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Rekler D, Ofek S, Kagan S, Friedlander G, Kalcheim C. Retinoic acid, an essential component of the roof plate organizer, promotes the spatiotemporal segregation of dorsal neural fates. Development 2024; 151:dev202973. [PMID: 39250350 PMCID: PMC11463963 DOI: 10.1242/dev.202973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 08/26/2024] [Indexed: 09/11/2024]
Abstract
Dorsal neural tube-derived retinoic acid promotes the end of neural crest production and transition into a definitive roof plate. Here, we analyze how this impacts the segregation of central and peripheral lineages, a process essential for tissue patterning and function. Localized in ovo inhibition in quail embryos of retinoic acid activity followed by single-cell transcriptomics unraveled a comprehensive list of differentially expressed genes relevant to these processes. Importantly, progenitors co-expressed neural crest, roof plate and dI1 interneuron markers, indicating a failure in proper lineage segregation. Furthermore, separation between roof plate and dI1 interneurons is mediated by Notch activity downstream of retinoic acid, highlighting their crucial role in establishing the roof plate-dI1 boundary. Within the peripheral branch, where absence of retinoic acid resulted in neural crest production and emigration extending into the roof plate stage, sensory progenitors failed to separate from melanocytes, leading to formation of a common glia-melanocyte cell with aberrant migratory patterns. In summary, the implementation of single-cell RNA sequencing facilitated the discovery and characterization of a molecular mechanism responsible for the segregation of dorsal neural fates during development.
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Affiliation(s)
- Dina Rekler
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem 9112102, Israel
| | - Shai Ofek
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem 9112102, Israel
| | - Sarah Kagan
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem 9112102, Israel
| | - Gilgi Friedlander
- The Mantoux Bioinformatics Institute of the Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Chaya Kalcheim
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem 9112102, Israel
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2
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Bedois AMH, Parker HJ, Price AJ, Morrison JA, Bronner ME, Krumlauf R. Sea lamprey enlightens the origin of the coupling of retinoic acid signaling to vertebrate hindbrain segmentation. Nat Commun 2024; 15:1538. [PMID: 38378737 PMCID: PMC10879103 DOI: 10.1038/s41467-024-45911-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 02/06/2024] [Indexed: 02/22/2024] Open
Abstract
Retinoic acid (RA) is involved in antero-posterior patterning of the chordate body axis and, in jawed vertebrates, has been shown to play a major role at multiple levels of the gene regulatory network (GRN) regulating hindbrain segmentation. Knowing when and how RA became coupled to the core hindbrain GRN is important for understanding how ancient signaling pathways and patterning genes can evolve and generate diversity. Hence, we investigated the link between RA signaling and hindbrain segmentation in the sea lamprey Petromyzon marinus, an important jawless vertebrate model providing clues to decipher ancestral vertebrate features. Combining genomics, gene expression, and functional analyses of major components involved in RA synthesis (Aldh1as) and degradation (Cyp26s), we demonstrate that RA signaling is coupled to hindbrain segmentation in lamprey. Thus, the link between RA signaling and hindbrain segmentation is a pan vertebrate feature of the hindbrain and likely evolved at the base of vertebrates.
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Affiliation(s)
- Alice M H Bedois
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Hugo J Parker
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Andrew J Price
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Jason A Morrison
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Robb Krumlauf
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA.
- Department of Anatomy and Cell Biology, Kansas University Medical Center, Kansas City, MO, 66160, USA.
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3
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Bedois AMH, Parker HJ, Bronner ME, Krumlauf R. Sea lamprey enlightens the origin of the coupling of retinoic acid signaling to vertebrate hindbrain segmentation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.07.548143. [PMID: 37461675 PMCID: PMC10350081 DOI: 10.1101/2023.07.07.548143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Retinoic acid (RA) is involved in antero-posterior patterning of the chordate body axis and, in jawed vertebrates, has been shown to play a major role at multiple levels of the gene regulatory network (GRN) regulating hindbrain segmentation. Knowing when and how RA became coupled to the core hindbrain GRN is important for understanding how ancient signaling pathways and patterning genes can evolve and generate diversity. Hence, we investigated the link between RA signaling and hindbrain segmentation in the sea lamprey Petromyzon marinus, an important jawless vertebrate model providing clues to decipher ancestral vertebrate features. Combining genomics, gene expression, and functional analyses of major components involved in RA synthesis (Aldh1as) and degradation (Cyp26s), we demonstrate that RA signaling is coupled to hindbrain segmentation in lamprey. Thus, the link between RA signaling and hindbrain segmentation is a pan vertebrate feature of the hindbrain and likely evolved at the base of vertebrates.
