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Abstract
A prominent anatomical feature of the peripheral nervous system is the segmentation of mixed (motor, sensory and autonomic) spinal nerves alongside the spinal cord. During early development their axon growth cones avoid the developing vertebral elements by traversing the anterior/cranial half of each somite-derived sclerotome, so ensuring the separation of spinal nerves from vertebral bones as axons extend towards their peripheral targets. A glycoprotein expressed on the surface of posterior half-sclerotome cells confines growth cones to the anterior half-sclerotomes by contact repulsion. A closely similar glycoprotein is expressed in avian and mammalian grey matter, where we hypothesize it may have evolved to regulate neural plasticity in birds and mammals.
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Affiliation(s)
- Roger Keynes
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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2
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Loregger A, Grandl M, Mejías-Luque R, Allgäuer M, Degenhart K, Haselmann V, Oikonomou C, Hatzis P, Janssen KP, Nitsche U, Gradl D, van den Broek O, Destree O, Ulm K, Neumaier M, Kalali B, Jung A, Varela I, Schmid RM, Rad R, Busch DH, Gerhard M. The E3 ligase RNF43 inhibits Wnt signaling downstream of mutated β-catenin by sequestering TCF4 to the nuclear membrane. Sci Signal 2015; 8:ra90. [PMID: 26350900 DOI: 10.1126/scisignal.aac6757] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Given its fundamental role in development and cancer, the Wnt-β-catenin signaling pathway is tightly controlled at multiple levels. RING finger protein 43 (RNF43) is an E3 ubiquitin ligase originally found in stem cells and proposed to inhibit Wnt signaling by interacting with the Wnt receptors of the Frizzled family. We detected endogenous RNF43 in the nucleus of human intestinal crypt and colon cancer cells. We found that RNF43 physically interacted with T cell factor 4 (TCF4) in cells and tethered TCF4 to the nuclear membrane, thus silencing TCF4 transcriptional activity even in the presence of constitutively active mutants of β-catenin. This inhibitory mechanism was disrupted by the expression of RNF43 bearing mutations found in human gastrointestinal tumors, and transactivation of the Wnt pathway was observed in various cells and in Xenopus embryos when the RING domain of RNF43 was mutated. Our findings indicate that RNF43 inhibits the Wnt pathway downstream of oncogenic mutations that activate the pathway. Mimicking or enhancing this inhibitory activity of RNF43 may be useful to treat cancers arising from aberrant activation of the Wnt pathway.
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Affiliation(s)
- Anke Loregger
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany
| | - Martina Grandl
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany
| | - Raquel Mejías-Luque
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany
| | - Michael Allgäuer
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany. Medical Department II, Technische Universität München, Munich 81675, Germany
| | - Kathrin Degenhart
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany
| | - Verena Haselmann
- Institute for Clinical Chemistry, University Medical Centre Mannheim, Mannheim 68167, Germany
| | - Christina Oikonomou
- Division of Molecular Biology and Genetics, Biomedical Sciences Research Center "Alexander Fleming," Vari 16672, Greece
| | - Pantelis Hatzis
- Division of Molecular Biology and Genetics, Biomedical Sciences Research Center "Alexander Fleming," Vari 16672, Greece
| | - Klaus-Peter Janssen
- Department of Surgery, Technische Universität München, Munich 81675, Germany
| | - Ulrich Nitsche
- Department of Surgery, Technische Universität München, Munich 81675, Germany
| | - Dietmar Gradl
- Zoologisches Institut II, Karlsruhe Institute of Technology, Karlsruhe 76131, Germany
| | | | | | - Kurt Ulm
- Institute of Medical Statistics and Epidemiology, Technische Universität München, Munich 81675, Germany
| | - Michael Neumaier
- Institute for Clinical Chemistry, University Medical Centre Mannheim, Mannheim 68167, Germany
| | - Behnam Kalali
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany
| | - Andreas Jung
- Institute of Pathology, University of Munich, Munich 80337, Germany
| | - Ignacio Varela
- Instituto de Biomedicina y Biotecnología de Cantabria, Santander 39011, Spain
| | - Roland M Schmid
- Medical Department II, Technische Universität München, Munich 81675, Germany
| | - Roland Rad
- Medical Department II, Technische Universität München, Munich 81675, Germany
| | - Dirk H Busch
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany
| | - Markus Gerhard
- Institut für Medizinische Mikrobiologie, Immunologie und Hygiene, Technische Universität München, Munich 81675, Germany.
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3
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Takahashi Y, Yasuhiko Y, Takahashi J, Takada S, Johnson RL, Saga Y, Kanno J. Metameric pattern of intervertebral disc/vertebral body is generated independently of Mesp2/Ripply-mediated rostro-caudal patterning of somites in the mouse embryo. Dev Biol 2013; 380:172-84. [PMID: 23727513 DOI: 10.1016/j.ydbio.2013.05.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 02/03/2023]
Abstract
The vertebrae are derived from the sclerotome of somites. Formation of the vertebral body involves a process called resegmentation, by which the caudal half of a sclerotome is combined with the rostral half of the next sclerotome. To elucidate the relationship between resegmentation and rostro-caudal patterning of somite, we used the Uncx4.1-LacZ transgene to characterize the resegmentation process. Our observations suggested that in the thoracic and lumbar vertebrae, the Uncx4.1-expressing caudal sclerotome gave rise to the intervertebral disc (IVD) and rostral portion of the vertebral body (VB). In the cervical vertebrae, the Uncx4.1-expressing caudal sclerotome appeared to contribute to the IVD and both caudal and rostral ends of the VB. This finding suggests that the rostro-caudal gene expression boundary does not necessarily coincide with the resegmentation boundary. This conclusion was supported by analyses of Mesp2 KO and Ripply1/2 double KO embryos lacking rostral and caudal properties, respectively. Resegmentation was not observed in Mesp2 KO embryos, but both the IVD and whole VB were formed from the caudalized sclerotome. Expression analysis of IVD marker genes including Pax1 in the wild-type, Mesp2 KO, and Ripply1/2 DKO embryos also supported the idea that a metameric pattern of IVD/VB is generated independently of Mesp2/Ripply-mediated rostro-caudal patterning of somite. However, in the lumbar region, IVD differentiation appeared to be stimulated by the caudal property and suppressed by the rostral property. Therefore, we propose that rostro-caudal patterning of somites is not a prerequisite for metameric patterning of the IVD and VB, but instead required to stimulate IVD differentiation in the caudal half of the sclerotome.
