TY  - JOUR
A1  - Dandekar, Thomas
A1  - Ribes, V.
A1  - Tollervey, David
T1  - Schizosaccharomyces pombe U4 small nuclear RNA closely resembles vertebrate U4 and is required for growth
N2  - No abstract available
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29771
ER  - 
TY  - JOUR
A1  - Dandekar, Thomas
A1  - Tollervey, David
T1  - Cloning of Schizosaccharomyces pombe genes encoding the U1,U2,U3 and U4 snRNAs
N2  - No abstract available
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29919
ER  - 
TY  - JOUR
A1  - Grafe, U.
A1  - Linsenmair, Karl Eduard
T1  - Protogynous sex change in the Reed Frog: Hyperolius viridiflavus
N2  - Observations on captive reed frogs Hyperolius viridijlavus ommatostictus showed that seven out of 24 females changed into males. Sex change occurred without any hormone treatment and resulted in completely functional males. The adaptive value is discussed in terms of maximizing life-time reproductive success. Hyperolius r. ommatostictus is the first amphibian known to show functional sex reversal.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30990
ER  - 
TY  - JOUR
A1  - Raulf, Friedrich
A1  - Mäueler, Winfried
A1  - Robertson, Scott M.
A1  - Schartl, Manfred
T1  - Localization of cellular src mRNA during development and in the differentiated bipolar neurons of the adult neural retina in Xiphophorus
N2  - The expression of the c-src gene in embryonie and adult tissue of the teleost fish Xiphophorus helleri was analyzed by in-situ hybridization. The highly conserved fish c-src gene was found to be expressed at high levels in midterm embryos, where c-src mRNA was localized in developing neurons of the sensory layer of the differentiating retina and in the developing brain. In adult tissues the expression of c-src was found to persist in certain cell types of the brain and the neural retina, especially in the bipolar cells of the inner nuclear layer, which are postmitotic, fully differentiated mature neurons. Thus c-src in Xiphophorus appears to be a developmentally regulated proto-oncogene which is important for neuronal differentiation during organogenesis, but whose persistence of expression in certain terminally differentiated neurons strongly suggests a particular maintenance function for c-src in these cells as well.
KW  - Schwertkärpfling
KW  - Messenger-RNS
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86703
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Holstein, Thomas
A1  - Robertson, Scott M.
A1  - Barnekow, Angelika
T1  - Preferential expression of a pp60c-src related protein tyrosine kinase activity in nerve cells of the early metazoan Hydra (Coelenterates)
N2  - It has been suggested that the proto-oncogene c-src plays a functional role in developing neurons, and in the mature nerve cells of higher vertebrales. The coelenterate Hydra represents tbe most primitive known organism possessing nerve cells. With Southern blot hybridizations we have demonstrated src-related sequences in Hydra. Antisera specific for the c-src gene product (pp60 c-src) of birds and mammals precipitate a protein from Hydra cell extracts with a tyrosine-specific protein kinase activity. Studies of tissues and cells fractionated from a temperature sensitive mutant of Hydra which is depleted of interstitial (including nerve) cells at tbe non-permissive temperature, have indicated the src-like kinase of Hydra to be preferentially expressed in nerve cells. The high conservation of structural features and of the expression pattern indicates a basic function for pp60c-src in neurons.
KW  - Protein-Tyrosin-Kinasen
KW  - Nervenzelle
KW  - Süßwasserpolypen
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86179
ER  - 
TY  - JOUR
A1  - Merz, H.
A1  - Fliedner, A.
A1  - Lehrnbecher, T.
A1  - Sebald, Walter
A1  - Müller-Hermelink, H. K.
A1  - Feller, A. C.
T1  - Cytokine expression in B-cell non-Hodgkin lymphomas
N2  - No abstract available
KW  - Biochemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62539
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
T1  - Homology of melanoma-inducing loci in the genus Xiphophorus
N2  - Several species of the genus Xiphophorus are polymorphic for specific pigment patterns. Same of these give rise to malignant melanoma following the appropriate crossings. For one of these pattern Iod from the platyfish Xiphophorus maculatus the melanoma-inducing gene has been doned and found to encode a novel receptor tyrosine kinase, designated Xmrk. Using molecular probes from this gene in Southern blot analyses on single fish DNA preparations from 600 specimens of different populations of various species of the genus Xiphophorus and their hybrids, either with or without melanomapredisposing pattern, it was shown that all individuals contain the Xmrk gene as a proto-oncogene. It is located on the sex chromosome. All fish that carry a melanoma-predisposing locus which has been identified by Mendelian genetics contain an additional copy of Xmrk, closely linked to a specific melanophore pattern locus on the sex chromosome. The melanoma-inducing loci of the different species and populations are homologous. The additional copy of Xmrk obviously arose by a geneduplication event, thereby acquiring the oncogenic potential. The homology of the melanomainducing Iod points to a similar mechanism of tumor suppression in all feral fish populations of the different species of the genus Xiphophorus.
KW  - Physiologische Chemie
KW  - Xiphophorus
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61757
ER  - 
TY  - JOUR
A1  - Dracopoli, Nicholas C.
A1  - Feltquate, David M.
A1  - Sam, Brigitta
A1  - Schartl, Manfred
T1  - Taql and Mspl RFLPs are detected by the human 2,3-biphosphoglycerate mutase (BPGM) cDNA
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61763
ER  - 
TY  - JOUR
A1  - Friedenreich, Hildegard
A1  - Schartl, Manfred
T1  - Transient expression directed by homologous and heterologous promoter and enhancer sequences in fish cells
N2  - ln order to construct fish specific expression vectors for studies on gene regulation in vitro and in vivo a variety of heterologous enhancers and promoters from mammals and from viruses of higher vertebrate cells were tested for expression of the bacterial chloramphenicol acetyl transferase reporter gene in three teleost fish cell lines. Several viral enhancers were found to be constitutively active at high Ieveis. The human metallothionein promoter showed inducible expression in the presence of heavy metal Ions. A fish sequence was isolated that can be used as a homologous constitutively active promoter for expression of foreign genes. Using the human growth hormone gene with an active promoter in fish cells for transient expression insufficient splicing and Iack of translation were observed, pointing to limitations in the use of heterologous genes in gene transfer experiments. On the contrary, some heterologous promoters and enhancers functioned in fish c as weil as in their cell type of origin, indicating t at corresponding transcription factors are sufficient conserved between fish and human over a period of 900 million years of Independent evolution.
