1
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Sampath Kumar A, Tian L, Bolondi A, Hernández AA, Stickels R, Kretzmer H, Murray E, Wittler L, Walther M, Barakat G, Haut L, Elkabetz Y, Macosko EZ, Guignard L, Chen F, Meissner A. Spatiotemporal transcriptomic maps of whole mouse embryos at the onset of organogenesis. Nat Genet 2023; 55:1176-1185. [PMID: 37414952 PMCID: PMC10335937 DOI: 10.1038/s41588-023-01435-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/25/2023] [Indexed: 07/08/2023]
Abstract
Spatiotemporal orchestration of gene expression is required for proper embryonic development. The use of single-cell technologies has begun to provide improved resolution of early regulatory dynamics, including detailed molecular definitions of most cell states during mouse embryogenesis. Here we used Slide-seq to build spatial transcriptomic maps of complete embryonic day (E) 8.5 and E9.0, and partial E9.5 embryos. To support their utility, we developed sc3D, a tool for reconstructing and exploring three-dimensional 'virtual embryos', which enables the quantitative investigation of regionalized gene expression patterns. Our measurements along the main embryonic axes of the developing neural tube revealed several previously unannotated genes with distinct spatial patterns. We also characterized the conflicting transcriptional identity of 'ectopic' neural tubes that emerge in Tbx6 mutant embryos. Taken together, we present an experimental and computational framework for the spatiotemporal investigation of whole embryonic structures and mutant phenotypes.
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Affiliation(s)
- Abhishek Sampath Kumar
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Luyi Tian
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Adriano Bolondi
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Amèlia Aragonés Hernández
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Robert Stickels
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Graduate School of Arts and Sciences, Harvard University, Cambridge, MA, USA
| | - Helene Kretzmer
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Evan Murray
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Lars Wittler
- Department of Developmental Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Maria Walther
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Gabriel Barakat
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Leah Haut
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Yechiel Elkabetz
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Evan Z Macosko
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - Léo Guignard
- Aix Marseille University, Toulon University, Centre National de la Recherche Scientifique, Laboratoire d'Informatique et Systèmes 7020, Turing Centre for Living Systems, Marseille, France
| | - Fei Chen
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | - Alexander Meissner
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, Berlin, Germany.
- Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA.
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2
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Transcription factors dysregulated in three complex birth defects datasets. REPRODUCTIVE AND DEVELOPMENTAL MEDICINE 2022. [DOI: 10.1097/rd9.0000000000000018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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3
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DeSesso JM. Of embryos and tumors: Cyclopia and the relevance of mechanistic teratology. Birth Defects Res 2019; 112:219-233. [PMID: 31883318 DOI: 10.1002/bdr2.1636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/03/2019] [Accepted: 12/11/2019] [Indexed: 12/28/2022]
Abstract
Embryos and tumors share several characteristics, but embryos differ from tumors in their coordination of cellular- and tissue-level processes, including organized differentiation, remodeling of tissues through apoptosis, and disciplined migrations of cells. Embryonic cellular events are kept on track through orderly cell-cell communication via signal transduction pathways. If the pathways are disrupted, development is perturbed, and malformation may result. Despite profound differences between embryos and tumors, the study of one has benefited our understanding of the other. Using cyclopia as an example, the history of humans' beliefs concerning and reactions to this horrific malformation are explored. During the latter half of the 20th century, interest in cyclopic sheep from high pastures in western Idaho led to the discovery that cyclopia occurred after pregnant ewes foraged in fields containing corn lily (Veratrum californicum). Eventually, the proximate teratogen was identified as cyclopamine (a steroidal alkaloid). The teratogenic mechanism was identified as inhibition of the sonic hedgehog (Shh) signal transduction pathway. Alert cancer researchers noted that a prominent form of medulloblastoma (a devasting childhood brain tumor) overexpressed Shh. Cyclopamine effectively inhibited the tumor in mice and killed human medulloblastoma cells in vitro. Thus, over a 60-year period, a molecule causing hideous malformations and much emotional pain was discovered and then found capable of restraining a destructive tumor, potentially saving children's lives and sparing emotional devastation of their families. The success of identifying cyclopamine as a cause of cyclopia and a potential cure for medulloblastoma emerged from mechanistic research shared by multiple disciplines.
