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Abstract
The supraoptic nucleus (SON) is a particularly good model for the study of cell-type specific gene expression because it contains two distinct neuronal phenotypes, the oxytocin (OT) and vasopressin (AVP) synthesising magnocellular neurones (MCNs). The MCNs are found in approximately equal numbers and selectively express either the OT or the AVP gene in approximately 97% of the MCN population in the SON. An unresolved issue has been to determine what mechanisms are responsible for the highly selective regulation of the cell-type specific expression of OT and AVP genes in the MCNs. Previous attempts to address this question have used various bioinformatic and molecular approaches, which included using heterologous cell lines to study the putative cis-elements in the OT and AVP genes, and the use of OT and/or AVP transgenes in transgenic rodents. The data from all of the above studies identified a region < 0.6 kbp upstream of OT exon I and approximately 3 kb upstream of AVP exon I as being sufficient to produce cell-specific expression of the OT and AVP genes, respectively, although they failed to identify the specific cis-domains responsible for the MCN-specific gene expression. An alternative experimental approach to perform promoter deletion analysis in vivo (i.e. to use stereotaxic viral vector gene transfer into the SON to further dissect the cis-elements in the OT and AVP genes) will be described here. This in vivo method uses adeno-associated viral (AAV) vectors expressing OT-promoter deletion constructs and utilises the enhanced green fluorescent protein (EGFP) as the reporter. The AAV constructs are stereotaxically injected into the rat brain above the SON and, 2 weeks post injection, the rats are sacrificed and assayed for EGFP expression. Using this method, it has been possible to identify specific regions upstream of the transcription start site in the OT and AVP gene promoters that are responsible for conferring the cell-type specificity of the OT and AVP gene expression in the SON.
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Affiliation(s)
- H Gainer
- Section on Molecular Neuroscience, Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
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2
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Tsubota T, Ohashi Y, Tamura K, Sato A, Miyashita Y. Optogenetic manipulation of cerebellar Purkinje cell activity in vivo. PLoS One 2011; 6:e22400. [PMID: 21850224 PMCID: PMC3151259 DOI: 10.1371/journal.pone.0022400] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 06/21/2011] [Indexed: 11/19/2022] Open
Abstract
Purkinje cells (PCs) are the sole output neurons of the cerebellar cortex. Although their anatomical connections and physiological response properties have been extensively studied, the causal role of their activity in behavioral, cognitive and autonomic functions is still unclear because PC activity cannot be selectively controlled. Here we developed a novel technique using optogenetics for selective and rapidly reversible manipulation of PC activity in vivo. We injected into rat cerebellar cortex lentiviruses expressing either the light-activated cationic channel channelrhodopsin-2 (ChR2) or light-driven chloride pump halorhodopsin (eNpHR) under the control of the PC-specific L7 promoter. Transgene expression was observed in most PCs (ChR2, 92.6%; eNpHR, 95.3%), as determined by immunohistochemical analysis. In vivo electrophysiological recordings showed that all light-responsive PCs in ChR2-transduced rats increased frequency of simple spike in response to blue laser illumination. Similarly, most light-responsive PCs (93.8%) in eNpHR-transduced rats decreased frequency of simple spike in response to orange laser illumination. We then applied these techniques to characterize the roles of rat cerebellar uvula, one of the cardiovascular regulatory regions in the cerebellum, in resting blood pressure (BP) regulation in anesthetized rats. ChR2-mediated photostimulation and eNpHR-mediated photoinhibition of the uvula had opposite effects on resting BP, inducing depressor and pressor responses, respectively. In contrast, manipulation of PC activity within the neighboring lobule VIII had no effect on BP. Blue and orange laser illumination onto PBS-injected lobule IX didn't affect BP, indicating the observed effects on BP were actually due to PC activation and inhibition. These results clearly demonstrate that the optogenetic method we developed here will provide a powerful way to elucidate a causal relationship between local PC activity and functions of the cerebellum.
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Affiliation(s)
- Tadashi Tsubota
- Department of Physiology, The University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Yohei Ohashi
- Department of Physiology, The University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Keita Tamura
- Department of Physiology, The University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Ayana Sato
- Department of Physiology, The University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan
- Department of Physics, The University of Tokyo School of Science, Bunkyo-ku, Tokyo, Japan
| | - Yasushi Miyashita
- Department of Physiology, The University of Tokyo School of Medicine, Bunkyo-ku, Tokyo, Japan
- Department of Physics, The University of Tokyo School of Science, Bunkyo-ku, Tokyo, Japan
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3
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Jensen KK, Manfra DJ, Grisotto MG, Martin AP, Vassileva G, Kelley K, Schwartz TW, Lira SA. The human herpes virus 8-encoded chemokine receptor is required for angioproliferation in a murine model of Kaposi's sarcoma. THE JOURNAL OF IMMUNOLOGY 2005; 174:3686-94. [PMID: 15749907 DOI: 10.4049/jimmunol.174.6.3686] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Kaposi's sarcoma (KS)-associated herpesvirus or human herpes virus 8 is considered the etiological agent of KS, a highly vascularized neoplasm that is the most common tumor affecting HIV/AIDS patients. The KS-associated herpesvirus/human herpes virus 8 open reading frame 74 encodes a constitutively active G protein-coupled receptor known as vGPCR that binds CXC chemokines with high affinity. In this study, we show that conditional transgenic expression of vGPCR by cells of endothelial origin triggers an angiogenic program in vivo, leading to development of an angioproliferative disease that resembles KS. This angiogenic program consists partly in the expression of the angiogenic factors placental growth factor, platelet-derived growth factor B, and inducible NO synthase by the vGPCR-expressing cells. Finally, we show that continued vGPCR expression is essential for progression of the KS-like phenotype and that down-regulation of vGPCR expression results in reduced expression of angiogenic factors and regression of the lesions. Together, these findings implicate vGPCR as a key element in KS pathogenesis and suggest that strategies to block its function may represent a novel approach for the treatment of KS.
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MESH Headings
- Animals
- Becaplermin
- Disease Models, Animal
- Doxycycline/pharmacology
- Gene Expression/drug effects
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/immunology
- Herpesvirus 8, Human/pathogenicity
- Humans
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Transgenic
- Neovascularization, Pathologic
- Nitric Oxide Synthase/metabolism
- Nitric Oxide Synthase Type II
- Placenta Growth Factor
- Platelet-Derived Growth Factor/metabolism
- Pregnancy Proteins/metabolism
- Proto-Oncogene Proteins c-sis
- Receptors, Chemokine/genetics
- Receptors, Chemokine/physiology
- Sarcoma, Kaposi/blood supply
- Sarcoma, Kaposi/etiology
- Sarcoma, Kaposi/immunology
- Sarcoma, Kaposi/pathology
- Viral Proteins/genetics
- Viral Proteins/physiology
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Affiliation(s)
- Kristian K Jensen
- Immunobiology Center, Mount Sinai School of Medicine, New York, NY 10029, USA
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4
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Young WS, Gainer H. Transgenesis and the study of expression, cellular targeting and function of oxytocin, vasopressin and their receptors. Neuroendocrinology 2003; 78:185-203. [PMID: 14583651 DOI: 10.1159/000073702] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2003] [Accepted: 08/12/2003] [Indexed: 11/19/2022]
Abstract
The neuropeptides oxytocin and vasopressin and the neurons in the hypothalamus that synthesize them have been a rich source for the exploration and understanding of both the brain and the endocrine system. Because of their large size and compact nuclear organization the magnocellular neurons of the hypothalamoneurohypophysial system have traditionally attracted scientists using state-of-the-art techniques, including the subject of this review, transgenesis. We discuss the role of transgenics in deciphering gene elements necessary for the appropriate expression of oxytocin and vasopressin and to deliver exogenous genes, such as green fluorescent protein, selectively to secretory granules in the neurons in the hypothalamoneurohypophysial system. Finally, we review the studies of mice whose genes for oxytocin and, most recently, for the oxytocin and vasopressin receptors have been knocked out through homologous recombination.
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Affiliation(s)
- W Scott Young
- National Institute of Mental Health and Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892-4068, USA.