KW  - Physiologische Chemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61774
ER  - 
TY  - JOUR
A1  - Clauss, Gerd
A1  - Winkler, Christoph
A1  - Lohmeyer, Jürgen
A1  - Anders, Fritz
A1  - Schartl, Manfred
T1  - Oncofetal antigen in Xiphophorus detected by monoclonal antibodies directed against melanoma-associated antigens
N2  - Monoclonal antlbodies (MAbs) directed against Xiphophorus melanoma cells were deve(oped and tested by lndirect immunofluorescence and Immunoperoxidase staining for reactivity with a panel of I 5 allogeneic tissues and 12 allogeneic cell llnes. The reactivity of such MAbs was restricted to melanoma cells from tumor biopsies and melanoma-derived cell lines. ln addition, all embryonie cells of all histiotypes from developmental stages later than mld·organogenesis and from corresponding short term in vitro cultures reacted with these MAbs. ln contrast, normal tissues and organs from adult fish dlsplayed no reactivity, thus implying that the melanoma-associated antigens detected by the MAbs described are oncofetal antigens.
KW  - Physiologische Chemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61784
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Hameister, H.
A1  - Henry, I.
A1  - Junien, C.
A1  - Braun, T.
A1  - Arnold, H. H.
T1  - The human MyoD1 (MYF3) gene maps on the short arm of chromosome 11 but is not associated with the WAGR locus or the region for the Beckwith-Wiedemann syndrome
N2  - The human gene encoding the myogenic determination factor myf3 (mouse MyoD1) has been mapped to the short arm of chromosome 11. Analysis of several somatic cell hybrids containing various derivatives with deletions or translocations revealed that the human MyoD (MYF3) gene is not associated with the WAGR locus at chromosomal band 11pl3 nor with the loss of the heterozygosity region at 11p15.5 related to the Beckwith-Wiedemann syndrome. Subregional mapping by in situ hybridization with an myf3 specific probe shows that the gene resides at the chromosomal band llp14, possibly at llp14.3.
KW  - Biochemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59221
ER  - 
TY  - JOUR
A1  - van Heyningen, V.
A1  - Bickmore, W. A.
A1  - Seawright, A.
A1  - Fletcher, J. M.
A1  - Maule, J.
A1  - Fekete, G.
A1  - Gessler, Manfred
A1  - Bruns, G. A.
A1  - Huerre-Jeanpierre, C.
A1  - Junien, C.
T1  - Role for the Wilms tumor gene in genital development?
N2  - No abstract available
KW  - Biochemie
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59238
ER  - 
TY  - JOUR
A1  - Fiala, Brigitte
A1  - Maschwitz, Ulrich
T1  - Studies on the south east asian ant-plant association Crematogaster borneensis / Macaranga: adaptations of the ant partner.
N2  - C. borneensis (Myrmicinae) lives in dose association with several myrmecophytic species of the South East Asian pioneer tree genus Macaranga (Euphorbiaceae). The ants are adapted to the plants so dosely that they do not survive away from it. The only food they utilize is provided as food bodies by the plant and honeydew from specific scale insects kept inside the hollow internodes. The anatomy of the digestive tract is also adapted to life on the host plant: the crop is very sm all and can store only minute food quantities. C. borneensis exdusively colonizes certain Macaranga species. Queens as weIl as workers are able to recognize their host plant species, probably by chemical cues. Colony founding queens swarm throughout the year, mostly during darkness. There is strong competition among queens for host plants. Queens do not carry scale insects on their nuptial flight. Worker ants are active day and night. Most of them patrol and collect food bodies on the younger parts of the host plant. An important characteristic is their deaning behaviour, which results in removal of aIl foreign objects. Even though they are rather smalI, workers respond very aggressively to certain kinds of disturbance of the host plant. The ants attack most phytophagous insects and are especially effective in killing and removing smalI, softbodied herbivores (e.g. caterpillars). They do not possess a functional sting, but apply defensive secretion and-once biting an intruder-will not let go. Their effective alarm system results in a mass attack, which provides adequate defence for the colony and the host plant. A comparison with another Crematogaster species further illustrated the special adaptations of C. borneensis to its host plant.
N2  - Untersuchungen über die südostasiatische Ameisen·Pflanzen-Vergesellschaftung Cremattogaster borneensis Maoaranga : Anpassungen des Ameisenpartners 213 C. borneensis (Myrmicinae) lebt in enger Gemeinschaft mit myrmekophytischen Arten der südostasiatischen Pionierbaumgattung Macaranga (Euphorbiaceae) . Die Ameise ist so eng an die Pflanze adaptiert, daß sie getrennt von ihr nicht lebensfähig ist. Die Nahrung bezieht C. borneensis in Form von Nährkörperchen ausschließlich von der Pflanze. Im Sproßachseninnern gehaltene spezifische Schildläuse bieten eine weitere Nahrungsquelle. Die Adaptationen erstrecken sich bis auf die Anatomie des Verdauungstraktes : Der Kropf ist sehr klein und kann nur geringe Nahrungsmengen speichern. C. borneensis besiedelt spezifisch nur Macaranga-Pflanzen. Sowohl Königinnen als auch Arbeiterinnen sind in der Lage, die Wirtspflanze zu erkennen, wobei offenbar chemische Reize eine Rolle spielen. Die koloniegründenden Königinnen schwärmen das gesamte Jahr über, das Schwärmen erfolgt überwiegend während der Dunkelheit. Um die besiedlungsfähigen Macaranga-Pflanzen herrscht ein starker Konkurrenzdruck. Die beteiligten Schildlausarten sind spezifisch für die Assoziation. Sie werden nicht von der Königin beim Hochzeitsflug mitgenommen. Die Arbeiterinnen sind tag- und nachtaktiv. Die meisten Tiere halten sich im jüngsten Drittel der Pflanze auf, wo sie patrouillieren und Nährkörperchen sammeln. Mittels eines spezifischen Säuberungsverhaltens entfernen die Arbeiterinnen alle Fremdobjekte von der Pflanze. Trotz ihrer geringen Größe attackieren die Ameisen eine Vielzahl phytophager Insekten und sind dabei besonders effektiv in der Abwehr kleiner, wenig sklerotisierter Tiere wie z.B. Raupen. Sie verfügen zwar nicht ' über einen funktionsfähigen Stachel, setzen aber Wehrsekrete ein und beißen sich hartnäckig fest . Mit Hilfe eines effektiven Alarmierungssystems, das einen Massenangriff ermöglicht, gewährleisten sie eine Verteidigung ihrer Kolonien und damit gleichzeitig ihrer Wirtspflanze. Eine Vergleich mit einer anderen Crematogaster-Art demonstriert die besonderen Adaptationen von C. borneensis an ihre Wirtspflanze.
