References of "Hrabe de Angelis, M"
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See detailCharacterization of a new, dominant V124E mutation in the mouse alphaA-crystallin-encoding gene.
Graw, J.; Loster, J.; Soewarto, D. et al

in Investigative Ophthalmology & Visual Science (2001), 42(12), 2909-15

PURPOSE: During an ethylnitrosourea (ENU) mutagenesis screening, mice were tested for the occurrence of dominant cataracts. The purpose of the study was morphologic description, mapping of the mutant gene ... [more ▼]

PURPOSE: During an ethylnitrosourea (ENU) mutagenesis screening, mice were tested for the occurrence of dominant cataracts. The purpose of the study was morphologic description, mapping of the mutant gene, and characterization of the underlying molecular lesion in a particular mutant, Aey7. METHODS: Isolated lenses were photographed and histologic sections of the eye were analyzed according to standard procedures. Linkage analysis was performed with a set of microsatellite markers covering all autosomal chromosomes. cDNA was amplified after reverse transcription of lens mRNA. For PCR, cDNA or genomic DNA was used as a template. RESULTS: Nuclear opacity and posterior suture anomaly were visible at eye opening and progressed to a nuclear and zonular cataract at 2 months of age. The opacity as well as the microphthalmia was more pronounced in the homozygotes than in the heterozygotes. The mutation was mapped to chromosome 17 between the markers D17Mit133 and D17Mit180. This position made the alphaA-crystallin-encoding gene (Cryaa) an excellent candidate gene. Sequence analysis revealed a mutation of a T to an A at position 371 in the Cryaa cDNA. The mutation was confirmed by an additional MnlI restriction site in the genomic DNA of homozygous mutants leading to replacement of Val with Glu at codon 124 affecting the C-terminal region of the alphaA-crystallin. CONCLUSIONS: The Aey7 mutant represents the first dominant mouse cataract mutation affecting the Cryaa gene. The mutation leads to progressive opacification of the lens. Compared with the beta- and gamma-crystallin-encoding genes, mutations in the alpha-crystallin-encoding genes are rare. [less ▲]

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See detailAey2, a new mutation in the betaB2-crystallin-encoding gene of the mouse.
Graw, J.; Loster, J.; Soewarto, D. et al

in Investigative Ophthalmology & Visual Science (2001), 42(7), 1574-80

PURPOSE: During an ethylnitrosourea (ENU) mutagenesis screen, mice were tested for the occurrence of dominant cataracts. One particular mutant was found that caused progressive opacity and was referred to ... [more ▼]

PURPOSE: During an ethylnitrosourea (ENU) mutagenesis screen, mice were tested for the occurrence of dominant cataracts. One particular mutant was found that caused progressive opacity and was referred to as Aey2. The purpose of the study was to provide a morphologic description, to map the mutant gene, and to characterize the underlying molecular lesion. METHODS: Isolated lenses were photographed, and histologic sections of the eye were analyzed according to standard procedures. Linkage analysis was performed using a set of microsatellite markers covering all autosomal chromosomes. cDNA from candidate genes was amplified after reverse transcription of lens mRNA. RESULTS: The cortical opacification visible at eye opening progressed to an anterior suture cataract and reached its final phenotype as total opacity at 8 weeks of age. There was no obvious difference between heterozygous and homozygous mutants. The mutation was mapped to chromosome 5 proximal to the marker D5Mit138 (8.7 +/- 4.2 centimorgan [cM]) and distal to D5Mit15 (12.8 +/- 5.4 cM). No recombinations were observed to the markers D5Mit10 and D5Mit25. This position makes the genes within the betaA4/betaB-crystallin gene cluster excellent candidate genes. Sequence analysis revealed a mutation of T-->A at position 553 in the Crybb2 gene, leading to an exchange of Val for GLU: It affects the same region of the Crybb2 gene as in the Philly mouse. Correspondingly, the loss of the fourth Greek key motif is to be expected. CONCLUSIONS: The Aey2 mutant represents the second allele of Crybb2 in mice. Because an increasing number of beta- and gamma-crystallin mutations have been reported, a detailed phenotype-genotype correlation will allow a clearer functional understanding of beta- and gamma-crystallins. [less ▲]

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See detailSequence interpretation. Functional annotation of mouse genome sequences.
Nadeau, J. H.; Balling, Rudi UL; Barsh, G. et al

in Science (2001), 291(5507), 1251-5

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See detailThe Notch ligand Jagged1 is required for inner ear sensory development.
Kiernan, A. E.; Ahituv, N.; Fuchs, H. et al

in Proceedings of the National Academy of Sciences of the United States of America (2001), 98(7), 3873-8

