TY  - JOUR
A1  - Schartl, Manfred
A1  - Schmidt, C. R.
A1  - Anders, A.
A1  - Barnekow, A.
T1  - Elevated expression of the cellular src gene in tumors of differing etiologies in Xiphophorus
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61889
ER  - 
TY  - JOUR
A1  - Hügle, Barbara
A1  - Scheer, Ulrich
A1  - Franke, Werner W.
T1  - Ribocharin: a nuclear M\(_r\) 40,000 protein specific to precursor particles of the large ribosomal subunit
N2  - Using a monoclonal antibody (No-194) we have identified, in Xenopus laevis and other amphibia, an acidic protein of M, 40,000 (ribocharin) which is specifically associated with the granular component of the nucleolus and nucleoplasmic 65S particles. These particles contain the nuclear 28S rRNA and apparently represent the precursor to the large ribosomal subunit in nucleocytoplasmic transit. By immunoelectron microscopy ribocharin has been localized in the granular component of the nucleolus and in interchromatin granules. During mitosis ribocharin-containing particles are associated with surfaces of chromosomes and are recollected in the reconstituting nucleoli in late telophase. We suggest that ribocharin is a specific component of precursor particles of the large ribosomal subunit, which dissociates from the 65S particle before passage through the nuclear envelope, and is reutilized in ribosome biogenesis.
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41169
ER  - 
TY  - JOUR
A1  - Hügle, Barbara
A1  - Hazan, Rachel
A1  - Scheer, Ulrich
A1  - Franke, Werner W.
T1  - Localization of ribosomal protein S1 in the granular component of the interphase nucleolus and its distribution during mitosis
N2  - Using antibodies to various nucleolar and ribosomal proteins, we define, by immunolocalization in situ, the distribution of nucleolar proteins in the different morphological nucleolar subcompartments. In the present study we describe the nucleolar localization of a specific ribosomal protein (51) by immunofluorescence and immunoelectron microscopy using a monoclonal antibody (R5 1-105). In immunoblotting experiments, this antibody reacts specifically with the largest and most acidic protein of the small ribosomal subunit (51) and shows wide interspecies cross-reactivity from amphibia to man. Beside its localization in cytoplasmic ribosomes, this protein is found to be specifically localized in the granular component of the nucleolus and in distinct granular aggregates scattered over the nucleoplasm. This indicates that ribosomal protein 51, in contrast to reports on other ribosomal proteins, is not bound to nascent pre-rRNA transcripts but attaches to preribosomes at later stages of rRNA processing and maturation. This protein is not detected in the residual nucleolar structures of cells inactive in rRNA synthesis such as amphibian and avian erythrocytes. During mitosis, the nucleolar material containing ribosomal protein 51 undergoes a remarkable transition and shows a distribution distinct from that of several other nucleolar proteins. In prophase, the nucleolus disintegrates and protein 51 appears in numerous small granules scattered throughout the prophase nucleus. During metaphase and anaphase, a considerable amount of this protein is found in association with the surfaces of all chromosomes and finely dispersed in the cell plasm. In telophase, protein 51-containing material reaccumulates in granular particles in the nucleoplasm of the newly formed nuclei and, finally, in the re-forming nucleoli. These observations indicate that the nucleolus-derived particles containing ribosomal protein 51 are different from cytoplasmic ribosomes and, in the living cell, are selectively recollected after mitosis into the newly formed nuclei and translocated into a specific nucleolar subcompartment, i.e ., the granular component. The nucleolar location of ribosomal protein 51 and its rearrangement du'ring mitosis is discussed in relation to the distribution of other nucleolar proteins.
KW  - Cytologie
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39695
ER  - 
TY  - JOUR
A1  - Dandekar, Thomas
A1  - Gramsch, Christian
A1  - Houghton, Richard A.
A1  - Schultz, Rüdiger
T1  - Affinity purification of \(\beta\)-endorphin-like material from NG108CC15 cells by means of the monoclonal \(\beta\)-endorphin antibody 3-E7
N2  - No abstract available
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29896
ER  - 
TY  - JOUR
A1  - Linsenmair, Karl Eduard
T1  - Individual and family recognition in subsocial arthropods, in particular in the desert isopod Hemilepistus reaumuri
N2  - Individual recogmtlon in the non-eusocial arthropods is, according to our present knowledge, predominantly found in the frame of permanent or temporary monogamy. In some cases, e. g. in stomatopods and possibly other marine crustaceans too, individual recognition may serve to allow identification of (i) individuals within dominance hierarchies or (ii) neighbours in territorial species thus helping to avoid the repetition of unnecessary and costly fights. Kin recognition is experimentally proven only in some isopod species (genera Hemilepistus and Porcel/io) and in the primitive cockroach (termite?) Cryptocercus. The «signatures» or «discriminators» used in the arthropods are chemical. It is assumed that the identifying substances are mainly genetically determined and in this paper I shall discuss possible evolutionary origins. The main part of this account is devoted to the presentation of some aspects of the highly developed individual and kin identification and recognition system in the desert isopod Hemilepistus reaumuri - a pure monogamous species in which pairs together with their progeny form strictly exclusive family units. Amongst other things problems of (i) mate choice, (ii) learning to recognize a partner, (iii) avoiding the un adaptive familiarization with aliens are treated. Monogamy under present conditions is for both sexes the only suitable way of maximizing reproductive success; an extremely strong selection pressure must act against every attempt to abandon monogamy under the given ecological conditions. The family «badges» which are certainly always blends of different discriminator substances are extremely variable. This variability is mainly due to genetical differences and is not environmentally caused. It is to be expected that intra-family variabiliry exists in respect of the production of discriminator substances. Since the common badge of a family is the result of exchanging and mixing individual substances, and since the chemical nature of these discriminators requires direct body contacts in order to acquire those substances which an individual does not produce itself, problems must arise with molting. These difficulties do indeed exist and they are aggravated by the fact that individuals may produce substances which do not show up in the common family badge. An efficient learning capability on the one hand and the use of inhibiting properties of newly molted isopods help to solve these problems. In the final discussion three questions are posed and - partly at least - answered; (i) why are families so strictly exclusive, (ii) how many discriminator substances have to be produced to provide a variability allowing families to remain exclusive under extreme conditions of very high population densities, (iii) what is the structure of the family badge and what does an individual have to learn apart from the badge in order not to mistake a family member for an alien or vice versa.
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33957
ER  - 
TY  - JOUR
A1  - Anders, F.
A1  - Schartl, Manfred
A1  - Barnekow, A.
A1  - Schmidt, C. R.
A1  - Luke, W.
A1  - Jaenel-Dess, G.