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5
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Si-Hoe SL, Wells S, Murphy D. Production of transgenic rodents by the microinjection of cloned DNA into fertilized one-cell eggs. Mol Biotechnol 2001; 17:151-82. [PMID: 11395864 DOI: 10.1385/mb:17:2:151] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Transgenic technologies that enable rapid movement between genotype and phenotype through specific loss-of-function, overexpression, or misexpression phenotypes will be crucial in the elucidation of gene sequences emerging from genome projects. This article describes detailed procedures for the generation of transgenic mice and rats by the injection of cloned DNA into the pronuclei of fertilized one-cell eggs.
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Affiliation(s)
- S L Si-Hoe
- Molecular Neuroendocrinology Research Group, Univ. Res. Centre for Neuroendocrinology, Univ. Bristol, Bristol Royal Infirmary, Marlborough Street, Bristol, BS2 8HW, UK
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6
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Transgenic Models for Studies of Oxytocin and Vasopressin. TRANSGENIC MODELS IN ENDOCRINOLOGY 2001. [DOI: 10.1007/978-1-4615-1633-0_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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7
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Feng G, Mellor RH, Bernstein M, Keller-Peck C, Nguyen QT, Wallace M, Nerbonne JM, Lichtman JW, Sanes JR. Imaging neuronal subsets in transgenic mice expressing multiple spectral variants of GFP. Neuron 2000; 28:41-51. [PMID: 11086982 DOI: 10.1016/s0896-6273(00)00084-2] [Citation(s) in RCA: 2375] [Impact Index Per Article: 99.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We generated transgenic mice in which red, green, yellow, or cyan fluorescent proteins (together termed XFPs) were selectively expressed in neurons. All four XFPs labeled neurons in their entirety, including axons, nerve terminals, dendrites, and dendritic spines. Remarkably, each of 25 independently generated transgenic lines expressed XFP in a unique pattern, even though all incorporated identical regulatory elements (from the thyl gene). For example, all retinal ganglion cells or many cortical neurons were XFP positive in some lines, whereas only a few ganglion cells or only layer 5 cortical pyramids were labeled in others. In some lines, intense labeling of small neuronal subsets provided a Golgi-like vital stain. In double transgenic mice expressing two different XFPs, it was possible to differentially label 3 neuronal subsets in a single animal.
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Affiliation(s)
- G Feng
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, Missouri 63110, USA
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8
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Masland RH, Raviola E. Confronting complexity: strategies for understanding the microcircuitry of the retina. Annu Rev Neurosci 2000; 23:249-84. [PMID: 10845065 DOI: 10.1146/annurev.neuro.23.1.249] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The mammalian retina contains upward of 50 distinct functional elements, each carrying out a specific task. Such diversity is not rare in the central nervous system, but the retina is privileged because its physical location, the distinctive morphology of its neurons, the regularity of its architecture, and the accessibility of its inputs and outputs permit a unique variety of experiments. Recent strategies for confronting the retina's complexity attempt to marry genetic approaches to new kinds of anatomical and electrophysiological techniques.
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Affiliation(s)
- R H Masland
- Howard Hughes Medical Institute, Massachusetts General Hospital, Boston 02114, USA.
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9
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Waschek JA, Bravo DT, Sena M, Casillas R, Rodriguez W, Nguyen T, Colburn S. Targeting of embryonic and postnatal autonomic and enteric neurons with a vasoactive intestinal peptide transgene. J Neurochem 1999; 73:1739-48. [PMID: 10501223 DOI: 10.1046/j.1471-4159.1999.731739.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The neuropeptide vasoactive intestinal peptide (VIP) is expressed in several distinct sites in the CNS, in cholinergic and enteric ganglia, and in a small subpopulation of neurons within sympathetic ganglia. Previous studies on the human VIP gene indicate that transcription in neural crest-derived neuroblastoma and pheochromocytoma cell lines is controlled in part by multiple regulatory elements located along 4.5 kb of upstream 5' flanking sequence. In the current studies, transgenic mice were created with a chimeric gene consisting of 16.5 kb of the mouse VIP gene fused to the beta-galactosidase reporter. In situ hybridization analysis in adult mice indicated that reporter gene expression was correctly targeted to neurons in the esophagus, stomach, small intestine, and colon. No expression was observed in the brain, including regions that contain abundant VIP-expressing cells, such as the thalamus, amygdala, cerebral cortex, hippocampus, and suprachiasmatic nucleus. Analysis of transgene expression in neonatal and embryonic day 13.5 mice revealed a near perfect correlation between VIP and beta-galactosidase gene expression in cranial cholinergic ganglia and the superior cervical ganglia, and lack of transgene expression in sensory ganglia and in nonneuronal tissue. Potential ectopic transgene expression was observed in neonates, in the cerebellar external granule layer and in a small subpopulation of neurons in the olfactory epithelium. We conclude that the 16.5 kb of VIP gene used in these studies contains sequences sufficient for directing expression specifically to VIP neurons in the PNS, and that sequences located elsewhere on the gene are required for proper CNS expression. The VIP gene sequences used here should be capable of targeting other gene products to specific populations of embryonic and adult peripheral neurons without causing significant expression in the CNS.
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Affiliation(s)
- J A Waschek
- Department of Psychiatry and Mental Retardation Research Center, University of California at Los Angeles, 90024-1759, USA
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10
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Lubon H. Transgenic animal bioreactors in biotechnology and production of blood proteins. BIOTECHNOLOGY ANNUAL REVIEW 1999; 4:1-54. [PMID: 9890137 DOI: 10.1016/s1387-2656(08)70066-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The regulatory elements of genes used to target the tissue-specific expression of heterologous human proteins have been studied in vitro and in transgenic mice. Hybrid genes exhibiting the desired performance have been introduced into large animals. Complex proteins like protein C, factor IX, factor VIII, fibrinogen and hemoglobin, in addition to simpler proteins like alpha 1-antitrypsin, antithrombin III, albumin and tissue plasminogen activator have been produced in transgenic livestock. The amount of functional protein secreted when the transgene is expressed at high levels may be limited by the required posttranslational modifications in host tissues. This can be overcome by engineering the transgenic bioreactor to express the appropriate modifying enzymes. Genetically engineered livestock are thus rapidly becoming a choice for the production of recombinant human blood proteins.
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Affiliation(s)
- H Lubon
- Plasma Derivatives Department, American Red Cross, Rockville, Maryland, USA.
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11
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Moore AW, Schedl A, McInnes L, Doyle M, Hecksher-Sorensen J, Hastie ND. YAC transgenic analysis reveals Wilms' tumour 1 gene activity in the proliferating coelomic epithelium, developing diaphragm and limb. Mech Dev 1998; 79:169-84. [PMID: 10349631 DOI: 10.1016/s0925-4773(98)00188-9] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Wilms' Tumour 1 gene (WT1) is required for the correct development of the urogenital system. To examine its regulation and expression, we created several transgenic mouse lines containing a beta-galactosidase reporter driven by the human WT1 promoter. A 5 kb promoter weakly recapitulated a subset of the endogenous Wt1 expression pattern. In contrast, 470 and 280 kb YAC transgenes reproduced the correct pattern with high activity and highlighted new expression sites. Wt1 is expressed in the septum transversum revealing how its mutation causes diaphragmatic defects. Wt1 expression in the limb demarcates a zone between chondrogenic and apoptotic domains. Finally, Wt1 is expressed in mesenchymal cells derived from the coelomic epithelium. Based upon these and further data we discuss a Wt1 role in epithelial<-->mesenchymal transitions.
