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Hansen J, von Melchner H, Wurst W. Mutant non-coding RNA resource in mouse embryonic stem cells. Dis Model Mech 2021; 14:14/2/dmm047803. [PMID: 33729986 PMCID: PMC7875499 DOI: 10.1242/dmm.047803] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/14/2020] [Indexed: 01/23/2023] Open
Abstract
Gene trapping is a high-throughput approach that has been used to introduce insertional mutations into the genome of mouse embryonic stem (ES) cells. It is performed with generic gene trap vectors that simultaneously mutate and report the expression of the endogenous gene at the site of insertion and provide a DNA sequence tag for the rapid identification of the disrupted gene. Large-scale international efforts assembled a gene trap library of 566,554 ES cell lines with single gene trap integrations distributed throughout the genome. Here, we re-investigated this unique library and identified mutations in 2202 non-coding RNA (ncRNA) genes, in addition to mutations in 12,078 distinct protein-coding genes. Moreover, we found certain types of gene trap vectors preferentially integrating into genes expressing specific long non-coding RNA (lncRNA) biotypes. Together with all other gene-trapped ES cell lines, lncRNA gene-trapped ES cell lines are readily available for functional in vitro and in vivo studies.
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Affiliation(s)
- Jens Hansen
- Institute of Developmental Genetics, Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany
| | - Harald von Melchner
- Department of Molecular Hematology, University Hospital Frankfurt, Goethe University, D-60590 Frankfurt am Main, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany .,Technische Universität München-Weihenstephan, c/o Helmholtz Zentrum München, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.,German Center for Neurodegenerative Diseases (DZNE), Site Munich, Feodor-Lynen-Str. 17, D-81377 Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Adolf-Butenandt-Institut, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 17, D-81377 München, Germany
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2
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Park E, Elidrissi A, Schuller-Levis G, Chadman KK. Taurine Partially Improves Abnormal Anxiety in Taurine-Deficient Mice. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1155:905-921. [PMID: 31468456 DOI: 10.1007/978-981-13-8023-5_76] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Taurine is abundant in various tissues including the brain, muscle, heart, spleen, liver and kidney with various physiological functions. Since taurine is produced by cysteine sulfinic acid decarboxylase (CSAD) in the liver and kidney, taurine-deficient mice without CSAD have been investigated for abnormal physiological functions such as retinal development, immune, pancreatic and liver function. In this study, the behavioral effects and abnormal brain development caused by low taurine in the developing brain were examined. In neonatal brains of homozygous CSAD knockout mice (HO), taurine was reduced by 85%, compared to wild-type mice (WT). Taurine was reduced by 35% in the brains of 2 month-old HO, compared to WT. Anxiety, motor coordination and autistic-like behaviors were evaluated at 2 months of age using five behavioral tests: elevated plus maze, open field, social approach, marble burying and accelerating rotarod. Mice were tested from 3 groups including WT, HO and HO with oral treatment of 0.2% taurine in the drinking water (HOT). HOT were born from HO dams treated with taurine from before pregnancy and were continuously treated with taurine in the drinking water after weaning. The taurine levels in the brain and plasma of HOT were restored to WT at 2 months of age. Taurine-deficiency did not lead to changes in autistic-like behaviors as the HO were not significantly different from WT in marble burying and social approach. However, taurine-deficiency increased anxiety-like behavior in HO in the elevated plus maze and open field, compared to WT. Taurine treatment significantly restored the HOT to WT levels of anxiety-like behavior in the elevated plus maze. However, changes in exploratory activity in the open field were not improved with taurine treatment. There was a slight difference in motor ability as the WT mice stayed on the accelerating rotarod longer that the HO and HOT, but the difference was significant in the HOT during the first trial only, compared to WT.These data support hypothesis that taurine is essential for the emotional development of the brain. First, taurine is remarkably low in the neonatal brain of HO, compared to the adult brain of HO. Second, taurine treatment in HO partially improves anxiety-like behavior to WT.