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Affiliation(s)
- Yu Takahashi
- Cellular & Molecular Toxicology Division, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagayaku, Tokyo 158-8501, Japan.
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4
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Ashe A, Butterfield NC, Town L, Courtney AD, Cooper AN, Ferguson C, Barry R, Olsson F, Liem KF, Parton RG, Wainwright BJ, Anderson KV, Whitelaw E, Wicking C. Mutations in mouse Ift144 model the craniofacial, limb and rib defects in skeletal ciliopathies. Hum Mol Genet 2012; 21:1808-23. [PMID: 22228095 DOI: 10.1093/hmg/ddr613] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mutations in components of the intraflagellar transport (IFT) machinery required for assembly and function of the primary cilium cause a subset of human ciliopathies characterized primarily by skeletal dysplasia. Recently, mutations in the IFT-A gene IFT144 have been described in patients with Sensenbrenner and Jeune syndromes, which are associated with short ribs and limbs, polydactyly and craniofacial defects. Here, we describe an N-ethyl-N-nitrosourea-derived mouse mutant with a hypomorphic missense mutation in the Ift144 gene. The mutant twinkle-toes (Ift144(twt)) phenocopies a number of the skeletal and craniofacial anomalies seen in patients with human skeletal ciliopathies. Like other IFT-A mouse mutants, Ift144 mutant embryos display a generalized ligand-independent expansion of hedgehog (Hh) signalling, in spite of defective ciliogenesis and an attenuation of the ability of mutant cells to respond to upstream stimulation of the pathway. This enhanced Hh signalling is consistent with cleft palate and polydactyly phenotypes in the Ift144(twt) mutant, although extensive rib branching, fusion and truncation phenotypes correlate with defects in early somite patterning and may reflect contributions from multiple signalling pathways. Analysis of embryos harbouring a second allele of Ift144 which represents a functional null, revealed a dose-dependent effect on limb outgrowth consistent with the short-limb phenotypes characteristic of these ciliopathies. This allelic series of mouse mutants provides a unique opportunity to uncover the underlying mechanistic basis of this intriguing subset of ciliopathies.
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Affiliation(s)
- Alyson Ashe
- Epigenetics Laboratory, Queensland Institute for Medical Research, Herston, Queensland 4006, Australia
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Murdoch JN, Copp AJ. The relationship between sonic Hedgehog signaling, cilia, and neural tube defects. BIRTH DEFECTS RESEARCH. PART A, CLINICAL AND MOLECULAR TERATOLOGY 2010; 88:633-52. [PMID: 20544799 PMCID: PMC3635124 DOI: 10.1002/bdra.20686] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The Hedgehog signaling pathway is essential for many aspects of normal embryonic development, including formation and patterning of the neural tube. Absence of the sonic hedgehog (shh) ligand is associated with the midline defect holoprosencephaly, whereas increased Shh signaling is associated with exencephaly and spina bifida. To complicate this apparently simple relationship, mutation of proteins required for function of cilia often leads to impaired Shh signaling and to disruption of neural tube closure. In this article, we review the literature on Shh pathway mutants and discuss the relationship between Shh signaling, cilia, and neural tube defects.
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Affiliation(s)
- Jennifer N Murdoch
- Centre for Biomedical Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, UK.
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6
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Nakatomi M, Wang XP, Key D, Lund JJ, Turbe-Doan A, Kist R, Aw A, Chen Y, Maas RL, Peters H. Genetic interactions between Pax9 and Msx1 regulate lip development and several stages of tooth morphogenesis. Dev Biol 2010; 340:438-49. [PMID: 20123092 DOI: 10.1016/j.ydbio.2010.01.031] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 01/26/2010] [Accepted: 01/26/2010] [Indexed: 01/28/2023]
Abstract
Developmental abnormalities of craniofacial structures and teeth often occur sporadically and the underlying genetic defects are not well understood, in part due to unknown gene-gene interactions. Pax9 and Msx1 are co-expressed during craniofacial development, and mice that are single homozygous mutant for either gene exhibit cleft palate and an early arrest of tooth formation. Whereas in vitro assays have demonstrated that protein-protein interactions between Pax9 and Msx1 can occur, it is unclear if Pax9 and Msx1 interact genetically in vivo during development. To address this question, we compounded the Pax9 and Msx1 mutations and observed that double homozygous mutants exhibit an incompletely penetrant cleft lip phenotype. Moreover, in double heterozygous mutants, the lower incisors were consistently missing and we find that transgenic BMP4 expression partly rescues this phenotype. Reduced expression of Shh and Bmp2 indicates that a smaller "incisor field" forms in Pax9(+/-);Msx1(+/-) mutants, and dental epithelial growth is substantially reduced after the bud to cap stage transition. This defect is preceded by drastically reduced mesenchymal expression of Fgf3 and Fgf10, two genes that encode known stimulators of epithelial growth during odontogenesis. Consistent with this result, cell proliferation is reduced in both the dental epithelium and mesenchyme of double heterozygous mutants. Furthermore, the developing incisors lack mesenchymal Notch1 expression at the bud stage and exhibit abnormal ameloblast differentiation on both labial and lingual surfaces. Thus, Msx1 and Pax9 interact synergistically throughout lower incisor development and affect multiple signaling pathways that influence incisor size and symmetry. The data also suggest that a combined reduction of PAX9 and MSX1 gene dosage in humans may increase the risk for orofacial clefting and oligodontia.
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Affiliation(s)
- Mitsushiro Nakatomi
- Institute of Human Genetics, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK
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7
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Abstract
Neural tube defects (NTDs) are among the most common structural birth defects observed in humans. Mouse models provide an excellent experimental system to study the underlying causes of NTDs. These models not only allow for identification of the genes required for neurulation, they provide tractable systems for uncovering the developmental, pathological and molecular mechanisms underlying NTDs. In addition, mouse models are essential for elucidating the mechanisms of gene-environment and gene-gene interactions that contribute to the multifactorial inheritance of NTDs. In some cases these studies have led to development of approaches to prevent NTDs and provide an understanding of the underlying molecular mechanism of these therapies prevent NTDs.