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Affiliation(s)
- John M DeSesso
- Exponent, Alexandria, Virginia.,Georgetown University School of Medicine, Washington, District of Columbia
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4
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Grinblat Y, Lipinski RJ. A forebrain undivided: Unleashing model organisms to solve the mysteries of holoprosencephaly. Dev Dyn 2019; 248:626-633. [PMID: 30993762 DOI: 10.1002/dvdy.41] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/10/2019] [Accepted: 04/10/2019] [Indexed: 12/13/2022] Open
Abstract
Evolutionary conservation and experimental tractability have made animal model systems invaluable tools in our quest to understand human embryogenesis, both normal and abnormal. Standard genetic approaches, particularly useful in understanding monogenic diseases, are no longer sufficient as research attention shifts toward multifactorial outcomes. Here, we examine this progression through the lens of holoprosencephaly (HPE), a common human malformation involving incomplete forebrain division, and a classic example of an etiologically complex outcome. We relate the basic underpinning of HPE pathogenesis to critical cell-cell interactions and signaling molecules discovered through embryological and genetic approaches in multiple model organisms, and discuss the role of the mouse model in functional examination of HPE-linked genes. We then outline the most critical remaining gaps to understanding human HPE, including the conundrum of incomplete penetrance/expressivity and the role of gene-environment interactions. To tackle these challenges, we outline a strategy that leverages new and emerging technologies in multiple model systems to solve the puzzle of HPE.
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Affiliation(s)
- Yevgenya Grinblat
- Department of Integrative Biology, University of Wisconsin, Madison, Wisconsin.,Department of Neuroscience, University of Wisconsin, Madison, Wisconsin.,McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin
| | - Robert J Lipinski
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin.,Molecular and Environmental Toxicology Center, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
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5
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Dunham C, McFadden D, Dahlgren L, Butler B, Hamilton S, McKinnon M. Congenital Hypothalamic "Hamartoblastoma" Versus "Hamartoma": Suggestions for Neuropathologic Terminology Emanating From a Mid-gestational Autopsy Case of Pallister-Hall Syndrome. Pediatr Dev Pathol 2018; 21:324-331. [PMID: 28429635 DOI: 10.1177/1093526617701338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Pallister-Hall syndrome (PHS) is a rare malformative disorder that is due to truncating functional repressor mutations in GLI3. Since the seminal publication in 1980, hypothalamic tumors have been recognized to be a cardinal feature of PHS. In their original description of the neuropathologic features of PHS, Clarren et al. coined the term "hamartoblastoma" to characterize what they deemed to be a dual malformative and neoplastic mass of the hypothalamus. In subsequent published cases/series of PHS, the term "hamartoma" was often substituted for hamartoblastoma given what appeared to be a benign natural history of this lesion. Additional confusion in the literature has ensued since most hypothalamic hamartomas (HH) encountered on the clinical neuropathology service are "isolated" in nature (ie, no other congenital malformations) and present in a very different and stereotypical fashion with gelastic seizures and/or precocious puberty. While genomic investigations of isolated HH have begun to uncover a mutational profile of these cases, GLI3 mutations have only been recognized in a small subset of isolated HH. Herein, we describe the autopsy findings from a 21-week gestational age fetus with features of PHS. Moreover, we provide a detailed description of the hypothalamic tumor affecting this fetus and propose a novel subclassification of HH, distinguishing syndromic from isolated forms based upon the presence or absence of neocortical-like areas.