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Affiliation(s)
- A W Moore
- MRC Human Genetics Unit, Western General Hospital, Edinburg, UK
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12
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Rökaeus A, Waschek JA. Tissue-specific enhancement and restriction of galanin gene expression in transgenic mice by 5' flanking sequences. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1998; 60:150-9. [PMID: 9757022 DOI: 10.1016/s0169-328x(98)00162-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Galanin (GAL) is a 29/30 amino acid residue neuropeptide that regulates a wide variety of neuroendocrine functions. Galanin is expressed in specific populations of neurons in the hypothalamus and other regions of the brain and in numerous peripheral sites. Previous studies in which galanin-reporter genes were transfected into neural crest-derived neuroblastoma and other tumor cells indicated that cell-specific galanin expression is controlled by gene elements on the 5' flanking sequence which enhance and restrict transcriptional activity. To determine how the gene sequences act in vivo, we first determined the distribution of endogenous galanin gene expression in normal mice. Galanin mRNA was detected in several parts of the central nervous system (CNS), and in several peripheral organs, including the pituitary, pancreas, small and large intestine, adrenal gland, lung, tongue, testes, ovary-fallopian tubes, and uterus, but not at detectable levels in the heart, liver, kidney, urinary bladder or skeletal muscle. We then created several lines of transgenic mice which contained either 5 or 0.131 kilobases (kb) of the bovine galanin gene 5' flanking sequence fused to the luciferase (luc) reporter gene (5GAL-luc vs. 0.1GAL-luc mice, respectively) and compared luciferase activity in these and other organs. In some regions of the CNS that expressed high amounts of galanin mRNA, such as the spinal cord, hypothalamus, thalamus, and medulla, transgene expression was significantly higher in 5GAL-luc vs. 0.1GAL-luc mice, whereas in certain other regions of the brain and in all peripheral organs, the ratio was strikingly reversed. It is concluded that 5 kb of flanking sequence contains elements that mediate basal transcriptional activity in certain parts of the CNS, but also contains sequences that restrict expression in many tissues. However, because the larger transgene was expressed at very low levels in some peripheral sites of high galanin expression such as the pituitary, pancreas, adrenal gland, and intestine, it is concluded that sequences on the 5 kb transgene are not sufficient to direct expression to these peripheral tissues in mice.
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Affiliation(s)
- A Rökaeus
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77, Stockholm, Sweden.
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13
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DiMattia GE, Rhodes SJ, Krones A, Carrière C, O'Connell S, Kalla K, Arias C, Sawchenko P, Rosenfeld MG. The Pit-1 gene is regulated by distinct early and late pituitary-specific enhancers. Dev Biol 1997; 182:180-90. [PMID: 9073460 DOI: 10.1006/dbio.1996.8472] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The differentiation of three anterior pituitary cell types is regulated by the tissue-specific POU domain factor Pit-1, which is initially expressed on Embryonic Day 13.5-14 in mice. The Pit-1 gene remains continuously, highly expressed in the somatotrope, thyrotrope, and lactotrope cells of the adult. Using the Pit-1-defective Snell dwarf as a genetic background, we demonstrate that the Pit-1 gene utilizes distinct enhancers for initial gene activation and for subsequent autoregulation (required for maintenance of expression) and that Pit-1-dependent activation of the distal enhancer can be mediated in the absence of the early enhancer. These two distinct enhancers provide the basis for temporally specific regulation by discrete pituitary-specific factors, events likely to be prototypic for regulation of other classes of genes encoding transcription factors controlling terminal differentiation.
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Affiliation(s)
- G E DiMattia
- Howard Hughes Medical Institute, Department and School of Medicine, University of California at San Diego, La Jolla 92093-0648, USA
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14
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Ratty AK, Jeong SW, Nagle JW, Chin H, Gainer H, Murphy D, Venkatesh B. A systematic survey of the intergenic region between the murine oxytocin- and vasopressin-encoding genes. Gene X 1996; 174:71-8. [PMID: 8863731 DOI: 10.1016/0378-1119(96)00370-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The genomic region between the oxytocin (OT) and vasopressin (VP) genes in the two strains of mice was independently sequenced by our two groups. In this report, we present our collated sequence data and analyses. The mouse intergenic region (MUIGR) was aligned to that of the rat, which has been reported to contain 6.4-kb long interspersed nuclear element (LINE). The MUIGR sequences in the two mice strains did not contain any LINE sequences. This suggests that the approximately 3.5-kb sequence that is conserved between the rat and mouse intergenic regions is likely to be involved in the regulation of OT and VP expression. We also observed several conserved putative transcription factor recognition sequences. Analysis of the MUIGR revealed the lack of any significant ORFs, but the presence of several repetitive elements.
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Affiliation(s)
- A K Ratty
- Institute of Molecular and Cell Biology, National University of Singapore, Singapore.
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15
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Ye P, Xing Y, Dai Z, D'Ercole AJ. In vivo actions of insulin-like growth factor-I (IGF-I) on cerebellum development in transgenic mice: evidence that IGF-I increases proliferation of granule cell progenitors. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1996; 95:44-54. [PMID: 8873975 DOI: 10.1016/0165-3806(96)00492-0] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The in vivo actions of insulin-like growth factor-I (IGF-I) on cerebellum development have been investigated in transgenic (Tg) mice (IGF-II/I Tg mice) in whom an IGF-II promoter-driven IGF-I transgene is highly expressed in cerebellum. Compared to normal littermates, the brains of IGF-II/I Tg mice exhibited overgrowth beginning from the second week of postnatal life. Among the brain regions examined, cerebellum exhibited the greatest increase in size, such that by 50 days of age cerebellar weight and DNA content were increased by 90% and 143%, respectively, compared to littermate controls. Morphological studies of adult IGF-II/I Tg mice showed that the total number of granule and Purkinje cells was increased by 82% and 20%, respectively, findings consistent with the increased cerebellar DNA content and indicating that the increased cerebellar weight was due in part to an increase in cell number. The thickness of the molecular layer also was increased in IGF-II/I Tg mice. During early postnatal development the number of external granular layer cells, as well as the number of BrdU labeled external granular cells, was increased. These data strongly indicate that IGF-I increases granule cell number by a mechanism that involves the stimulation of granule cell progenitor proliferation. Our findings also indicate that IGF-I influences the growth of Purkinje cells and possibly of other cell types in the cerebellum.
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Affiliation(s)
- P Ye
- Department of Pediatrics, University of North Carolina at Chapel Hill 27599-7220, USA
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16
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Greenberg BD, Savage MJ, Howland DS, Ali SM, Siedlak SL, Perry G, Siman R, Scott RW. APP transgenesis: approaches toward the development of animal models for Alzheimer disease neuropathology. Neurobiol Aging 1996; 17:153-71. [PMID: 8744397 DOI: 10.1016/0197-4580(96)00001-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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17
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Ali SM, Siedlak SL, Gonzalez-DeWhitt PA, Altman RA, Glendening JM, Lowery DE, Savage MJ, Polites HG, Perry G, Greenberg BD. Artifactual strain-specific signs of incipient brain amyloidosis in APP transgenic mice. Neurobiol Aging 1996; 17:223-34. [PMID: 8744403 DOI: 10.1016/0197-4580(95)02065-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In an attempt to generate transgenic mice modeling Alzheimer-type amyloidogenesis, the COOH-terminal 103 residue human APP segment was expressed in brain regions known to be vulnerable in AD. Transfected cells overexpressing this transgene were previously shown to develop intracytoplasmic inclusions that were immunoreactive with antibodies to the APP COOH-terminus. Transgenic C57B6/SJL mice produced transgene-coded mRNA in their brains at levels up to sixfold above endogenous APP, most abundantly within cortical and hippocampal pyramidal neurons. Immunocytochemistry with anti-A beta antibodies revealed occasional structures that resembled diffuse amyloid, but which could not be detected on serial sections. Immunolabeling with antibodies to APP regions NH2-terminal to the transgene-coded domain revealed elevated immunoreactivity within perikarya and neurites in regions expressing the highest transgene and endogenous APP mRNA levels, similar to observations previously reported within vulnerable neurons in AD brain. However, subsequent breeding revealed that this phenotype segregated with the B6/SJL background rather than the transgene, thus emphasizing the importance of genetic background to observations of putative AD-type pathology in transgenic animals.