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Affiliation(s)
- Alice M. H. Bedois
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Hugo J. Parker
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Marianne E. Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Robb Krumlauf
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
- Department of Anatomy and Cell Biology, Kansas University Medical Center, Kansas City, Kansas 66160, USA
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4
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Rekler D, Kalcheim C. Completion of neural crest cell production and emigration is regulated by retinoic-acid-dependent inhibition of BMP signaling. eLife 2022; 11:72723. [PMID: 35394423 PMCID: PMC8993216 DOI: 10.7554/elife.72723] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 03/02/2022] [Indexed: 12/21/2022] Open
Abstract
Production and emigration of neural crest cells is a transient process followed by the emergence of the definitive roof plate. The mechanisms regulating the end of neural crest ontogeny are poorly understood. Whereas early crest development is stimulated by mesoderm-derived retinoic acid, we report that the end of the neural crest period is regulated by retinoic acid synthesized in the dorsal neural tube. Inhibition of retinoic acid signaling in the neural tube prevents the normal upregulation of BMP inhibitors in the nascent roof plate and prolongs the period of BMP responsiveness which otherwise ceases close to roof plate establishment. Consequently, neural crest production and emigration are extended well into the roof plate stage. In turn, extending the activity of neural crest-specific genes inhibits the onset of retinoic acid synthesis in roof plate suggesting a mutual repressive interaction between neural crest and roof plate traits. Although several roof plate-specific genes are normally expressed in the absence of retinoic acid signaling, roof plate and crest markers are co-expressed in single cells and this domain also contains dorsal interneurons. Hence, the cellular and molecular architecture of the roof plate is compromised. Collectively, our results demonstrate that neural tube-derived retinoic acid, via inhibition of BMP signaling, is an essential factor responsible for the end of neural crest generation and the proper segregation of dorsal neural lineages. The division between the central nervous system – formed by the brain and spinal cord – and the peripheral nervous system – which consists of the neurons that sense and relay information to and from the body – takes place early during embryonic development. Initially, the nervous system consists of a tube of cells called the neural tube. From the top region of this tube, some cells change their shape, exit the tube and migrate to different places in the developing body. These cells are called the ‘neural crest’, and they form many different structures, including the peripheral nervous system. Neural crest cells keep leaving the neural tube for a period of time, but after that, the neural tube stops producing them. At this point, the region of the neural tube that had been producing neural crest cells becomes the ‘roof plate’ of the central nervous system, a structure that is essential for the development of specific groups of neurons in the brain and spinal cord. In bird embryos, a protein called bone morphogenetic protein (BMP) is essential for neural crest production because it triggers the migration of these cells away from the neural tube. Before the roof plate is formed, the activity of BMP is blocked by proteins known as BMP inhibitors, which stop more cells from leaving the neural tube. Around the time when neural crest formation stops, another molecule called retinoic acid begins to be synthesized in the top region of the neural tube. Rekler and Kalcheim asked whether retinoic acid is involved in the transition from neural crest to roof plate. To test this hypothesis, Rekler and Kalcheim blocked the activity of retinoic acid in the neural tube of quail embryos at the time when they should stop producing neural crest cells. This resulted in embryos in which the neural tube keeps producing neural crest cells after the roof plate has formed. In these embryos, individual cells in the resulting ‘roof plate’ produced both proteins that are normally only found in neural crest cells, and proteins typically exclusive to the roof plate. This suggests that, in the absence of retinoic acid activity, the segregation of neural crest identity from roof plate identity is compromised. Rekler and Kalcheim also found that, in the embryos where retinoic acid activity had been blocked, the cells in the area where the roof plate should be produced virtually no BMP inhibitors, and exhibited extended BMP activity. This allowed neural crest cells to continue forming and migrating away from the neural tube well after the period when they would stop in a normal embryo. These results indicate that retinoic acid stops the production of neural crest cells by repressing BMP activity in the roof plate of the neural tube. Rekler and Kalcheim’s experiments shed light on the mechanisms that allow the central and peripheral nervous systems to become segregated. This could increase our understanding of the origin of several neurodevelopmental disorders, potentially providing insights into their treatment or prevention. Additionally, the process of neural crest production and exit from the neural tube is highly similar to the process of metastasis in many invasive cancers. Thus, by understanding how the production of neural crest cells is terminated, it may be possible to learn how to prevent malignant cancer cells from spreading through the body.