A1  - Anders, A.
T1  - The genes that carcinogens act upon
N2  - No abstract available.
KW  - Onkogen
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72704
ER  - 
TY  - JOUR
A1  - Barnekow, Angelika
A1  - Gessler, Manfred
T1  - Activation of the pp60\(^{c-src}\) kinase during differentiation of monomyelocytic cells in vitro
N2  - Tbe proto-oncogene c-src, the cellular homolog of the Rous sarcoma virus (RSV) transforming gene v-src, is expressed in a tissue-specific and age-dependent manner. Its physiological function, although still unknown, appears to be more closely related to differentiation processes than to proliferation processes. To obtain more information about the physiological role of the c-src gene in cells, we have studied differentiation-dependent alterations using the human HL-60 leukaemia cell line as a model system. Induction of monocytic and granulocytic differentiation of HL-60 cells by 12-0-tetradecanoylphorbol-13-acetate (TPA) and dimethylsulfoxide (DMSO) is associated with an activation of the pp60<sup>c-src</sup> tyrosine kinase, but not with increased c-src gene expression. Control experiments exclude an interaction of TPA and DMSO themselves with the pp60<sup>c-src</sup> kinase.
KW  - Biochemie
KW  - c-src
KW  - differentiation
KW  - protein tyrosine kinase
KW  - protooncogene
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59278
ER  - 
TY  - JOUR
A1  - Weich, H. A.
A1  - Sebald, Walter
A1  - Schairer, H. U.
A1  - Hoppe, J.
T1  - The human osteosarcoma cell line U-2 OS expresses a 3.8 kilobase mRNA which codes for the sequence of the PDGF-B chain
N2  - A cDNA clone of about 2500 basepairswas prepared from the human osteosarcoma cellline U-2 OS by hybridizing with a v-sis probe. Sequence analysis showed that this cDNA contains the coding region for the PDGF-B chain. Here we report that the mitogen secreted by these osteosarcoma cells contains the PDGF-B chain and is probably a homodimer of two B-chains.
KW  - Biochemie
KW  - Platelet-derived growthfactor
KW  - cDNA
KW  - Oncogene
KW  - Tumor cell
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62588
ER  - 
TY  - JOUR
A1  - Hoppe, J.
A1  - Gatti, D.
A1  - Weber, H.
A1  - Sebald, Walter
T1  - Labeling of individual amino acid residues in the membrane-embedded F\(_0\) part of the F\(_1\) F\(_0\) ATP synthase from Neurospora crassa. Influence of oligomycin and dicyclohexylcarbodiimide
N2  - Three F0 subunits and the F\(_1\) subunit P of the ATP synthase from Neurospora crassa were labeled with the lipophilic photoactivatable reagent 3-(trifluoromethyl)-3-(m-[\(^{125}\)I]iodophenyl)diazirine ([\(^{125}\)I]TID). In the proteolipid subunit which was the most heavily labeled polypeptide labeling was confmed to five residues at the NH2-terminus and five residues at the C-terminus ofthe protein. Labeling occurred at similar positions compared with the homologaus protein (subunit c) in the ATP synthase from Escherichia coli, indicating a similar structure of the proteolipid subunits in their respective organisms. The inhibitors oligomycin and dicyclohexylcarbodiimide did not change the pattern of accessible surface residues in the proteolipid, suggesting that neither inhibitor induces gross conformational changes. However, in the presence of oligomycin, the extent oflabeling in some residues was reduced. Apparently, these residues provide part of the binding site for the inhibitor. After reaction with dicyclohexylcarbodiimide an additional labeled amino acid was found at position 65 corresponding to the invariant carbodümide-binding glutamic acid. These results and previous observations indicate that the carboxyl side chain of Glu-65 is located at the protein-lipid interphase. The idea is discussed that proton translocation occurs at the interphase between different types if F\(_0\) subunits. Dicyclohexylcarbodiimide or oligomycin might disturb this essential interaction between the F\(_0\) subunits.
KW  - Biochemie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62598
ER  - 
TY  - JOUR
A1  - Hoppe, J.
A1  - Sebald, Walter
T1  - Topological studies suggest that the pathway of the protons through F\(_0\) is provided by amino acid residues accessible from the lipid phase
N2  - The structure of the F0 part of ATP synthases from E. coli and Neurospora crassa was analyzed by hydrophobic surface labeling with [125I]TID. In the E. co/i F0 all three subunits were freely accessible to the reagent, suggesting that these subunits are independently integrated in the membrane. Labeted amino acid residues were identified by Edman degradation of the dicyclohexylcarbodiimide binding (DCCD) proteins from E. coli and Neurospora crassa. The very similar patterns obtained with the two homologaus proteins suggested the existence of tightly packed cx-helices. The oligomeric structure of the DCCD binding protein appeared to be very rigid since little, if any, change in the labeling patternwas observed upon addition of oligomycin or DCCD to membranes from Neurospora crassa. When membrancs were pretrcated with DCCD prior to the reaction with [125I]TID an additionally labeled amino acid appeared at the position of Glu·65 which binds DCCD covalently, indicating the Jocation of this inhibitor on the outside of the oligomer. It is suggested that proton conduction occurs at the surface of the oligomer of the DCCD binding protein. Possibly this oligomer rotates against the subunit a or b and thus enables proton translocation. Conserved residues in subunit a, probably located in the Iipid bilayer, might participate in the pro· ton translocation mechanism.
N2  - La structure de la partie F0 de l'ATP synthase a ete analysee au moyen de marquage par /e reactif hydrophobe TJD[125 I]. Les trois sous-unites de E. coli F0 sont accessibles au reactif ce qui semble indiquer que ces sous-unites sont integrees dans Ia membrane defaron independante. Les amino-acides marques ont ete identifies par Ia degradation d'Edman des profeines d'E. coli et de Neurospora associees au dicyclohexylcarbodiimide (DCCD). L 'analogie des courbes obtenues pour /es deux proteines homologues suggere l'existence d'a-helices rangees de faron serree. La structure oligomerique de Ia proreine associee au DCCD semble etre tres rigide puisque pratiquement aucun changement dans /e marquage n 'a ete observe par addition d'oligomycine ou de DCCD aux membranes de Neurospora crassa. Quand /es membranes sont traitees avec /e DCCD avant Ia reaction avec TJD[125 I], un amino-acide additionnellement marque apparait a Ia position Glu·65 et forme avec le DCCD une Iiaison covalente. Ce dernier resu/tat indique Ia localisation de cet inhibiteur a /'exterieur de J'oligo· mere. II semble donc que Ia conduction des protons ait lieu a Ia surface de /'oligomere de Ia proteine associee au DCCD. II serait possib/e que l'o/igomere se retourne contre Ia sous-unite a ou b, permettunt de ce fait Ia translocation des protons. Les residus conserves de Ia sous-unite a, probab/ement Jocalises dans Ia double couche lipidique, pourraient participer au mecanisme de translocation des protons.