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Affiliation(s)
- C Dunham
- 1 Department of Pathology and Laboratory Medicine, Children and Women's Health Centre of BC, Vancouver, British Columbia, Canada
| | - D McFadden
- 1 Department of Pathology and Laboratory Medicine, Children and Women's Health Centre of BC, Vancouver, British Columbia, Canada
| | - L Dahlgren
- 2 Department of Obstetrics and Gynecology, Children and Women's Health Centre of BC, Vancouver, British Columbia, Canada
| | - B Butler
- 2 Department of Obstetrics and Gynecology, Children and Women's Health Centre of BC, Vancouver, British Columbia, Canada
| | - S Hamilton
- 3 Department of Medical Genetics, Children and Women's Health Centre of BC, Vancouver, British Columbia, Canada
| | - M McKinnon
- 3 Department of Medical Genetics, Children and Women's Health Centre of BC, Vancouver, British Columbia, Canada
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6
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Wang B, Zhang Y, Dong H, Gong S, Wei B, Luo M, Wang H, Wu X, Liu W, Xu X, Zheng Y, Sun M. Loss of Tctn3 causes neuronal apoptosis and neural tube defects in mice. Cell Death Dis 2018; 9:520. [PMID: 29725084 PMCID: PMC5938703 DOI: 10.1038/s41419-018-0563-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/23/2018] [Accepted: 04/03/2018] [Indexed: 12/18/2022]
Abstract
Tctn3 belongs to the Tectonic (Tctn) family and is a single-pass membrane protein localized at the transition zone of primary cilia as an important component of ciliopathy-related protein complexes. Previous studies showed that mutations in Tctn1 and Tctn2, two members of the tectonic family, have been reported to disrupt neural tube development in humans and mice, but the functions of Tctn3 in brain development remain elusive. In this study, Tctn3 knockout (KO) mice were generated by utilizing the piggyBac (PB) transposon system. We found that Tctn3 KO mice exhibited abnormal global development, including prenatal lethality, microphthalmia, polysyndactyly, and abnormal head, sternum, and neural tube, whereas Tctn3 heterozygous KO mice did not show abnormal development or behaviors. Further, we found that the mRNA levels of Gli1 and Ptch1, downstream signaling components of the Shh pathway, were significantly reduced. Likewise, neural tube patterning-related proteins, such as Shh, Foxa2, and Nkx2.2, were altered in their distribution. Interestingly, Tctn3 KO led to significant changes in apoptosis-related proteins, including Bcl-2, Bax, and cleaved PARP1, resulting in reduced numbers of neuronal cells in embryonic brains. Tctn3 KO inhibited the PI3K/Akt signaling pathway but not the mTOR-dependent pathway. The small molecule SC79, a specific Akt activator, blocked apoptotic cell death in primary mouse embryonic fibroblasts from Tctn3 KO mice. Finally, NPHP1, a protein with anti-apoptotic ability, was found to form a complex with Tctn3, and its levels were decreased in Tctn3 KO mice. In conclusion, our results show that Tctn3 KO disrupts the Shh signaling pathway and neural tube patterning, resulting in abnormal embryonic development, cellular apoptosis, and prenatal death in mice.
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Affiliation(s)
- Bin Wang
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.,Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Yingying Zhang
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Hongli Dong
- Department of Neurology, Suzhou Hospital of Traditional Chinese Medicine, Suzhou City, 215123, Jiangsu, China
| | - Siyi Gong
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.,Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Bin Wei
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Man Luo
- Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China
| | - Hongyan Wang
- Obstetrics and Gynecology Hospital Research Center, Institute of Reproduction and Development, Fudan University, Shanghai, 200433, China.,State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xiaohui Wu
- State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China.,Institute of Developmental Biology & Molecular Medicine, Fudan University, Shanghai, 200433, China
| | - Wei Liu
- Department of Pathology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China
| | - Xingshun Xu
- Institute of Neuroscience, Soochow University, Suzhou City, 215123, Jiangsu, China.
| | - Yufang Zheng
- Obstetrics and Gynecology Hospital Research Center, Institute of Reproduction and Development, Fudan University, Shanghai, 200433, China. .,State Key Laboratory of Genetic Engineering, MOE Key Laboratory of Contemporary Anthropology, and Collaborative Innovation Center for Genetics & Development, School of Life Sciences, Fudan University, Shanghai, 200438, China. .,Institute of Developmental Biology & Molecular Medicine, Fudan University, Shanghai, 200433, China.
| | - Miao Sun
- Institute for Fetology, the First Affiliated Hospital of Soochow University, Suzhou City, 215006, Jiangsu, China.
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7
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Liu B, Zhou K, Wu X, Zhao C. Foxg1 deletion impairs the development of the epithalamus. Mol Brain 2018; 11:5. [PMID: 29394901 PMCID: PMC5797387 DOI: 10.1186/s13041-018-0350-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/24/2018] [Indexed: 12/14/2022] Open
Abstract
The epithalamus, which is dorsal to the thalamus, consists of the habenula, pineal gland and third ventricle choroid plexus and plays important roles in the stress response and sleep-wake cycle in vertebrates. During development, the epithalamus arises from the most dorsal part of prosomere 2. However, the mechanism underlying epithalamic development remains largely unknown. Foxg1 is critical for the development of the telencephalon, but its role in diencephalic development has been under-investigated. Patients suffering from FOXG1-related disorders exhibit severe anxiety, sleep disturbance and choroid plexus cysts, indicating that Foxg1 likely plays a role in epithalamic development. In this study, we identified the specific expression of Foxg1 in the developing epithalamus. Using a "self-deletion" approach, we found that the habenula significantly expanded and included an increased number of habenular subtype neurons. The innervations, particularly the habenular commissure, were severely impaired. Meanwhile, the Foxg1 mutants exhibited a reduced pineal gland and more branched choroid plexus. After ablation of Foxg1 no obvious changes in Shh and Fgf signalling were observed, suggesting that Foxg1 regulates the development of the epithalamus without the involvement of Shh and Fgfs. Our findings provide new insights into the regulation of the development of the epithalamus.
