This is the first study on the neuro-muscular and developmental effects of BMAA exposure on aquatic vertebrates. The present findings, plus the potentially widespread production of BMAA in aquatic cyanobacteria, indicate a need for information of exposure levels, duration and toxic outcomes in aquatic biota.
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Affiliation(s)
- E L Purdie
- Division of Molecular and Environmental Microbiology, College of Life Sciences, University of Dundee, Dundee, DD1 5LX, UK.
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35
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Abstract
The aetiology of the three-dimensional spinal deformity of idiopathic scoliosis (IS) is unknown. Progressive adolescent idiopathic scoliosis (AIS) that mainly affects girls is generally attributed to relative anterior spinal overgrowth from a mechanical mechanism (torsion) during the adolescent growth spurt. Established biological risk factors to AIS are growth velocity and potential residual spinal growth assessed by maturity indicators. Spine slenderness and ectomorphy in girls are thought to be risk factors for AIS. Claimed biomechanical susceptibilities are (1) a fixed lordotic area and hypokyphosis and (2) concave periapical rib overgrowth. MRI has revealed neuroanatomical abnormalities in approximately 20% of younger children with IS. A neuromuscular cause for AIS is probable but not established. Possible susceptibilities to AIS in tissues relate to muscles, ligaments, discs, skeletal proportions and asymmetries, the latter also affecting soft tissues (e.g. dermatoglyphics). AIS is generally considered to be multi-factorial in origin. The many anomalies detected, particularly left-right asymmetries, have led to spatiotemporal aetiologic concepts involving chronomics and the genome altered by nurture without the necessity for a disease process. Genetic susceptibilities defined in twins are being evaluated in family studies; polymorphisms in the oestrogen receptor gene are associated with curve severity. A neurodevelopmental concept is outlined for the aetiology of progressive AIS. This concept involves lipid peroxidation and, if substantiated, has initial therapeutic potential by dietary anti-oxidants. Growth saltations have not been evaluated in IS.
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Abstract
In recent years molecular genetics has revolutionized the study of somitogenesis in developmental biology and advances that have taken place in animal models have been applied successfully to human disease. Abnormal segmentation in man is a relatively common birth defect and advances in understanding have come through the study of cases clustered in families using DNA linkage analysis and candidate gene approaches, the latter stemming directly from knowledge gained through the study of animal models. Only a minority of abnormal segmentation phenotypes appear to follow Mendelian inheritance but three genes--DLL3, MESP2 and LNFG--have now been identified for spondylocostal dysostosis (SCD), a spinal malformation characterized by extensive hemivertebrae, trunkal shortening and abnormally aligned ribs with points of fusion. In affected families autosomal recessive inheritance is followed. These genes are all important components of the Notch signaling pathway. Other genes within the pathway cause diverse phenotypes such as Alagille syndrome (AGS) and CADASIL, conditions that may have their origin in defective vasculogenesis. This review deals mainly with SCD, with some consideration of AGS. Significant future challenges lie in identifying causes of the many abnormal segmentation phenotypes in man but it is hoped that combined approaches in collaboration with developmental biologists will reap rewards.
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Affiliation(s)
- Peter D Turnpenny
- Clinical Genetics Department, Royal Devon & Exeter Hospital, Gladstone Road, Exeter EX1 2ED, United Kingdom.
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Inohaya K, Takano Y, Kudo A. The teleost intervertebral region acts as a growth center of the centrum: in vivo visualization of osteoblasts and their progenitors in transgenic fish. Dev Dyn 2008; 236:3031-46. [PMID: 17907202 DOI: 10.1002/dvdy.21329] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The vertebral column is a defined feature of vertebrates. In birds and mammals, the sclerotome yields cartilaginous material for the vertebral column. In teleosts, however, it remains uncertain whether the sclerotome participates in vertebral column formation. To investigate osteoblast development in the teleost, we established transgenic systems that allow in vivo observation of osteoblasts and their progenitors marked by fluorescence of DsRed and enhanced green fluorescent protein (EGFP), respectively. In twist-EGFP transgenic medaka, EGFP-positive cells first appeared in the ventromedial portion of respective somites corresponding to the sclerotome, migrated dorsally around the notochord, and concentrated in the intervertebral regions. Ultrastructural analysis of the intervertebral regions revealed that some of these cells were directly located on the osteoidal surface of the perichordal centrum, and enriched with rough endoplasmic reticulum in their cytoplasm. By using the double transgenic medaka of twist-EGFP and osteocalcin-DsRed, we clarified that the EGFP-positive cells in the intervertebral region differentiated into mature osteoblasts expressing the DsRed. In vivo bone labeling in fact confirmed active matrix formation and mineralization of the perichordal centrum exclusively in the intervertebral region of zebrafish larvae as well as medaka larvae. These findings strongly suggest that the teleost intervertebral region acts as a growth center of the perichordal centrum, where the sclerotome-derived cells differentiate into osteoblasts.