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Affiliation(s)
- Irene E Zohn
- Children's Research Institute, Children's National Medical Center, Washington, DC, USA
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8
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Archangelo LF, Greif PA, Hölzel M, Harasim T, Kremmer E, Przemeck GKH, Eick D, Deshpande AJ, Buske C, de Angelis MH, Saad STO, Bohlander SK. The CALM and CALM/AF10 interactor CATS is a marker for proliferation. Mol Oncol 2008; 2:356-67. [PMID: 19383357 DOI: 10.1016/j.molonc.2008.08.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 08/26/2008] [Accepted: 08/27/2008] [Indexed: 01/05/2023] Open
Abstract
The CATS protein was recently identified as a novel CALM interacting protein. CATS increases the nuclear and specifically the nucleolar localization of the leukemogenic CALM/AF10 fusion protein. We cloned and characterized the murine Cats gene. Detailed analysis of murine Cats expression during mouse embryogenesis showed an association with rapidly proliferating tissues. Interestingly, the Cats transcript is highly expressed in murine hematopoietic cells transformed by CALM/AF10. The CATS protein is highly expressed in leukemia, lymphoma and tumor cell lines but not in non-proliferating T-cells or human peripheral blood lymphocytes. CATS protein levels are cell cycle dependent and it is induced by mitogens, suggesting a role of CATS in the control of cell proliferation and possibly CALM/AF10-mediated leukemogenesis.
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Affiliation(s)
- Leticia Fröhlich Archangelo
- Department of Medicine III, University of Munich Hospital Grosshadern, German Research Center for Environmental Health, Munich, Germany
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9
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Stelzer C, Brimmer A, Hermanns P, Zabel B, Dietz UH. Expression profile of Papss2 (3'-phosphoadenosine 5'-phosphosulfate synthase 2) during cartilage formation and skeletal development in the mouse embryo. Dev Dyn 2007; 236:1313-8. [PMID: 17436279 DOI: 10.1002/dvdy.21137] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Sulfation of proteoglycans is a very important posttranslational modification in chondrocyte growth and development. The enzyme 3'-phosphoadenosine 5'-phosphosulfate synthase (PAPSS) catalyzes the biosynthesis of PAPS (3'-phosphoadenosine 5'-phosphosulfate), which serves as the universal sulfate donor compound for all sulfotransferase reactions (Schwartz and Domowicz [2002] Glycobiology 109:143-151). Two major isoenzymes, PAPS synthase 1 (PAPSS1) and PAPS synthase 2 (PAPSS2) were identified in higher organisms for the synthesis of PAPS. PAPSS1 is the more prominent isoform and is ubiquitously expressed in human adult tissues, including cartilage, while PAPSS2 shows a more restricted expression pattern and appears to be the major variant in growth plate cartilage (Fuda et al. [2002] Biochem J 365(Pt 2):497-504). Mutations within the murine and the human PAPSS2 genes are responsible for diseases affecting the skeletal system (Kurima et al. [1998] Proc Natl Acad Sci USA 95:8681-8685; ul Haque et al. [1998] Nat Genet 20:157-162), like the spondyloepimetaphyseal dysplasia (SEMD) Pakistani type. To further elucidate the function of Papss2 within the developing skeleton, we investigated the expression pattern of the murine gene at different developmental stages. We detected Papss2 mRNA starting from 11.5 days post coitum (dpc) at the sites of first chondrogenic condensations and the expression continued in all cartilaginous elements tested of 12.5 dpc, 13.5 dpc, 16.5 dpc embryos, and newborn mice. Papss2 transcripts were also observed in other tissues such as heart, tongue, kidney, and neuronal tissues. However, the most significant levels of Papss2 mRNA were found in condensing and proliferating chondrocytes, whereas hypertrophic chondrocytes show a dramatic down-regulation of Papss2 mRNA expression, indicating an important role of the gene product for cartilage growth and development in mouse embryo.
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10
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Li N, Volff JN, Wizenmann A. Rab23 GTPase is expressed asymmetrically in Hensen's node and plays a role in the dorsoventral patterning of the chick neural tube. Dev Dyn 2007; 236:2993-3006. [DOI: 10.1002/dvdy.21331] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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11
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Guimera J, Weisenhorn DV, Wurst W. Megane/Heslike is required for normal GABAergic differentiation in the mouse superior colliculus. Development 2006; 133:3847-57. [PMID: 16968817 DOI: 10.1242/dev.02557] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The mouse Mgn protein (Helt) is structurally related to the neurogenic Drosophila hairy and Enhancer of split [h/E(spl)]proteins, but its unique structural properties distinguish it from other members of the family. Mgn expression shows a spatiotemporal correlation with GABAergic markers in several brain regions. We report here that homozygous Mgn-null mice die between the second and the fifth postnatal week of age, and show a complete depletion of Gad65 and Gad67 expression in the superior colliculus and a reduction in the inferior colliculus. Other brain regions, as well as other neural systems, are not affected. The progenitor GABAergic cells appear to be generated in right numbers but fail to become GABAergic neurons. The phenotype of the mice is consistent with reduced GABAergic activity. Thus, our in vivo study provides evidence that Mgn is the key regulator of GABAergic neurons, controlling their specification in the dorsal midbrain. Another conclusion from our results is that the function of Mgn shows a previously unrecognized role for h/E(spl)-related transcription factors in the dorsal midbrain GABAergic cell differentiation. Vertebrate h/E(spl)-related genes can no longer be regarded solely as a factors that confer generic neurogenic properties, but as key components for the subtype-neuronal identity in the mammalian CNS.
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Affiliation(s)
- Jordi Guimera
- GSF-National Research Center for Environment and Health, Institute of Developmental Genetics, 35/8006, Ingolstädter Landstrasse, 1, Neuherberg, Germany.
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Baffi MO, Moran MA, Serra R. Tgfbr2 regulates the maintenance of boundaries in the axial skeleton. Dev Biol 2006; 296:363-74. [PMID: 16824508 PMCID: PMC1800905 DOI: 10.1016/j.ydbio.2006.06.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 05/27/2006] [Accepted: 06/01/2006] [Indexed: 02/01/2023]
Abstract
Previously, we showed that deletion of the TGF-beta type II receptor (Tgfbr2) in Type II Collagen (Col2a) expressing cells results in defects in the development of the axial skeleton. Defects included a reduction in size and alterations in the shape of specific vertebral elements. Anterior lateral and dorsal elements of the vertebrae were missing or irregularly shaped. Vertebral bodies were only mildly affected, but the intervertebral disc (IVD) was reduced or missing. In this manuscript, we show that alterations in the initiation or proliferation of cartilage are not detected in the axial skeleton. However, the expression domain of Fibromodulin (Fmod), a marker of the IVD, was reduced and the area of the future IVD contained peanut agglutinin (PNA) staining cartilage. Next, we show that the expression domains of Pax1 and Pax9, which are preferentially expressed in the caudal sclerotome, are expanded over the entire rostral to caudal length of the sclerotome segment. Dorsal-ventral patterning was not affected in these mice as accessed by expression of Pax1, Pax9, and Msx1. Proliferation was modestly reduced in the loose cells of the sclerotome. The results suggest that signaling through Tgfbr2 regulates the maintenance of boundaries in the sclerotome and developing axial skeleton.