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32689
ER  - 
TY  - JOUR
A1  - Weising, K.
A1  - Fiala, Brigitte
A1  - Ramloch, K.
A1  - Kahl, K.
A1  - Epplen, J. T.
T1  - Olingonucleotide fingerprinting in angiosperms
N2  - No abstract available
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42884
ER  - 
TY  - JOUR
A1  - Dabauvalle, Marie-Christine
A1  - Loos, Karin
A1  - Scheer, Ulrich
T1  - Identification of a soluble precursor complex essential for nuclear pore assembly in vitro
N2  - No abstract available
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32801
ER  - 
TY  - JOUR
A1  - Dandekar, Thomas
A1  - Sibbald, Peter R.
T1  - Trans-splicing of pre-mRNA is predicted to occur in a wide range of organisms including vertebrates
N2  - No abstract available
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29798
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Poustka, Annemarie
A1  - Cavenee, Webster
A1  - Neve, Rachael L.
A1  - Orkin, Stuart H.
A1  - Bruns, Gail A.
T1  - Homozygous deletion in Wilms tumours of a zinc-finger gene identified by chromosome jumping
N2  - No abstract available
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30122
ER  - 
TY  - JOUR
A1  - Barnekow, Angelika
A1  - Jahn, Reinhard
A1  - Schartl, Manfred
T1  - Synaptophysin: a substrate for the protein tyrosine kinase pp60c-src in intact synaptic vesicles
N2  - Expression of pp60 c-src, the first well defined proto-oncogene product, is developmentally regulated and tissue-specific, with neuronal tissues displaying high amounts of the c-src encoded pp60 c-src kinase activity. In the central nervous system pp60 s-src is preferentially expressed in regions characterized by a high content of grey matter and elevated density of nerve terminals. In this study we show for the first time a direct interaction between pp60 c-src and synaptophysin as a physiological target protein in neurons by demonstrating that endogenous pp60 c-src is able to phosphorylate synaptophysin (p38). p38 is a major constituent of the synaptic vesicle membrane protein and is thought to play a key role in the exocytosis of small synaptic vesicles and possibly small clear vesicles in neuroendocrine cells.
KW  - Synaptophysin
KW  - Synaptische Vesikel
KW  - Protein-Tyrosin-Kinasen
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86168
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Nanda, Indrajit
A1  - Schlupp, Ingo
A1  - Parzefall, Jakob
A1  - Schmid, Michael
A1  - Epplen, Jörg T.
T1  - Genetic variation in the clonal vertebrate Poecilia formosa is limited to few truly hypervariable loci
N2  - No abstract available.
KW  - Amazon Molly
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86359
ER  - 
TY  - JOUR
A1  - Schartl, Angelika
A1  - Schartl, Manfred
T1  - Genes and cancer: Molecular biology of the melanoma oncogene of Xiphophorus
N2  - No abstract available.
KW  - Schwertkärpfling
KW  - Krebs <Medizin>
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72670
ER  - 
TY  - JOUR
A1  - Lehrnbecher, T.
A1  - Merz, H.
A1  - Sebald, Walter
A1  - Poot, M.
T1  - Interleukin 4 drives phytohemagglutinin-activated T cells through several cell cycles: no synergism between interleukin 2 and interleukin 4
N2  - Cell kinetic studies of T cells stimulated with the interleukin 2 (11-2), D-4, or both lymphokines were performed with conventional [3H] thymidine incorporation and with the bivariate BrdU/Hoechst technique. 11-2 and 11-4 are able to drive phytohemagglutininactivated T cells through more than one cell cycle. Neither synergistic nor inhibitory efl'ect on T -cell proliferationwas seen for the stimulation with both 11-2 and 11-4 as compared with the effect ofll-2 alone. The quantitative data ofthe cell cycle distribution ofphytohemagglutininactivated T cells suggestthat the population ofll-4-responsive cells is at least an overlapping population, if not a real subset of the ·population of the 11-2-responsive cells.
KW  - Biochemie
KW  - BrdU-Hoechst
KW  - cell cycle
KW  - flow cytometry
KW  - interleukin 2
KW  - interleukin 4
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62491
ER  - 
TY  - JOUR
A1  - Merz, H.
A1  - Fliedner, A.
A1  - Orscheschek, K.
A1  - Binder, T.
A1  - Sebald, Walter
A1  - Müller-Hermelink, H. K.
A1  - Feller, A. C.
T1  - Cytokine expression in T-cell lymphomas and Hodgkin's disease. Its possible implication in autocrine or paracrine production as a potential basis for neoplastic growth
N2  - No abstract available
KW  - Biochemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62483
ER  - 
TY  - JOUR
A1  - Kruse, N.
A1  - Lehrnbecher, T.
A1  - Sebald, Walter
T1  - Site-directed mutagenesis reveals the importance of disulfide bridges and aromatic residues for structure and proliferative activity of human interleukin-4
N2  - Mutant proteins (muteins) of human lnterleukin-4 (llA) were constructed by means of in vitro mutagenesis. The muteins were expressed in E. co/1, submitted to a renaturation and purification protocol and analysed for biological activity. Exchange of the cysteines at either position 46 or 99 which form one of the three disulfide bridges resulted. in a nearly co•mplete loss · of biological actiyity and an unstable protein. The exchange of tyrosine 124 also inactivated the protein, while a mutation of tyrosine 56 left some residual activity. Exchange of the other four cysteines or of · the single tryptophane had smaller etTects.