KW  - Biochemie
KW  - conduction de protons
KW  - proteines membranaires
KW  - carbenes
KW  - proton conduction
KW  - membrane proteins
KW  - carbenes
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62602
ER  - 
TY  - JOUR
A1  - Gabellini, N.
A1  - Sebald, Walter
T1  - Nucleotide sequence and transcription of the fbc operon from Rhodopseudomonas sphaeroides. Evaluation of the deduced amino acid sequences of the FeS protein, cytochrome b and cytochrome c\(_1\)
N2  - No abstract available
KW  - Biochemie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62615
ER  - 
TY  - JOUR
A1  - McCarthy, J. E.
A1  - Sebald, Walter
A1  - Gross, G.
A1  - Lammers, R.
T1  - Enhancement of translational efficiency by the Escherichia coli atpE translational initiation region: its fusion with two human genes
N2  - No abstract available
KW  - Biochemie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62626
ER  - 
TY  - JOUR
A1  - Kobelt, Frank
A1  - Linsenmair, Karl Eduard
T1  - Adaptations of the reed frog Hyperolius viridiflavus to its arid environment. I. The skin of Hyperolius viridiflavus nitidulus in wet and dry season conditions.
N2  - Hyperolius viridiflavus nitidulus inhabits parts of the seasonally very hot and dry West African savanna. During the long lasting dry season, the small frog is sitting unhidden on mostly dry plants and has to deal with high solar radiation load (SRL), evaporative water loss (EWL) and small energy reserves. It seems to be very badly equipped to survive such harsh climatic conditions (unfavorable surface to volume ratio, very limited capacity to störe energy and water). Therefore, it must have developed extraordinary efficient mechanisms to solve the mentioned Problems. Some of these mechanisms are to be looked for within the skin of the animal (e.g. protection against fast desiccation, deleterious effects of UV radiation and over-heating). The morphology of the wet season skin is, in most aspects, that of a "normal" anuran skin. It differs in the Organization of the processes of the melanophores and in the arrangement of the chromatophores in the Stratum spongiosum, forming no "Dermal Chromatophore Unit". During the adaptation to dry season conditions the number of iridophores in dorsal and ventral skin is increased 4-6 times compared to wet season skin. This increase is accompanied by a very conspicuous change of the wet season color pattern. Now, at air temperatures below 35° C the color becomes brownish white or grey and changes to a brilliant white at air temperatures near and over 40° C. Thus, in dry season State the frog retains its ability for rapid color change. In wet season State the platelets of the iridophores are irregularly distributed. In dry season State many platelets become arranged almost parallel to the surface. These purine crystals probably act as quarter-wave-length interference reflectors, reducing SRL by reflecting a considerable amount of the radiated energy input. EWL is as low as that of much larger xeric reptilians. The impermeability of the skin seems to be the result of several mechanisms (ground substance, iridophores, lipids, mucus) supplementing each other. The light red skin at the pelvic region and inner sides of the limbs is specialized for rapid uptake of water allowing the frog to replenish the unavoidable EWL by using single drops of dew or rain, available for only very short periods.
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30551
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
A1  - Hansmann, Paul
A1  - Falk, Heinz
A1  - Sitte, Peter
T1  - Ultrastructural localization of DNA in two Cryptomonas species by use of a monoclonal DNA-antibody
N2  - Immunogold cytochemistry - DNA localization - Cryptomonas nucleomorph The distribution and subcellular localization of DNA in the unicellular alga Cryptomonas has been investigated electron-microscopically by indirect immunocytochemistry, using a monoclonal DNA antibody and a gold-Iabeled secondary antibody. This technique proved to be very sensitive and entirely specific. DNA could be demonstrated in four different compartments (nucleus, nucleomorph, plastid, and mitochondrion). Within the plastid, DNA is concentrated in stroma regions that are localized preferentially around the center of the organelle. The mitochondrion contains several isolated DNA-containing regions (nucleoids). Within the nucleus, most of the DNA is localized in the 'condensed' chromatin. DNA was also detectable in small areas of the nucleolus, whereas the interchromatin space of the nucleus appeared almost devoid of DNA. Within the nucleomorph, DNA is distributed inhomogeneously in the matrix. DNA could furthermore be detected in restricted areas of the 'fibrillogranular body' of the nucleomorph, resembling the situation encountered in the nucleol us. The presence of DNA and its characteristic distribution in the nucleomorph provide additional, strong evidence in favour of the interpretation of that organelle as the residual nucleus of a eukaryotic endosymbiont in Cryptomonas.
KW  - Cytologie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39746
ER  - 
TY  - JOUR
A1  - Schultz, Rüdiger
A1  - Metzner, Katharina
A1  - Dandekar, Thomas
A1  - Gramsch, Christian
T1  - Opiates induce long-term increases in prodynorphin derived peptide levels in the guinea-pig myenteric plexus
N2  - No abstract available
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29809
ER  - 
TY  - JOUR
A1  - Hadjiolova, Krassimira
A1  - Rose, Kathleen M.
A1  - Scheer, Ulrich
T1  - Immunolocalization of nucleolar proteins after D-galactosamine-induced inhibition of transcription in rat hepatocytes
N2  - No abstract available
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33205
ER  - 
TY  - JOUR
A1  - Reimer, Georg
A1  - Scheer, Ulrich
A1  - Peters, Jan-Michael
A1  - Tan, Eng M.
T1  - Immunolocalization and partial characterization of a nucleolar autoantigen (PM-Scl) associated with polymyositis / scleroderma overlap syndromes.
N2  - Precipitating anti-PM-Sel antibodies are present in sera from patients with polymyositis. scleroderma. and polymyositis/scleroderma overlap syndromes. By indirect immunofluorescence microscopy. anti-PM-Scl antibodies stained the nucleolus in cells of different tissues and species. suggesting that the antigen is highly conserved. By electron microscopy, anti-PM-Scl antibodies reacted primarily with the granular component of the nuc1eolus. Drugs that inhibit rRNA synthesis had a marked effect on the expression of PM-Scl antigen. In actinomycin D-treated cells, immunofluorescence staining by anti-PM-Scl was signüicantly reduced with residual staining restricted to the granular regions of nuc1eoli. Treatment with 5,6-dichloro-beta-D- ribofuranosylbenzimidazole (DRB) also selectively reduced nuc1eolar staining. On a molecular level, anti-PM-Sel antibodies precipitated 11 polypeptides with molecular weights (Mr) ranging from 110,000 to 20,000. The Mr 80,000 and 20.000 polypeptides were phosphorylated. Evidence suggests that the PM-Scl antigen complex may be related to a prerlbosomal particle.