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Affiliation(s)
- Dina Rekler
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
| | - Chaya Kalcheim
- Department of Medical Neurobiology, Institute of Medical Research Israel-Canada (IMRIC) and the Edmond and Lily Safra Center for Brain Sciences (ELSC), Hebrew University of Jerusalem-Hadassah Medical School, Jerusalem, Israel
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5
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Rankin SA, Steimle JD, Yang XH, Rydeen AB, Agarwal K, Chaturvedi P, Ikegami K, Herriges MJ, Moskowitz IP, Zorn AM. Tbx5 drives Aldh1a2 expression to regulate a RA-Hedgehog-Wnt gene regulatory network coordinating cardiopulmonary development. eLife 2021; 10:69288. [PMID: 34643182 PMCID: PMC8555986 DOI: 10.7554/elife.69288] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 09/23/2021] [Indexed: 12/14/2022] Open
Abstract
The gene regulatory networks that coordinate the development of the cardiac and pulmonary systems are essential for terrestrial life but poorly understood. The T-box transcription factor Tbx5 is critical for both pulmonary specification and heart development, but how these activities are mechanistically integrated remains unclear. Here using Xenopus and mouse embryos, we establish molecular links between Tbx5 and retinoic acid (RA) signaling in the mesoderm and between RA signaling and sonic hedgehog expression in the endoderm to unveil a conserved RA-Hedgehog-Wnt signaling cascade coordinating cardiopulmonary (CP) development. We demonstrate that Tbx5 directly maintains expression of aldh1a2, the RA-synthesizing enzyme, in the foregut lateral plate mesoderm via an evolutionarily conserved intronic enhancer. Tbx5 promotes posterior second heart field identity in a positive feedback loop with RA, antagonizing a Fgf8-Cyp regulatory module to restrict FGF activity to the anterior. We find that Tbx5/Aldh1a2-dependent RA signaling directly activates shh transcription in the adjacent foregut endoderm through a conserved MACS1 enhancer. Hedgehog signaling coordinates with Tbx5 in the mesoderm to activate expression of wnt2/2b, which induces pulmonary fate in the foregut endoderm. These results provide mechanistic insight into the interrelationship between heart and lung development informing CP evolution and birth defects.
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Affiliation(s)
- Scott A Rankin
- Center for Stem Cell and Organoid Medicine (CuSTOM), Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
| | - Jeffrey D Steimle
- Department of Pediatrics, University of Chicago, Chicago, United States.,Department of Pathology, University of Chicago, Chicago, United States.,Department of Human Genetics, University of Chicago, Chicago, United States
| | - Xinan H Yang
- Department of Pediatrics, University of Chicago, Chicago, United States.,Department of Pathology, University of Chicago, Chicago, United States.,Department of Human Genetics, University of Chicago, Chicago, United States
| | - Ariel B Rydeen
- Department of Pediatrics, University of Chicago, Chicago, United States.,Department of Pathology, University of Chicago, Chicago, United States.,Department of Human Genetics, University of Chicago, Chicago, United States
| | - Kunal Agarwal
- Center for Stem Cell and Organoid Medicine (CuSTOM), Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
| | - Praneet Chaturvedi
- Center for Stem Cell and Organoid Medicine (CuSTOM), Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, United States
| | - Kohta Ikegami
- Department of Pediatrics, University of Chicago, Chicago, United States
| | | | - Ivan P Moskowitz
- Department of Pediatrics, University of Chicago, Chicago, United States.,Department of Pathology, University of Chicago, Chicago, United States.,Department of Human Genetics, University of Chicago, Chicago, United States
| | - Aaron M Zorn
- Center for Stem Cell and Organoid Medicine (CuSTOM), Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, United States.,University of Cincinnati, College of Medicine, Department of Pediatrics, Chicago, United States
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6
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Estermann MA, Hirst CE, Major AT, Smith CA. The homeobox gene TGIF1 is required for chicken ovarian cortical development and generation of the juxtacortical medulla. Development 2021; 148:dev199646. [PMID: 34387307 PMCID: PMC8406534 DOI: 10.1242/dev.199646] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 07/13/2021] [Indexed: 12/12/2022]
Abstract
During early embryogenesis in amniotic vertebrates, the gonads differentiate into either ovaries or testes. The first cell lineage to differentiate gives rise to the supporting cells: Sertoli cells in males and pre-granulosa cells in females. These key cell types direct the differentiation of the other cell types in the gonad, including steroidogenic cells. The gonadal surface epithelium and the interstitial cell populations are less well studied, and little is known about their sexual differentiation programs. Here, we show the requirement of the homeobox transcription factor gene TGIF1 for ovarian development in the chicken embryo. TGIF1 is expressed in the two principal ovarian somatic cell populations: the cortex and the pre-granulosa cells of the medulla. TGIF1 expression is associated with an ovarian phenotype in estrogen-mediated sex reversal experiments. Targeted misexpression and gene knockdown indicate that TGIF1 is required, but not sufficient, for proper ovarian cortex formation. In addition, TGIF1 is identified as the first known regulator of juxtacortical medulla development. These findings provide new insights into chicken ovarian differentiation and development, specifically cortical and juxtacortical medulla formation.
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Affiliation(s)
| | | | | | - Craig Allen Smith
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton VIC 3800, Australia
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7
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Joshi P, Skromne I. A theoretical model of neural maturation in the developing chick spinal cord. PLoS One 2020; 15:e0244219. [PMID: 33338079 PMCID: PMC7748286 DOI: 10.1371/journal.pone.0244219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/04/2020] [Indexed: 11/21/2022] Open
Abstract
Cellular differentiation is a tightly regulated process under the control of intricate signaling and transcription factors interaction network working in coordination. These interactions make the systems dynamic, robust and stable but also difficult to dissect. In the spinal cord, recent work has shown that a network of FGF, WNT and Retinoic Acid (RA) signaling factors regulate neural maturation by directing the activity of a transcription factor network that contains CDX at its core. Here we have used partial and ordinary (Hill) differential equation based models to understand the spatiotemporal dynamics of the FGF/WNT/RA and the CDX/transcription factor networks, alone and in combination. We show that in both networks, the strength of interaction among network partners impacts the dynamics, behavior and output of the system. In the signaling network, interaction strength determine the position and size of discrete regions of cell differentiation and small changes in the strength of the interactions among networking partners can result in a signal overriding, balancing or oscillating with another signal. We also show that the spatiotemporal information generated by the signaling network can be conveyed to the CDX/transcription network to produces a transition zone that separates regions of high cell potency from regions of cell differentiation, in agreement with most in vivo observations. Importantly, one emerging property of the networks is their robustness to extrinsic disturbances, which allows the system to retain or canalize NP cells in developmental trajectories. This analysis provides a model for the interaction conditions underlying spinal cord cell maturation during embryonic axial elongation.