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Affiliation(s)
| | | | - Rosa Serra
- *Corresponding author. Fax: +1 205 975 5648. E-mail address: (R. Serra)
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Guimera J, Vogt Weisenhorn D, Echevarría D, Martínez S, Wurst W. Molecular characterization, structure and developmental expression of Megane bHLH factor. Gene 2006; 377:65-76. [PMID: 16644143 DOI: 10.1016/j.gene.2006.02.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Revised: 02/27/2006] [Accepted: 02/27/2006] [Indexed: 11/16/2022]
Abstract
We report here the full-length sequence identification, molecular characterization, detailed demarcation expression analysis relevant to morphological marker genes and mapping of a bHLH transcription gene, referred to as Megane (Mgn). Mgn protein is structurally related to the neurogenic Drosophila hairy and Enhancer of split (h/E(spl)) proteins. The unique structural properties of Mgn factor in several characteristic residues define the gene as related to h/E(spl), but distinguish it from previously identified mammalian members of the family. Mgn is a single copy gene on mouse chromosome 8 and encodes a 27kDa protein that functions in the nucleus. First expression of Mgn is detected at mouse embryonic day 9.5 within the most rostral part of the cephalic flexure of the developing midbrain. Later, Mgn expression extends into other alar areas of the midbrain and forebrain, developmentally controlled in a regional specific pattern.
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Affiliation(s)
- Jordi Guimera
- GSF-National Research Center for Environment and Health, Institute of Developmental Genetics, Neuherberg, Germany.
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14
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Oostra RJ, Maas M. Bifid ribs and unusual vertebral anomalies diagnosed in an anatomical specimen. Gorlin syndrome? Am J Med Genet A 2006; 140:2135-8. [PMID: 16955411 DOI: 10.1002/ajmg.a.31418] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A hitherto unknown combination of multiple bifid ribs, as seen in Gorlin syndrome (GS), interpedicular fusion and apparent malsegmentation of vertebral laminae at various upper thoracic levels was found in the skeleton of a newborn infant. This specific combination of anomalies is also seen in the mouse open brain (opb) mutant. Since the genes involved in GS (Patched2) and opb (rab23) both play an essential role in the hedgehog signaling pathway, it is likely that the cause of the anomalies presented here is to be sought in impaired functioning of this pathway.
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Affiliation(s)
- Roelof-Jan Oostra
- Department of Anatomy & Embryology, Academic Medical Center, University of Amsterdam, The Netherlands.
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15
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Machka C, Kersten M, Zobawa M, Harder A, Horsch M, Halder T, Lottspeich F, Hrabé de Angelis M, Beckers J. Identification of Dll1 (Delta1) target genes during mouse embryogenesis using differential expression profiling. Gene Expr Patterns 2005; 6:94-101. [PMID: 15979417 DOI: 10.1016/j.modgep.2005.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2005] [Revised: 03/29/2005] [Accepted: 04/19/2005] [Indexed: 11/17/2022]
Abstract
The Notch signaling pathway has pleiotropic functions during mammalian embryogenesis. It is required for the patterning and differentiation of the presomitic and somitic paraxial mesoderm and of the neural tube. We used DNA-chip expression profiling and 2D-gel electrophoresis combined with peptide mass fingerprinting to identify genes and proteins differentially regulated in E10.5 Dll1 (delta-like 1, Delta1) mutant embryos. The differential expression profiling approach identified 47 regulated transcripts and 40 differentially expressed proteins. The majority of these genes has until now not been associated with Notch signaling. Subsequent whole-mount in situ hybridization confirmed that a subset of the identified transcripts has restricted and distinct patterns of expression in E10.5 mouse embryos. For most genes these expression patterns were affected in the presomitic mesoderm, in differentiating somites of Dll1 mutant embryos and in the neural tube and cells differentiating from it. Similar effects were observed in embryos homozygous for the Headturner (Htu) and pudgy (pu) mutations, which are alleles of the Notch ligands Jag1 and Dll3. The regulated expression of a subset of the proteins was validated by immunoblots. Remarkably six of the proteins down-regulated in Dll1 mutant embryos are proteasome subunits. The large set of regulated genes identified in this differential expression profiling approach is an important resource for further functional studies.
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Affiliation(s)
- C Machka
- Institute of Experimental Genetics, GSF-National Research Center, Ingolstädter Landstr.1, 85764 Neuherberg, Germany
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16
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Jakupoglu C, Przemeck GKH, Schneider M, Moreno SG, Mayr N, Hatzopoulos AK, de Angelis MH, Wurst W, Bornkamm GW, Brielmeier M, Conrad M. Cytoplasmic thioredoxin reductase is essential for embryogenesis but dispensable for cardiac development. Mol Cell Biol 2005; 25:1980-8. [PMID: 15713651 PMCID: PMC549365 DOI: 10.1128/mcb.25.5.1980-1988.2005] [Citation(s) in RCA: 287] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two distinct thioredoxin/thioredoxin reductase systems are present in the cytosol and the mitochondria of mammalian cells. Thioredoxins (Txn), the main substrates of thioredoxin reductases (Txnrd), are involved in numerous physiological processes, including cell-cell communication, redox metabolism, proliferation, and apoptosis. To investigate the individual contribution of mitochondrial (Txnrd2) and cytoplasmic (Txnrd1) thioredoxin reductases in vivo, we generated a mouse strain with a conditionally targeted deletion of Txnrd1. We show here that the ubiquitous Cre-mediated inactivation of Txnrd1 leads to early embryonic lethality. Homozygous mutant embryos display severe growth retardation and fail to turn. In accordance with the observed growth impairment in vivo, Txnrd1-deficient embryonic fibroblasts do not proliferate in vitro. In contrast, ex vivo-cultured embryonic Txnrd1-deficient cardiomyocytes are not affected, and mice with a heart-specific inactivation of Txnrd1 develop normally and appear healthy. Our results indicate that Txnrd1 plays an essential role during embryogenesis in most developing tissues except the heart.