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33191
ER  - 
TY  - JOUR
A1  - Linsenmair, Karl Eduard
T1  - Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment: II. Some aspects of the water economy of H. viridiflavus nitidulus under wet and dry ...
N2  - Adaptations to aridity ofthe reedfrog Hyperolius viridiflavus nitidulus, living in different parts of the seasonally very dry and hot West African savanna, are investigated ...
KW  - Zoologie
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78395
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
T1  - Injection of antibodies into the nucleus of amphibian oocytes: an experimental means of interfering with gene expression in the living cell
N2  - No abstract available
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41182
ER  - 
TY  - JOUR
A1  - Mahsberg, Dieter
T1  - Contact chemoreception of prey in hunting scorpions
N2  - Scorpions commonly are assumed to hunt on living prey. But under laboratory conditions they also respond very sensitively to dead insects lying on the substrate. In many cases the motionless prey is seized and consumed. It was investigated how this behavior can be elicited. The buthid scorpions Androctonus australis (L.) and Buthus occitanus (Am.) not only find motionless prey again which was stung but managed to escape before dying: They also respond to extracts of the cuticle of prey insects. After touching prey marks' either with the tips of the chelae fingers or the tarsi of the walking legs or the pectine organs specific responses (searching, seizing, feeding) are released at a high rate. Behavioral experiments demonstrate for the first time the chemosensitivity of the pectine organs for which only mechanosensitivity had been proofed formerly. Mechanical as well as contact chemical stimulation of these organs cause scorpions to orient towards the stimulus source which is grasped, retained and consumed or rejected depending on its quality. The probably responsible chemosensitive receptors are already described in the literature. The possible adaptive value and the biological significance of contact chemoreception in prey catching and in other aspects of the life of scorpions is discussed.
KW  - Skorpion
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45784
ER  - 
TY  - JOUR
A1  - Maueler, W.
A1  - Eigenbrodt, E.
A1  - Schartl, Manfred
T1  - Intermediary metabolism of normal and tumorous tissue of Xiphophorus (Teleostei: Poeciliidae)
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61855
ER  - 
TY  - JOUR
A1  - Barnekow, A.
A1  - Schartl, Manfred
T1  - Comparative studies on the src proto-oncogene and its gene product pp60\(^{c-src}\) in normal and neoplastic tissues of lower vertebrates
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61869
ER  - 
TY  - JOUR
A1  - Kleene, R.
A1  - Pfanner, N.
A1  - Pfaller, R.
A1  - Link, T. A.
A1  - Sebald, Walter
A1  - Neupert, W.
A1  - Tropschug, M.
T1  - Mitochondrial porin of Neurospora crassa: cDNA cloning, in vitro expression and import into mitochondria
N2  - No abstract available
KW  - Biochemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62566
ER  - 
TY  - JOUR
A1  - Römisch, J.
A1  - Tropschug, M.
A1  - Sebald, Walter
A1  - Weiss, H.
T1  - The primary structure of cytochrome c\(_1\) from Neurospora crassa
N2  - No abstract available
KW  - Biochemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62578
ER  - 
TY  - JOUR
A1  - Barnekow, A.
A1  - Paul, E.
A1  - Schartl, Manfred
T1  - Expression of the c-src protooncogene in human skin tumors
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61870
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Rose, Kathleen M.
A1  - Reimer, Georg
A1  - Hügle-Dörr, Barbara
A1  - Scheer, Ulrich
T1  - Inhibition of nucleolar reformation after microinjection of antibodies to RNA polymerase I into mitotic cells
N2  - The formation of daughter nuclei and the reformation of nucleolar structures was studied after microinjection of antibodies to RNA polymerase I into dividing cultured cells (PtK2). The fate of several nucleolar proteins representing the three main structural subcomponents of the nucleolus was examined by immunofluorescence and electron microscopy. The results show that the RNA polymerase I antibodies do not interfere with normal mitotic progression or the early steps of nucleologenesis, i.e. , the aggregation of nucleolar material into prenucleolar bodies. However,they inhibit the telophasic coalescence of the prenucleolar bodies into the chromosomal nucleolar organizer regions, thus preventing the formation of new nucleoli. These prenucleolar bodies show a fibrillar organization that also compositionally resembles the dense fibrillar component of interphase nucleoli . We conclude that during normal nucleologenesis the dense fibrillar component forms from preformed entities around nucleolar organizer regions, and that this association seems to be dependent on the presence of an active form of RNA polymerase I.
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33247
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
A1  - Raska, I.
T1  - Immunocytochemical localization of RNA polymerase I in the fibrillar centers of nucleoli
N2  - No abstract available
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39618
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
T1  - Structure of lampbrush chromosome loops during different states of transcriptional activity as visualized in the presence of physiological salt concentrations
N2  - Lampbrush chromosomes of amphibian oocytes were isolated in the presence of near-physiological salt concentrations, to preserve their native state, and studied by electron microscopy of ultrathin s~dions. The transcriptional state of the lampbrush chromosomes was experimentally modulated by incubating the oocytes for various time periods in medium containing actinomycin D. The observations show that the structure of the lateral loops changes rapidly in response to alterations in transcriptional activity. During decreasing transcriptional activity and reduced packing density of transcripts, the chromatin axis first condensed into nucleosomes and then into an approximately 30 nm thick higher order chromatin fiber. Packaging of the loop axis into supranucleosomal structures may contribute to the foreshortening and retraction of the loops observed during inhibition of transcription and in later stages of meiotic prophase. The increasing packing density of the DNA during the retraction process of the loops could also be visualized by immunofluorescence microscopy using antibodies to DNA. The dependence of the loop chromatin structure on transcriptional activity is discussed in relation to current views of mechanisms involved in gene activation.
KW  - lampbrush chromosomes
KW  - chromatin structure
KW  - electron microscopy
KW  - immunofluorescence microscopy
KW  - DNA antibodies
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39304
ER  - 
TY  - JOUR
A1  - Dandekar, Thomas
A1  - Schulz, R.
T1  - Evidence for the expression of peptides derived from three opioid precursors in NG 108CC15 hybrid cells
N2  - No abstract available
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29909
ER  - 
TY  - JOUR
A1  - Maschwitz, U.
A1  - Fiala, Brigitte
A1  - Dolling, W. R.