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Affiliation(s)
- Bin Liu
- Key Laboratory of Developmental Genes and Human Diseases, MOE, School of Medicine, Southeast University, Nanjing, 210009, People's Republic of China
| | - Kaixing Zhou
- Key Laboratory of Developmental Genes and Human Diseases, MOE, School of Medicine, Southeast University, Nanjing, 210009, People's Republic of China
| | - Xiaojing Wu
- Key Laboratory of Developmental Genes and Human Diseases, MOE, School of Medicine, Southeast University, Nanjing, 210009, People's Republic of China
| | - Chunjie Zhao
- Key Laboratory of Developmental Genes and Human Diseases, MOE, School of Medicine, Southeast University, Nanjing, 210009, People's Republic of China. .,Depression Center, Institute for Brain Disorders, Beijing, 100069, China.
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8
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Agbu SO, Liang Y, Liu A, Anderson KV. The small GTPase RSG1 controls a final step in primary cilia initiation. J Cell Biol 2017; 217:413-427. [PMID: 29038301 PMCID: PMC5748968 DOI: 10.1083/jcb.201604048] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 08/18/2016] [Accepted: 09/21/2017] [Indexed: 12/11/2022] Open
Abstract
Primary cilia are essential for normal development and tissue homeostasis, but the mechanisms that remodel the centriole to promote cilia initiation are not well understood. Agbu et al. report that mouse RSG1, a small GTPase, regulates a late step in cilia initiation, downstream of TTBK2 and the CPLANE protein INTU. Primary cilia, which are essential for normal development and tissue homeostasis, are extensions of the mother centriole, but the mechanisms that remodel the centriole to promote cilia initiation are poorly understood. Here we show that mouse embryos that lack the small guanosine triphosphatase RSG1 die at embryonic day 12.5, with developmental abnormalities characteristic of decreased cilia-dependent Hedgehog signaling. Rsg1 mutant embryos have fewer primary cilia than wild-type embryos, but the cilia that form are of normal length and traffic Hedgehog pathway proteins within the cilium correctly. Rsg1 mother centrioles recruit proteins required for cilia initiation and dock onto ciliary vesicles, but axonemal microtubules fail to elongate normally. RSG1 localizes to the mother centriole in a process that depends on tau tubulin kinase 2 (TTBK2), the CPLANE complex protein Inturned (INTU), and its own GTPase activity. The data suggest a specific role for RSG1 in the final maturation of the mother centriole and ciliary vesicle that allows extension of the ciliary axoneme.
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Affiliation(s)
- Stephanie O Agbu
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY.,Biochemistry, Cell and Molecular Biology Program, Weill Graduate School of Medical Sciences of Cornell University, New York, NY
| | - Yinwen Liang
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Aimin Liu
- Department of Biology, Eberly College of Science, The Pennsylvania State University, University Park, PA
| | - Kathryn V Anderson
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY
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9
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Diencephalic Size Is Restricted by a Novel Interplay Between GCN5 Acetyltransferase Activity and Retinoic Acid Signaling. J Neurosci 2017; 37:2565-2579. [PMID: 28154153 DOI: 10.1523/jneurosci.2121-16.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 01/20/2023] Open
Abstract
Diencephalic defects underlie an array of neurological diseases. Previous studies have suggested that retinoic acid (RA) signaling is involved in diencephalic development at late stages of embryonic development, but its roles and mechanisms of action during early neural development are still unclear. Here we demonstrate that mice lacking enzymatic activity of the acetyltransferase GCN5 ((Gcn5hat/hat )), which were previously characterized with respect to their exencephalic phenotype, exhibit significant diencephalic expansion, decreased diencephalic RA signaling, and increased diencephalic WNT and SHH signaling. Using a variety of molecular biology techniques in both cultured neuroepithelial cells treated with a GCN5 inhibitor and forebrain tissue from (Gcn5hat/hat ) embryos, we demonstrate that GCN5, RARα/γ, and the poorly characterized protein TACC1 form a complex in the nucleus that binds specific retinoic acid response elements in the absence of RA. Furthermore, RA triggers GCN5-mediated acetylation of TACC1, which results in dissociation of TACC1 from retinoic acid response elements and leads to transcriptional activation of RA target genes. Intriguingly, RA signaling defects caused by in vitro inhibition of GCN5 can be rescued through RA-dependent mechanisms that require RARβ. Last, we demonstrate that the diencephalic expansion and transcriptional defects seen in (Gcn5hat/hat ) mutants can be rescued with gestational RA supplementation, supporting a direct link between GCN5, TACC1, and RA signaling in the developing diencephalon. Together, our studies identify