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Affiliation(s)
- Cemile Jakupoglu
- Department of Comparative Medicine, Institute of Clinical Molecular Biology and Tumor Genetics, GSF, Marchioninistr. 25, D-81377 Munich, Germany
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17
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Willer T, Prados B, Falcón-Pérez JM, Renner-Müller I, Przemeck GKH, Lommel M, Coloma A, Valero MC, de Angelis MH, Tanner W, Wolf E, Strahl S, Cruces J. Targeted disruption of the Walker-Warburg syndrome gene Pomt1 in mouse results in embryonic lethality. Proc Natl Acad Sci U S A 2004; 101:14126-31. [PMID: 15383666 PMCID: PMC521095 DOI: 10.1073/pnas.0405899101] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
O-mannosylation is an important protein modification in eukaryotes that is initiated by an evolutionarily conserved family of protein O-mannosyltransferases. The first mammalian protein O-mannosyltransferase gene described was the human POMT1. Mutations in the hPOMT1 gene are responsible for Walker-Warburg syndrome (WWS), a severe recessive congenital muscular dystrophy associated with defects in neuronal migration that produce complex brain and eye abnormalities. During embryogenesis, the murine Pomt1 gene is prominently expressed in the neural tube, the developing eye, and the mesenchyme. These sites of expression correlate with those in which the main tissue alterations are observed in WWS patients. We have inactivated a Pomt1 allele by gene targeting in embryonic stem cells and produced chimeras transmitting the defect allele to offspring. Although heterozygous mice were viable and fertile, the total absence of Pomt1(-/-) pups in the progeny of heterozygous intercrosses indicated that this genotype is embryonic lethal. An analysis of the mutant phenotype revealed that homozygous Pomt1(-/-) mice suffer developmental arrest around embryonic day (E) 7.5 and die between E7.5 and E9.5. The Pomt1(-/-) embryos present defects in the formation of Reichert's membrane, the first basement membrane to form in the embryo. The failure of this membrane to form appears to be the result of abnormal glycosylation and maturation of dystroglycan that may impair recruitment of laminin, a structural component required for the formation of Reichert's membrane in rodents. The targeted disruption of mPomt1 represents an example of an engineered deletion of a known glycosyltransferase involved in O-mannosyl glycan synthesis.
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Affiliation(s)
- Tobias Willer
- Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, D-93040 Regensburg, Germany
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18
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Pfister S, Przemeck GKH, Gerber JK, Beckers J, Adamski J, Hrabé de Angelis M. Interaction of the MAGUK family member Acvrinp1 and the cytoplasmic domain of the Notch ligand Delta1. J Mol Biol 2003; 333:229-35. [PMID: 14529612 DOI: 10.1016/j.jmb.2003.08.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The evolutionarily conserved Notch signal transduction pathway regulates cell fate and cellular differentiation in various tissues and has essential functions in embryonic patterning and tumorigenesis. Cell-cell signaling by the Notch pathway is mediated by the interaction of the transmembrane receptor Notch with its ligands Delta or Jagged presented on adjacent cells. Whereas signal transduction to Notch expressing cells has been described, it is unclear whether Delta-dependent signaling may exist within the Delta-expressing cell. Here, we report on the identification of Acvrinp1, a MAGUK family member, interacting with the intracellular domain of Delta1 (Dll1). We confirmed the interaction between Dll1 and Acvrinp1 by pull-down experiments in vitro and in a mammalian two-hybrid system in vivo. We delimited the fourth PDZ domain of Acvrinp1 and the PDZ-binding domain of Dll1 as major interacting domains. In situ expression analyses in mouse embryos revealed that Dll1 and Acvrinp1 show partly overlapping but distinct expression patterns, for example, in the central nervous system and the vibrissae buds. Further, we found that expression of Acvrinp1 is altered in Dll1 loss-of-function mouse embryos.
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MESH Headings
- Activin Receptors, Type II/genetics
- Activin Receptors, Type II/metabolism
- Adaptor Proteins, Signal Transducing
- Amino Acid Sequence
- Animals
- Carrier Proteins
- Cytoplasm
- Gene Expression Regulation, Developmental
- Glutathione Transferase/metabolism
- Guanylate Kinases
- HeLa Cells/metabolism
- Homozygote
- Humans
- In Situ Hybridization
- Intracellular Signaling Peptides and Proteins
- Ligands
- Membrane Proteins/deficiency
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Molecular Sequence Data
- Nervous System/embryology
- Nucleoside-Phosphate Kinase
- Protein Structure, Tertiary
- Proteins
- RNA Probes
- Receptors, Cell Surface
- Receptors, Notch
- Saccharomyces cerevisiae
- Sequence Homology, Amino Acid
- Signal Transduction
- Two-Hybrid System Techniques
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Affiliation(s)
- Sabine Pfister
- GSF-National Research Center for Environment and Health, Institute of Experimental Genetics, Ingolstaedter Landstr 1, D-85764 Neuherberg, Germany
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19
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Santagati F, Abe K, Schmidt V, Schmitt-John T, Suzuki M, Yamamura KI, Imai K. Identification of Cis-regulatory Elements in the Mouse Pax9/Nkx2-9 Genomic Region: Implication for Evolutionary Conserved Synteny. Genetics 2003; 165:235-42. [PMID: 14504231 PMCID: PMC1462746 DOI: 10.1093/genetics/165.1.235] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
We previously reported close physical linkage between Pax9 and Nkx2-9 in the human, mouse, and pufferfish (Fugu rubripes) genomes. In this study, we analyzed cis-regulatory elements of the two genes by comparative sequencing in the three species and by transgenesis in the mouse. We identified two regions including conserved noncoding sequences that possessed specific enhancer activities for expression of Pax9 in the medial nasal process and of Nkx2-9 in the ventral neural tube. Remarkably, the latter contained the consensus Gli-binding motif. Interestingly, the identified Pax9 cis-regulatory sequences were located in an intron of the neighboring gene Slc25a21. Close examination of an extended genomic interval around Pax9 revealed the presence of strong synteny conservation in the human, mouse, and Fugu genomes. We propose such an intersecting organization of cis-regulatory sequences in multigenic regions as a possible mechanism that maintains evolutionary conserved synteny.