Within the mammalian inner ear there are six separate sensory regions that subserve the functions of hearing and balance, although how these sensory regions become specified remains unknown. Each sensory ... [more ▼]

Within the mammalian inner ear there are six separate sensory regions that subserve the functions of hearing and balance, although how these sensory regions become specified remains unknown. Each sensory region is populated by two cell types, the mechanosensory hair cell and the supporting cell, which are arranged in a mosaic in which each hair cell is surrounded by supporting cells. The proposed mechanism for creating the sensory mosaic is lateral inhibition mediated by the Notch signaling pathway. However, one of the Notch ligands, Jagged1 (Jag1), does not show an expression pattern wholly consistent with a role in lateral inhibition, as it marks the sensory patches from very early in their development--presumably long before cells make their final fate decisions. It has been proposed that Jag1 has a role in specifying sensory versus nonsensory epithelium within the ear [Adam, J., Myat, A., Roux, I. L., Eddison, M., Henrique, D., Ish-Horowicz, D. & Lewis, J. (1998) Development (Cambridge, U.K.) 125, 4645--4654]. Here we provide experimental evidence that Notch signaling may be involved in specifying sensory regions by showing that a dominant mouse mutant headturner (Htu) contains a missense mutation in the Jag1 gene and displays missing posterior and sometimes anterior ampullae, structures that house the sensory cristae. Htu/+ mutants also demonstrate a significant reduction in the numbers of outer hair cells in the organ of Corti. Because lateral inhibition mediated by Notch predicts that disruptions in this pathway would lead to an increase in hair cells, we believe these data indicate an earlier role for Notch within the inner ear. [less ▲]

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See detailCharacterization of a mutation in the lens-specific MP70 encoding gene of the mouse leading to a dominant cataract.
Graw, J.; Loster, J.; Soewarto, D. et al

in Experimental Eye Research (2001), 73(6), 867-76

During an ethylnitrosourea mutagenesis screen, Aey5, a new mouse mutation exhibiting an autosomal dominant congenital cataract was isolated. The cataractous phenotype is visible at the eye opening and ... [more ▼]

During an ethylnitrosourea mutagenesis screen, Aey5, a new mouse mutation exhibiting an autosomal dominant congenital cataract was isolated. The cataractous phenotype is visible at the eye opening and progresses to a nuclear and zonular cataract at 2 months of age with no difference in onset or severity between heterozygous and homozygous mutants. Histological analysis revealed that fiber cell differentiation continues at the lens bow region, but the cell nuclei do not degrade normally and remain in the deeper cortex. Further, the lens nucleus has clefts of various sizes while the remainder of the eye was morphologically normal. The mutation was mapped to chromosome 3 between the markers D3Mit101 and D3Mit77 near the connexin encoding genes Gja5 and Gja8. Sequence analysis revealed no differences in the Gja5 gene, but identified a T-->C mutation at position 191 in the Gja8 gene, which was confirmed by an additional Mva 12691 restriction site in the genomic DNA of homozygous mutants. This mutation results in Val-->Ala substitution at codon 64 of connexin50 (Cx50) also known as lens membrane protein 70 (MP70). Aey5 represents the second dominant mouse cataract mutant affecting Cx50, a membrane protein preferentially expressed in the lens. Since both mutations affect similar regions in the first extracellular domain this region appears to be critically important for its function in lens transparency. [less ▲]

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See detailEnu mouse mutagenesis: generation of mouse mutants with aberrant plasma IgE levels.
Alessandrini, F.; Jakob, T.; Wolf, A. et al

in International Archives of Allergy & Immunology (2001), 124(1-3), 25-8

BACKGROUND: The ENU Mouse Mutagenesis Project aims at a large-scale, systematic production of mouse mutants using the alkylating agent ethyl-nitrosourea (ENU). Offspring of mutagenized mice are subjected ... [more ▼]