KW  - Biochemie
KW  - Interleukin 4 (human)
KW  - Recombinant
KW  - ln vitro mutagenesis
KW  - Structure-function
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62505
ER  - 
TY  - JOUR
A1  - Preiser, J. C.
A1  - Schmartz, D.
A1  - Van der Linden, P.
A1  - Content, J.
A1  - Vanden Bussche, P.
A1  - Buurman, W.
A1  - Sebald, Werner
A1  - Dupont, E.
A1  - Pinsky, M. R.
A1  - Vincent, J. L.
T1  - Interleukin-6 administration has no acute hemodynamic or hematologic effect in the dog
N2  - To investigate the possible hemodynamic efl'ects of interleukin-6 (IL-6), a single dose of 15 mcg/kg of recombinant IL-6 isolated from Escherichia coli was injected intravenously in six pentobarbital-anesthetized dogs. After 30 min, saline infusion was performed to maintain the - pulmonary artery balloon-occluded pressure at baseline Ievel. The animals were observed for up to 5 hours. No other hemodynamic alteration was observed than a gradual decline in cardiac output attributed to anesthesia. Hematologic variables, blood glucose, and total serum proteins were also constant. IL-6 levels were markedly elevated in the blood, bot no tumor necrosis factor activity was detected. Thus a primary role for IL-6 in the early cardiovascular alterations associated with septic shock seems unlikely.
KW  - Biochemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62511
ER  - 
TY  - JOUR
A1  - Tony, H. P.
A1  - Lehrnbecher, T.
A1  - Merz, H.
A1  - Sebald, Werner
A1  - Wilhelm, M.
T1  - Regulation of IL-4 responsiveness in lymphoma B cells
N2  - The responsiveness to IL-4 with and without costimulation with anti-IgM antibodies or phorbolester was studied in 35 cases of low grade non-Hodgkin Iymphoma by analyzing enhancement of CD23 and HLA dass li expression. The predominant phenotype responds directly to IL-4. Separate differentiation states can be distinguished according to coordinate or differential upregulation of CD23 and HLA dass II molecules by IL-4 alone, and differences in responsiveness to anti-IgM antibodies. A particular subgroup of B-lymphoma cells defines a separate stage of B-eeil differentiation. They fail to express high affinity binding sites for IL-4 and accordingly do not respond to IL-4- mediated signals. Cross-linking membrane lgM receptors or direct activation of protein kinase C via phorbolester induces IL-4 receptor expression and subsequent IL-4 reactivity.
KW  - Biochemie
KW  - B lymphocytes
KW  - CD23
KW  - CLL
KW  - HLA class ll
KW  - IL-4
KW  - IL-4-receptor
KW  - membrane immunoglobulin
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62520
ER  - 
TY  - JOUR
A1  - Förnzler, Dorothee
A1  - Wittbrodt, Joachim
A1  - Schartl, M.anfred
T1  - Analysis of an esterase linked to a locus involved in the regulation of the melanoma oncogene and isolation of polymorphic marker sequences in Xiphophorus
N2  - Melanoma formation in Xiphophorus hybrids is mediated by a growth factor receptor tyrosine kinase oncogene encoded by the Tu locus. In the wild-type parental fish no tumors occur due to the activity of a locus that regulates the activity of the melanoma oncogene. Molecu/ar identification of this regulatory locus (R) requires a precise physical map of the chromosomal region. Therefore we studied esterase isozymes in Xiphophorus, two of which have been previously reported to be linked to locus R. We confinn that ES 1 is a distant marker for R ( approx. 30cM), and contrary to earlier studies, we show that this isozyme is present in all species of the genus and at similar activity Ievels in all organs tested. ES4, which has also been reported to be linked to R, was found to be a misclassification of liver ES1. In an attempt to identify markersthat bridge the large distance between ESl and R, we have generated DNA probes which are highly polymorphic. They will be useful in finding Iandmarks on a physical map of the R-containing chromosomal region.
KW  - Physiologische Chemie
KW  - Xiphophorus
KW  - melanoma ; oncogene regulation ; esterase ; molecular marker sequences
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61726
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Schlupp, Ingo
A1  - Schartl, Angelika
A1  - Meyer, Manfred K.
A1  - Nanda, Indrajit
A1  - Schmid, Michael
A1  - Epplen, Jörg T.
A1  - Parzefall, Jakob
T1  - On the stability of dispensable constituents of the eukaryotic genome: Stability of coding sequences versus truly hypervariable sequences in a clonal vertebrate, the amazon molly, Poecilia formosa
N2  - In dooal unisexual vertebrales, the genes specifying the males become dispensable. To study tbe rate of such geoes the gynogeoetic all-female fisb Poecilillfonnolll was treated with androgens. Phenotypic males were obtained that exbibited the complete set of male cbaracteristics of dosely related gooocboristic species, induding body proportions, pigmentation, the extremely complex insemination apparatus of poecilüd fish, sexual bebavior, and spermatogeoesls. Tbe apparent stabllity of such genic structures, induding those involved in androgen regulation, is contrasted by high instability of noncoding sequeaces. Frequent mutations, thelr donal transmission, and at least two truly hypervariable Iod leading to individual difl'ereaces between these othenrise donal organisms were detected by DNA fingerprinting. These observations substantiate the concept that also in "ameiotic" vertebrates certain compartments of the genome are more prooe to mutatiooal alterations than others.
KW  - Physiologische Chemie
KW  - DNA fingerprinting
KW  - androgen-induced masculinization
KW  - gynogeaesls
KW  - simple repeat sequences
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61731
ER  - 
TY  - JOUR
A1  - Winkler, Christoph
A1  - Vielkind, Jürgen R.