a novel, nonhistone substrate for GCN5 whose modification regulates a previously undescribed, tissue-specific mechanism of RA signaling that is required to restrict diencephalic size during early forebrain development.SIGNIFICANCE STATEMENT Changes in diencephalic size and shape, as well as SNPs associated with retinoic acid (RA) signaling-associated genes, have been linked to neuropsychiatric disorders. However, the mechanisms that regulate diencephalic morphogenesis and the involvement of RA signaling in this process are poorly understood. Here we demonstrate a novel role of the acetyltransferase GCN5 in a previously undescribed mechanism of RA signaling in the developing forebrain that is required to maintain the appropriate size of the diencephalon. Together, our experiments identify a novel nonhistone substrate of GCN5, highlight an essential role for both GCN5 and RA signaling in early diencephalic development, and elucidate a novel molecular regulatory mechanism for RA signaling that is specific to the developing forebrain.
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10
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Pan YB, Gong Y, Ruan HF, Pan LY, Wu XK, Tang C, Wang CJ, Zhu HB, Zhang ZM, Tang LF, Zou CC, Wang HB, Wu XM. Sonic hedgehog through Gli2 and Gli3 is required for the proper development of placental labyrinth. Cell Death Dis 2015; 6:e1653. [PMID: 25695606 PMCID: PMC4669788 DOI: 10.1038/cddis.2015.28] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/14/2015] [Accepted: 01/15/2015] [Indexed: 01/20/2023]
Abstract
Sonic hedgehog (Shh) functions as a conserved morphogen in the development of various organs in metazoans ranging from Drosophila to humans. Here, we have investigated the potential roles and underlying mechanisms of Shh signaling in murine placentation. Immunostaining revealed the abundant expression of the main components of Shh pathway in both the trophectoderm of blastocysts and developing placentas. Disruption of Shh led to impaired vascularogenesis of yolk sac, less branching and malformation of placental labyrinth, thereby leading to a robust decrease in capacity of transplacental passages. Moreover, placenta-specific gene incorporation by lentiviral transduction of mouse blastocysts and blastocyst transplantation robustly knocked down the expression of Gli3 and Gli2 in placenta but not in embryos. Finally, Gli3 knockdown in Shh−/− placentas partially rescued the defects of both yolk sac and placental labyrinth, and robustly restored the capacity of transplacental passages. Gli2 knockdown in Shh+/− placentas affected neither the capacity of tranplacental passages nor the vascularogenesis of yolk sac, however, it partially phenocopied the labyrinthine defects of Shh−/− placentas. Taken together, these results uncover that both Shh/Gli2 and Shh/Gli3 signals are required for proper development of murine placentas and are possibly essential for pregnant maintenance.
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Affiliation(s)
- Y B Pan
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Y Gong
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - H F Ruan
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - L Y Pan
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - X K Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - C Tang
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - C J Wang
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - H B Zhu
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Z M Zhang
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - L F Tang
- Department of Internal Medicine, The Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - C C Zou
- Department of Internal Medicine, The Affiliated Children Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - H B Wang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - X M Wu
- Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
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11
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Croizier S, Chometton S, Fellmann D, Risold PY. Characterization of a mammalian prosencephalic functional plan. Front Neuroanat 2015; 8:161. [PMID: 25610375 PMCID: PMC4285092 DOI: 10.3389/fnana.2014.00161] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/09/2014] [Indexed: 11/13/2022] Open
Abstract
Hypothalamic organizational concepts have greatly evolved as the primary hypothalamic pathways have been systematically investigated. In the present review, we describe how the hypothalamus arises from a molecularly heterogeneous region of the embryonic neural tube but is first differentiated as a primary neuronal cell cord (earliest mantle layer). This structure defines two axes that align onto two fundamental components: a longitudinal tractus postopticus(tpoc)/retinian component and a transverse supraoptic tract(sot)/olfactory component. We then discuss how these two axonal tracts guide the formation of all major tracts that connect the telencephalon with the hypothalamus/ventral midbrain, highlighting the existence of an early basic plan in the functional organization of the prosencephalic connectome.