T1  - New trophobiotic symbioses of ants with South East Asian bugs
N2  - A trophobiotic relationship between two species of phloem-feeding plataspid bugs and an ant, Meranoplus mucronatus, was discovered on tree trunks in Malaysia. Similar relationships were found between coreid bugs and Crematogaster sp. and Anoplolepis longipes, on bamboo in the same area. The ants recruit to groups of the bugs and feed on the liquid, sugar-rich faeces of the larvae, stimulating release of the honeydew by tactile signals. They protect all stages of the bugs from disturbance by biting and by the use of defensive secretions. Phloem-feeding bugs in the families Plataspidae and Coreidae need long sty lets to pierce the thick bark of their host tree. The different methods of accommodating the resting stylets in these two families are described. The plataspids are described as Tropidotylus servus sp. novo and T. minister sp. novo A coreid previously reported in association with M. mucronatus in Malaya is described as Hygia cliens sp. novo The coreids on bamboo were determined as Cloresmus spp. and Notobitus affinis.
KW  - Ants
KW  - Coreidae
KW  - Heteroptera
KW  - Malaya
KW  - New Species
KW  - Plataspidae
KW  - Trophobiosis
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34030
ER  - 
TY  - JOUR
A1  - Reimer, Georg
A1  - Rose, Kathleen M.
A1  - Scheer, Ulrich
A1  - Tan, Eng M.
T1  - Autoantibody to RNA polymerase I in scleroderma sera
N2  - Autoantibodies to components of the nucleolus are a unique serological feature of patients with scleroderma. There are autoantibodies of several specificities; one type produces a speckled pattern of nucleolar staining in immunofluorescence. In actinomycin D and 5,6-dichloro-{j-D-ribofuranosylbenzimidazoletreated Vero cells, staining was restricted to the fibrillar and not the granular regions. By double immunofluorescence, specific rabbit anti-RNA polymerase I antibodies stained the same fibrillar structures in drug-segregated nucleoli as scleroderma sera. Scleroderma sera immunoprecipitated 13 polypeptides from (35S)methionine-labeled HeLa cell extract with molecular weights ranging from 210,000 to 14,000. Similar polypeptides were precipitated by rabbit anti-RNA polymerase I antibodies, and their common identities were confirmed in immunoabsorption experiments. Microinjection of purified IgG from a patient with speckled nucleolar staining effectively inhibited ribosomal RNA transcription. Autoantibodies to RNA polymerase I were restricted to certain patients with scleroderma and were not found in other autoimmune diseases.
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34294
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
A1  - Messner, Karin
A1  - Hazan, Rachel
A1  - Raska, Ivan
A1  - Hansmann, Paul
A1  - Falk, Heinz
A1  - Spiess, Eberhard
A1  - Franke, Werner W.
T1  - High sensitivity immunolocalization of double and single-stranded DNA by a monoclonal antibody
N2  - A monoclonal antibody (AK 30-10) is described which specifically reacts with DNA both in double and single-stranded forms but not with other molecules and structures, including deoxyribonucleotides and RNAs. When used in immunocytochemical experiments on tissue sections and permeabilized cultured cells, this antibody detects DNA-containing structures, even when the DNA is present in very small amounts. Examples of high resolution detection include the DNA present in amplified extrachromosomal nucleoli, chromomeres of lampbrush chromosomes, mitochondria, chloroplasts and mycoplasmal particles. In immunoelectron microscopy using the immunogold technique, the DNA was localized in distinct substructures such as the "fibrillar centers" of nucleoli and certain stromal centers in chloroplasts. The antibody also reacts with DNA of chromatin of living cells, as shown by microinjection into cultured mitotic cells and into nuclei of amphibian oocytes. The potential value and the limitations of immunocytochemical DNA detection are discussed.
KW  - Cytologie
KW  - DNA antibodies
KW  - monoclonal antibodies
KW  - DNA immunolocalization
KW  - chromatin
KW  - mycoplasma tests
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41063
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Schröder, Johannes Horst
T1  - A new species of the genus Xiphophorus Heckel 1848, endemic to northern Coahuila, Mexico (Pisces: Poeciliidae)
N2  - Xiphophorus meyeri n. sp. is described as an endemic to Muzquiz, Coahuila, Mexico. It appears to be the northernmost species of the genus. The new species is related to X. couchianus and X. gordoni, but differs morphologically from those by dorsal fin ray number, by the expression of some gonopodial features and most markedly by the appearance of macromelanophores or tr-melanophores.
KW  - Schwertkräpfling
KW  - Coahuila
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-87117
ER  - 
TY  - JOUR
A1  - Peschke, Klaus
A1  - Mahsberg [geb. Krapf], Dieter
A1  - Fuldner, Dietrich
T1  - Ecological separation, functional relationships, and limiting resources in a carrion insect community
N2  - 1. Thr ecological separation of 19 carrion inscet species (adults and some of their larvae) was investigated at rabbit carcasses in North Bavaria (FRG) referring to 4 niche dimensions. In the (1.) macrohabitats (forest - clearing) the distribution of saprophageous beetle larvae was mainly considered, for (2.) seasonality the differential abundance of blow flies (Colliphoridae). (3.) The stages of decay were correlated with the temperature dependent development of blow fly maggots affecting the abundance of competing saprophageous beetles and of carnivors preying upon maggots of different size classes. By using ( 4.) microhabitats (spatial subdivision of a carcass) as further niche dimension, the dustering of speries using similar food resources was domonstrated in a niche overlap dendrogram.
2. The quantitative effect of predators on blow fly maggots was investigated both in field and laboratory experiments. Predation upon maggots rcduces their scramble competition, resulting in a higher pupal weight. Thus, the reproductive succcss of the blow flies seems to be buffered by the developmental flexibility of the calliphorids. The numerical effect of predators and parasitoids on the blow fly pupae was also quantified.
3. In a case study on the staphylinid beetle, Aleochara curtula, we investigated the diffenntial abundance of sexes. The ratio at which the males and females arrive at the carcass is balanced. Here the beetles feed and copulated. Females depart into the vicinity of the carrion much earlier than males, thus shifting the sex ratio to a maale bias. In the surroundings the females deposit their eggs, and the parasitoid first instar larvae search for scattered blow fly pupae. The temporal and spatial distribution of both sexes of A. curtula is thus not only affected by the food allocation of the adults, but a.lso by limiting resources of mating end egg laying sites as well as larval hosts.
KW  - Aaskäfer
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86361
ER  - 
TY  - JOUR
A1  - Foerster, Wolfgang
A1  - Schartl, Manfred
T1  - Karyotype and isozyme patterns of five species of Aulonocara REGAN, 1922
N2  - No abstract available.