A1  - Schartl, Manfred
T1  - Transient expression of foreign DNA during embryonic and larval development of the medaka fish (Oryzias latipes)
N2  - Species of small fish are becoming useful tools for studies on vertebrate development. Wehave investigated the developing embryo of the Japanese medaka for its application as a transient expression system for the in vivo analysis of gene regulation and function. The temporaland spatial expression patterns ofbacterial chloramphenicol acetyltransferase and galactosidase reporter genes injected in supercoiled plasmid form into the cytoplasm of one cell of the two-cell stage embryo was promoter-specific. The transient expression was found to be mosaic within the tissue and organs reflecting the unequal distribution of extrachromosomal foreign DNA and the intensive cell mixing movements that occur in fish embryogenesis. The expression data are consistent with data on DNA fate. Foreign DNA persisted during embryogenesis and was still detectable in some 3- and 9-month-old adult fish; it was found in high molecular weight form as weil as in circular plasmid conformations. The DNA was replicated during early and late embryogenesis. Our data indicate that the developing medaka embryo is a powerful in vivo assay system for studies of gene regulation and function.
KW  - Physiologische Chemie
KW  - Medaka - Genetransfer - Transient expression - DNA fate - Fish developmental biology
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61743
ER  - 
TY  - JOUR
A1  - Haas, Albert
A1  - Brehm, Klaus
A1  - Kreft, Jürgen
A1  - Goebel, Werner
T1  - Cloning, characterization, and expression in Escherichia coli of a gene encoding Listeria seeligeri catalase, a bacterial enzyme highly homologous to mammalian catalases
N2  - A gene coding for catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) of the grain-positive bacterium Listeria seeligeri was cloned from a plasmid library of EcoRI-digested chromosomal DNA, with Escherichia coli DHSa as a host. The recombinant catalase was expressed in E. coli to an enzymatic activity approximately SO times that of the combined E. coli catalases. The nucleutide sequence was determined, and the deduced amino acid sequence revealed 43.2% amino acid sequence identity between bovine liver catalase and L. seeligeri catalase. Most of the amino acid residues which are involved in catalytic activity, the formation of the active center accession channel, and heme binding in bovine liver catalase were also present in L. seeligeri catalase at the corresponding positions. The recombinant protein contained 488 amino acid residues and had a calculated molecular weight of 55,869. The predicted isoelectric point was 5.0. Enzymatic and genetic analyses showed that there is most probably a single catalase of this type in L. seeligeri. A perfect 21-bp inverted repeat, which was highly homologous to previously reported binding sequences of the Fur (ferric uptake regulon) protein of E. coli, was detected next to the putative promoter region of tbe L. seeligeri catalase gene.
KW  - Biologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60536
ER  - 
TY  - JOUR
A1  - Schülein, Ralf
A1  - Kreft, Jürgen
A1  - Gonski, Sigrid
A1  - Goebel, Werner
T1  - Preprosubtilisin Carlsberg processing and secretion is blocked after deletion of amino acids 97-101 in the mature part of the enzyme
N2  - During an investigation into the substrate specificity and processing of subtilisin Carlsberg from Bacillus licheniformis, two major independent findings were made: (i) as has been shown previously, a stretch of five amino acids (residues 97-101 of the mature enzyme) that loops out into the binding cleft is involved in substrate binding by subtilisin Carlsberg. In order to see whether this loop element also determines substrate specificity, the coding region for these five amino acids was deleted from the cloned gene for subtilisin Carlsberg by site-directed mutagenesis. Unexpectedly the resulting mutant preproenzyme (P42c, M<sub>r</sub>=42 kDa) was not processed to the mature form (M<sub>r</sub> = 30 kDa) and was not released into the medium by a proteasedeficient B. subtilis host strain; rather, it accumulated in the cell membrane. This result demonstrates that the integrity of this loop element, which is very distant from the processing cleavage sites in the preproenzyme, is required for secretion of subtilisin Carlsberg. (ii) In culture supernatants from B. subtilis harbouring the cloned wild-type subtilisin Carlsberg gene the transient appearance (at 0-3 h after onset of stationary phase) of a processing intermediate (P38c, M<sub>r</sub> = 38 kDa) oftbis protease could be demonstrated. P38c very probably represents a genuine proform of subtilisin Carlsberg.
KW  - Biologie
KW  - Bacillus
KW  - Proenzyme
KW  - Subtilisin maturation
KW  - Site-directed mutagenesis
KW  - Subtilisin Carlsberg
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60577
ER  - 
TY  - JOUR
A1  - Vortkamp, A.
A1  - Thias, U.
A1  - Gessler, Manfred
A1  - Rosenkranz, W.
A1  - Kroisel, P. M.
A1  - Tommerup, N.
A1  - Kruger, G.
A1  - Gotz, J.
A1  - Pelz, L.
A1  - Grzeschik, Karl-Heinz
T1  - A somatic cell hybrid panel and DNA probes for physical mapping of human chromosome 7p
N2  - No abstract available
KW  - Biochemie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59217
ER  - 
TY  - JOUR
A1  - Dabauvalle, Marie-Christine
A1  - Loos, Karin
A1  - Merkert, Hilde
A1  - Scheer, Ulrich
T1  - Spontaneous assembly of pore complex-containing membranes ("Annulate lamellae") in Xenopus egg extract in the absence of chromatin
N2  - No abstract available
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32797
ER  - 
TY  - JOUR
A1  - Dandekar, Thomas
A1  - Tollervey, D.
T1  - Thirty-three nucleotides of 5' flanking sequence including the TATA box are necessary and sufficient for efficient U2 snRNA transcription in Schizosaccharomycespombe
N2  - No abstract available
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29959
ER  - 
TY  - JOUR
A1  - Dandekar, Thomas
A1  - Stripecke, Renata
A1  - Gray, Nicola K.
A1  - Goossen, Britta
A1  - Constable, Anne
A1  - Johansson, Hans E.
A1  - Hentze, Matthias W.
T1  - Identification of a novel iron-responsive element in murine and human erythroid \(\delta\)-aminolevulinic acid synthase mRNA
N2  - No abstract available
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29929
ER  - 
TY  - JOUR
A1  - Maschwitz, Ulrich
A1  - Fiala, Brigitte
A1  - Moog, J.