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Affiliation(s)
- Sophie Croizier
- EA 3922, SFR FED 4234, UFR Sciences Médicales et Pharmaceutiques, Université de Franche-Comté Besançon, France
| | - Sandrine Chometton
- EA 3922, SFR FED 4234, UFR Sciences Médicales et Pharmaceutiques, Université de Franche-Comté Besançon, France
| | - Dominique Fellmann
- EA 3922, SFR FED 4234, UFR Sciences Médicales et Pharmaceutiques, Université de Franche-Comté Besançon, France
| | - Pierre-Yves Risold
- EA 3922, SFR FED 4234, UFR Sciences Médicales et Pharmaceutiques, Université de Franche-Comté Besançon, France
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12
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Suárez R, Gobius I, Richards LJ. Evolution and development of interhemispheric connections in the vertebrate forebrain. Front Hum Neurosci 2014; 8:497. [PMID: 25071525 PMCID: PMC4094842 DOI: 10.3389/fnhum.2014.00497] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 06/19/2014] [Indexed: 12/20/2022] Open
Abstract
Axonal connections between the left and right sides of the brain are crucial for bilateral integration of lateralized sensory, motor, and associative functions. Throughout vertebrate species, forebrain commissures share a conserved developmental plan, a similar position relative to each other within the brain and similar patterns of connectivity. However, major events in the evolution of the vertebrate brain, such as the expansion of the telencephalon in tetrapods and the origin of the six-layered isocortex in mammals, resulted in the emergence and diversification of new commissural routes. These new interhemispheric connections include the pallial commissure, which appeared in the ancestors of tetrapods and connects the left and right sides of the medial pallium (hippocampus in mammals), and the corpus callosum, which is exclusive to eutherian (placental) mammals and connects both isocortical hemispheres. A comparative analysis of commissural systems in vertebrates reveals that the emergence of new commissural routes may have involved co-option of developmental mechanisms and anatomical substrates of preexistent commissural pathways. One of the embryonic regions of interest for studying these processes is the commissural plate, a portion of the early telencephalic midline that provides molecular specification and a cellular scaffold for the development of commissural axons. Further investigations into these embryonic processes in carefully selected species will provide insights not only into the mechanisms driving commissural evolution, but also regarding more general biological problems such as the role of developmental plasticity in evolutionary change.
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Affiliation(s)
- Rodrigo Suárez
- Queensland Brain Institute, The University of QueenslandBrisbane, QLD, Australia
| | - Ilan Gobius
- Queensland Brain Institute, The University of QueenslandBrisbane, QLD, Australia
| | - Linda J. Richards
- Queensland Brain Institute, The University of QueenslandBrisbane, QLD, Australia
- School of Biomedical Sciences, The University of QueenslandBrisbane, QLD, Australia
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Dirian L, Galant S, Coolen M, Chen W, Bedu S, Houart C, Bally-Cuif L, Foucher I. Spatial regionalization and heterochrony in the formation of adult pallial neural stem cells. Dev Cell 2014; 30:123-36. [PMID: 25017692 DOI: 10.1016/j.devcel.2014.05.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/25/2014] [Accepted: 05/14/2014] [Indexed: 01/10/2023]
Abstract
Little is known on the embryonic origin and related heterogeneity of adult neural stem cells (aNSCs). We use conditional genetic tracing, activated in a global or mosaic fashion by cell type-specific promoters or focal laser uncaging, coupled with gene expression analyses and Notch invalidations, to address this issue in the zebrafish adult telencephalon. We report that the germinal zone of the adult pallium originates from two distinct subtypes of embryonic progenitors and integrates two modes of aNSC formation. Dorsomedial aNSCs derive from the amplification of actively neurogenic radial glia of the embryonic telencephalon. On the contrary, the lateral aNSC population is formed by stepwise addition at the pallial edge from a discrete neuroepithelial progenitor pool of the posterior telencephalic roof, activated at postembryonic stages and persisting lifelong. This dual origin of the pallial germinal zone allows the temporally organized building of pallial territories as a patchwork of juxtaposed compartments.