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Affiliation(s)
- Piyush Joshi
- Division of Pediatric Neuro-oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Isaac Skromne
- Department of Biology, University of Richmond, Richmond, Virginia, United States of America
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8
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Li Y, Gong H, Ding J, Zhao F, Du J, Wan J, Zhang J, Liu S, Li J, Wang L, Zhou B. Inhibition of GSK3 Represses the Expression of Retinoic Acid Synthetic Enzyme ALDH1A2 via Wnt/β-Catenin Signaling in WiT49 Cells. Front Cell Dev Biol 2020; 8:94. [PMID: 32258025 PMCID: PMC7092725 DOI: 10.3389/fcell.2020.00094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 02/04/2020] [Indexed: 02/02/2023] Open
Abstract
Organogenesis, including renal development, requires an appropriate retinoic acid concentration, which is established by differential expression of aldehyde dehydrogenase 1 family member A2 (ALDH1A2) and cytochrome P450 family 26 subfamily A/B/C member 1 (CYP26A1/B1/C1). In the fetal kidney, ALDH1A2 expresses in the developing stroma and renal vesicle and its derivatives but does not present in the ureteric bud. It remains unclear what may contribute to this expression pattern. Here we show that the glycogen synthase kinase 3 alpha/beta (GSK3A/B) inhibitor CHIR99021 significantly represses ALDH1A2 expression in WiT49, which is a Wilms’ tumor cell line that exhibits “triphasic” differential potential and is used as a fetal kidney cell model. CHIR99021 fails to suppress ALDH1A2 as β-catenin is inhibited, suggesting that the downregulation of ALDH1A2 by CHIR99021 is through Wnt/β-catenin signaling. Ectopic expression of mouse Wnt1, Wnt3a, Wnt4, and Wnt9b represses ALDH1A2 expression in WiT49 cells. Using immunohistochemistry, we show an inverse correlation of Aldh1a2 expression with β-catenin in rat E18.5 kidney. ChIP demonstrated that β-catenin is recruited to the ALDH1A2 promoter, the conserved intron1G, and another site within intron 1 of ALDH1A2. Using a luciferase assay, we further show that the ALDH1A2 promoter and the intron1G element are involved in the repression of ALDH1A2 expression by CHIR99021. Our work demonstrates that ALDH1A2 expression can be directly repressed by the Wnt/β-catenin signaling in fetal kidney cells, suggesting that Wnt/β-catenin may play a role in maintaining the expression pattern of ALDH1A2 in the fetal kidney, thus controlling the availability and localization of retinoic acid and regulating aspects of kidney development.
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Affiliation(s)
- Yifan Li
- Central Laboratory, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China.,Shenzhen Key Lab of Endogenous Infection, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Hui Gong
- Central Laboratory, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Jiangfeng Ding
- Department of Stomotology, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Fujuan Zhao
- Department of Pathology, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Jihui Du
- Central Laboratory, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Jun Wan
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China.,Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
| | - Juan Zhang
- Department of Pathology, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Shaoxiong Liu
- Department of Pathology, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Jing Li
- Department of Endocrinology, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Lei Wang
- Central Laboratory, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
| | - Bei Zhou
- Central Laboratory, Huazhong University of Science and Technology Union Shenzhen Hospital and the Affiliated Shenzhen Sixth Hospital of Guangdong Medical University, Shenzhen, China
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9
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Leung B, Shimeld SM. Evolution of vertebrate spinal cord patterning. Dev Dyn 2019; 248:1028-1043. [PMID: 31291046 DOI: 10.1002/dvdy.77] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/14/2019] [Accepted: 06/15/2019] [Indexed: 12/17/2022] Open
Abstract
The vertebrate spinal cord is organized across three developmental axes, anterior-posterior (AP), dorsal-ventral (DV), and medial-lateral (ML). Patterning of these axes is regulated by canonical intercellular signaling pathways: the AP axis by Wnt, fibroblast growth factor, and retinoic acid (RA), the DV axis by Hedgehog, Tgfβ, and Wnt, and the ML axis where proliferation is controlled by Notch. Developmental time plays an important role in which signal does what and when. Patterning across the three axes is not independent, but linked by interactions between signaling pathway components and their transcriptional targets. Combined this builds a sophisticated organ with many different types of cell in specific AP, DV, and ML positions. Two living lineages share phylum Chordata with vertebrates, amphioxus, and tunicates, while the jawless fish such as lampreys, survive as the most basally divergent vertebrate lineage. Genes and mechanisms shared between lampreys and other vertebrates tell us what predated vertebrates, while those also shared with other chordates tell us what evolved early in chordate evolution. Between these lie vertebrate innovations: genetic and developmental changes linked to evolution of new morphology. These include gene duplications, differences in how signals are received, and new regulatory connections between signaling pathways and their target genes.