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Affiliation(s)
- S M Ali
- Upjohn Company, Kalamazoo, MI 49001, USA
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18
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Waschek JA. Transgenic targeting of neuroendocrine peptide genes in the hypothalamic-pituitary axis. Mol Neurobiol 1995; 10:205-17. [PMID: 7576308 DOI: 10.1007/bf02740676] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A large number of neuroendocrine peptide genes have been tested for their ability to target expression to the hypothalamus and pituitary in transgenic mice. This has resulted in a number of powerful applications, for example, ablation or immortalization of specific cell types, and analysis of transcription regulatory sequences. The greatest amount of success in targeting cells of the neuroendocrine axis has been in the pituitary and has utilized regulatory sequences of genes that are normally expressed in pituitary. Greater difficulties have been encountered in directing expression to specific neurons in the hypothalamus. A primary goal of this review is to consider collectively the data obtained by a number of laboratories in order to draw conclusions about the general sequence requirements for achieving cell-specific expression. The data suggest that the mechanisms controlling cell-specific expression of neuropeptide genes in the hypothalamus are complex and involve multiple regulatory elements that may reside within the gene or many kilobases away from the promoter. These elements act positively and negatively in different cells to enhance or restrict expression, and may include sequences that shield a transgene from regulatory influences of other genes near the point of chromosomal insertion.
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Affiliation(s)
- J A Waschek
- Department of Psychiatry, University of California, Los Angeles 90024-1759, USA
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Kobayashi K, Morita S, Sawada H, Mizuguchi T, Yamada K, Nagatsu I, Fujita K, Kreitman RJ, Pastan I, Nagatsu T. Immunotoxin-mediated conditional disruption of specific neurons in transgenic mice. Proc Natl Acad Sci U S A 1995; 92:1132-6. [PMID: 7862648 PMCID: PMC42652 DOI: 10.1073/pnas.92.4.1132] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We have developed a transgenic approach, termed immunotoxin-mediated cell targeting (IMCT), to ablate conditionally selective neurons in the brain with the cytotoxic activity of immunotoxins. Transgenic mice were created that express the human interleukin 2 receptor alpha subunit (IL-2R alpha) under the control of the dopamine beta-hydroxylase (DBH) gene promoter. The animals were treated intracerebroventricularly with a recombinant immunotoxin, anti-Tac(Fv)-PE40, which selectively kills animal cells bearing human IL-2R alpha. The immunotoxin caused a characteristic behavioral abnormality only in the transgenic mice. This was accompanied by a dramatic loss of DBH-containing neurons and a significant decrease in DBH activity and norepinephrine levels in various regions of the brain. IMCT should provide a general technique to create animal models of human neurodegenerative disorders by targeting neurons or other cell types.
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Affiliation(s)
- K Kobayashi
- Institute for Comprehensive Medical Science, School of Medicine, Fujita Health University, Toyoake, Japan
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20
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Mayo KE, Godfrey PA, Suhr ST, Kulik DJ, Rahal JO. Growth hormone-releasing hormone: synthesis and signaling. RECENT PROGRESS IN HORMONE RESEARCH 1995; 50:35-73. [PMID: 7740167 DOI: 10.1016/b978-0-12-571150-0.50007-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The molecular characterization of GHRH and the GHRH receptor provides a framework for understanding the hypothalamic regulation of pituitary somatotroph function. The signaling events discerned from our investigation of GHRH receptor structure and function form the basis of a model for GHRH action, which is shown in Fig. 20. GHRH interaction with its seven transmembrane domain Gs-coupled receptor on the somatotroph (step 1) leads to the release of growth hormone from secretory granules (step 2), which is likely to involve a G protein-mediated interaction with ion channels, and to a stimulation of intracellular cAMP accumulation (step 3) (Mayo, 1992; Lin et al., 1992; Gaylinn et al., 1993). In several cell types tested, elevated cAMP leads to the phosphorylation and activation of the transcription factor CREB by protein kinase A (Gonzalez and Montminy, 1989; Sheng et al., 1991), and one target gene for CREB action is the pituitary-specific transcription factor Pit-1 or GHF-1 (step 4) (Bodner et al., 1988; Ingraham et al., 1988; McCormick et al., 1990). Pit-1 is a prototypic POU domain protein that is required for the appropriate regulation of the growth hormone gene in somatotroph cells, thus providing a pathway by which a GHRH signal can lead to increased growth hormone synthesis in the pituitary (step 5). In addition, Pit-1 is likely to directly regulate the synthesis of the GHRH receptor (step 6), in that the receptor is not expressed in the pituitary of dw/dw mice that lack functional Pit-1 (Lin et al., 1992), and a cotransfected Pit-1 expression construct can activate the GHRH receptor promoter in transiently transfected CV1 cells (Lin et al., 1993). It remains to be determined whether additional direct regulation of the GHRH receptor gene in response to the cAMP signaling pathway occurs (step 7). The inhibitory peptide somatostatin presumably interacts with this same signaling pathway through G protein-mediated suppression of the cAMP pathway (Tallent and Reisine, 1992; Bell and Reisine, 1993). In agreement with the importance of this signaling system for normal growth, a transgene encoding a nonphosphorylatable mutant CREB protein, which blocks the function of the endogenous CREB protein, is able to cause somatotroph hypoplasia and dwarfism in mice when its expression is targeted to pituitary somatotrophs (Struthers et al., 1991). Several steps in the signaling pathway leading to growth hormone secretion are subject to disruption, resulting in growth hormone deficiency.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- K E Mayo
- Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208, USA
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21
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D'Ercole AJ, Dai Z, Xing Y, Boney C, Wilkie MB, Lauder JM, Han VK, Clemmons DR. Brain growth retardation due to the expression of human insulin like growth factor binding protein-1 in transgenic mice: an in vivo model for the analysis of igf function in the brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1994; 82:213-22. [PMID: 7531120 DOI: 10.1016/0165-3806(94)90164-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Three lines of transgenic (Tg) mice carrying a fusion gene linking the mouse metallothionein-I promoter to a cDNA encoding human insulin-like growth factor binding protein-1 (hIGFBP-1) were found to express the transgene in brain. As judged by comparing Tg brain weights to those of non-transgenic littermates, adult hemizygotic Tg mice of each line exhibited brain growth retardation (16.2%, 14.4% and 8.1% reductions in weight, respectively in each line). In two lines, total brain DNA and protein content were decreased. Further analysis indicated that the brain growth retardation was manifested in the second week of postnatal life. Given that the insulin-like growth factors (IGFs) stimulate cell proliferation and/or survival in neural cultures and that hIGFBP-1, when present in a molar excess, inhibits IGF interactions with their cell surface receptors, the brain growth retardation in hIGFBP-1 Tg mice likely results from hIGFBP-1 inhibition of IGF-stimulated growth-promoting actions. These hIGFBP-1 Tg mice should prove useful in defining IGF actions during postnatal brain maturation.
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Affiliation(s)
- A J D'Ercole
- Department of Pediatrics, University of North Carolina at Chapel Hill 27599-7220
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22
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Banerjee SA, Roffler-Tarlov S, Szabo M, Frohman L, Chikaraishi DM. DNA regulatory sequences of the rat tyrosine hydroxylase gene direct correct catecholaminergic cell-type specificity of a human growth hormone reporter in the CNS of transgenic mice causing a dwarf phenotype. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1994; 24:89-106. [PMID: 7968381 DOI: 10.1016/0169-328x(94)90121-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Transgenic mice bearing 4.8 kilobases (kb) of upstream rat tyrosine hydroxylase (TH) sequences linked to a human growth hormone gene (hGH) exhibited cell-specific expression of hGH in all the appropriate catecholaminergic neurons in the central nervous system (CNS), although with different penetrance in two different mouse lineages. No ectopic expression was observed in any brain or peripheral region in one founder and its progeny. In another founder there was some ectopic expression in addition to appropriate and high levels of tissue-specific expression in all catecholaminergic areas. These results identify regulatory sequences that are sufficient for targeting expression to all catecholaminergic CNS neurons. Also, expression of exogenous hGH in the hypothalamus caused a dwarf phenotype, generating a novel genetic model for GH deficiency of hypothalamic origin.