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Affiliation(s)
- Fabio Santagati
- GSF-National Research Center for Environment and Health, Institute of Developmental Genetics, D-85764 Neuherberg, Germany
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20
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Kokubu C, Wilm B, Kokubu T, Wahl M, Rodrigo I, Sakai N, Santagati F, Hayashizaki Y, Suzuki M, Yamamura KI, Abe K, Imai K. Undulated short-tail Deletion Mutation in the Mouse Ablates Pax1 and Leads to Ectopic Activation of Neighboring Nkx2-2 in Domains That Normally Express Pax1. Genetics 2003; 165:299-307. [PMID: 14504237 PMCID: PMC1462742 DOI: 10.1093/genetics/165.1.299] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Previous studies have indicated that the Undulated short-tail deletion mutation in mouse Pax1 (Pax1Un-s) not only ablates Pax1, but also disturbs a gene or genes nearby Pax1. However, which gene(s) is involved and how the Pax1Un-s phenotype is confined to the Pax1-positive tissues remain unknown. In the present study, we determined the Pax1Un-s deletion interval to be 125 kb and characterized genes around Pax1. We show that the Pax1Un-s mutation affects four physically linked genes within or near the deletion, including Pax1, Nkx2-2, and their potential antisense genes. Remarkably, Nkx2-2 is ectopically activated in the sclerotome and limb buds of Pax1Un-s embryos, both of which normally express Pax1. This result suggests that the Pax1Un-s deletion leads to an illegitimate interaction between remotely located Pax1 enhancers and the Nkx2-2 promoter by disrupting an insulation mechanism between Pax1 and Nkx2-2. Furthermore, we show that expression of Bapx1, a downstream target of Pax1, is more strongly affected in Pax1Un-s mutants than in Pax1-null mutants, suggesting that the ectopic expression of Nkx2-2 interferes with the Pax1-Bapx1 pathway. Taken together, we propose that a combination of a loss-of-function mutation of Pax1 and a gain-of-function mutation of Nkx2-2 is the molecular basis of the Pax1Un-s mutation.
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Affiliation(s)
- Chikara Kokubu
- GSF-National Research Center for Environment and Health, Institute of Developmental Genetics, 85764 Neuherberg, Germany
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21
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Buchberger A, Nomokonova N, Arnold HH. Myf5 expression in somites and limb buds of mouse embryos is controlled by two distinct distal enhancer activities. Development 2003; 130:3297-307. [PMID: 12783799 DOI: 10.1242/dev.00557] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The initiation of skeletal muscle development in the mouse embryo is strictly associated with the expression of the muscle-specific transcription factor Myf5, the first of four myogenic regulatory factors (MRFs) to be expressed in muscle progenitors, and ablation of the Myf5 gene prevents myogenesis. The complex spatiotemporal expression pattern of Myf5 depends on many discrete regulatory elements that are dispersed over long distances throughout the gene locus. These multiple control modules act differently in the various muscle precursor populations, presumably in response to diverse signals that control myogenesis. A potent enhancer region regulating Myf5 expression in limb muscles and somites has been identified previously at -58/-48 kb upstream of the transcriptional start site (Hadchouel et al., 2000). Here, we focus on the physical and functional dissection of this control region. We demonstrate that a conserved sequence of 270 bp located around -57 kb is required and sufficient to drive Myf5 expression in limbs and to maintain it in somites. A second enhancer nearby is responsible for Myf5 transcription in occipital/cranial somites. This enhancer activity also directs expression accurately to the myotome, preventing ectopic expression in the dermomyotome during the second phase of Myf5 gene activation in somites. Our data suggest that the enhancer identified here collaborates with other somitic enhancers to ensure correct myotomal Myf5 expression. Moreover, it constitutes an important element that mediates somitic expression after the initial and transient Myf5 activation through a previously described sonic hedgehog-dependent early epaxial enhancer.
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Affiliation(s)
- Astrid Buchberger
- Department of Cell and Molecular Biology, Technical University of Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany
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22
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Przemeck GKH, Heinzmann U, Beckers J, Hrabé de Angelis M. Node and midline defects are associated with left-right development in Delta1 mutant embryos. Development 2003; 130:3-13. [PMID: 12441287 DOI: 10.1242/dev.00176] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Axes formation is a fundamental process of early embryonic development. In addition to the anteroposterior and dorsoventral axes, the determination of the left-right axis is crucial for the proper morphogenesis of internal organs and is evolutionarily conserved in vertebrates. Genes known to be required for the normal establishment and/or maintenance of left-right asymmetry in vertebrates include, for example, components of the TGF-beta family of intercellular signalling molecules and genes required for node and midline function. We report that Notch signalling, which previously had not been implicated in this morphogenetic process, is required for normal left-right determination in mice. We show, that the loss-of-function of the delta 1 (Dll1) gene causes a situs ambiguous phenotype, including randomisation of the direction of heart looping and embryonic turning. The most probable cause for this left-right defect in Dll1 mutant embryos is a failure in the development of proper midline structures. These originate from the node, which is disrupted and deformed in Dll1 mutant embryos. Based on expression analysis in wild-type and mutant embryos, we suggest a model, in which Notch signalling is required for the proper differentiation of node cells and node morphology.
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MESH Headings
- Abnormalities, Multiple/genetics
- Animals
- Body Patterning/genetics
- Cell Differentiation/genetics
- Embryonic and Fetal Development
- Gene Expression Regulation, Developmental
- Heart/embryology
- Heart Defects, Congenital/genetics
- Homozygote
- Intracellular Signaling Peptides and Proteins
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Mice, Knockout
- Mice, Mutant Strains
- Notochord/abnormalities
- Notochord/embryology
- Organizers, Embryonic/abnormalities
- Organizers, Embryonic/cytology
- Organizers, Embryonic/embryology
- Random Allocation
- Receptor, Notch1
- Receptor, Notch2
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Signal Transduction
- Transcription Factors
- Transforming Growth Factor beta/metabolism
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Affiliation(s)
- Gerhard K H Przemeck
- GSF, Institute of Experimental Genetics, Ingolstaedter Landstr 1, D-85764 Neuherberg, Germany
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23
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Herron BJ, Lu W, Rao C, Liu S, Peters H, Bronson RT, Justice MJ, McDonald JD, Beier DR. Efficient generation and mapping of recessive developmental mutations using ENU mutagenesis. Nat Genet 2002; 30:185-9. [PMID: 11818962 DOI: 10.1038/ng812] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Treatment with N-ethyl-N-nitrosourea (ENU) efficiently generates single-nucleotide mutations in mice. Along with the renewed interest in this approach, much attention has been given recently to large screens with broad aims; however, more finely focused studies have proven very productive as well. Here we show how mutagenesis together with genetic mapping can facilitate the rapid characterization of recessive loci required for normal embryonic development. We screened third-generation progeny of mutagenized mice at embryonic day (E) 18.5 for abnormalities of organogenesis. We ascertained 15 monogenic mutations in the 54 families that were comprehensively analyzed. We carried out the experiment as an outcross, which facilitated the genetic mapping of the mutations by haplotype analysis. We mapped seven of the mutations and identified the affected locus in two lines. Using a hierarchical approach, it is possible to maximize the efficiency of this analysis so that it can be carried out easily with modest infrastructure and resources.