BACKGROUND: The ENU Mouse Mutagenesis Project aims at a large-scale, systematic production of mouse mutants using the alkylating agent ethyl-nitrosourea (ENU). Offspring of mutagenized mice are subjected to a multiparameter screen to detect alterations in various phenotypes with the ultimate goal of identifying novel genes relevant for the expression of the phenotype. Using this approach, we have analyzed plasma IgE concentrations to identify mouse mutants with aberrant plasma IgE levels. METHODS AND RESULTS: ENU-mutagenized male C3HeB/FeJ were mated to wild-type females to produce F1 offspring. F1 animals were analyzed for alterations in their plasma IgE concentrations that showed a dominant mode of inheritance, or bred further to screen for recessive phenotypes. Plasma IgE concentrations were determined by ELISA and a normal range for plasma IgE was established using C3HeB/FeJ wild-type animals. So far we have tested 6568 F1 animals. Repeated testing confirmed a stable aberrant IgE phenotype in 124 animals. To confirm the genetic basis of the observed phenotype, these mice were subjected to confirmation crossing. Currently we have established 9 independent mutant mouse lines (3 with high plasma IgE and 6 with plasma IgE below detection limit) that have been genetically confirmed and additional 24 variant mouse lines are currently undergoing confirmation testing. CONCLUSION: ENU mouse mutagenesis allowed us to generate and identify mouse mutants with aberrant plasma IgE levels, which may be used to characterize novel genes involved in IgE regulation and may serve as animal models for IgE-mediated diseases. [less ▲]

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See detailThe clinical-chemical screen in the Munich ENU Mouse Mutagenesis Project: screening for clinically relevant phenotypes.
Rathkolb, B.; Decker, T.; Fuchs, E. et al

in Mammalian Genome : Official Journal of the International Mammalian Genome Society (2000), 11(7), 543-6

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See detailThe large-scale Munich ENU-mouse-mutagenesis screen.
Soewarto, D.; Fella, C.; Teubner, A. et al

in Mammalian Genome : Official Journal of the International Mammalian Genome Society (2000), 11(7), 507-10

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See detailScreening for dysmorphological abnormalities--a powerful tool to isolate new mouse mutants.
Fuchs, H.; Schughart, K.; Wolf, E. et al

in Mammalian Genome : Official Journal of the International Mammalian Genome Society (2000), 11(7), 528-30

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See detailFrom developmental biology to developmental toxicology.
Balling, Rudi UL; Hrabe de Angelis, M.

in Annals of the New York Academy of Sciences (2000), 919

Progress derived from the human genome project will have tremendous impact on toxicology. Questions concerning genetic susceptibility or resistance to toxic compound exposure and the dissection of the ... [more ▼]

Progress derived from the human genome project will have tremendous impact on toxicology. Questions concerning genetic susceptibility or resistance to toxic compound exposure and the dissection of the molecular mechanisms involved will be at the forefront of future toxicological research. In recent years, it was recognized that many of the molecular control mechanisms of embryogenesis have been conserved during evolution. The relevance of these observations for toxicology and the application of genetic approaches using mouse mutants as a tool for functional genome analysis are discussed. [less ▲]

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See detailThe biochemical metabolite screen in the Munich ENU Mouse Mutagenesis Project: determination of amino acids and acylcarnitines by tandem mass spectrometry.
Rolinski, B.; Arnecke, R.; Dame, T. et al

in Mammalian Genome : Official Journal of the International Mammalian Genome Society (2000), 11(7), 547-51

BACKGROUND: Gene mutations often result in altered protein expression and, in turn, lead to changes in metabolite levels in one or more distinct biochemical pathways. Traditional analytical methods for ... [more ▼]

BACKGROUND: Gene mutations often result in altered protein expression and, in turn, lead to changes in metabolite levels in one or more distinct biochemical pathways. Traditional analytical methods for metabolite determination are usually time consuming, expensive, and, thus, not suitable for high throughput analysis. However, recent developments in electrospray-tandem-mass-spectrometry allow comprehensive metabolite scanning from very small amounts of blood with high speed, cost effectiveness, and accuracy. METHODS: A blood spot from a filter paper equivalent to 3 microl of blood was punched out and transferred to a 96-well microtiter plate. After addition of a set of 14 stable isotope-labeled internal standards, amino acids and acylcarnitines were extracted with methanol. The dried residue was derivatized with butanolic hydrochloric acid and subjected to MSMS analysis. RESULTS: Acyl-carnitines were all determined by a precursor ion scan of 85 Da. Neutral loss scanning of 102 Da was suitable for the quantitation of threonine, serine, proline, histidine, alanine, aspartic acid, glutamic acid, methionine, tyrosine, phenylalanine, isoleucine/leucine and valine. Glycine was detected by a loss of a 56-Da fragment, whereas a 119-Da loss was suitable for the measurement of citrulline, ornithine, arginine, and lysine. Specific problems encountered: owing to their identical molecular weight, isoleucine and leucine could not be quantitated separately, and, owing to their instability, glutamine and asparagine were found to be decarboxylated to their respective acids. Determination was linear over the concentration range tested (20 to 1000 micromol/L), and intraassay and interassay coefficients of variation were in the range of 10-15%. CONCLUSION: ESI-MSMS proved to be a highly sensitive, linear, and sufficiently precise method for the quantitative determination of amino acids and acylcarnitines in mouse blood, allowing large-scale screening applications when speed and cost effectiveness are mandatory. [less ▲]