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Affiliation(s)
- Brigid Leung
- Department of Zoology, University of Oxford, Oxford, UK
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10
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Link between the causative genes of holoprosencephaly: Zic2 directly regulates Tgif1 expression. Sci Rep 2018; 8:2140. [PMID: 29391420 PMCID: PMC5794963 DOI: 10.1038/s41598-018-20242-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 01/15/2018] [Indexed: 02/07/2023] Open
Abstract
One of the causal genes for holoprosencephaly (HPE) is ZIC2 (HPE5). It belongs to the zinc finger protein of the cerebellum (Zic) family of genes that share a C2H2-type zinc finger domain, similar to the GLI family of genes. In order to clarify the role of Zic2 in gene regulation, we searched for its direct target genes using chromatin immunoprecipitation (ChIP). We identified TGIF1 (HPE4), another holoprosencephaly-causative gene in humans. We identified Zic2-binding sites (ZBS) on the 5′ flanking region of Tgif1 by in vitro DNA binding assays. ZBS were essential for Zic2-dependent transcriptional activation in reporter gene assays. Zic2 showed a higher affinity to ZBS than GLI-binding sequences. Zic2-binding to the cis-regulatory element near the Tgif1 promoter may be involved in the mechanism underlying forebrain development and incidences of HPE.
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11
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New Insights Into the Roles of Retinoic Acid Signaling in Nervous System Development and the Establishment of Neurotransmitter Systems. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 330:1-84. [PMID: 28215529 DOI: 10.1016/bs.ircmb.2016.09.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Secreted chiefly from the underlying mesoderm, the morphogen retinoic acid (RA) is well known to contribute to the specification, patterning, and differentiation of neural progenitors in the developing vertebrate nervous system. Furthermore, RA influences the subtype identity and neurotransmitter phenotype of subsets of maturing neurons, although relatively little is known about how these functions are mediated. This review provides a comprehensive overview of the roles played by RA signaling during the formation of the central and peripheral nervous systems of vertebrates and highlights its effects on the differentiation of several neurotransmitter systems. In addition, the evolutionary history of the RA signaling system is discussed, revealing both conserved properties and alternate modes of RA action. It is proposed that comparative approaches should be employed systematically to expand our knowledge of the context-dependent cellular mechanisms controlled by the multifunctional signaling molecule RA.
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12
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Developmental Mechanism of Limb Field Specification along the Anterior-Posterior Axis during Vertebrate Evolution. J Dev Biol 2016; 4:jdb4020018. [PMID: 29615584 PMCID: PMC5831784 DOI: 10.3390/jdb4020018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/16/2016] [Accepted: 05/17/2016] [Indexed: 12/19/2022] Open
Abstract
In gnathostomes, limb buds arise from the lateral plate mesoderm at discrete positions along the body axis. Specification of these limb-forming fields can be subdivided into several steps. The lateral plate mesoderm is regionalized into the anterior lateral plate mesoderm (ALPM; cardiac mesoderm) and the posterior lateral plate mesoderm (PLPM). Subsequently, Hox genes appear in a nested fashion in the PLPM and provide positional information along the body axis. The lateral plate mesoderm then splits into the somatic and splanchnic layers. In the somatic layer of the PLPM, the expression of limb initiation genes appears in the limb-forming region, leading to limb bud initiation. Furthermore, past and current work in limbless amphioxus and lampreys suggests that evolutionary changes in developmental programs occurred during the acquisition of paired fins during vertebrate evolution. This review presents these recent advances and discusses the mechanisms of limb field specification during development and evolution, with a focus on the role of Hox genes in this process.
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13
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Nim HT, Furtado MB, Costa MW, Rosenthal NA, Kitano H, Boyd SE. VISIONET: intuitive visualisation of overlapping transcription factor networks, with applications in cardiogenic gene discovery. BMC Bioinformatics 2015; 16:141. [PMID: 25929466 PMCID: PMC4426166 DOI: 10.1186/s12859-015-0578-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/20/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Existing de novo software platforms have largely overlooked a valuable resource, the expertise of the intended biologist users. Typical data representations such as long gene lists, or highly dense and overlapping transcription factor networks often hinder biologists from relating these results to their expertise. RESULTS VISIONET, a streamlined visualisation tool built from experimental needs, enables biologists to transform large and dense overlapping transcription factor networks into sparse human-readable graphs via numerically filtering. The VISIONET interface allows users without a computing background to interactively explore and filter their data, and empowers them to apply their specialist knowledge on far more complex and substantial data sets than is currently possible. Applying VISIONET to the Tbx20-Gata4 transcription factor network led to the discovery and validation of Aldh1a2, an essential developmental gene associated with various important cardiac disorders, as a healthy adult cardiac fibroblast gene co-regulated by cardiogenic transcription factors Gata4 and Tbx20. CONCLUSIONS We demonstrate with experimental validations the utility of VISIONET for expertise-driven gene discovery that opens new experimental directions that would not otherwise have been identified.