A1  - Saw, L. G.
T1  - Two new myrmecophytic associations from the Malay Peninsula: ants of the genus Cladomyrma as partners of Saraca thaipingensis and Crypteronia griffithii
N2  - In Peninsular Malaysia the trees Saraca thaipingensis (Caesalpiniaceae) and Crypteronia griffithii (Crypteroniaceae) are inhabited by ants. In the vicinity ofGombak, near Kuala Lumpur, the hollow internodes of young Saraca thaipingensis plants are colonized mainly by two Cladomyrma species. In larger trees a Crematogaster sp. is also found. Crypteronia griffithii is inhabited by a third species of Cladomyrma. None of these species is conspecific with any of the three Cladomyrma taxa so far described. The colonies are founded by single mated queens, which have a conspicuous, sphecid wasp-like behaviour when searching for host plants and nest sites. They chew holes into the plant intern odes and hollow them out to provide nest sites. Coccids and pseudococcids are cultivated within the internodes. The homopterans are not carried by queens on their nuptial flights. They apparently find their way by themselves into the cavities or are perhaps carried there by the worker ants. The Cladomyrma ants on Crypteronia are not aggressive, in contrast to those on Saraca thaipingensis. The relationship of Crypteronia with ants seems to be obligatory, whereas Saraca was only partly colonized by Cladomyrma. The interaction of Saraca with Crematogaster sp. is loose and facultative, since the Crematogaster sp. also lives on other tree species. Our studies have now revealed four Cladomyrma spp. which are regularly associated with plants. The genus therefore seems to have an entirely myrmecophytic way of life.
KW  - Myrmecophytism ; Malaysia ; trophobionts ; colony foundation ; Cladomyrma
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32992
ER  - 
TY  - JOUR
A1  - Schlupp, I.
A1  - Parzefall, J.
A1  - Schartl, Manfred
T1  - Male mate choice in mixed bisexual/-unisexual breeding complexes of Poecilia (Teleostei: Poeciliidae)
N2  - The livebearing all-female fish Poecilia formosa reproduces by gynogenesis, a modified form of parthenogenesis. P. formosa forms at least two breeding complexes: in its northern range it exists sympatrically with Poecilia latipinna and in its southern range with Poecilia mexicana. Differences between these complexes and their possible origin are discussed. Embryogenesis is triggered by sperm of males of these closely related sympatric species. Because inheritance is stricdy maternal, from the male point of view energy and time invested are totally lost. In this study we wanted to elucidate whether males are able to distinguish between conspecific and parasitic females. It could be shown that males are able to distinguish females optically, but that this ability was obscured as soon as chemical and/or tactile contact was possible. Furthermore, we found that females in an attractive phase of their sexual cycle are always preferred, regardless of species. This is possibly the mechanism by which parasitic females obtain the matings they need to reproduce.
KW  - Poecilia (Teleostei: Poeciliidae)
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80309
ER  - 
TY  - JOUR
A1  - Malitschek, B.
A1  - Schartl, Manfred
T1  - Rapid identification of recombinant baculoviruses using PCR
N2  - no abstract available
KW  - PCR
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-80328
ER  - 
TY  - JOUR
A1  - Fiala, Brigitte
A1  - Maschwitz, Ulrich
T1  - Extrafloral nectaries in the genus Macaranga (Euphorbiaceae) in Malaysia: comparative studies of their possible significance as predispositions for myrmecophytism.
N2  - So me species of the paleotropical tree genus Macaranga (Euphorbiaceae) live in elose association with ants. Thc genus comprises the full range of species from those not regularly inhabited by ants to obligate myrmecophytes. In Malaysia (peninsular and Borneo) 23 ofthe 52 species areknown to be ant-associated (44%). The simplest structural adaptation of plants to attract ants are extrafloral nectaries. We studied the distribution of extraflural nectaries in the genus Macaranga to assess the significance of this character as a possible predisposition for the evolution of obligate myrmecophytism. All species have marginal glands on the leaves. However, only the glands of nonmyrmecophytic species function as nectaries, whereas liquids secreted by these glands in myrmecophytic species did not contain sugar. Some non-myrmecophytic Macaranga and transitional Macaranga species in addition have extrafloral nectaries on the leaf blade near the petiole insertion. All obligatorily myrmecophytic Macaranga species, however, lack additional glands on the lamina. The non-myrmecophytic species are visited by a variety of different ant species, whereas myrmecophytic Macaranga are associated only with one specific ant-partner. Since these ants keep scale insects in the hollow sterns, reduction of nectary production in ant-inhabited Macaranga seems to be biologically significant. We interpret this as a means of (a) saving the assimilates and (b) stabilization of maintenance of the association's specificity. Competition with other ant species for food rewards is avoided and thereby danger ofweakening the protective function ofthe obligate antpartner for the plant is reduced. A comparison with other euphorb species living in the same habitats as Macaranga showed that in genera in which extrafloral nectaries are widespread, no myrmecophytes have evolved. Possession of extrafloral nectaries does not appear to be essential for the development of symbiotic ant-plant interactions. Other predispositions such as nesting space might have played a more important role.
KW  - Macaranga
KW  - extrafloral nectaries
KW  - ant-plant interactions
KW  - evolution of myrmecophytism
KW  - Malaysia
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42863
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Erbelding-Denk, Claudia
A1  - Nanda, Indrajit
A1  - Schmid, Michael
A1  - Schröder, Johannes Horst
A1  - Epplen, Jörg T.
T1  - Mating success of subordinate males in a poeciliid fish species, Limia perugiae
N2  - No abstract available.