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Affiliation(s)
- S A Banerjee
- Department of Microbiology, Tufts University School of Medicine, Boston, MA 02111
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23
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Nagatsu I, Karasawa N, Yamada K, Sakai M, Fujii T, Takeuchi T, Arai R, Kobayashi K, Nagatsu T. Expression of human tyrosine hydroxylase-chloramphenicol acetyltransferase (CAT) fusion gene in the brains of transgenic mice as examined by CAT immunocytochemistry. J Neural Transm (Vienna) 1994; 96:85-104. [PMID: 7857598 DOI: 10.1007/bf01277931] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have produced transgenic (Tg) mice carrying 5.0-kb fragment from the 5'-flanking region of the human tyrosine hydroxylase (hTH) gene fused to a reporter gene, chloramphenicol acetyltransferase (CAT) [Sasaoka et al. (1992) Mol Brain Res 16: 274-286]. In the brain of the Tg mice, CAT expression has been observed in catecholaminergic (CAnergic) neurons and also in non-CAnergic neurons. The aim of the present study is to examine in detail the cell-type specific expression of the hTH-CAT fusion gene in the brain of the Tg mice, by use of immunohistochemistry for CAT, TH, and aromatic L-amino acid decarboxylase (AADC). CAT-immunoreactive cells were found in CAnergic brain regions which contained TH-positive cells, and also in non-CAnergic brain regions which contained no TH-labeled cells. The non-CAnergic brain regions that represented CAT-stained cells were further divided into two groups: (i) regions containing AADC-labeled cells, for example, bed nucleus of the stria terminalis, nucleus suprachiasmaticus, mammillary body, nucleus raphe dorsalis, inferior colliculus, and nucleus parabrachialis, and (ii) regions containing no AADC-positive cells, for example, main olfactory bulb (except A16), accessory olfactory bulb, nucleus olfactorius anterior, caudoputamen, septum, nucleus accumbens, hippocampus, medial nucleus of the amygdala, entorhinal cortex, nucleus supraopticus, and parasubiculum. The results indicate that the 5.0-kb DNA fragment flanking the 5' end of the hTH gene may contain the element(s) specific for neuron-specific TH expression but which may be insufficient to attenuate ectopic expression.
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Affiliation(s)
- I Nagatsu
- Department of Anatomy, School of Medicine, Fujita Health University, Toyoake, Japan
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24
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Rupprecht CE, Shankar V, Hanlon CA, Hamir A, Koprowski H. Beyond Pasteur to 2001: future trends in lyssavirus research? Curr Top Microbiol Immunol 1994; 187:325-40. [PMID: 7859497 DOI: 10.1007/978-3-642-78490-3_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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25
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Lira SA, Schickler M, Wassarman PM. cis-acting DNA elements involved in oocyte-specific expression of mouse sperm receptor gene mZP3 are located close to the gene's transcription start site. Mol Reprod Dev 1993; 36:494-9. [PMID: 8305213 DOI: 10.1002/mrd.1080360414] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We report that cis-acting DNA elements involved in oocyte-specific expression of the mouse sperm receptor gene (mZP3) are located close to the gene's transcription start site. Mice bearing a transgene that consists of only 153 nt of mZP3 5'-flanking region fused to the firefly luciferase gene (153-ZP3/LUC) expressed the reporter gene in ovary not in a wide variety of tissues; although two of three lines carrying 153-ZP3/LUC also expressed the transgene in forebrain and hypothalamus. Within the ovaries of transgenic mice, luciferase activity was restricted to growing oocytes. However, levels of luciferase activity in these oocytes were lower than those in oocytes from mice bearing transgenes that contain a larger segment of mZP3 5'-flanking region (470-6,500 nt) fused to the firefly luciferase gene. Mice bearing a transgene that consists of 470 nt of mZP3 5'-flanking region and mZP3 intragenic sequences (ZDT) were also analyzed. The presence of mZP3 intragenic sequences did not result in significantly increased levels of firefly luciferase activity in oocytes of mice carrying the ZDT transgene. Overall, these results suggest that as little as 153 nt of mZP3 5'-flanking region is sufficient to target expression of the firefly luciferase gene to mouse oocytes and that the mZP3 intragenic sequences probably do not contain enhancer elements. Rather, enhancer elements are probably present between-153 and -470 nt of the mZP3 5'-flanking region.
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Affiliation(s)
- S A Lira
- Department of Cell and Developmental Biology, Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110
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26
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Grant FD, Reventos J, Kawabata S, Miller M, Gordon JW, Majzoub JA. Transgenic mouse models of vasopressin expression. Hypertension 1993; 22:640-5. [PMID: 8406671 DOI: 10.1161/01.hyp.22.4.640] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Arginine vasopressin is a nine-amino acid neuropeptide hormone important in the regulation of water metabolism. It also may have a role in other physiological functions, such as blood pressure regulation and the response to stress. Whole animal studies have provided a good understanding of vasopressin physiology and regulation of the normal vasopressin gene, and in vitro cell culture studies have demonstrated important features of the intracellular regulation of vasopressin gene expression. Transgenic mice provide useful models for the study of the in vivo regulation of gene expression. Previously reported mouse lines transgenic with vasopressin gene constructs have not expressed the transgene in a tissue distribution similar to that detected for the endogenous mouse vasopressin gene. An 8.2-kb genomic construct of the rat vasopressin gene, including 3 kb each of 5' and 3' flanking sequences, has been used to develop a line of transgenic mice. These animals express the transgene in a tissue-specific manner, demonstrate appropriate osmotic regulation of transgenic vasopressin mRNA, and have normal water metabolism. Animals homozygous for the 8.2-kb transgene have increased basal plasma levels of vasopressin peptide but have no apparent change in basal water metabolism. The findings with this and other previously reported mouse lines transgenic for vasopressin constructs provide a basis for developing future transgenic lines to study the in vivo regulation of the vasopressin gene.
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Affiliation(s)
- F D Grant
- Division of Endocrinology, Children's Hospital, Boston, Mass. 02115
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27
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Probing keratinocyte and differentiation specificity of the human K5 promoter in vitro and in transgenic mice. Mol Cell Biol 1993. [PMID: 7684490 DOI: 10.1128/mcb.13.6.3176] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Keratins K5 and K14 form the extensive intermediate filament network of mitotically active basal cells in all stratified epithelia. We have explored the regulatory mechanisms governing cell-type-specific and differentiation stage-specific expression of the human K5 gene in transiently transfected keratinocytes in vitro and in transgenic mice in vivo. Six thousand base pairs of 5' upstream K5 sequence directed proper basal cell-specific expression in all stratified epithelia. Surprisingly, as few as 90 bp of the K5 promoter still directed expression to stratified epithelia, with expression predominantly in epidermis, hair follicles, and tongue. Despite keratinocyte-preferred expression, the truncated K5 promoter displayed departures from basal to suprabasal expression in epidermis and from outer root sheath to inner root sheath expression in the follicle, with some regional variations in expression as well. To begin to elucidate the molecular controls underlying the keratinocyte specificity of the truncated promoter, we examined protein-DNA interactions within this region. A number of keratinocyte nuclear proteins bind to a K5 gene segment extending from -90 to +32 bp and are functionally involved in transcriptional regulation in vitro. Interestingly, several of these factors are common to both the K5 and K14 promoters, although they appear to be distinct from those previously implicated in keratinocyte specificity. Mutagenesis studies indicate that factors binding in the vicinity of the TATA box and transcription initiation are responsible for the cell type specificity of the truncated K5 promoter.
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28
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Rubinstein M, Japón MA, Low MJ. Introduction of a point mutation into the mouse genome by homologous recombination in embryonic stem cells using a replacement type vector with a selectable marker. Nucleic Acids Res 1993; 21:2613-7. [PMID: 8392702 PMCID: PMC309589 DOI: 10.1093/nar/21.11.2613] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The introduction of small mutations instead of null alleles into the mouse genome has broad applications to the study of protein structure-function relationships and the creation of animal models of human genetic diseases. To test a simple mutational strategy we designed a targeting vector for the mouse proopiomelanocortin (POMC) gene containing a single nucleotide insertion that converts the initial tyrosine codon of beta-endorphin 1-31 to a premature translational termination codon and introduces a unique Hpal endonuclease restriction site. The targeting vector also contains a neo cassette immediately 3' to the last POMC exon and a herpes simplex virus thymidine kinase cassette to allow positive and negative selection. Homologous recombination occurred at a frequency of 1/30 clones of electroporated embryonic stem cells selected in G418 and gancyclovir. 10/11 clones identified initially by a polymerase chain reaction (PCR) strategy had the predicted structure without evidence of concatemer formation by Southern blot analysis. We used a combination of Hpa I digestion of PCR amplified fragments and direct nucleotide sequencing to further confirm that the point mutation was retained in 9/10 clones. The POMC gene was transcriptionally silent in embryonic stem cells and the targeted allele was not activated by the downstream phosphoglycerate kinase-1 promoter that transcribed the neo gene. Under the electroporation conditions used, we have demonstrated that a point mutation can be introduced with high efficiency and precision into the POMC gene using a replacement type vector containing a retained selectable marker without affecting expression of the allele in the embryonic stem cells. A similar strategy may be useful for a wide range of genes.