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Affiliation(s)
- Hieu T Nim
- Systems Biology Institute (SBI) Australia, Monash University, Clayton, VIC, 3800, Australia.
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia.
| | - Milena B Furtado
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia.
| | - Mauro W Costa
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia.
| | - Nadia A Rosenthal
- Systems Biology Institute (SBI) Australia, Monash University, Clayton, VIC, 3800, Australia.
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia.
- National Heart and Lung Institute, Imperial College London, London, W12 0NN, UK.
| | - Hiroaki Kitano
- Systems Biology Institute (SBI) Australia, Monash University, Clayton, VIC, 3800, Australia.
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia.
- Sony Computer Science Laboratories, Inc., Higashigotanda, Shinagawa, Tokyo, Japan.
- Okinawa Institute of Science and Technology, Onna, Onna-son, Kunigami, Okinawa, Japan.
| | - Sarah E Boyd
- Systems Biology Institute (SBI) Australia, Monash University, Clayton, VIC, 3800, Australia.
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia.
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Signaling through retinoic acid receptors in cardiac development: Doing the right things at the right times. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:94-111. [PMID: 25134739 DOI: 10.1016/j.bbagrm.2014.08.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/19/2014] [Accepted: 08/04/2014] [Indexed: 11/23/2022]
Abstract
Retinoic acid (RA) is a terpenoid that is synthesized from vitamin A/retinol (ROL) and binds to the nuclear receptors retinoic acid receptor (RAR)/retinoid X receptor (RXR) to control multiple developmental processes in vertebrates. The available clinical and experimental data provide uncontested evidence for the pleiotropic roles of RA signaling in development of multiple embryonic structures and organs such eyes, central nervous system, gonads, lungs and heart. The development of any of these above-mentioned embryonic organ systems can be effectively utilized to showcase the many strategies utilized by RA signaling. However, it is very likely that the strategies employed to transfer RA signals during cardiac development comprise the majority of the relevant and sophisticated ways through which retinoid signals can be conveyed in a complex biological system. Here, we provide the reader with arguments indicating that RA signaling is exquisitely regulated according to specific phases of cardiac development and that RA signaling itself is one of the major regulators of the timing of cardiac morphogenesis and differentiation. We will focus on the role of signaling by RA receptors (RARs) in early phases of heart development. This article is part of a Special Issue entitled: Nuclear receptors in animal development.
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Lara-Ramírez R, Zieger E, Schubert M. Retinoic acid signaling in spinal cord development. Int J Biochem Cell Biol 2013; 45:1302-13. [PMID: 23579094 DOI: 10.1016/j.biocel.2013.04.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Revised: 03/25/2013] [Accepted: 04/02/2013] [Indexed: 12/13/2022]
Abstract
Retinoic acid (RA) is an important signaling molecule mediating intercellular communication through vertebrate development. Here, we present and discuss recent information on the roles of the RA signaling pathway in spinal cord development. RA is an important player in the patterning and definition of the spinal cord territory from very early stages of development, even before the appearance of the neural plate and further serves a role in the patterning of the spinal cord both along the dorsoventral and anteroposterior axes, particularly in the promotion of neuronal differentiation. It is thus required to establish a variety of neuronal cell types at specific positions of the spinal cord. The main goal of this review is to gather information from vertebrate models, including fish, frogs, chicken and mice, and to put this information in a comparative context in an effort to visualize how the RA pathway was incorporated into the evolving vertebrate spinal cord and to identify mechanisms that are both common and different in the various vertebrate models. In doing so, we try to reconstruct how spinal cord development has been regulated by the RA signaling cascade through vertebrate diversification, highlighting areas which require further studies to obtain a better understanding of the evolutionary events that shaped this structure in the vertebrate lineage.
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Affiliation(s)
- Ricardo Lara-Ramírez
- Laboratoire de Biologie du Développement de Villefranche-sur-Mer, UMR 7009 - CNRS/UPMC, EvoInSiDe Team, Observatoire Océanologique, 181 Chemin du Lazaret, BP 28, 06230 Villefranche-sur-Mer, France
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16
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Tanaka M. Molecular and evolutionary basis of limb field specification and limb initiation. Dev Growth Differ 2012; 55:149-63. [PMID: 23216351 DOI: 10.1111/dgd.12017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/20/2012] [Accepted: 10/09/2012] [Indexed: 11/30/2022]
Abstract
Specification of limb field and initiation of limb development involve multiple steps, each of which is tightly regulated both spatially and temporally. Recent developmental analyses on various vertebrates have provided insights into the molecular mechanisms that specify limb field and have revealed several genetic interactions of signals involved in limb initiation processes. Furthermore, new approaches to the study of the developmental mechanisms of the lateral plate mesoderm of amphioxus and lamprey embryos have given us clues to understand the evolutionary scenarios that led to the acquisition of paired appendages during evolution. This review highlights such recent findings and discusses the mechanisms of limb field specification and limb bud initiation during development and evolution.