KW  - Lebendgebärende Zahnkarpfen
KW  - Perugia-Kärpfling
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86349
ER  - 
TY  - JOUR
A1  - Adam, Dieter
A1  - Maueler, Winfried
A1  - Schartl, Manfred
T1  - Transcriptional activation of the melanoma inducing Xmrk oncogene in Xiphophorus
N2  - The melanoma inducing locus of Xiphophorus encodes a tumorigenic version of a novel putative receptor tyrosine kinase (Xmrk). To elucidate the mechanism of oncogenic activation of Xmrk, we compared the structure and expression of two oncogenic loci with the corresponding proto-oncogene. Only minor structural alterations were found to be specific for the oncogenic Xmrk genes. Marked overexpression of the oncogene transcripts in melanoma, which are approximately 1 kb shorter than the proto-oncogene transcript, correlates with the malignancy of the tumors. The tumor transcripts are derived from an alternative transcription start site that is used only in the oncogenic loci. Thus, oncogenic activation of the melanoma inducing Xmrk gene appears primarily to be due to novel transcriptional control and overexpression.
KW  - Schwertkärpfling
KW  - Onkogen
KW  - Melanom
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-87584
ER  - 
TY  - JOUR
A1  - Hannig, Gerhard
A1  - Ottilie, Sabine
A1  - Schartl, Manfred
T1  - Conservation of structure and expression of the c-yes and fyn genes in lower vertebrates
N2  - The src-gene family in mammals and birds consists of 9 closely related protein tyrosine kinases. We have cloned the c-yes and fyn bomologues of the src-family from the teleost fish Xiphophorus helleri. Both genes show a high degree of sequence conservation and exhibit all structural motifs diagnostic for functional src-like protein tyrosine kinases. Sequence comparisons revealed three domains (exon 2, exons 3--6, exons 7-12) which evolve at different rates. Both genes exhibit an identical expression pattern, with preferential expression in neural tissues. No transcripts of c-yes were found in liver wbich is contrary to the situation in higher vertebrales. In malignant melanoma, elevated Ieveis of c-yes andfyn were detected indicating a possible function during secondary steps of tumor progression for src-related tyrosine kinases.
KW  - Konservierung
KW  - Gen
KW  - Niedere Wirbeltiere
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86723
ER  - 
TY  - JOUR
A1  - Thiry, Marc
A1  - Scheer, Ulrich
A1  - Goessens, Guy
T1  - Localization of nucleolar chromatin by immunocytochemistry and in situ hybridization at the electron microscopic level
N2  - Nucleoli are the morphological expression of the activity of a defined set of chromosomal segments bearing rRNA genes. The topological distribution and composition of the intranucleolar chromatin as well as the definition of nucleolar structures in which enzymes of the rDNA transcription machinery reside have been investigated in mammalian cells by various immunogold labelling approaches at the ultrastructural level. The precise intranucleolar location of rRNA genes has been further specified by electron microscopic in situ hybridization with a non-autoradiographic procedure. Our results indicate that the fibrillar centers are the sole nucleolar structures where rDNA, core histones, RNA polymerase I and DNA to po isomerase I are located together. Taking into account the potential value and limitations of immunoelectron microscopic techniques, we propose that transcription of the rRNA genes takes place within the confines of the fibrillar centers, probably close to the boundary regions to the surrounding dense fibrillar component.
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39289
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Adam, Dieter
T1  - Molecular cloning, structural characterization, and analysis of transcription of the melanoma oncogene of xiphophorus
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61989
ER  - 
TY  - JOUR
A1  - Schlupp, Ingo
A1  - Parzefall, Jakob
A1  - Epplen, Jörg T.
A1  - Nanda, Indrajit
A1  - Schmid, Michael
A1  - Schartl, Manfred
T1  - Pseudomale behaviour and spontaneous masculinization in the all-female teleost Poecilia formosa (Teleostei: Poeciliidae)
N2  - Pseudosexual behaviour is a rare phenomenon associated with unisexuality in vertebrates. In the gynogenetic, all-female teleost Poecilia formosa, rare individuals occur that resemble males of closely related gonochoristic species both in behaviour and external morphology. These masculinized gynogens and normal gynogens are members of the same clone, as demonstrated by DNA-fingerprinting. The behaviour of these masculinized gynogens is described and compared to the behaviour of the gonochoristic species Poecilia mexicana, P. latipinna and their hybrid as weil as androgen-treated individuals of P. formosa. No statistically significant difTerences were found between masculinized gynogens and hormonetreated individuals nor between the gonochoristic P. mexicana and P. latipinna males. Differences exist between gonochoristic and unisexual species. Passihle causes and effects of masculinized gynogens are discussed.
KW  - Physiologische Chemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61688
ER  - 
TY  - JOUR
A1  - Kruse, N.
A1  - Tony, H. P.
A1  - Sebald, Walter
T1  - Conversion of human interleukin-4 into a high affinity antagonist by a single amino acid replacement
N2  - lnterleukin-4 (IL-4) represents a prototypic lymphokine (for a recent review see Paul, 1991). It promotes differentiation of B-cells and the proliferation of T- and B-cell, and other cell types of the lymphoid system. An antagonist of human IL-4 was discovered during the studies presented here after Tyr124 of the recombinant proteinbad been substituted by an aspartic acid residue. This IL-4 variant, Y124D, bound with high affinity to the IL-4 receptor (K\(_D\) = 310 pM), but retained no detectable proliferative activity for T -<:ells and inhibited IL-4-dependent T -cell proliferation competitively (K\(_i\) = 620 pM). The loss of efficacy in variant Y124D was estimated to be > 100-fold on the basis of a weak partial agonist activity for the very sensitive induction of CD23 positive B-cells. The subsitution of Tyr124 by either phenylalanine, histidine, asparagine, Iysine or glycine resulted in partial agonist variants with unaltered receptor binding atTmity and relatively small deficiencies in efficacy. These results demoostrate that high affinity binding and signal generation can be uncoupled efticiently in a Iigand of a receptor betonging to the recently identified hematopoietin receptor family. In addition we show for the first time, that a powerful antagonist acting on the IL-4 receptor system can be derived from the IL-4 protein.
KW  - Biochemie
KW  - drug design
KW  - partial agonists
KW  - receptor signalling
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62469
ER  - 
TY  - JOUR
A1  - Dummer, R.
A1  - Posseckert, G.
A1  - Nestle, F.
A1  - Witzgall, R.
A1  - Burger, M.
A1  - Becker, J. C.
A1  - Schäfer, E.
A1  - Wiede, J.