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Affiliation(s)
- Eunkyue Park
- Department of Developmental Neurobiology, New York Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA.
| | - Abdeslem Elidrissi
- Department of Biological Science, College of Staten Island, Staten Island, NY, USA
| | - Georgia Schuller-Levis
- Department of Developmental Neurobiology, New York Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
| | - Kathryn K Chadman
- Department of Developmental Neurobiology, New York Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA
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3
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Yamane T, Ito C, Washino A, Isono K, Yamazaki H. Repression of Primitive Erythroid Program Is Critical for the Initiation of Multi-Lineage Hematopoiesis in Mouse Development. J Cell Physiol 2016; 232:323-330. [PMID: 27171571 DOI: 10.1002/jcp.25422] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 05/10/2016] [Indexed: 11/11/2022]
Abstract
Formation of the hematopoietic cells occurs in multiple steps. The first hematopoietic cells observed during ontogeny are primitive erythrocytes, which are produced in the early yolk sac within a limited temporal window. Multi-lineage hematopoiesis, which supplies almost the entire repertoire of blood cell lineages, lags behind primitive erythropoiesis in the tissue. However, molecular mechanisms regulating sequential generation of primitive erythrocytes and multipotent hematopoietic progenitors in the yolk sac are largely unknown. In this study, the transcription factors involved in the development of hematopoietic cells were examined in purified progenitor cell populations from pluripotent stem cell cultures and from the yolk sac of developing embryos. We found that the earliest committed hematopoietic progenitors highly expressed Gata1, Scl/tal1, and Klf1 genes. Expression of these transcription factors, which is known to form a core erythroid transcriptional network, explained the prompt generation of primitive erythrocytes from these earliest progenitors. Importantly, the multipotent hematopoietic cells, which lack the differentiation potential into primitive erythroid cells, down-regulated these genes during a transition from the earliest committed progenitors. In addition, we showed that Pu.1 is involved in the multipotent cell differentiation through the suppression of erythroid transcription program. We propose that these molecular mechanisms governed by transcription factors form sequential waves of primitive erythropoiesis and multi-lineage hematopoiesis in the early yolk sac of developing embryos. J. Cell. Physiol. 232: 323-330, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Toshiyuki Yamane
- Department of Stem Cell and Developmental Biology, Mie University Graduate School of Medicine, Tsu, Japan.
| | - Chie Ito
- Department of Stem Cell and Developmental Biology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Aya Washino
- Department of Stem Cell and Developmental Biology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Kana Isono
- Department of Stem Cell and Developmental Biology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Hidetoshi Yamazaki
- Department of Stem Cell and Developmental Biology, Mie University Graduate School of Medicine, Tsu, Japan
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4
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Development of a novel cysteine sulfinic Acid decarboxylase knockout mouse: dietary taurine reduces neonatal mortality. JOURNAL OF AMINO ACIDS 2014; 2014:346809. [PMID: 24639894 PMCID: PMC3929995 DOI: 10.1155/2014/346809] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/13/2013] [Accepted: 12/15/2013] [Indexed: 12/31/2022]
Abstract
We engineered a CSAD KO mouse to investigate the physiological roles of taurine. The disruption of the CSAD gene was verified by Southern, Northern, and Western blotting. HPLC indicated an 83% decrease of taurine concentration in the plasma of CSAD−/−. Although CSAD−/− generation (G)1 and G2 survived, offspring from G2 CSAD−/− had low brain and liver taurine concentrations and most died within 24 hrs of birth. Taurine concentrations in G3 CSAD−/− born from G2 CSAD−/− treated with taurine in the drinking water were restored and survival rates of G3 CSAD−/− increased from 15% to 92%. The mRNA expression of CDO, ADO, and TauT was not different in CSAD−/− compared to WT and CSAD mRNA was not expressed in CSAD−/−. Expression of Gpx 1 and 3 was increased significantly in CSAD−/− and restored to normal levels with taurine supplementation. Lactoferrin and the prolactin receptor were significantly decreased in CSAD−/−. The prolactin receptor was restored with taurine supplementation. These data indicated that CSAD KO is a good model for studying the effects of taurine deficiency and its treatment with taurine supplementation.
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5
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Davis J, Maillet M, Miano JM, Molkentin JD. Lost in transgenesis: a user's guide for genetically manipulating the mouse in cardiac research. Circ Res 2012; 111:761-77. [PMID: 22935533 DOI: 10.1161/circresaha.111.262717] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The advent of modern mouse genetics has benefited many fields of diseased-based research over the past 20 years, none perhaps more profoundly than cardiac biology. Indeed, the heart is now arguably one of the easiest tissues to genetically manipulate, given the availability of an ever-growing tool chest of molecular reagents/promoters and "facilitator" mouse lines. It is now possible to modify the expression of essentially any gene or partial gene product in the mouse heart at any time, either gain or loss of function. This review is designed as a handbook for the nonmouse geneticist and/or junior investigator to permit the successful manipulation of any gene or RNA product in the heart, while avoiding artifacts. In the present review, guidelines, pitfalls, and limitations are presented so that rigorous and appropriate examination of cardiac genotype-phenotype relationships can be performed. This review uses examples from the field to illustrate the vast spectrum of experimental and design details that must be considered when using genetically modified mouse models to study cardiac biology.