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Affiliation(s)
- Keiji Inohaya
- Department of Biological Information, Tokyo Institute of Technology, Yokohama, Japan
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Abstract
Pediatric spinal deformity is a common manifestation of multiple disorders. The clinical picture varies depending on the age at presentation, the severity of the curve at the time of diagnosis, and the underlying cause. Knowledge of the natural history of these varied conditions, the dynamics of growth in the developing spine, and normal axial skeletal biomechanics are fundamental in planning an appropriate treatment. Furthermore, in many instances the spinal anomaly is just part of the problem in a globally affected patient. Treatment alternatives must be judged based on their capacity to positively alter the natural course of the disease and provide a long-standing solution into a patient's adulthood.
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Affiliation(s)
- Mauricio A Campos
- Department of Orthopaedics and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA
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Yeo GH, Cheah FSH, Jabs EW, Chong SS. Zebrafish twist1 is expressed in craniofacial, vertebral, and renal precursors. Dev Genes Evol 2007; 217:783-9. [PMID: 17929053 DOI: 10.1007/s00427-007-0187-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Accepted: 09/18/2007] [Indexed: 10/22/2022]
Abstract
TWIST1 encodes a transcription factor that contains a highly conserved basic helix-loop-helix DNA-binding domain and a WR motif. We have isolated a full-length complementary DNA of the zebrafish ortholog of TWIST1 and determined its genomic organization. Inter-species comparisons reveal a remarkable degree of conservation at the gene structure, nucleotide, and predicted peptide levels across large evolutionary distances. Using reverse-transcription polymerase chain reaction analysis and in situ hybridization analyses of whole mount and cryosectioned zebrafish embryos, we detected maternal twist1 transcript in the zygote. During somitogenesis, twist1 transcripts were detected in the intermediate mesoderm from the 2-somite to 18-somite stages, followed by expression in the somites from the 5-somite stage to the 24-somite stage. Also, beginning at the two-somite stage, twist1 expression was observed in head mesenchyme and, subsequently, in neural crest-derived pharyngeal arches as the embryo developed. At the 24-hpf stage, twist1 transcripts were also observed in the ventral tail-bud region. These observations are consistent with a role for twist1 in craniofacial, vertebral, and early renal development.
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Affiliation(s)
- Gare-Hoon Yeo
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, 5 Lower Kent Ridge Road, Singapore 119074, Singapore
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Abstract
The analysis of the development of the skeletal system has been greatly facilitated by the availability of a large number of mouse mutants with skeletal defects. Whereas for many of these mutants a description of the main phenotypic abnormalities is known, molecular insight into the ontogeny of the skeletal system is limited. One of the few skeletal mutants for which the molecular basis is known is undulated. These mice have a defect in the differentiation of the sclerotome and Pax-1, a mouse paired-box containing gene, has been identified as a candidate gene for this mutation. A molecular analysis of three independent undulated alleles revealed that in each case the Pax-1 gene is affected. One of the alleles could be classified as a null allele, in which the Pax-1 gene is deleted. A phenotypic analysis shows that Pax-1 is required for proper differentiation of intervertebral discs and vertebral bodies.