A1  - Sebald, Walter
A1  - Burg, G.
T1  - Soluble interleukin-2 receptors inhibit interleukin 2-dependent proliferation and cytotoxicity: explanation for diminished natural killer cell activity in cutaneous T-cell lymphomas in vivo?
N2  - No abstract available
KW  - Biochemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62473
ER  - 
TY  - JOUR
A1  - Hong, Yunhan
A1  - Schartl, Manfred
T1  - Structure of the rainbow trout metallothionein A gene
N2  - To investigate the regulation of metallothionein-encoding genes in fish, we have isolated and sequenced the rainbow trout metallothionein-A-encoding gene (tMT-A) by polymerase chain reaction. This gene spans about 1.1 kb, consists of three exons and two introns, and has an A+ T-rieb 5' -region which contains a TATAAA signal, and two metal responsive elements (MREs). The transcription start point is centered around an A residue 81 nt upstream of the ATG codon.
KW  - Physiologische Chemie
KW  - Recombinant DNA ; polymerase chain reaction ; metallothionein gene ; rainbow trout ; fish
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61679
ER  - 
TY  - JOUR
A1  - Wittbrodt, Joachim
A1  - Lammers, Reiner
A1  - Malitschek, Barbara
A1  - Ullrich, Axel
A1  - Schartl, Manfred
T1  - Xmrk receptor tyrosine kinase is activated in Xiphophorus malignant melanoma
N2  - Xmrk encodes a putative transmembrane glycoprotein of the tyrosine kinase family and is a melanoma-inducing gene in Xiphophorus. We attempted to investigate the biological function of the putative Xmrk receptor by characterizing its signalling properties. Since a potential Iigand for Xmrk has not yet been identified, it has been difficult to analyse the biochemical properlies and biological function of this cell surface protein. In an approach towards such analyses, the Xmrk extracellular domain was replaced by the closely related Iigand-binding domain sequences of the human epidennal growth factor receptor (HER) and the ligand-induced activity of the chimeric HER-Xmrk proteinwas examined. We show that the Xmrk protein is a functional receptor tyrosine kinase, is highly active in malignant melanoma and displays a constitutive autophosphorylation activity possibly due to an activating mutation in its extracellular or transmembrane domain. In the focus formation assay the HER-Xmrk chimera is a potent transfonning protein equivalent to other tyrosine kinase oncoproteins.
KW  - Physiologische Chemie
KW  - chimeric RTKs
KW  - melanoma
KW  - RTK
KW  - Xiphophorus
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61699
ER  - 
TY  - JOUR
A1  - Götz, Rudolf
A1  - Raulf, Friedrich
A1  - Schartl, Manfrad
T1  - Brain-derived neurotrophic factor is more highly conserved in structure and function than nerve growth factor during vertebrate evolution
N2  - Mammalian nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are members of a protein family with perfectly conserved domains arranged around the cysteine residues thought to stabilize an invariant three-dimensional scaffold in addition to distinct sequence motifs that convey different neuronal functions. To study their structural and functional conservation during evolution, we have compared NGF and BDNF from a lower vertebrate, the teleost fi.sh Xiphophorus, with the mammalian homlogues. Genomic clones encoding fish NGF and BDNF were isolated by cross-hybridization using probes from the cloned mammalian factors. Fish NGF and BDNF were expressed by means of recombinant vaccinia viruses, purified, and their neuronal survival specificities for different classes of neurons were found to mirror those of the mammalian factors. The half-maximal survival concentration for chick sensory neurons was 60 pg/ml for both fish and mammalian purifi.ed recombinant BDNF. However, the activity ofrecombinant fish NGF on both chick sensory and sympathetic neurons was 6 ng,lml, 75-fold lower than that of mouse NGF. The different functional conservation of NGF and BDNF is also reflected in their structures. The DNA-deduced amino acid sequences of processed mature fish NGF and BDNF showed, compared to mouse, 63% and 90% identity, respectively, indicating that NGF bad reached an optimized structure later than BDNF. The retrograde extrapolation of these data indicates that NGF and BDNF evolved at strikingly different rates ftom a common ancestral gene about 600 million years ago. By RNA gel blot anaJysis NGF mRNA was detected during late embryonie development; BDNF was present in adult brain.
KW  - Physiologische Chemie
KW  - Brain-derived neurotrophic factor
KW  - Nerve growth factor
KW  - Fish
KW  - Recombinant protein expression
KW  - Neuronal survival
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61703
ER  - 
TY  - JOUR
A1  - Nanda, Indrajit
A1  - Schartl, Manfred
A1  - Feichtinger, Wolfgang
A1  - Epplen, Jörg T.
A1  - Schmid, Michael
T1  - Early stages of sex chromosome differentiation in fish as analysed by simple repetitive DNA sequences
N2  - Animal sex chromosome evolution has started on different occasions with a homologous pair of autosomes leading to morphologically differentiated gonosomes. In contrast to other vertebrate classes, among fishes cytologically dernonstrahle sex chromosomes are rare. In reptiles, certain motifs of simple tandemly repeated DNA sequences like (gata)\(_n\)/(gaca)\(_m\) are associated with the constitutive heterochromatin of sex chromosomes. In this study a panel of simple repetitive sequence probes was hybridized to restriction enzyme digested genomic DNA of poeciliid fishes. Apparent male heterogamety previously established by genetic experiments in Poecilia reticulata (guppy) was correlated with male-specific hybridization using the (GACA)\(_4\) probe. The (GATA)\(_4\) oligonucleotide identifies certain male guppies by a Y chromosomal polymorphism in the outbred population. In cantrast none of the genetically defined heterogametic situations in Xiphophorus could be verified consistently using the collection of simple repetitive sequence probes. Only individuals from particular populations produced sex-specific patterns of hybridization with (GATA)\(_4\). Additional poeciliid species (P. sphenops, P. velifera) harbour different sex-specifically organized simple repeat motifs. The observed sex-specific hybridization patterns were substantiated by banding analyses of the karyotypes and by in situ hybridization using the (GACA)\(_4\) probe.
KW  - Physiologische Chemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61715
ER  -