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Affiliation(s)
- Jennifer Davis
- Department of Pediatrics, University of Cincinnati, Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, 240 Albert Sabin Way, S4.409, Cincinnati, OH 45229, USA
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6
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Mayasari NI, Mukougawa K, Shigeoka T, Kawakami K, Kawaichi M, Ishida Y. Mixture of differentially tagged Tol2 transposons accelerates conditional disruption of a broad spectrum of genes in mouse embryonic stem cells. Nucleic Acids Res 2012; 40:e97. [PMID: 22447447 PMCID: PMC3401447 DOI: 10.1093/nar/gks262] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Among the insertional mutagenesis techniques used in the current international knockout mouse project (KOMP) on the inactivation of all mouse genes in embryonic stem (ES) cells, random gene trapping has been playing a major role. Gene-targeting experiments have also been performed to individually and conditionally knockout the remaining ‘difficult-to-trap’ genes. Here, we show that transcriptionally silent genes in ES cells are severely underrepresented among the randomly trapped genes in KOMP. Our conditional poly(A)-trapping vector with a common retroviral backbone also has a strong bias to be integrated into constitutively transcribed genome loci. Most importantly, conditional gene disruption could not be successfully accomplished by using the retrovirus vector because of the frequent development of intra-vector deletions/rearrangements. We found that one of the cut and paste-type DNA transposons, Tol2, can serve as an ideal platform for gene-trap vectors that ensures identification and conditional disruption of a broad spectrum of genes in ES cells. We also solved a long-standing problem associated with multiple vector integration into the genome of a single cell by incorporating a mixture of differentially tagged Tol2 transposons. We believe our strategy indicates a straightforward approach to mass-production of conditionally disrupted alleles for genes in the target cells.
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Affiliation(s)
- N Ika Mayasari
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma-shi, Nara 630-0192, Japan
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7
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Samuels ME. Saturation of the human phenome. Curr Genomics 2011; 11:482-99. [PMID: 21532833 PMCID: PMC3048311 DOI: 10.2174/138920210793175886] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Revised: 06/22/2010] [Accepted: 06/22/2010] [Indexed: 12/26/2022] Open
Abstract
The phenome is the complete set of phenotypes resulting from genetic variation in populations of an organism. Saturation of a phenome implies the identification and phenotypic description of mutations in all genes in an organism, potentially constrained to those encoding proteins. The human genome is believed to contain 20-25,000 protein coding genes, but only a small fraction of these have documented mutant phenotypes, thus the human phenome is far from complete. In model organisms, genetic saturation entails the identification of multiple mutant alleles of a gene or locus, allowing a consistent description of mutational phenotypes for that gene. Saturation of several model organisms has been attempted, usually by targeting annotated coding genes with insertional transposons (Drosophila melanogaster, Mus musculus) or by sequence directed deletion (Saccharomyces cerevisiae) or using libraries of antisense oligonucleotide probes injected directly into animals (Caenorhabditis elegans, Danio rerio). This paper reviews the general state of the human phenome, and discusses theoretical and practical considerations toward a saturation analysis in humans. Throughout, emphasis is placed on high penetrance genetic variation, of the kind typically asociated with monogenic versus complex traits.
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Affiliation(s)
- Mark E Samuels
- Centre de Recherche de Ste-Justine, 3175, Côte Ste-Catherine, Montréal QC H3T 1C5, Canada
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8
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High throughput gene trapping and postinsertional modifications of gene trap alleles. Methods 2011; 53:347-55. [DOI: 10.1016/j.ymeth.2010.12.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 12/27/2010] [Accepted: 12/31/2010] [Indexed: 11/17/2022] Open
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9
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von Melchner H, Stewart AF. Methods for extracting function from mammalian genomes. Methods 2011; 53:329-30. [PMID: 21392581 DOI: 10.1016/j.ymeth.2011.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2011] [Indexed: 10/18/2022] Open
Affiliation(s)
- Harald von Melchner
- Department for Molecular Hematology, University of Frankfurt Medical School, 60590 Frankfurt am Main, Germany.