KW  - Aulonocara
KW  - Karyotyp
KW  - Isoenzym
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86774
ER  - 
TY  - JOUR
A1  - Adam, D.
A1  - Wittbrodt, J.
A1  - Telling, A.
A1  - Schartl, Manfred
T1  - RFLP for an EGF-receptor related gene associated with the melanoma oncogene locus of Xiphophorus maculatus
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61822
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
A1  - Peter, R. U.
T1  - Progressive growth of fish tumors after transplantation into thymus-aplastic (nu/nu) mice
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61833
ER  - 
TY  - JOUR
A1  - Schartl, Manfred
T1  - A sex chromosomal restriction-fragment-length marker linked to melanoma-determining Tu loci in Xiphophorus
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61842
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Bruns, Gail A. P.
T1  - Molecular mapping and cloning of the breakpoints of a chromosome 11p14.1-p13 deletion associated with the AGR syndrome
N2  - Chromosome 11p13 is frequently rearranged in individuals with the WAGR syndrome (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) or parts of this syndrome. To map the cytogenetic aberrations molecularly, we screened DNA from cell Unes with known WAGR-related chromosome abnormalities for rearrangements with pulsed fleld gel (PFG) analysis using probes deleted from one chromosome 11 homolog of a WAGR patient. The first alteration was detected in a cell line from an individual with aniridia, genitourinary anomalies, mental retardation, and a deletion described as 11p14.1-p13. We have located one breakpoint close to probe HU11-164B and we have cloned both breakpoint sites as well as the junctional fragment. The breakpoints subdivide current intervals on the genetic map, and the probes for both sides will serve as important additional markers for a long-range restriction map of this region. Further characterization and sequencing of the breakpoints may yield insight into the mechanisms by which these deletions occur.
KW  - Biochemie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59264
ER  - 
TY  - JOUR
A1  - Goebel, Werner
A1  - Chakraborty, T.
A1  - Kreft, Jürgen
T1  - Bacterial hemolysins as virulence factors
N2  - No abstract available
KW  - Biologie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60553
ER  - 
TY  - JOUR
A1  - Goebel, Werner
A1  - Kathariou, S.
A1  - Kuhn, M.
A1  - Sokolovic, Z.
A1  - Kreft, Jürgen
A1  - Köhler, S.
A1  - Funke, D.
A1  - Chakraborty, T.
A1  - Leimeister-Wächter, M.
T1  - Hemolysin from Listeria-biochemistry, genetics and function in pathogenesis
N2  - No abstract available
KW  - Biologie
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60563
ER  - 
TY  - JOUR
A1  - Thiry, Marc
A1  - Scheer, Ulrich
A1  - Goessens, Guy
T1  - Immunoelectron microscopic study of nucleolar DNA during mitosis in Ehrlich tumour cells
N2  - In order to investigate the DNA localization within Ehrlich tumor cell nucleoli during mitosis, two recent immunocytochemical methods using either an anti-DNA or an anti-bromodeoxyuridine (BrdU) monoclonal antibody have been applied. In both cases, the immunogold labeling has been performed on ultrathin sections of cells embedded either in Lowicryl K4M or in Epon, respectively. Identical results are observed with both immunocytochemical approaches. In the interphase nucleolus, besides the labeling of the perinucleolar chromatin shell and of its intranucleolar invaginations which penetrate into the nucleolar body and often terminate at the fibrillar centers, a few gold particles are also preferentially found towards the peripheral region of the fibrillar centers. In contrast, the dense fibrillar component and the granular component are never labeled. During mitosis, the fibrillar centers persist at the chromosomal nucleolus organizing regions (NOR's) and can be selectively stained by the silver method. However, these metaphase fibrillar centers are no longer decorated by the DNA- or BrdU antibodies. These results indicate that until the end of prophase, rRNA genes are present inside the fibrillar center material, disappear during metaphase and reappear in reconstituting nucleoli during telophase. Thus, fibrillar centers appear to represent structures sui generis, which are populated by rRNA genes only when the nucleolus is functionally active. In segregated nucleoli after actinomycin D treatment, the DNA labeling is exclusively restricted to the perinucleolar chromatin blocks. These findings also suggest that the DNA content of the fibrillar center material varies according to the rRNA transcription level of the cells. The results are discussed in the light of the present knowledge of the functional organization of the nucleolus.
KW  - Cytologie
KW  - Nucleolus
KW  - DNA
KW  - mitosis
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40745
ER  - 
TY  - JOUR
A1  - Rose, Kathleen M.
A1  - Szopa, Jan
A1  - Han, Fu-Sheng
A1  - Cheng, Yung-Chi
A1  - Richter, Arndt
A1  - Scheer, Ulrich
T1  - Association of DNA topoisomerase I and RNA polymerase I: A possible role for topoisomerase I in ribosomal gene transcription
N2  - RNA polymerase I preparations purified from a rat hepatoma contained DNA topoisomerase activity. The DNA topoisomerase associated with the polymerase had an Mr of 110000, required Mg2+ but not ATP, and was recognized by anti-topoisomerase I antibodies. When added to RNA polymerase I preparations containing topoisomerase activity, anti-topoisomerase I antibodies were able to inhibit the DNA relaxing activity of the preparation as well as RNA synthesis in vitro. RNA polymerase II prepared by analogous procedures did not contain topoisomerase activity and was not recognized by the antibodies. The topoisomerase I: polymerase I complex was reversibly dissociated by column chromatography on Sephacryl S200 in the presence of 0.25 M (NH4hS04. Topoisomerase I was immunolocalized in the transcriptionally active ribosomal gene complex containing RNA polymerase I in situ. These data indicate that topoisomerase I and RNA polymerase I are tightly complexed both in vivo and in vitro, and suggest a role for DNA topoisomerase I in the transcription of ribosomal genes.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33901
ER  - 
TY  - JOUR
A1  - Reimer, Georg
A1  - Raska, Ivan
A1  - Scheer, Ulrich
A1  - Tan, Eng M.
T1  - Immunolocalization of 7-2-ribonucleoprotein in the granular component of the nucleolus
N2  - Certain autoimmune sera contain antibodies against a nucleolar ribonucleoprotein particle associated with 7-2-RNA (R. Reddy et al. (1983) J. Bioi. Chem . 258, 1383; C. Hashimoto and J. A. Steitz (1983) J. Bioi. Chem. 258, 1379). In this study, we showed by immunofluorescence microscopy that antibodies reactive with 7-2-ribonucleoprotein immunolocalized in the granular regions of actinomycin D and 5,6-dichloro-I-j3-D-ribofuranosylbenzimidazole (DRB)-segregated nucleoli from Vero cells. By electron microscopic immunocytochemistry, antigen-antibody complexes were located in the granular component of transcriptionally active nucleoli from rat liver hepatocytes and HeLa cells. Anti-7- 2-RNP antibodies from two autoimmune sera immunoprecipitated a major protein of Mr 40,000 from e5S] methionine-Iabeled HeLa cell extract. The immunolocalization data suggest that 7-2-ribonucleoprotein may be involved in stages of ribosome biogenesis which take place in the granular component of the nucleolus, i.e., assembly, maturation, and/or transport of preribosomes
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33890
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Schmidt-Zachmann, Marion S.