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Affiliation(s)
- R Balling
- Department of Molecular Biology, Max-Planck Institute of Biophysical Chemistry, Göttingen, Germany
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Turnpenny PD, Alman B, Cornier AS, Giampietro PF, Offiah A, Tassy O, Pourquié O, Kusumi K, Dunwoodie S. Abnormal vertebral segmentation and the notch signaling pathway in man. Dev Dyn 2007; 236:1456-74. [PMID: 17497699 DOI: 10.1002/dvdy.21182] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Abnormal vertebral segmentation (AVS) in man is a relatively common congenital malformation but cannot be subjected to the scientific analysis that is applied in animal models. Nevertheless, some spectacular advances in the cell biology and molecular genetics of somitogenesis in animal models have proved to be directly relevant to human disease. Some advances in our understanding have come through DNA linkage analysis in families demonstrating a clustering of AVS cases, as well as adopting a candidate gene approach. Only rarely do AVS phenotypes follow clear Mendelian inheritance, but three genes-DLL3, MESP2, and LNFG-have now been identified for spondylocostal dysostosis (SCD). SCD is characterized by extensive hemivertebrae, trunkal shortening, and abnormally aligned ribs with points of fusion. In familial cases clearly following a Mendelian pattern, autosomal recessive inheritance is more common than autosomal dominant and the genes identified are functional within the Notch signaling pathway. Other genes within the pathway cause diverse phenotypes such as Alagille syndrome (AGS) and CADASIL, conditions that may have their origin in defective vasculogenesis. Here, we deal mainly with SCD and AGS, and present a new classification system for AVS phenotypes, for which, hitherto, the terminology has been inconsistent and confusing.
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Affiliation(s)
- Peter D Turnpenny
- Clinical Genetics, Royal Devon & Exeter Hospital, and Peninsula Medical School, Exeter, United Kingdom.
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Saitsu H, Yamada S, Uwabe C, Ishibashi M, Shiota K. Aberrant differentiation of the axially condensed tail bud mesenchyme in human embryos with lumbosacral myeloschisis. Anat Rec (Hoboken) 2007; 290:251-8. [PMID: 17525941 DOI: 10.1002/ar.20426] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Development of the posterior neural tube (PNT) in human embryos is a complicated process that involves both primary and secondary neurulation. Recently, we histologically examined 20 human embryos around the stage of posterior neuropore closure and found that the axially condensed mesenchyme (AM) intervened between the neural plate/tube and the notochord in the junctional region of the primary and secondary neural tubes. The AM appeared to be incorporated into the most ventral part of the primary neural tube, and no cavity was observed in the AM. In this study, we report three cases of human embryos with myeloschisis in which the open primary neural tube and the closed secondary neural tube overlap dorsoventrally. In all three cases, part of the closed neural tube was located ventrally to the open neural tube in the lumbosacral region. The open and closed neural tubes appeared to be part of the primary and the AM-derived secondary neural tubes, respectively. Thus, these findings suggest that, in those embryos with myeloschisis, the AM may not be incorporated into the ventral part of the primary neural tube but aberrantly differentiate into the secondary neural tube containing cavities, leading to dorsoventral overlapping of the primary and secondary neural tubes. The aberrant differentiation of the AM in embryos with lumbosacral myeloschisis suggests that the AM plays some roles in normal as well as abnormal development of the human posterior neural tube.
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Affiliation(s)
- Hirotomo Saitsu
- Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
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Abstract
Vertebrae display distinct morphological features at different levels of the body axis. Links between collinear Hox gene activation and the progressive mode of body axis elongation have provided a fascinating blueprint of the mechanisms for establishing these morphological identities. In this review, we first discuss the regulation and possible role of collinear Hox gene activation during body formation and then highlight the direct role of Hox genes in controlling cellular movements during gastrulation, therefore contributing to body formation. Additional related research aspects, such as imaging of chromatin regulation, roles of micro RNAs and evolutional findings are also discussed.
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Affiliation(s)
- Tadahiro Iimura
- Howard Hughes Medical Institute, Kansas City, Missouri 64110, USA
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Cassart M, Massez A, Cos T, Tecco L, Thomas D, Van Regemorter N, Avni F. Contribution of three-dimensional computed tomography in the assessment of fetal skeletal dysplasia. Ultrasound Obstet Gynecol 2007; 29:537-43. [PMID: 17444568 DOI: 10.1002/uog.4001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
OBJECTIVE To compare the diagnostic accuracy of two-dimensional (2D) ultrasound and three-dimensional (3D) computed tomography (CT) for the diagnosis of fetal skeletal anomalies. METHODS Eleven pregnant women underwent 2D ultrasound and 3D-CT. Ten fetuses presented skeletal anomalies on 2D ultrasound and one fetus had a normal ultrasound exam but a familial history of osteopetrosis. We compared retrospectively the diagnoses established on 2D ultrasound and 3D-CT with the neonatal and/or postmortem work-up, which were used as the gold standard. RESULTS 2D ultrasound provided the correct diagnosis in only two of the 11 cases. CT yielded the correct diagnosis in eight; in six of these, 2D ultrasound had been inconclusive. 3D-CT was more accurate than was 2D ultrasound in visualizing vertebral anomalies (abnormal shape of the vertebral bodies, abnormal interpedicular distance), pelvic bone malformations (delayed ossification of the pubic bones, abnormal acetabular shape) and enlarged metaphysis or synostoses in long bones. In three cases, neither 2D ultrasound nor CT provided the correct diagnosis. CONCLUSION In this series, which included a variety of skeletal dysplasias, 3D-CT had a better diagnostic yield than did 2D ultrasound. Both imaging techniques are useful in the management of fetal dysplasia; 2D ultrasound is a useful screening test and 3D-CT is a valuable complementary diagnostic tool.