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Affiliation(s)
- Mikiko Tanaka
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan.
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17
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Tanaka M, Onimaru K. Acquisition of the paired fins: a view from the sequential evolution of the lateral plate mesoderm. Evol Dev 2012; 14:412-20. [DOI: 10.1111/j.1525-142x.2012.00561.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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18
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Pittlik S, Begemann G. New sources of retinoic acid synthesis revealed by live imaging of an Aldh1a2-GFP reporter fusion protein throughout zebrafish development. Dev Dyn 2012; 241:1205-16. [DOI: 10.1002/dvdy.23805] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2012] [Indexed: 11/12/2022] Open
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Paschaki M, Lin SC, Wong RLY, Finnell RH, Dollé P, Niederreither K. Retinoic acid-dependent signaling pathways and lineage events in the developing mouse spinal cord. PLoS One 2012; 7:e32447. [PMID: 22396766 PMCID: PMC3292566 DOI: 10.1371/journal.pone.0032447] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 01/26/2012] [Indexed: 11/19/2022] Open
Abstract
Studies in avian models have demonstrated an involvement of retinoid signaling in early neural tube patterning. The roles of this signaling pathway at later stages of spinal cord development are only partly characterized. Here we use Raldh2-null mouse mutants rescued from early embryonic lethality to study the consequences of lack of endogenous retinoic acid (RA) in the differentiating spinal cord. Mid-gestation RA deficiency produces prominent structural and molecular deficiencies in dorsal regions of the spinal cord. While targets of Wnt signaling in the dorsal neuronal lineage are unaltered, reductions in Fibroblast Growth Factor (FGF) and Notch signaling are clearly observed. We further provide evidence that endogenous RA is capable of driving stem cell differentiation. Raldh2 deficiency results in a decreased number of spinal cord derived neurospheres, which exhibit a reduced differentiation potential. Raldh2-null neurospheres have a decreased number of cells expressing the neuronal marker β-III-tubulin, while the nestin-positive cell population is increased. Hence, in vivo retinoid deficiency impaired neural stem cell growth. We propose that RA has separable functions in the developing spinal cord to (i) maintain high levels of FGF and Notch signaling and (ii) drive stem cell differentiation, thus restricting both the numbers and the pluripotent character of neural stem cells.
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Affiliation(s)
- Marie Paschaki
- Development and Stem Cells Department, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique (UMR 7104), Institut National de la Santé et de la Recherche Médicale (U 964), Université de Strasbourg, Illkirch-Strasbourg, France
| | - Song-Chang Lin
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Rebecca Lee Yean Wong
- Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, The Texas A&M University System Health Science Center, Houston, Texas, United States of America
| | - Richard H. Finnell
- Department of Nutritional Sciences, Dell Pediatric Research Institute, University of Texas, Austin, Texas, United States of America
| | - Pascal Dollé
- Development and Stem Cells Department, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique (UMR 7104), Institut National de la Santé et de la Recherche Médicale (U 964), Université de Strasbourg, Illkirch-Strasbourg, France
| | - Karen Niederreither
- Department of Nutritional Sciences, Dell Pediatric Research Institute, University of Texas, Austin, Texas, United States of America
- * E-mail:
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Archbold HC, Yang YX, Chen L, Cadigan KM. How do they do Wnt they do?: regulation of transcription by the Wnt/β-catenin pathway. Acta Physiol (Oxf) 2012; 204:74-109. [PMID: 21624092 DOI: 10.1111/j.1748-1716.2011.02293.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Wnt/β-catenin signalling is known to play many roles in metazoan development and tissue homeostasis. Misregulation of the pathway has also been linked to many human diseases. In this review, specific aspects of the pathway's involvement in these processes are discussed, with an emphasis on how Wnt/β-catenin signalling regulates gene expression in a cell and temporally specific manner. The T-cell factor (TCF) family of transcription factors, which mediate a large portion of Wnt/β-catenin signalling, will be discussed in detail. Invertebrates contain a single TCF gene that contains two DNA-binding domains, the high mobility group (HMG) domain and the C-clamp, which increases the specificity of DNA binding. In vertebrates, the situation is more complex, with four TCF genes producing many isoforms that contain the HMG domain, but only some of which possess a C-clamp. Vertebrate TCFs have been reported to act in concert with many other transcription factors, which may explain how they obtain sufficient specificity for specific DNA sequences, as well as how they achieve a wide diversity of transcriptional outputs in different cells.