A1  - Hügle-Dörr, B.
A1  - Reimer, G.
A1  - Rose, K. M.
A1  - Scheer, Ulrich
T1  - Identification and definition of nucleolus-related fibrillar bodies in micronucleated cells
N2  - Small nucleolus-related bodies which occur in the nUcleoplasm of " micronuclei" lacking nucleolar organizers have been studied by immunofluorescence microscopy. These bodies stained specifically with three different antibodies directed against proteins that are normally associated with the dense fibrillar component of functional nucleoli, but not with antibodies specific for certain proteins of the granular component or the fibrillar centers. Our data show that, in the absence of rRNA genes, the various constituent proteins characteristic of the dense fibrillar component spontaneously assemble into spherical entities but that the subsequent fusion of these bodies into larger structures is prevented in these micronuclei. The similarity between these nucleolus-related bodies of micronuclei and the prenucleolar bodies characteristic of early stages of nucleologenesis during mitotic telophase is discussed.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39423
ER  - 
TY  - JOUR
A1  - Thiry, Marc
A1  - Scheer, Ulrich
A1  - Goessens, Guy
T1  - Localization of DNA within Ehrlich tumour cells nucleoli by immunoelectron microscopy
N2  - The distribution of DNA in Ehrlich tumour cell nucleoli was investigated by means of an immunocytochemical approach , involving a monoclonal antibody directed against double- and single-stranded DNA. Immunolabelling was performed . either before or after the embedding process. The postembedding labelling method allows better ultrastructural preservation than the preembedding labelling method. In particular, the various nucleolar components are well preserved and identifiable. In the nucleolus, labelling is particularly concentrated over the perinucleolar chromatin and over its intranucleolar invaginations, which penetrate the nucleolar body and often terminate at the fibrillar centres. In addition, aggregates of gold particles are found in the fibrillar centres, preferentially towards the peripheral regions. By contrast, the dense fibrillar component is completely devoid of labelling. The results seem to indicate that DNA containing the rDNA genes is located in the fibrillar centres, with a preference for the peripheral regions. This finding suggests that transcription of the rDNA genes should occur within the confines of the fibrillar centre, probably close to the boundary region of the surrounding dense fibrillar component. The results are discussed in the light of present knowledge of the functional organization of the nucleolus.
KW  - nucleolus
KW  - DNA
KW  - monoclonal antibody
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-39327
ER  - 
TY  - JOUR
A1  - Geise, W.
A1  - Linsenmair, Karl Eduard
T1  - Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. IV. Ecological significance of water economy with comments on thermoregulation and energy allocation
N2  - No abstract available
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30570
ER  - 
TY  - JOUR
A1  - Dabauvalle, Marie-Christine
A1  - Schulz, Barbara
A1  - Scheer, Ulrich
A1  - Peters, Reiner
T1  - Inhibition of nuclear accumulation of karyophilic proteins in living cells by microinjection of the lectin wheat germ agglutinin
N2  - No abstract available
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34288
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
A1  - Dabauvalle, Marie-Christine
A1  - Merkert, Hilde
A1  - Benavente, Ricardo
T1  - The nuclear envelope and the organization of the pore complexes
N2  - No abstract available
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-34275
ER  - 
TY  - JOUR
A1  - Linsenmair, Karl Eduard
A1  - Schmuck, R.
T1  - Adaptations of the reed frog Hyperbolius viridiflavus to its arid environment. III. Aspects of nitrogen metabolism and osmuregulation in the reed frog, H. viridiflavus taeniatus, with special reference to the role of iridophores
N2  - Reed frogs of the superspecies Hyperolius viridiflavus occur throughout the seasonally very dry and hot African savannas. Despite their small size (300-700 mg), estivating reed frogs do not avoid stressful conditions above ground by burrowing into the soil, but endure the inhospitable climate relatively unprotected, clinging to mostly dry grass sterns. They must have emcient mechanisms to enable them to survive e.g. very high temperatures, low relative hurnidities, and high solar radiation loads. Mechanisms must also have developed to prevent poisoning by the nitrogenous wastes that inevitably result from protein and nucleotide turnover. In contrast to fossorial amphibians, estivating reed frogs do not become torpid. Reduction in metabolism is therefore rather Iimited so that nitrogenous wastes accumulate faster in these frogs than in fossorial amphibians. This severely aggravates the osmotic problems caused by dehydration. During dry periods total plasma osmolarity greatly increases, mainly due to urea accumulation. Of the total urea accumulated over 42 days of experimental water deprivation, 30% was produced during the first 7 days. In the next 7 days rise in plasma urea content was negligible. This strong initial increase of urea is seen as a byproduct of elevated amino acid catabolism following the onset of dry conditions. Tbe rise in total plasma osmolarity due to urea accumulation, however, is not totally disadvantageous, but enables fast rehydration when water is available for very short periods only. Voiding of urine and feces eeases once evaporative water loss exceeds 10% of body weight. Tberefore, during continuous water deprivation, nitrogenous end products are not excreted. After 42 days of water deprivation, bladder fluid was substantially depleted, and urea coneentration in the remaining urine (up to 447 mM) was never greater than in plasma fluid. Feces voided at the end of the dry period after water uptake contained only small amounts of nitrogenous end products. DSF (dry season frogs) seemed not to be uricotelic. Instead, up to 35% of the total nitrogenous wastes produced over 42 days of water deprivation were deposited in an osmotically inert and nontoxic form in iridophore crystals. The increase in skin purine content averaged 150 µg/mg dry weight. If urea had been the only nitrogenous waste product during an estivation period of 42 days, lethal limits of total osmolarity (about 700 mOsm) would have been reached 10-14 days earlier. Thus iridophores are not only involved in colour change and in reducing heat load by radiation remission, but are also important in osmoregulation during dry periods. The seIective advantages of deposition of guanine rather than uric acid are discussed.
KW  - Biologie
KW  - Zoologie
KW  - Frosch
KW  - Hyperolius viridiflavus
KW  - Estivation
KW  - Osmoregulation
KW  - Nitrogen metabolism
KW  - lridophores
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78108
ER  - 
TY  - JOUR
A1  - Schmuck, R.