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Affiliation(s)
- Bruce J Herron
- Genetics Division, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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24
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Berti L, Mittler G, Przemeck GK, Stelzer G, Günzler B, Amati F, Conti E, Dallapiccola B, Hrabé de Angelis M, Novelli G, Meisterernst M. Isolation and characterization of a novel gene from the DiGeorge chromosomal region that encodes for a mediator subunit. Genomics 2001; 74:320-32. [PMID: 11414760 DOI: 10.1006/geno.2001.6566] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hemizygous deletions on chromosome 22q11.2 result in developmental disorders referred to as DiGeorge syndrome (DGS)/velocardiofacial syndrome (VCFS). We report the isolation of a novel gene, PCQAP (PC2 glutamine/Q-rich-associated protein), that maps to the DiGeorge typically deleted region and encodes a protein identified as a subunit of the large multiprotein complex PC2. PC2 belongs to the family of the human Mediator complexes, which exhibit coactivator function in RNA polymerase II transcription. Furthermore, we cloned the homologous mouse Pcqap cDNA. There is 83% amino acid identity between the human and the mouse predicted protein sequences, with 96% similarity at the amino- and carboxy-terminal ends. To assess the potential involvement of PCQAP in DGS/VCFS, its developmental expression pattern was analyzed. In situ hybridization of mouse embryos at different developmental stages revealed that Pcqap is ubiquitously expressed. However, higher expression was detected in the frontonasal region, pharyngeal arches, and limb buds. Moreover, analysis of subjects carrying a typical 22q11 deletion revealed that the human PCQAP gene was deleted in all patients. Many of the structures affected in DGS/VCFS evolve from Pcqap-expressing cells. Together with the observed haploinsufficiency of PCQAP in DGS/VCFS patients, this finding is consistent with a possible role for this novel Mediator subunit in the development of some of the structures affected in DGS/VCFS.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Carrier Proteins/genetics
- Cell Line
- Chromosome Mapping
- Chromosomes, Human, Pair 22/genetics
- Cloning, Molecular
- DNA Mutational Analysis
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- DiGeorge Syndrome/genetics
- Embryo, Mammalian/metabolism
- Exons
- Female
- Gene Expression
- Genes/genetics
- Glutamine/genetics
- HeLa Cells
- Humans
- In Situ Hybridization
- In Situ Hybridization, Fluorescence
- Introns
- Jurkat Cells
- Male
- Mediator Complex
- Mice
- Molecular Sequence Data
- Mutation
- Polymorphism, Single Nucleotide
- Protein Subunits
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
- Transcription Factors/genetics
- Tumor Cells, Cultured
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Affiliation(s)
- L Berti
- Department of Protein Biochemistry, Institute of Molecular Immunology-GSF, Munich, 81377, Germany
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25
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Abstract
The current genome-sequencing projects provide "word indices" of the book of life. A central post-genomic question will be how these words are three-dimensionally deployed in the generation of organism form. Gene expression studies of developing organisms contribute an increasing wealth of snapshot data on the activation of individual genes at selected locations and single moments in the developmental process. However, a comprehensive understanding of the dynamic activation of multiple genes and their functional role in controlling the 3D processes of collective cell behaviour, pattern formation and morphogenesis, requires special tools for a systematic description of spatio-temporal patterns of gene activation and the ensuing phenotypic effects. This article concentrates on new, computer-based tools for the 3D analysis of gene expression patterns in embryonic development and their use for the systematic establishment of comprehensive gene expression maps.
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Affiliation(s)
- J Streicher
- Integrative Morphology Group, Department of Anatomy, University of Vienna, Währingerstrasse 13, A-1090 Vienna, Austria.
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26
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Hadchouel J, Tajbakhsh S, Primig M, Chang TH, Daubas P, Rocancourt D, Buckingham M. Modular long-range regulation of Myf5 reveals unexpected heterogeneity between skeletal muscles in the mouse embryo. Development 2000; 127:4455-67. [PMID: 11003844 DOI: 10.1242/dev.127.20.4455] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The myogenic factor Myf5 plays a key role in muscle cell determination, in response to signalling cascades that lead to the specification of muscle progenitor cells. We have adopted a YAC transgenic approach to identify regulatory sequences that direct the complex spatiotemporal expression of this gene during myogenesis in the mouse embryo. Important regulatory regions with distinct properties are distributed over 96 kb upstream of the Myf5 gene. The proximal 23 kb region directs early expression in the branchial arches, epaxial dermomyotome and in a central part of the myotome, the epaxial intercalated domain. Robust expression at most sites in the embryo where skeletal muscle forms depends on an enhancer-like sequence located between −58 and −48 kb from the Myf5 gene. This element is active in the epaxial and hypaxial myotome, in limb muscles, in the hypoglossal chord and also at the sites of Myf5 transcription in prosomeres p1 and p4 of the brain. However later expression of Myf5 depends on a more distal region between −96 and −63 kb, which does not behave as an enhancer. This element is necessary for expression in head muscles but strikingly only plays a role in a subset of trunk muscles, notably the hypaxially derived ventral body muscles and also those of the diaphragm and tongue. Transgene expression in limb muscle masses is not affected by removal of the −96/-63 region. Epaxially derived muscles and some hypaxial muscles, such as the intercostals and those of the limb girdles, are also unaffected. This region therefore reveals unexpected heterogeneity between muscle masses, which may be related to different facets of myogenesis at these sites. Such regulatory heterogeneity may underlie the observed restriction of myopathies to particular muscle subgroups.