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Affiliation(s)
- H C Archbold
- Program in Cell and Molecular Biology, University of Michigan, Ann Arbor, 48109-1048, USA
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Onimaru K, Shoguchi E, Kuratani S, Tanaka M. Development and evolution of the lateral plate mesoderm: comparative analysis of amphioxus and lamprey with implications for the acquisition of paired fins. Dev Biol 2011; 359:124-136. [PMID: 21864524 DOI: 10.1016/j.ydbio.2011.08.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 08/05/2011] [Accepted: 08/05/2011] [Indexed: 12/28/2022]
Abstract
Possession of paired appendages is regarded as a novelty that defines crown gnathostomes and allows sophisticated behavioral and locomotive patterns. During embryonic development, initiation of limb buds in the lateral plate mesoderm involves several steps. First, the lateral plate mesoderm is regionalized into the cardiac mesoderm (CM) and the posterior lateral plate mesoderm (PLPM). Second, in the PLPM, Hox genes are expressed in a collinear manner to establish positional values along the anterior-posterior axis. The developing PLPM splits into somatic and splanchnic layers. In the presumptive limb field of the somatic layer, expression of limb initiation genes appears. To gain insight into the evolutionary sequence leading to the emergence of paired appendages in ancestral vertebrates, we examined the embryonic development of the ventral mesoderm in the cephalochordate amphioxus Branchiostoma floridae and of the lateral plate mesoderm in the agnathan lamprey Lethenteron japonicum, and studied the expression patterns of cognates of genes known to be expressed in these mesodermal layers during amniote development. We observed that, although the amphioxus ventral mesoderm posterior to the pharynx was not regionalized into CM and posterior ventral mesoderm, the lateral plate mesoderm of lampreys was regionalized into CM and PLPM, as in gnathostomes. We also found nested expression of two Hox genes (LjHox5i and LjHox6w) in the PLPM of lamprey embryos. However, histological examination showed that the PLPM of lampreys was not separated into somatic and splanchnic layers. These findings provide insight into the sequential evolutionary changes that occurred in the ancestral lateral plate mesoderm leading to the emergence of paired appendages.
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Affiliation(s)
- Koh Onimaru
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, B-17, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Promotion Corporation, 1919-1 Tancha, Onna, Okinawa 904-0412, Japan.
| | - Shigeru Kuratani
- Laboratory for Evolutionary Morphology, Center for Developmental Biology, Riken, 2-2-3 Minatojima minamimachi, Chuo-ku, Kobe 650-0047, Japan.
| | - Mikiko Tanaka
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, B-17, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
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Linney E, Donerly S, Mackey L, Dobbs-McAuliffe B. The negative side of retinoic acid receptors. Neurotoxicol Teratol 2011; 33:631-40. [PMID: 21767634 DOI: 10.1016/j.ntt.2011.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/03/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
This is a review of research that supports a hypothesis regarding early restriction of gene expression in the vertebrate embryo. We hypothesize that vertebrate retinoic acid receptors (RARs for several vertebrates but rars for zebrafish) are part of an embryonic, epigenetic switch whose default position, at the time of fertilization is "OFF". This is due to the assemblage of a rar-corepressor-histone deacetylase complex on retinoic acid response elements (RAREs) in regulatory regions of a subset of genes. In addition, selective and precise allocation of retinoic acid during early development through the interaction of Phase I enzymes throws the switch "ON" in a predictable, developmental manner. We are proposing that this is a basic, early embryonic switch that can cause the initiation of cascades of gene expression that are responsible for at least some early, diversification of cell phenotypes. Dehydrogenases and a subset of cytochrome p450 genes (cyp26a1, cyp26b1, and cyp26c1) play the major role in providing the retinoic acid and limiting its access. We also suggest that this mechanism may be playing a significant role in the repression of genes in undifferentiated stem cells.
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Affiliation(s)
- Elwood Linney
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, United States.
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Krispin S, Nitzan E, Kalcheim C. The dorsal neural tube: a dynamic setting for cell fate decisions. Dev Neurobiol 2011; 70:796-812. [PMID: 20683859 DOI: 10.1002/dneu.20826] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The dorsal neural tube first generates neural crest cells that exit the neural primordium following an epithelial-to-mesenchymal conversion to become sympathetic ganglia, Schwann cells, dorsal root sensory ganglia, and melanocytes of the skin. Following the end of crest emigration, the dorsal midline of the neural tube becomes the roof plate, a signaling center for the organization of dorsal neuronal cell types. Recent lineage analysis performed before the onset of crest delamination revealed that the dorsal tube is a highly dynamic region sequentially traversed by fate-restricted crest progenitors. Furthermore, prospective roof plate cells were shown to originate ventral to presumptive crest and to progressively relocate dorsalward to occupy their definitive midline position following crest delamination. These data raise important questions regarding the mechanisms of cell emigration in relation to fate acquisition, and suggest the possibility that spatial and/or temporal information in the dorsal neural tube determines initial segregation of neural crest cells into their derivatives. In addition, they emphasize the need to address what controls the end of neural crest production and consequent roof plate formation, a fundamental issue for understanding the separation between central and peripheral lineages during development of the nervous system.
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Affiliation(s)
- Shlomo Krispin
- Department of Medical Neurobiology, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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