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Affiliation(s)
- M Cassart
- Department of Medical Imaging, Erasme University Clinics, and Department of Fetal Medicine, Brugmann Hospital, Brussels, Belgium.
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Abstract
OBJECTIVE To assess clinical and sonographic fetal head position before induction of labor, position at delivery, and whether occiput posterior (OP) position is associated with adverse delivery outcome. METHODS Abdominal palpation and ultrasonographic fetal head and spine position were determined at 36 weeks or more of gestation in 289 women immediately before induction of labor and the head position at delivery noted. Chi-square, Mann-Whitney U tests, and logistic regression were used to assess whether OP position was associated with cesarean delivery. RESULTS Ninety-seven (36%) of 270 women with full outcome data had an OP position on ultrasonography before induction of labor. Of these 97 women, eight (8%) were OP at delivery. Sixty-eight percent of the 25 OP positions at delivery occurred due to a mal-rotation from a non-OP position during labor. Logistic regression showed that OP position before induction of labor was not an independent predictor of cesarean delivery (odds ratio 1.75, 95% confidence interval 0.97-3.15, P=.06). CONCLUSION Two thirds of OP positions at delivery after induction of labor occur due to a mal-rotation in labor from a non-OP position. Ultrasonography is an easy method of assessing fetal head position before induction of labor. In clinical practice, its usefulness is limited by the fact that, contrary to conventional teaching, OP position before induction of labor does not appear to be associated with an increased risk of cesarean delivery. LEVEL OF EVIDENCE II.
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Affiliation(s)
- Elisabeth Peregrine
- Department of Obstetrics and Gynaecology, University College London Hospitals, London, United Kingdom.
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Song JJ, Aswad R, Kanaan RA, Rico MC, Owen TA, Barbe MF, Safadi FF, Popoff SN. Connective tissue growth factor (CTGF) acts as a downstream mediator of TGF-beta1 to induce mesenchymal cell condensation. J Cell Physiol 2007; 210:398-410. [PMID: 17111364 DOI: 10.1002/jcp.20850] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mesenchymal cell (MC) condensation or the aggregation of MCs precedes chondrocyte differentiation and is required for subsequent cartilage formation during endochondral ossification. In this study, we used micromass cultures of C3H10T1/2 cells as an in vitro model system for studying MC condensation and the events important for this process. Transforming growth factor beta1 (TGF-beta1) served as the initiator of MC condensation in our model system and we were interested in determining whether CTGF functions as a downstream mediator of TGF-beta1. CTGF is a matricellular protein that has been found to be expressed in MC condensations and in the perichondrium. Micromass cultures of C3H10T1/2 cells condensed under TGF-beta1 stimulation concomitant with dramatic up-regulation of CTGF mRNA and protein levels. CTGF silencing by either CTGF siRNA or CTGF antisense oligonucleotide approaches showed that TGF-beta1-induced condensation was CTGF dependent. Furthermore, silencing of CTGF expression resulted in significant reductions in cell proliferation and migration, events that are crucial during MC condensation. In addition, up-regulation of Fibronectin (FN) and suppression of Sox9 expression by TGF-beta1 was also found to be mediated by CTGF. Immunofluorescence of developing mouse vertebrae showed that CTGF, TGF-beta1 and FN were co-expressed in condensations of MCs, while Sox9 expression was low at this stage. During subsequent chondrogenesis, Sox9 expression was high in chondrocytes while CTGF expression was limited to the perichondrium. Thus, CTGF is an essential downstream mediator of TGF-beta1-induced MC condensation through its effects on cell proliferation and migration. CTGF is also involved in up-regulating FN and suppressing Sox9 expression during TGF-beta1 induced MC condensation.