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10
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Cox BJ, Vollmer M, Tamplin O, Lu M, Biechele S, Gertsenstein M, van Campenhout C, Floss T, Kühn R, Wurst W, Lickert H, Rossant J. Phenotypic annotation of the mouse X chromosome. Genome Res 2010; 20:1154-64. [PMID: 20548051 PMCID: PMC2909578 DOI: 10.1101/gr.105106.110] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 05/11/2010] [Indexed: 10/19/2022]
Abstract
Mutational screens are an effective means used in the functional annotation of a genome. We present a method for a mutational screen of the mouse X chromosome using gene trap technologies. This method has the potential to screen all of the genes on the X chromosome without establishing mutant animals, as all gene-trapped embryonic stem (ES) cell lines are hemizygous null for mutations on the X chromosome. Based on this method, embryonic morphological phenotypes and expression patterns for 58 genes were assessed, approximately 10% of all human and mouse syntenic genes on the X chromosome. Of these, 17 are novel embryonic lethal mutations and nine are mutant mouse models of genes associated with genetic disease in humans, including BCOR and PORCN. The rate of lethal mutations is similar to previous mutagenic screens of the autosomes. Interestingly, some genes associated with X-linked mental retardation (XLMR) in humans show lethal phenotypes in mice, suggesting that null mutations cannot be responsible for all cases of XLMR. The entire data set is available via the publicly accessible website (http://xlinkedgenes.ibme.utoronto.ca/).
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Affiliation(s)
- Brian J. Cox
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1L7, Canada
| | - Marion Vollmer
- Institute of Stem Cell Research, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg 85764, Germany
| | - Owen Tamplin
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Mei Lu
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1L7, Canada
| | - Steffen Biechele
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Marina Gertsenstein
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada
- Toronto Centre for Phenogenomics, Transgenic Core, Toronto M5T 3H7, Canada
| | - Claude van Campenhout
- Institute of Stem Cell Research, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg 85764, Germany
| | - Thomas Floss
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg 85764, Germany
| | - Ralf Kühn
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg 85764, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg 85764, Germany
- MPI für Psychiatrie, München 80804, Germany
- Helmholtz Zentrum München, German Research Center for Environmental Health Institute of Developmental Genetics, Neuherberg 85764, Germany
- Technical University Weihenstephan, Lehrstuhl für Entwicklungsgenetik, c/o Helmholtz Zentrum München, Neuherberg 85764, Germany
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), Standort München, München 80336, Germany
| | - Heiko Lickert
- Institute of Stem Cell Research, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg 85764, Germany
| | - Janet Rossant
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Obstetrics and Gynecology, University of Toronto, Toronto, Ontario M5T 3H7, Canada
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11
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Floxin, a resource for genetically engineering mouse ESCs. Nat Methods 2009; 7:50-2. [PMID: 19966808 PMCID: PMC2895430 DOI: 10.1038/nmeth.1406] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Accepted: 11/12/2009] [Indexed: 11/26/2022]
Abstract
We describe a method for the highly efficient and precise targeted modification of gene trap loci in mouse embryonic stem cells (ESCs). Through the Floxin method, gene trap mutations are reverted and new DNA sequences inserted using Cre recombinase and a shuttle vector, pFloxin. Floxin technology is applicable to the existing collection of 24,149 compatible gene trap cell lines, which should enable the high-throughput modification of many genes in mouse ESCs.
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12
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Nguyen D, Xu T. The expanding role of mouse genetics for understanding human biology and disease. Dis Model Mech 2009; 1:56-66. [PMID: 19048054 DOI: 10.1242/dmm.000232] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
It has taken about 100 years since the mouse first captured our imagination as an intriguing animal for it to become the premier genetic model organism. An expanding repertoire of genetic technology, together with sequencing of the genome and biological conservation, place the mouse at the foremost position as a model to decipher mechanisms underlying biological and disease processes. The combined approaches of embryonic stem cell-based technologies, chemical and insertional mutagenesis have enabled the systematic interrogation of the mouse genome with the aim of creating, for the first time, a library of mutants in which every gene is disrupted. The hope is that phenotyping the mutants will reveal novel and interesting phenotypes that correlate with genes, to define the first functional map of a mammalian genome. This new milestone will have a great impact on our understanding of mammalian biology, and could significantly change the future of medical diagnosis and therapeutic development, where databases can be queried in silico for potential drug targets or underlying genetic causes of illnesses. Emerging innovative genetic strategies, such as somatic genetics, modifier screens and humanized mice, in combination with whole-genome mutagenesis will dramatically broaden the utility of the mouse. More significantly, allowing genome-wide genetic interrogations in the laboratory, will liberate the creativity of individual investigators and transform the mouse as a model for making original discoveries and establishing novel paradigms for understanding human biology and disease.