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Affiliation(s)
- M Rubinstein
- Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201-3098
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29
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Rhodes SJ, Chen R, DiMattia GE, Scully KM, Kalla KA, Lin SC, Yu VC, Rosenfeld MG. A tissue-specific enhancer confers Pit-1-dependent morphogen inducibility and autoregulation on the pit-1 gene. Genes Dev 1993; 7:913-32. [PMID: 8504933 DOI: 10.1101/gad.7.6.913] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Pit-1 is a tissue-specific POU domain factor obligatory for the appearance of three cell phenotypes in the anterior pituitary gland. Expression of the pit-1 gene requires the actions of a cell-specific 390-bp enhancer, located 10 kb 5' of the pit-1 transcription initiation site, within sequence that proves essential for effective pituitary targeting of transgene expression during murine development. The enhancer requires the concerted actions of a cell-specific cis-active element, Pit-1 autoregulatory sites, and atypical morphogen response elements. Pituitary ontogeny in the Pit-1-defective Snell dwarf mouse reveals that pit-1 autoregulation is not required for initial activation or continued expression during critical phases of Pit-1 target gene activation but, subsequently, is necessary for maintenance of pit-1 gene expression following birth. A potent 1,25-dihydroxyvitamin D3-responsive enhancer element defines a physiological site in which a single nucleotide alteration in the sequence of core binding motifs modulates the spacing rules for nuclear receptor response elements. Unexpectedly, the major retinoic acid response element is absolutely dependent on Pit-1 for retinoic acid receptor function. On this DNA element, Pit-1 appears to function as a coregulator of the retinoic acid receptor, suggesting an intriguing linkage between a cell-specific transcription factor and the actions of morphogen receptors that is likely to be prototypic of mechanisms by which other cell-specific transcription factors might confer morphogen receptor responsivity during mammalian organogenesis.
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Affiliation(s)
- S J Rhodes
- Eukaryotic Regulatory Biology Program, University of California, San Diego
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30
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Byrne C, Fuchs E. Probing keratinocyte and differentiation specificity of the human K5 promoter in vitro and in transgenic mice. Mol Cell Biol 1993; 13:3176-90. [PMID: 7684490 PMCID: PMC359757 DOI: 10.1128/mcb.13.6.3176-3190.1993] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Keratins K5 and K14 form the extensive intermediate filament network of mitotically active basal cells in all stratified epithelia. We have explored the regulatory mechanisms governing cell-type-specific and differentiation stage-specific expression of the human K5 gene in transiently transfected keratinocytes in vitro and in transgenic mice in vivo. Six thousand base pairs of 5' upstream K5 sequence directed proper basal cell-specific expression in all stratified epithelia. Surprisingly, as few as 90 bp of the K5 promoter still directed expression to stratified epithelia, with expression predominantly in epidermis, hair follicles, and tongue. Despite keratinocyte-preferred expression, the truncated K5 promoter displayed departures from basal to suprabasal expression in epidermis and from outer root sheath to inner root sheath expression in the follicle, with some regional variations in expression as well. To begin to elucidate the molecular controls underlying the keratinocyte specificity of the truncated promoter, we examined protein-DNA interactions within this region. A number of keratinocyte nuclear proteins bind to a K5 gene segment extending from -90 to +32 bp and are functionally involved in transcriptional regulation in vitro. Interestingly, several of these factors are common to both the K5 and K14 promoters, although they appear to be distinct from those previously implicated in keratinocyte specificity. Mutagenesis studies indicate that factors binding in the vicinity of the TATA box and transcription initiation are responsible for the cell type specificity of the truncated K5 promoter.
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Affiliation(s)
- C Byrne
- Department of Molecular Genetics and Cell Biology, Howard Hughes Medical Institute, University of Chicago, Illinois 60637
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31
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Crawford J, Mutchler K, Sullivan B, Lanigan T, Clark M, Russo A. Neural expression of a novel alternatively spliced and polyadenylated Gs alpha transcript. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)98427-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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32
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Morita S, Kobayashi K, Mizuguchi T, Yamada K, Nagatsu I, Titani K, Fujita K, Hidaka H, Nagatsu T. The 5'-flanking region of the human dopamine beta-hydroxylase gene promotes neuron subtype-specific gene expression in the central nervous system of transgenic mice. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1993; 17:239-44. [PMID: 8510498 DOI: 10.1016/0169-328x(93)90007-c] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Dopamine beta-hydroxylase (DBH, EC 1.14.17.1) catalyzes the conversion of dopamine to norepinephrine, the third step of catecholamine biosynthesis. We have previously created transgenic mice harboring a chimeric gene consisting of the 4-kb DNA fragment of the human DBH gene promoter and the human phenylethanolamine N-methyltransferase (PNMT, EC 2.1.1.28) cDNA, to express PNMT in norepinephrine- and epinephrine-producing cells in the brain, sympathetic ganglia, and adrenal medullary chromaffin cells (Kobayashi et al., Proc. Natl. Acad. Sci. U.S.A., 89 (1992) 1631-1635). In this paper, we produced for the first time the antibody that specifically detects human PNMT, but not mouse PNMT, with the synthetic oligopeptide characteristic of the human PNMT sequence, and used this antibody to investigate the cells expressing human PNMT in transgenic mice. Immunohistochemical analysis of transgenic mice showed typical expression of human PNMT immunoreactivity in norepinephrinergic and epinephrinergic neurons in brain, as well as norepinephrine- and epinephrine-producing cells in the adrenal gland, indicating that the 4-kb 5'-flanking region is essential for the tissue-specific expression of the DBH gene. We also detected the ectopic expression in some DBH-immunonegative cells in the olfactory bulb of transgenic mice.
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Affiliation(s)
- S Morita
- Department of Pharmacology, Nagoya University School of Medicine, Japan
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33
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Gow A, Friedrich VL, Lazzarini RA. Myelin basic protein gene contains separate enhancers for oligodendrocyte and Schwann cell expression. J Biophys Biochem Cytol 1992; 119:605-16. [PMID: 1383235 PMCID: PMC2289674 DOI: 10.1083/jcb.119.3.605] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The DNA sequence between position +36 and -1907 of the murine myelin basic protein gene contains the enhancer and promoter elements necessary for abundant and cell specific expression in transgenic mice. Surprisingly, the pattern of expression promoted by this DNA fragment is a subset of that exhibited by the endogenous myelin basic protein (MBP) gene. Fusion genes prepared with this promoter/enhancer and a Lac Z reporter gene are expressed only in oligodendrocytes and not in Schwann cells, whereas the endogenous MBP gene is expressed in both cell types. The level of transgene expression measured by nuclear run-on experiments is very substantial and rivals that of the endogenous MBP gene. Furthermore, this 1.9-kb DNA fragment directs transcription on the same (or very similar) developmental schedule as the endogenous gene. These results indicate that the MBP promoter/enhancer sequences are at least tripartite: a core promoter, the oligodendrocyte enhancer elements, and a third component that either expands the specificity of the oligodendrocyte enhancer to include Schwann cells or acts independently to specifically stimulate transcription in Schwann cells.