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Affiliation(s)
- J Hadchouel
- Département de Biologie Moleculaire, CNRS URA 1947, Institut Pasteur, 75724 Paris Cedex 15, France
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27
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Abstract
Major advances have been made in the last 10 years in the genetics of skeletogenesis. This has followed the general progress in our understanding of the genetic control of development in chicken and mouse and more recent advances in human genetics. This large field now encompasses three smaller but distinct fields of investigation. Those are skeleton patterning, cell differentiation in the skeleton, and cell function in the skeleton. This review focuses primarily on advances in understanding cell differentiation and cell function in the skeleton at the genetic level.
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Affiliation(s)
- G Karsenty
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
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28
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Streicher J, Donat MA, Strauss B, Spörle R, Schughart K, Müller GB. Computer-based three-dimensional visualization of developmental gene expression. Nat Genet 2000; 25:147-52. [PMID: 10835627 DOI: 10.1038/75989] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A broad understanding of the relationship between gene activation, pattern formation and morphogenesis will require adequate tools for three-dimensional and, perhaps four-dimensional, representation and analysis of molecular developmental processes. We present a novel, computer-based method for the 3D visualization of embryonic gene expression and morphological structures from serial sections. The information from these automatically aligned 3D reconstructions exceeds that from single-section and whole-mount visualizations of in situ hybridizations. In addition, these 3D models of gene-expression patterns can become a central component of a future developmental database designed for the collection and presentation of digitized, morphological and gene-expression data. This work is accompanied by a web site (http://www.univie.ac.at/GeneEMAC).
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Affiliation(s)
- J Streicher
- Integrative Morphology Group, Department of Anatomy, University of Vienna, Vienna, Austria.
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29
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Wang YK, Spörle R, Paperna T, Schughart K, Francke U. Characterization and expression pattern of the frizzled gene Fzd9, the mouse homolog of FZD9 which is deleted in Williams-Beuren syndrome. Genomics 1999; 57:235-48. [PMID: 10198163 DOI: 10.1006/geno.1999.5773] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The frizzled gene family is conserved from insects to mammals and codes for putative Wnt receptors that share a cysteine-rich extracellular domain and seven transmembrane domains. We previously identified a novel frizzled gene, FZD3, now renamed FZD9, in the Williams-Beuren syndrome (WBS) deletion region at chromosomal band 7q11.23 and showed that its product can interact with the Drosophila wingless protein. Here, we report the characterization of the mouse homolog Fzd9. The Fzd9 gene produces a 2.4-kb transcript encoding a 592-amino-acid protein with 95% identity to the human FZD9. Fzd9 was mapped to the conserved syntenic region on distal mouse chromosome 5. By RNA in situ hybridization studies of whole-mount embryos and sections we delineated the temporal and spatial expression patterns in the neural tube, trunk skeletal muscle precursors (myotomes), limb skeletal anlagen, craniofacial regions, and nephric ducts. In adult mouse tissue, the Fzd9 transcript is abundantly present in heart, brain, testis, and skeletal muscle. In testis, Fzd9 is expressed in all spermatogenic cell types. Immunohistochemical studies of cells transfected with a Fzd9 expression construct confirm that Fzd9 is a membrane protein. These results suggest potential Wnt ligands of Fzd9, a role of Fzd9 in skeletal muscle specification, and contributions of FZD9 to the WBS phenotype.
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MESH Headings
- Amino Acid Sequence
- Animals
- Blotting, Northern
- Cell Membrane/immunology
- Cell Membrane/metabolism
- Chromosome Mapping
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Embryo, Mammalian/metabolism
- Frizzled Receptors
- Gene Deletion
- Gene Expression
- Gene Expression Regulation, Developmental
- Humans
- In Situ Hybridization
- Male
- Mice
- Molecular Sequence Data
- Nervous System/embryology
- Nervous System/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/immunology
- Receptors, G-Protein-Coupled
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Somites/metabolism
- Testis/embryology
- Testis/metabolism
- Tissue Distribution
- Williams Syndrome/genetics
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Affiliation(s)
- Y K Wang
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305, USA
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30
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Grimm C, Spörle R, Schmid TE, Adler ID, Adamski J, Schughart K, Graw J. Isolation and embryonic expression of the novel mouse gene Hic1, the homologue of HIC1, a candidate gene for the Miller-Dieker syndrome. Hum Mol Genet 1999; 8:697-710. [PMID: 10072440 DOI: 10.1093/hmg/8.4.697] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The human gene HIC1 (hypermethylated in cancer) maps to chromosome 17p13.3 and is deleted in the contiguous gene disorder Miller-Dieker syndrome (MDS) [Makos-Wales et al. (1995) Nature Med., 1, 570-577; Chong et al. (1996) Genome Res., 6, 735-741]. We isolated the murine homologue Hic1, encoding a zinc-finger protein with a poxvirus and zinc-finger (POZ) domain and mapped it to mouse chromosome 11 in a region exhibiting conserved synteny to human chromosome 17. Comparison of genomic and cDNA sequences predicts two exons for the murine Hic1. The second exon exhibits 88% identity to the human HIC1 on DNA level. During embryonic development, Hic1 is expressed in mesenchymes of the sclerotomes, lateral body wall, limb and cranio-facial regions embedding the outgrowing peripheral nerves during their differentiation. During fetal development, Hic1 additionally is expressed in mesenchymes apposed to precartilaginous condensations, at many interfaces to budding epithelia of inner organs, and weakly in muscles. We observed activation of Hic1 expression in the embryonic anlagen of many tissues displaying anomalies in MDS patients. Besides lissencephaly, MDS patients exhibit facial dysmorphism and frequently additional birth defects, e.g. anomalies of the heart, kidney, gastrointestinal tract and the limbs (OMIM 247200). Thus, HIC1 activity may correlate with the defective development of the nose, jaws, extremities, gastrointestinal tract and kidney in MDS patients.
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MESH Headings
- Abnormalities, Multiple/genetics
- Amino Acid Sequence
- Animals
- Base Sequence
- Brain/abnormalities
- Chromosome Mapping
- DNA/chemistry
- DNA/genetics
- DNA/isolation & purification
- Embryo, Mammalian/chemistry
- Fetus/chemistry
- Gene Expression Regulation, Developmental
- Genes, Tumor Suppressor/genetics
- In Situ Hybridization
- In Situ Hybridization, Fluorescence
- Kruppel-Like Transcription Factors
- Mesoderm/chemistry
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Molecular Sequence Data
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Syndrome
- Tissue Distribution
- Transcription Factors/genetics
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Affiliation(s)
- C Grimm
- GSF-National Research Center for Environment and Health, Institute of Mammalian Genetics, D-85764 Neuherberg, Germany
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