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Affiliation(s)
- Duc Nguyen
- Howard Hughes Medical Institute, Department of Genetics, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06510, USA
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13
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De-Zolt S, Altschmied J, Ruiz P, von Melchner H, Schnütgen F. Gene-trap vectors and mutagenesis. Methods Mol Biol 2009; 530:29-47. [PMID: 19266330 DOI: 10.1007/978-1-59745-471-1_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Gene trapping can be used to introduce insertional mutations into the genome of mouse embryonic stem cells (ESCs). The method has been adapted for high-throughput use, in an effort to inactivate all genes in the mouse genome. Gene trapping is performed with vectors that simultaneously inactivate and report the expression of the trapped gene and provide a molecular tag for its rapid identification. Gene-trap approaches have been used successfully in the past by both academic and commercial organizations to create libraries of ESC lines harboring mutations in single genes that can be used for making mice. Presently, approximately 70% of the protein-coding genes in the mouse genome have been disrupted by gene-trap insertions. Here we describe the basic methodology used to induce and characterize gene-trap mutations in ESCs.
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Affiliation(s)
- Silke De-Zolt
- Department of Molecular Hematology, University of Frankfurt, Frankfurt am Main, Germany
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14
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Nkx2-5 transactivates the Ets-related protein 71 gene and specifies an endothelial/endocardial fate in the developing embryo. Proc Natl Acad Sci U S A 2009; 106:814-9. [PMID: 19129488 DOI: 10.1073/pnas.0807583106] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recent studies support the existence of a common progenitor for the cardiac and endothelial cell lineages, but the underlying transcriptional networks responsible for specification of these cell fates remain unclear. Here we demonstrated that Ets-related protein 71 (Etsrp71), a newly discovered ETS family transcription factor, was a novel downstream target of the homeodomain protein, Nkx2-5. Using genetic mouse models and molecular biological techniques, we demonstrated that Nkx2-5 binds to an evolutionarily conserved Nkx2-5 response element in the Etsrp71 promoter and induces the Etsrp71 gene expression in vitro and in vivo. Etsrp71 was transiently expressed in the endocardium/endothelium of the developing embryo (E7.75-E9.5) and was extinguished during the latter stages of development. Using a gene disruption strategy, we found that Etsrp71 mutant embryos lacked endocardial/endothelial lineages and were nonviable. Moreover, using transgenic technologies and transcriptional and chromatin immunoprecipitation (ChIP) assays, we further established that Tie2 is a direct downstream target of Etsrp71. Collectively, our results uncover a novel functional role for Nkx2-5 and define a transcriptional network that specifies an endocardial/endothelial fate in the developing heart and embryo.
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15
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Loss of mouse Ikbkap, a subunit of elongator, leads to transcriptional deficits and embryonic lethality that can be rescued by human IKBKAP. Mol Cell Biol 2008; 29:736-44. [PMID: 19015235 DOI: 10.1128/mcb.01313-08] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Familial dysautonomia (FD), a devastating hereditary sensory and autonomic neuropathy, results from an intronic mutation in the IKBKAP gene that disrupts normal mRNA splicing and leads to tissue-specific reduction of IKBKAP protein (IKAP) in the nervous system. To better understand the roles of IKAP in vivo, an Ikbkap knockout mouse model was created. Results from our study show that ablating Ikbkap leads to embryonic lethality, with no homozygous Ikbkap knockout (Ikbkap(-)(/)(-)) embryos surviving beyond 12.5 days postcoitum. Morphological analyses of the Ikbkap(-)(/)(-) conceptus at different stages revealed abnormalities in both the visceral yolk sac and the embryo, including stunted extraembryonic blood vessel formation, delayed entry into midgastrulation, disoriented dorsal primitive neural alignment, and failure to establish the embryonic vascular system. Further, we demonstrate downregulation of several genes that are important for neurulation and vascular development in the Ikbkap(-)(/)(-) embryos and show that this correlates with a defect in transcriptional elongation-coupled histone acetylation. Finally, we show that the embryonic lethality resulting from Ikbkap ablation can be rescued by a human IKBKAP transgene. For the first time, we demonstrate that IKAP is crucial for both vascular and neural development during embryogenesis and that protein function is conserved between mouse and human.