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Affiliation(s)
- Jason J Song
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Affiliation(s)
- Kenro Kusumi
- School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, AZ 85287-4501, USA.
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Handrigan GR, Wassersug RJ. The anuran Bauplan: a review of the adaptive, developmental, and genetic underpinnings of frog and tadpole morphology. Biol Rev Camb Philos Soc 2007; 82:1-25. [PMID: 17313522 DOI: 10.1111/j.1469-185x.2006.00001.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Anurans (frogs, toads, and their larvae) are among the most morphologically derived of vertebrates. While tightly conserved across the order, the anuran Bauplan (body plan) diverges widely from that of other vertebrates, particularly with respect to the skeleton. Here we address the adaptive, ontogenetic, and genetic bases of three such hallmark anuran features: (1) the absence of discrete caudal vertebrae, (2) a truncated axial skeleton, and (3) elongate hind limbs. We review the functional significance of each as it relates to the anuran lifestyle, which includes locomotor adaptations to both aquatic and terrestrial environments. We then shift our focus to the proximal origins of each feature, namely, ontogeny and its molecular regulation. Drawing on relatively limited data, we detail the development of each character and then, by extrapolating from comparative vertebrate data, propose molecular bases for these processes. Cast in this light, the divergent morphology of anurans emerges as a product of evolutionary modulation of the generalised vertebrate developmental machinery. Specifically, we hypothesise that: (1) the formation of caudal vertebrae is precluded due to a failure of sclerotomes to form cartilaginous condensations, perhaps resulting from altered expression of a suite of genes, including Pax1, Pax9, Msx1, Uncx-4.1, Sonic hedgehog, and noggin; (2) anteriorised Hox gene expression in the paraxial mesoderm has led to a rostral shift of morphological boundaries of the vertebral column; and, (3) spatial and temporal shifts in Hox expression may underlie the expanded tarsal elements of the anuran hind limb. Technology is currently in place to investigate each of these scenarios in the African clawed frog Xenopus. Experimental corroboration will further our understanding of the molecular regulation of the anuran Bauplan and provide insight into the origin of vertebrate morphological diversity as well as the role of development in evolution.
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Affiliation(s)
- Gregory R Handrigan
- Department of Biology, Dalhousie University 1355 Oxford Street, Halifax, Nova Scotia, Canada B3H 4J1.
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Sonographic examination of the fetal central nervous system: guidelines for performing the 'basic examination' and the 'fetal neurosonogram'. Ultrasound Obstet Gynecol 2007; 29:109-16. [PMID: 17200992 DOI: 10.1002/uog.3909] [Citation(s) in RCA: 263] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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Sewell W, Kusumi K. Genetic analysis of molecular oscillators in mammalian somitogenesis: Clues for studies of human vertebral disorders. ACTA ACUST UNITED AC 2007; 81:111-20. [PMID: 17600783 DOI: 10.1002/bdrc.20091] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The repeating pattern of the human vertebral column is shaped early in development, by a process called somitogenesis. In this embryonic process, pairs of mesodermal segments called somites are serially laid down along the developing neural tube. Somitogenesis is an iterative process, repeating at regular time intervals until the last somite is formed. This process lays down the vertebrate body axis from head to tail, making for a progression of developmental steps along the rostral-caudal axis. In this review, the roles of the Notch, Wnt, fibroblast growth factor, retinoic acid and other pathways are described during the following key steps in somitogenesis: formation of the presomitic mesoderm (PSM) and establishment of molecular gradients; prepatterning of the PSM by molecular oscillators; patterning of rostral-caudal polarity within the somite; formation of somite borders; and maturation and resegmentation of somites to form musculoskeletal tissues. Disruption of somitogenesis can lead to severe vertebral birth defects such as spondylocostal dysostosis (SCD). Genetic studies in the mouse have been instrumental in finding mutations in this disorder, and ongoing mouse studies should provide functional insights and additional candidate genes to help in efforts to identify genes causing human spinal birth defects.
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Affiliation(s)
- William Sewell
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287-4501, USA
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