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Affiliation(s)
- A Gow
- Brookdale Center for Molecular Biology, Mount Sinai Medical Center, New York 10029-6574
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34
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Cohen-Tannoudji M, Morello D, Babinet C. Unexpected position-dependent expression of H-2 and beta 2-microglobulin/lacZ transgenes. Mol Reprod Dev 1992; 33:149-59. [PMID: 1418983 DOI: 10.1002/mrd.1080330206] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In order to study sequences involved in the developmentally regulated and tissue-specific expression of the class I Major Histocompatibility Complex (MHC) genes, we have constructed several H-2/lacZ transgenic lines in which the 5' regulatory sequences of the H-2Kb gene are linked to the Escherichia coli beta-galactosidase (lacZ) gene. In five H-2/lacZ lines, the pattern of lacZ expression, detected histochemically varied greatly from line to line. None of the H-2/lacZ transgenes were transcribed in cells normally expressing a high level of endogenous H-2 molecules, although these H-2 regulatory sequences have been shown to be sufficient to drive tissue-specific expression of other reporter genes. Interestingly, when constructs containing 5' beta 2-microglobulin (beta 2m) regulatory sequences linked to lacZ were used to derive transgenic lines, similar results were obtained. A survey of lacZ labeling in H-2/lacZ and beta 2m/lacZ transgenic mice strongly suggests that these transgenes are very sensitive to position effect, lacZ expression being controlled by endogenous chromosomal regulatory elements specific for each insertion site. Here we describe the complex pattern of lacZ expression in the different transgenic lines during development; we discuss the unusual properties of these transgenes and underline their potential use for developmental studies and characterization of genomic sequences involved in spatiotemporal gene expression.
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35
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Affiliation(s)
- W S Young
- Laboratory of Cell Biology, National Institute of Mental Health, Bethesda, Maryland 20892, USA
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36
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Beaudet L, Charron G, Houle D, Tretjakoff I, Peterson A, Julien JP. Intragenic regulatory elements contribute to transcriptional control of the neurofilament light gene. Gene 1992; 116:205-14. [PMID: 1634118 DOI: 10.1016/0378-1119(92)90517-s] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To date, no DNA regions involved in the neuron-specific expression of the neurofilament light gene (NF-L) have been defined using transfection assays in cultured cells. To identify those regulatory regions in the human NF-L gene, we generated transgenic mice with a construct containing the basal NF-L promoter (-292 to +15) fused to the cat gene and with three DNA fragments of 21.5, 7.6 and 4.9 kb each, including NF-L with different lengths of either 5'- or 3'-flanking sequences. We show that the proximal NF-L 5' region (0.3 kb) constitutes a weak promoter and that it lacks information to confer neural specificity. However, appropriate expression in the nervous system occurred when this minimal promoter was combined with either 7.3 or 4.6 kb of NF-L sequences downstream from the transcription start point. We conclude that the intragenic NF-L region contains cis-acting elements conferring cell-type-specific regulation on the basal activity of the NF-L promoter. Interestingly, AP-2 motifs were found within homologously placed introns of all three NF genes, as well as in the promoter regulatory regions of many neuronal genes. We propose that the acquisition of introns by an ancestral intronless IF gene may have contributed to the emergence of a lineage of IF genes expressed in the nervous system.
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Affiliation(s)
- L Beaudet
- Montreal General Hospital Research Institute, Quebec, Canada
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37
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Affiliation(s)
- H Gainer
- Laboratory of Neurochemistry, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20892
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38
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Gardner DG, Camargo MJ, Behringer RR, Brinster RL, Baxter JD, Atlas SA, Laragh JH, Deschepper CF. Atrial natriuretic peptide synthesis in atrial tumors of transgenic mice. THE AMERICAN JOURNAL OF PHYSIOLOGY 1992; 262:E524-31. [PMID: 1373564 DOI: 10.1152/ajpendo.1992.262.4.e524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Transgenic mice harboring a chimeric gene linking mouse protamine 1 5'-flanking sequence to the coding sequence of the simian virus 40 T-antigen develop spontaneous rhabdomyosarcomas of the right atria. The presence of the tumors is accompanied by dramatic elevations in plasma atrial natriuretic peptide (ANP) immunoreactivity (1,698 +/- 993 vs. 60 +/- 18 fmol/ml for controls) and hematocrit (56 +/- 8 vs. 51 +/- 2 for controls). The immunoreactive ANP (irANP) present in the tumors is similar in size to irANP found in normal mouse atria. ANP mRNA transcripts present in the tumors also appear to be very similar in overall size and 5'-termini to those produced in normal cardiac tissue. Microscopically, the tumors are composed of a disorganized array of densely packed abnormal-appearing cells. Immunocytochemistry and in situ hybridization analysis reveal considerable heterogeneity in ANP gene expression. ANP peptide and mRNA are detectable throughout the parenchyma of the tumors, but absolute levels of expression vary widely among different cells in the population. These tumors represent a potentially valuable model for the study of inappropriate ANP secretion and may provide a tissue source for the development of an ANP-producing atrial cell line.
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Affiliation(s)
- D G Gardner
- Department of Medicine, University of California, San Francisco 94143
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39
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Swanson LW. Spatiotemporal patterns of transcription factor gene expression accompanying the development and plasticity of cell phenotypes in the neuroendocrine system. PROGRESS IN BRAIN RESEARCH 1992; 92:97-113. [PMID: 1302890 DOI: 10.1016/s0079-6123(08)61167-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- L W Swanson
- Department of Biological Sciences, University of Southern California, Los Angeles 90089-2520
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40
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Wray S, Gainer H. Models for the study of cell-specific neuropeptide gene expression. PROGRESS IN BRAIN RESEARCH 1992; 92:59-76. [PMID: 1302888 DOI: 10.1016/s0079-6123(08)61165-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- S Wray
- Laboratory of Neurochemistry, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD 20892
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41
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Murphy D, Ang HL, Zeng Q, Ho MY, Funkhouser J, Carter D. Neuropeptide gene expression in transgenic animals. PROGRESS IN BRAIN RESEARCH 1992; 92:77-96. [PMID: 1302889 DOI: 10.1016/s0079-6123(08)61166-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Transgenic animal techniques offer today's neuroscientist the ability to experimentally manipulate neurosecretory systems with a precision undreamt of by our predecessors. The range of techniques now available, building as it does on our growing knowledge of physiological systems at the inter- and intercellular level, allows us to critically define molecular lesions and ask about their consequences to the whole organism. Neuroscientist should grasp the opportunities afforded by these recent developments.
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Affiliation(s)
- D Murphy
- Neuropeptide Laboratory, National University of Singapore
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42
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Donoghue MJ, Alvarez JD, Merlie JP, Sanes JR. Fiber type- and position-dependent expression of a myosin light chain-CAT transgene detected with a novel histochemical stain for CAT. J Cell Biol 1991; 115:423-34. [PMID: 1717485 PMCID: PMC2289162 DOI: 10.1083/jcb.115.2.423] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We recently generated and characterized transgenic mice in which regulatory sequences from a myosin light chain gene (MLC1f/3f) are linked to the chloramphenicol acetyltransferase (CAT) gene. Transgene expression in these mice is specific to skeletal muscle and graded along the rostrocaudal axis: adult muscles derived from successively more caudal somites express successively higher levels of CAT. To investigate the cellular basis of these patterns of expression, we developed and used a histochemical stain that allows detection of CAT in individual cells. Our main results are as follows: (a) Within muscles, CAT is detected only in muscle fibers and not in associated connective tissue, blood vessels, or nerves. Thus, the tissue specificity of transgene expression observed by biochemical assay reflects a cell-type specificity demonstrable histochemically. (b) Within individual muscles, CAT levels vary with fiber type. Like the endogenous MLC1f/3f gene, the transgene is expressed at higher levels in fast-twitch (type II) than in slow-twitch (type I) muscle fibers. In addition, CAT levels vary among type II fiber subtypes, in the order IIB greater than IIX greater than IIA. (c) Among muscles that are similar in fiber type composition, the average level of CAT per fiber varies with rostrocaudal position. This position-dependent variation in CAT level is apparent even when fibers of a single type are compared. From these results, we conclude that fiber type and position affect CAT expression independently. We therefore infer the existence of separate fiber type-specific and positionally graded transcriptional regulators that act together to determine levels of transgene expression.