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Affiliation(s)
- Lara Dirian
- Institute of Neurobiology A. Fessard, Laboratory of Neurobiology and Development, CNRS UPR3294, Team Zebrafish Neurogenetics, Avenue de la Terrasse, Building 5, 91198 Gif-sur-Yvette, France
| | - Sonya Galant
- Institute of Neurobiology A. Fessard, Laboratory of Neurobiology and Development, CNRS UPR3294, Team Zebrafish Neurogenetics, Avenue de la Terrasse, Building 5, 91198 Gif-sur-Yvette, France
| | - Marion Coolen
- Institute of Neurobiology A. Fessard, Laboratory of Neurobiology and Development, CNRS UPR3294, Team Zebrafish Neurogenetics, Avenue de la Terrasse, Building 5, 91198 Gif-sur-Yvette, France
| | - Wenbiao Chen
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, 2213 Garland Ave, Nashville, TN 37232, USA
| | - Sébastien Bedu
- Institute of Neurobiology A. Fessard, Laboratory of Neurobiology and Development, CNRS UPR3294, Team Zebrafish Neurogenetics, Avenue de la Terrasse, Building 5, 91198 Gif-sur-Yvette, France
| | - Corinne Houart
- Medical Research Council Centre for Developmental Neurobiology, King's College London, London SE1 1UL, UK
| | - Laure Bally-Cuif
- Institute of Neurobiology A. Fessard, Laboratory of Neurobiology and Development, CNRS UPR3294, Team Zebrafish Neurogenetics, Avenue de la Terrasse, Building 5, 91198 Gif-sur-Yvette, France.
| | - Isabelle Foucher
- Institute of Neurobiology A. Fessard, Laboratory of Neurobiology and Development, CNRS UPR3294, Team Zebrafish Neurogenetics, Avenue de la Terrasse, Building 5, 91198 Gif-sur-Yvette, France.
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The vertebrate diencephalic MCH system: a versatile neuronal population in an evolving brain. Front Neuroendocrinol 2013; 34:65-87. [PMID: 23088995 DOI: 10.1016/j.yfrne.2012.10.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 10/05/2012] [Accepted: 10/10/2012] [Indexed: 11/22/2022]
Abstract
Neurons synthesizing melanin-concentrating hormone (MCH) are described in the posterior hypothalamus of all vertebrates investigated so far. However, their anatomy is very different according to species: they are small and periventricular in lampreys, cartilaginous fishes or anurans, large and neuroendocrine in bony fishes, or distributed over large regions of the lateral hypothalamus in many mammals. An analysis of their comparative anatomy alongside recent data about the development of the forebrain, suggests that although very different, MCH neurons of the caudal hypothalamus are homologous. We further hypothesize that their divergent anatomy is linked to divergence in the forebrain - in particular telencephalic evolution.
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MED12 mutations link intellectual disability syndromes with dysregulated GLI3-dependent Sonic Hedgehog signaling. Proc Natl Acad Sci U S A 2012; 109:19763-8. [PMID: 23091001 DOI: 10.1073/pnas.1121120109] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Recurrent missense mutations in the RNA polymerase II Mediator subunit MED12 are associated with X-linked intellectual disability (XLID) and multiple congenital anomalies, including craniofacial, musculoskeletal, and behavioral defects in humans with FG (or Opitz-Kaveggia) and Lujan syndromes. However, the molecular mechanism(s) underlying these phenotypes is poorly understood. Here we report that MED12 mutations R961W and N1007S causing FG and Lujan syndromes, respectively, disrupt a Mediator-imposed constraint on GLI3-dependent Sonic Hedgehog (SHH) signaling. We show that the FG/R961W and Lujan/N1007S mutations disrupt the gene-specific association of MED12 with a second Mediator subunit, CDK8, identified herein to be a suppressor of GLI3 transactivation activity. In FG/R961W and Lujan/N1007S patient-derived cells, we document enhanced SHH pathway activation and GLI3-target gene induction coincident with impaired recruitment of CDK8 onto promoters of GLI3-target genes, but not non-GLI3-target genes. Together, these findings suggest that dysregulated GLI3-dependent SHH signaling contributes to phenotypes of individuals with FG and Lujan syndromes and further reveal a basis for the gene-specific manifestation of pathogenic mutations in a global transcriptional coregulator.