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See detailLarge-scale N-ethyl-N-nitrosourea mutagenesis of mice--from phenotypes to genes.
Rathkolb, B.; Fuchs, E.; Kolb, H. J. et al

in Experimental Physiology (2000), 85(6), 635-44

The most important tool for obtaining insight into the function of genes is the use of mutant model organisms. Homologous recombination in embryonic stem cells allows the systematic production of mouse ... [more ▼]

The most important tool for obtaining insight into the function of genes is the use of mutant model organisms. Homologous recombination in embryonic stem cells allows the systematic production of mouse mutants for any gene that has been cloned. Gene trap strategies have been designed to interrupt even unknown genes which are tagged by the inserted vector and can be characterised structurally and functionally. Complementary to such 'gene-driven' approaches, 'phenotype-driven' approaches are necessary to identify new genes or gene products through a search for mutants with specific defects, uncovering the function of genetic pathways in physiological and pathological processes. Mutagenesis using the alkylating agent N-ethyl-N-nitrosourea (ENU) is a powerful approach for the production of such mouse mutants. Since ENU induces mainly point mutations in premeiotic spermatogonia, this strategy allows the production of multiple alleles of a particular gene, which is pivotal for a fine tuned analysis of its function. [less ▲]

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See detailReliable recovery of inbred mouse lines using cryopreserved spermatozoa.
Marschall, S.; Huffstadt, U.; Balling, Rudi UL et al

in Mammalian Genome : Official Journal of the International Mammalian Genome Society (1999), 10(8), 773-6

Since the mouse has become the most detailed model system to investigate the genetics and pathogenesis of human diseases, large numbers of new mouse strains have and continue to be produced. In nearly all ... [more ▼]

Since the mouse has become the most detailed model system to investigate the genetics and pathogenesis of human diseases, large numbers of new mouse strains have and continue to be produced. In nearly all animal facilities, the maintenance of breeding colonies is limited and mouse strains have to be archived in an efficient way. This study was undertaken to test the reliability of recovering mouse lines by use of cryopreserved spermatozoa from individual male mice. In contrast to many studies, spermatozoa and oocytes were derived from the same genetic background. 30 C3HeB/FeJ males belonging to three different categories (wild-type, F1-generation of ENU-treated males, and defined mutants) were recovered by producing at least 20 offspring from each donor. Independent of the experimental group, every single male was successfully recovered. Archiving mouse strains by cryopreservation of spermatozoa may, therefore, offer a reliable way to preserve genetically valuable mouse strains and provides an efficient management strategy for animal facilities. [less ▲]

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See detailMutation in the betaA3/A1-crystallin encoding gene Cryba1 causes a dominant cataract in the mouse.
Graw, J.; Jung, M.; Loster, J. et al

in Genomics (1999), 62(1), 67-73

During the mouse ENU mutagenesis screen, mice were tested for the occurrence of dominant cataracts. One particular mutant was discovered as a progressive opacity (Po). Heterozygotes show opacification of ... [more ▼]

During the mouse ENU mutagenesis screen, mice were tested for the occurrence of dominant cataracts. One particular mutant was discovered as a progressive opacity (Po). Heterozygotes show opacification of a superficial layer of the fetal nucleus, which progresses and finally forms a nuclear opacity. Since the homozygotes have already developed the total cataract at eye opening, the mode of inheritance is semidominant. Linkage analysis was performed using a set of genome-wide microsatellite markers. The mutation was mapped to chromosome 11 distal of the marker D11Mit242 (9.3 +/- 4.4 cM) and proximal to D11Mit36 (2.3 +/- 2.3 cM). This position makes the betaA3/A1-crystallin encoding gene Cryba1 an excellent candidate gene. Mouse Cryba1 was amplified from lens mRNA. Sequence analysis revealed a mutation of a T to an A at the second base of exon 6, leading to an exchange of Trp by Arg. Computer analysis predicts that the fourth Greek key motif of the affected betaA3/A1-crystallin will not be formed. Moreover, the mutation leads also to an additional splicing signal, to the skipping of the first 3 bp of exon 6, and finally to the deletion of the Trp residue. Both types of mRNA are present in the homozygous mutant lenses. The mutation will be referred to as Cryba1(po1). This particular mouse mutation provides an excellent animal model for a human congenital zonular cataract with suture opacities, which is caused by a mutation in the homologous gene. [less ▲]