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Affiliation(s)
- M J Donoghue
- Department of Molecular Biology, Washington University School of Medicine, St. Louis, Missouri 63110
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43
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Weis J, Fine SM, David C, Savarirayan S, Sanes JR. Integration site-dependent expression of a transgene reveals specialized features of cells associated with neuromuscular junctions. J Cell Biol 1991; 113:1385-97. [PMID: 1904446 PMCID: PMC2289028 DOI: 10.1083/jcb.113.6.1385] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
After skeletal muscle is denervated, fibroblasts near neuromuscular junctions proliferate more than fibroblasts distant from synaptic sites, and they accumulate adhesive molecules such as tenascin (Gatchalian, C. L., M. Schachner, and J. R. Sanes. 1989. J. Cell Biol. 108:1873-1890). This response could reflect signals that arise perisynaptically after denervation, preexisting differences between perisynaptic and extrasynaptic fibroblasts, or both. Here, we describe a line of transgenic mice in which patterns of transgene expression provide direct evidence for differences between perisynaptic and extrasynaptic fibroblasts in normal muscle. Transgenic mice were generated using regulatory elements from a major histocompatibility complex (MHC) class I gene linked to the Escherichia coli beta-galactosidase (lacZ) gene. Expression of lacZ was detected histochemically. In each of eight lines, lacZ was detected in different subsets of cells, none of which included lymphocytes. In contrast, endogenous MHC is expressed in most tissues and at high levels in lymphocytes. Thus, the MHC gene sequences appeared inactive in the transgene, and lacZ expression was apparently controlled by genomic regulatory elements that were specific for the insertion site. In one line, cells close to the neuromuscular junction were lacZ positive in embryonic and young postnatal mice. Electron microscopy identified these cells as fibroblasts and Schwann cells associated with motor nerve terminals, as well as endoneurial fibroblasts, perineurial cells, and Schwann cells in the distal branches of motor nerves. No intramuscular cells greater than 200 microns from synaptic sites were lacZ positive. These results indicate that there are molecular differences between perisynaptic and extrasynaptic fibroblasts even in normal muscle and that diverse perisynaptic cell types share a specific pattern of gene expression.
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Affiliation(s)
- J Weis
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110
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44
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Teitelman G. Cellular and molecular analysis of pancreatic islet cell lineage and differentiation. RECENT PROGRESS IN HORMONE RESEARCH 1991; 47:259-94; discussion 294-7. [PMID: 1745822 DOI: 10.1016/b978-0-12-571147-0.50012-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- G Teitelman
- Department of Neurology, Cornell University Medical College, New York, New York 10021
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45
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46
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Young WS, Reynolds K, Shepard EA, Gainer H, Castel M. Cell-specific expression of the rat oxytocin gene in transgenic mice. J Neuroendocrinol 1990; 2:917-25. [PMID: 19215438 DOI: 10.1111/j.1365-2826.1990.tb00660.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract The genes for the posterior pituitary hormones oxytocin (OT) and vasopressin (VP) are expressed in magnocellular neurons of the hypothalamus. Previous attempts to obtain cell-specific expression of OT and VP transgenes in mice have been unsuccessful using constructs containing only the OT or VP genes. As the endogenous genes are located near each other on the same chromosome, we investigated four transgenic mouse lines incorporating a single 5.2 k bp construct of rat genomic deoxyribonucleic acid with 1.63 k bp and 3.55 k bp of the OT and VP genes, respectively. Rat OT transcripts were detected only in transgenic mouse OT neurons of the paraventricular and supraoptic nuclei in two lines. The levels of endogenous and transgene OT transcripts increased in response to 10 days of lactation. Furthermore, rat OT-associated neurophysin immunoreactivity was detected in magnocellular cell bodies as well as in the posterior pituitary of the transgenic but not the control mice. Cell-specific rat VP expression was not detected in these transgenic mice.
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Affiliation(s)
- W S Young
- Laboratory of Cell Biology, National Institute of Mental Health, Bethesda, Maryland, USA
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47
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Affiliation(s)
- A Messing
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison 53706
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48
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Begemann M, Tan SS, Cunningham BA, Edelman GM. Expression of chicken liver cell adhesion molecule fusion genes in transgenic mice. Proc Natl Acad Sci U S A 1990; 87:9042-6. [PMID: 2123350 PMCID: PMC55097 DOI: 10.1073/pnas.87.22.9042] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The tissue-specific expression of the chicken liver cell adhesion molecule (L-CAM) was studied by generating transgenic mice. The rat insulin II promoter was fused to a chicken L-CAM cDNA or to chicken genomic L-CAM sequences. Mice carrying the cDNA showed no expression of L-CAM. Mice carrying L-CAM genomic sequences showed expression in the beta cells of the pancreas, suggesting that sequences in introns or in flanking regions are required for expression. Murine L-CAM was undetectable in the beta cells of the pancreas of those transgenic mice expressing chicken L-CAM and thus appeared to be down-regulated, but expression of the mouse protein was not altered at other sites. Chicken L-CAM was also found in extrapancreatic tissues such as skin, kidney, liver, lung, intestine, blood vessels, and the choroid plexus and leptomeninges of the central nervous system. These findings raised the possibility that the chicken L-CAM gene contains cis regulatory elements that interfere with the specificity of a tissue-specific promoter such as the rat insulin promoter. To test this hypothesis, transgenic mice were produced with a construct containing the murine neurofilament promoter fused to genomic chicken L-CAM sequences. Chicken L-CAM was expressed in the brain and spinal cord, where L-CAM is not normally found, but it was also found in some nonneural tissues (kidney, liver, intestine, lung) in which L-CAM is normally expressed. The combined results suggest that tissue-specific cis-acting elements in the chicken L-CAM gene, when combined with heterologous promoters/enhancers, can generate novel patterns of gene expression.
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Affiliation(s)
- M Begemann
- Rockefeller University, New York, NY 10021
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49
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Schweisguth F, Yanicostas C, Payre F, Lepesant JA, Vincent A. cis-regulatory elements of the Drosophila blastoderm-specific serendipity alpha gene: ectopic activation in the embryonic PNS promoted by the deletion of an upstream region. Dev Biol 1989; 136:181-93. [PMID: 2509261 DOI: 10.1016/0012-1606(89)90140-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The Drosophila serendipity alpha gene (sry alpha) is specifically expressed at the blastoderm stage in all somatic cells. By deletion analysis of sry alpha-lacZ fusion genes, the sry alpha cis-acting regulatory elements have been restricted to the [-311, +130] 5'-region of the gene and separated in two domains. The [-118, +130] domain is sufficient for transcriptional activation at the blastoderm stage. The [-311, -118] domain is required for a full level of expression. Deletion of this upstream domain leads to a secondary pattern of lacZ expression in precursor cells of the peripheral nervous system (PNS). The sry alpha gene is not itself secondarily expressed in the PNS, as shown by in situ hybridization. The patterns of expression of the different sry alpha-lacZ fusion genes suggest a combinatorial mode of regulation of sry alpha expression at blastoderm.
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50
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Cambi F, Fung B, Chikaraishi D. 5' flanking DNA sequences direct cell-specific expression of rat tyrosine hydroxylase. J Neurochem 1989; 53:1656-9. [PMID: 2571679 DOI: 10.1111/j.1471-4159.1989.tb08567.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Tyrosine hydroxylase (TH) is selectively expressed in catecholaminergic neurons and in chromaffin cells of the adrenal medulla. Constructs in which 5' flanking sequences of the rat TH gene directed expression of bacterial chloramphenicol acetyltransferase (CAT) were transfected into cell lines and assayed for transient expression of CAT. In most nonexpressing cell lines, CAT levels were less than 5% of that found in a TH-positive pheochromocytoma line (PC8b). In two lines described here, a rat anterior pituitary cell line (GH4) and a rat fibroblast line (Fr3T3), CAT expression reached 12 and 20%, respectively, of the PC8b level. Greater than 90% of the PC8b activity was lost when sequences between -212 and -187 (in relation to the transcriptional initiation site) were deleted. Further deletions that removed the cyclic AMP response element (CRE) (-45) and the TATA box at -29 reduced transcriptional activity to background in all three lines. These data suggest that 212 nucleotides of the 5' sequence are sufficient for pheochromocytoma expression and that information between -212 and -187, which includes an AP1 site (-206 to -200), is essential for full transcriptional activity. In addition, sites for other protein transcription factors (AP2, POU/Oct, SP1, and CRE) reside between -221 and -38 and are largely conserved between the human and rat gene.
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Affiliation(s)
- F Cambi
- Neuroscience Program, Tufts School of Medicine, Boston, Massachusetts
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