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16
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Schnütgen F, Hansen J, De-Zolt S, Horn C, Lutz M, Floss T, Wurst W, Noppinger PR, von Melchner H. Enhanced gene trapping in mouse embryonic stem cells. Nucleic Acids Res 2008; 36:e133. [PMID: 18812397 PMCID: PMC2582619 DOI: 10.1093/nar/gkn603] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Gene trapping is used to introduce insertional mutations into genes of mouse embryonic stem cells (ESCs). It is performed with gene trap vectors that simultaneously mutate and report the expression of the endogenous gene at the site of insertion and provide a DNA tag for rapid identification of the disrupted gene. Gene traps have been employed worldwide to assemble libraries of mouse ESC lines harboring mutations in single genes, which can be used to make mutant mice. However, most of the employed gene trap vectors require gene expression for reporting a gene trap event and therefore genes that are poorly expressed may be under-represented in the existing libraries. To address this problem, we have developed a novel class of gene trap vectors that can induce gene expression at insertion sites, thereby bypassing the problem of intrinsic poor expression. We show here that the insertion of the osteopontin enhancer into several conventional gene trap vectors significantly increases the gene trapping efficiency in high-throughput screens and facilitates the recovery of poorly expressed genes.
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Affiliation(s)
- Frank Schnütgen
- Department of Molecular Hematology, University of Frankfurt Medical School, Frankfurt am Main, Germany
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17
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Tanaka TS, Davey RE, Lan Q, Zandstra PW, Stanford WL. Development of a gene-trap vector with a highly sensitive fluorescent protein reporter system for expression profiling. Genesis 2008; 46:347-56. [PMID: 18615730 DOI: 10.1002/dvg.20404] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
SUMMARY Combining high-content screening (HCS) with random gene-trap mutagenesis could be a powerful tool to investigate transcriptional networks, cell signaling, chemical genetics, and developmental processes. However, a critical limitation has been poor quantification of reporter expression per cell. To overcome this hurdle, we generated a variety of Gtx-based expression cassettes and re-evaluated translational enhancement of arrayed Gtx segments in tandem by HCS. We then modified the cassette into a new polyA trap vector, which consists of a variant of yellow fluorescent protein, Venus, in combination with the Gtx segments. Expression of Venus was detected in about 60% of trapped genes assayed in embryonic stem cell (ESC) cultures, comparable to expression screening of LacZ-based vectors. Furthermore, tetraploid aggregations using a clone encoding a gene-trap insertion into Twist2 demonstrated identical spatiotemporal expression between Venus and Twist2. This highly sensitive reporter system is amenable to high-throughput expression-based real-time HCS including single cell analyses.
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Affiliation(s)
- Tetsuya S Tanaka
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
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Gene trapping: an antibody-dependent approach for verifying integration in your favorite gene. Cell Mol Biol Lett 2008; 13:614-20. [PMID: 18618084 PMCID: PMC6275795 DOI: 10.2478/s11658-008-0028-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2008] [Accepted: 06/10/2008] [Indexed: 11/21/2022] Open
Abstract
Gene trapping is used to introduce genome-wide insertional mutations in embryonic stem cells. Determining the integration site is based on highthroughput PCR, which has inevitable possibilities for mistakes, thus necessitating clone verification prior to the generation of mutant mice. Here, we propose a rapid method to validate gene identity based on the fact that many high throughput gene-trapping integrations result in fusion proteins encompassing the N-terminal portion of the gene of interest and LacZ being expressed in embryonic stem cells. Our method utilizes an immunoprecipitation assay using a specific N-terminal-directed antibody to the protein product of the gene of interest followed by a color LacZ assay of the immunoprecipitate, strongly supporting the formation of a fusion protein when the color develops.
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Hernandez-Valladares M, Naessens J, Iraqi FA. Gene-knockout mice in malaria research: useful or misleading? Trends Parasitol 2007; 23:522-6. [PMID: 17951110 DOI: 10.1016/j.pt.2007.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 08/22/2007] [Accepted: 08/22/2007] [Indexed: 10/22/2022]
Abstract
Gene-knockout mice have been extensively used in the study of several malaria-induced pathologies. Some investigators believe that the deficient, infected mice mimic disease aspects produced in the absence of the target gene, but others believe that the deficient mice models mainly explain the effects of compensatory, related molecules. Comparison of some of the most relevant knockout mouse studies for understanding cerebral malaria and parasitemia and their related human reports shows that gene-knockout mice are useful tools that support conclusions from human genetic studies. These mice have helped to indicate new resistance genes against human malaria and have provided valuable information about mechanisms of malaria resistance in mice.
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