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See detailTailchaser (Tlc): a new mouse mutation affecting hair bundle differentiation and hair cell survival.
Kiernan, A. E.; Zalzman, M.; Fuchs, H. et al

in Journal of Neurocytology (1999), 28(10-11), 969-85

We have undertaken a phenotypic approach in the mouse to identifying molecules involved in inner ear function by N-ethyl-N-nitrosourea mutagenesis followed by screening for new dominant mutations ... [more ▼]

We have undertaken a phenotypic approach in the mouse to identifying molecules involved in inner ear function by N-ethyl-N-nitrosourea mutagenesis followed by screening for new dominant mutations affecting hearing or balance. The pathology and genetic mapping of the first of these new mutants, tailchaser (Tlc), is described here. Tlc/+ mutants display classic behavioural symptoms of a vestibular dysfunction, including head-shaking and circling. Behavioural testing of ageing mice revealed a gradual deterioration of both hearing and balance function, indicating that the pathology caused by the Tlc mutation is progressive, similar to many dominant nonsyndromic deafnesses in humans. Based on scanning electron microscopy (SEM) studies, Tlc clearly plays a developmental role in the hair cells of the cochlea since the stereocilia bundles fail to form the characteristic V-shape pattern around the time of birth. By young adult stages, Tlc/+ outer hair bundles are grossly disorganised although inner hair bundles appear relatively normal by SEM. Increased compound action potential thresholds revealed that the Tlc/+ cochlear hair cells were not functioning normally in young adults. Similar to inner hair cells, the hair bundles of the vestibular hair cells also do not appear grossly disordered. However, all types of hair cells in the Tlc/+ inner ear eventually degenerate, apparently regardless of the degree of organisation of their hair bundles. We have mapped the Tlc mutation to a 12 cM region of chromosome 2, between D2Mit164 and D2Mit423. Based on the mode of inheritance and map location, Tlc appears to be a novel mouse mutation affecting both hair cell survival and stereocilia bundle development. [less ▲]

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See detailLarge scale ENU screens in the mouse: genetics meets genomics.
Hrabe de Angelis, M.; Balling, Rudi UL

in Mutation research (1998), 400(1-2), 25-32

The worldwide effort to completely sequence the human and mouse genome will be accomplished within the next years. The focus of current activities within the framework of human genome research is mainly ... [more ▼]

The worldwide effort to completely sequence the human and mouse genome will be accomplished within the next years. The focus of current activities within the framework of human genome research is mainly on the assembly of high resolution genetic and physical maps and genomic sequencing. Cloning of new genes is getting more easy using those maps. Nevertheless, it is necessary to work on a systematic analysis of gene function. Results obtained from these efforts will be of enormous value for future biological and biomedical research. However, even the complete sequence will not in all cases reveal the molecular and cellular role of the different genes. Therefore, the next phase of the Human Genome Project will have at its core the functional analysis of genes. Those genes relevant for the diagnosis, prevention and therapy of human diseases are of particular interest. Looking at the history of life sciences, mutants have been the most important tool to obtain insight into the biological function of genes. The mouse is the model of choice for the study of inherited diseases in man. In order to meet the requirements for functional human genome analysis, we need a large number of mouse mutants similar to the collection of mutants available for other model organisms such as flys and worms. To fully apply the power of genetics, multiple alleles of the same gene such as hypomorphs or hypermorphs are required. Efficient production of mouse mutants showing specific phenotypes can be achieved by the use of ethylnitrosourea (ENU). ENU is the most powerful mutagen known and we currently see a renaissance of ENU mutagenesis. The application of ENU mutagenesis is reviewed and discussed in the context of a new era of functional genomics. [less ▲]

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See detailWe need more mutants: Plans for a large scale ENU mouse mutagenesis screen
Balling, Rudi UL; Hrabe de Angelis, M; Schughart, K et al

in OECD Proceedings (1998), (98), 103-111

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