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Robertshaw E, Kiecker C. Phylogenetic origins of brain organisers. SCIENTIFICA 2012; 2012:475017. [PMID: 24278699 PMCID: PMC3820451 DOI: 10.6064/2012/475017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 06/21/2012] [Indexed: 06/02/2023]
Abstract
The regionalisation of the nervous system begins early in embryogenesis, concomitant with the establishment of the anteroposterior (AP) and dorsoventral (DV) body axes. The molecular mechanisms that drive axis induction appear to be conserved throughout the animal kingdom and may be phylogenetically older than the emergence of bilateral symmetry. As a result of this process, groups of patterning genes that are equally well conserved are expressed at specific AP and DV coordinates of the embryo. In the emerging nervous system of vertebrate embryos, this initial pattern is refined by local signalling centres, secondary organisers, that regulate patterning, proliferation, and axonal pathfinding in adjacent neuroepithelium. The main secondary organisers for the AP neuraxis are the midbrain-hindbrain boundary, zona limitans intrathalamica, and anterior neural ridge and for the DV neuraxis the notochord, floor plate, and roof plate. A search for homologous secondary organisers in nonvertebrate lineages has led to controversy over their phylogenetic origins. Based on a recent study in hemichordates, it has been suggested that the AP secondary organisers evolved at the base of the deuterostome superphylum, earlier than previously thought. According to this view, the lack of signalling centres in some deuterostome lineages is likely to reflect a secondary loss due to adaptive processes. We propose that the relative evolutionary flexibility of secondary organisers has contributed to a broader morphological complexity of nervous systems in different clades.
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Affiliation(s)
- Ellen Robertshaw
- MRC Centre for Developmental Neurobiology, King's College London, 4th Floor, New Hunt's House, Guy's Hospital Campus, London SE1 1UL, UK
| | - Clemens Kiecker
- MRC Centre for Developmental Neurobiology, King's College London, 4th Floor, New Hunt's House, Guy's Hospital Campus, London SE1 1UL, UK
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Haddad-Tóvolli R, Heide M, Zhou X, Blaess S, Alvarez-Bolado G. Mouse thalamic differentiation: gli-dependent pattern and gli-independent prepattern. Front Neurosci 2012; 6:27. [PMID: 22371696 PMCID: PMC3283895 DOI: 10.3389/fnins.2012.00027] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 02/08/2012] [Indexed: 12/17/2022] Open
Abstract
Sonic hedgehog (Shh) signaling is essential for thalamic development. The Gli transcription factors act downstream of Shh – while Gli2 is the major activator (GliA), Gli3 acts primarily as a repressor (GliR). The thalamus is remarkable among dorsal structures because of its proximity to the mid-diencephalic organizer, a unique dorsal Shh source. This lends complexity to the interactions between Shh, Gli2, and Gli3, suggesting the presence of a dorsal Gli activator which elsewhere is found only ventrally, and making the dissection of thalamic Gli functions particularly interesting. A current model based on mutant phenotypes in telencephalon and midbrain postulates a degree of reciprocal antagonism of Shh and Gli3 in dorsal brain regions. To approach the role of Gli factors in thalamic specification we first analyzed mice deficient in Gli2 or Gli3. In Gli2 mutants, the thalamus is small and poorly differentiated with the exception of the medial and intralaminar nuclei which, in contrast, are specifically and severely affected by Gli3 inactivation. Gbx2 expression is very reduced in the Gli3 mutant. Most thalamic nuclei are present in both mutants, although incompletely differentiated, as reflected by the loss of specific markers. The ventral posterior group, revealed by novel specific marker Hes1, is present in both mutants and extends axons to the telencephalon. To test the Gli3/Shh interaction we generated a novel mutant deficient in Gli3 and neuroepithelial Shh. The thalamus of the n-Shh/Gli3 double mutants is very large and very poorly differentiated except for a broad domain of Gbx2, Lhx2, and Calb2 expression. In utero electroporation experiments on wild type embryos suggest that a stage-specific factor acting early is responsible for this prepattern. We show that, in the thalamus, GliA acts downstream of Shh to specify pattern and size of the thalamic nuclei to the exception of the medial and intralaminar groups. Gli3A can partially substitute for Gli2A in the Gli2 mutant. GliR is essential for specification and growth of the medial and intralaminar nuclei, contributes to the specification of other thalamic nuclei and reduces thalamic size. GliA (from neuroepithelial Shh signaling) and GliR do not show reciprocal antagonism in the thalamus, and their joint abolition does not rescue the wild type phenotype.
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Affiliation(s)
- Roberta Haddad-Tóvolli
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
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