A1  - Kobelt, F.
A1  - Linsenmair, Karl Eduard
T1  - Adaptations of the reed frog Hyperbolius viridiflavus (Anura, Hyperbolidae) to its arid environment: V. Iridophores and nitrogen metabolism
N2  - Ofall amphibians living in arid habitats, reed frogs (belonging to the super species Hyperolius viridiflavus) are the most peculiar. Froglets are able to tolerate dry periods of up to 35 days or longer immediately after metamorphosis, in climatically exposed positions. They face similar problems to estivating juveniles, i.e. enduranee of long periods of high temperature and low RH with rather limited energy and water reserves. In addition, they must have had to develop meehanisms to prevent poisoning by nitrogenous wastes that rapidly accumulate during dry periods as a metabolie consequenee of maintaining a non-torpid state. During dry periods, plasma osmolarity of H. v. taeniatus froglets strongly increased, mainly through urea accumulation. Urea accumulation was also observed during metamorphic climax. During postmetamorphic growth, chromatophores develop with the density and morphology typical of the adult pigmentary pattern. The dermal iridophore layer, which is still incomplete at this time, is fully developed within 4-8 days after metamorphosis, irrespective of maintenance conditions. These iridophores mainly contain the purines guanine and hypoxanthine. The ability of these purines to reflect light provides an excellent basis for the role of iridophores in temperature regulation. In individuals experiencing dehydration stress, the initial rate of purine synthesis is doubled in eomparison to specimens continuously maintained under wet season conditions. This increase in synthesis rate leads to a rapid increase in the thiekness of the iridophore layer, thereby effectively reducing radiation absorption. Thus, the danger of overheating is diminished during periods of water shortage when evaporative cooling must be avoided. After the development of an iridophore layer of sufficient thickness for effective radiation reflectance, synthesis of iridophore pigments does not cease. Rather, this pathway is further used during the remaining dry season for solving osmotic problems eaused by accumulation of nitrogenous wastes. During prolonged water deprivation, in spite of reduced metabolic rates, purine pigments are produced at the same rate as in wet season conditions. This leads to a higher relative proportion of nitrogen end products being stored in skin pigments under dry season conditions. At the end of an experimental dry season lasting 35 days, up to 38% of the accrued nitrogen is stored in the form of osmotically inactive purines in thc skin. Thus the osmotic problems caused by evaporative water loss and urea production are greatly reduced.
KW  - Biologie
KW  - Zoologie
KW  - Frosch
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78094
ER  - 
TY  - JOUR
A1  - Mäueler, Winfried
A1  - Raulf, Friedrich
A1  - Schartl, Manfred
T1  - Expression of proto-oncogenes in embryonic, adult, and transformed tissue of Xiphophorus (Teleostei: Poeciliidae)
N2  - In Xiphophorus the causative, primary cellular oncogene for melanoma formation has been assigned by classical genetics to a sex-chromosomal locus, designated Tu. Activation of Tu was proposed to be the result of the elimination of Tu-specific regulatory genes which normally suppress the transforming function in the nontumorous state. In order to understand the role which known proto-oncogenes migbt play in this process, we have analysed the expression of src, erb A, erb B, ras, abl, sis and mil related genes from Xiphophorus during embryogenesis, in non-tumorous organs and in melanoma cells. For src, ras, erb B and sis a differential expression during embryogenesis and/or in normal organs was detected, with preferential expression of src in neural tissues, a high abundance of sis transcripts in an embryonal epitheloid cellline and of erbB transcripts in the head nephros. In melanoma cells ras, src and a v-erb B related gene were found to be expressed. The src gene most likely is more involved in secondary processes during tumor progression, while the expression of the v-erb B related gene might be transformation-specific because recently such a sequence was found to map to the close vicinity of the Tu-locus.
KW  - Schwertkärpfling
KW  - Protoonkogen
KW  - Gewebe
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86233
ER  - 
TY  - JOUR
A1  - Maueler, W.
A1  - Barnekow, A.
A1  - Eigenbrodt, E.
A1  - Raulf, F.
A1  - Falk, H. F.
A1  - Telling, A.
A1  - Schartl, Manfred
T1  - Different regulation of oncogene expression in tumor and embryonal cells of Xiphophorus
N2  - Melanoma formation in the poeciliid fish Xiphophorus is mediated primarily by a cellular oncogene, designated Tu. Elimination of Tu-specific genes releases the transforming function of Tu and leads to melanoma formation. Southern blot analyses revealed a tight linkage of a v-erb B related gene to the Tu-locus and Northern blot analyses of RNA of solid melanomas indicated a coordinated deregulation and for mutational activation of several oncogenes. In order to get a better insight into the regulation of oncogene expression in normal and transformed cells of Xiphophorus, we studied the expression of Xsrc, Xras, Xmyc, Xerb A, Xsis, and the v-erb B related gene in a melanoma derived cell line (PSM) and an embryonic cell line (A2) under conditions of low growth factor supply. Both celllines express the Xsrc, Xmyc, and Xras genes, while PSM cells in addition express the v-erb B related gene and A2 cells the Xsis gene. In PSM cells serum deprivation leads to an accumulation of most of the oncogene mRNAs analysed. This is most apparent for a 5.0 kb transcript of the v-erb B related gene, probably due to an increase in transcript stability. The levels of these mRNAs returned to normal within 2h after stimulation with 10% fetal calf serum. At the protein level we observed an initial decrease followed by an increase of the n-p60c-src kinase (the protein product of tbe Xsrc gene) activity in cells deprived of serum. Serum stimulation restored a normal pp60"-src kinase activity. In contrast serum deprivation of A2 cells reduced the transcript amounts of each of the oncogenes analysed. The same holds true for one beta-tubulin transcript, while the level of a second beta-tubulin transcript was unaffected. Serum stimulation led to a reactivation of Xras and Xsrc after a delay of approximately 48b. The pp60(c-src) kinase activity was found to be 6-10 times lower as compared to the PSM cells and did not differ between serum deprived and serum stimulated cells. Enzyme activities and isoenzyme patterns of several glycolytic enzymes were found to be not affected by serum deprivation and stimulation in both celllines.
KW  - Schwertkärpfling
KW  - Tumorzelle
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86240
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Reimer, Georg
A1  - Rose, Kathleen M.
A1  - Hügle-Dörr, Barbara
A1  - Scheer, Ulrich
T1  - Nucleolar changes after microinjection of antibodies to RNA polymerase I into the nucleus of mammalian cells
N2  - After microinjection of antibodies against RNA polymerase I into the nuclei of cultured rat kangaroo (PtKz) and rat (RVF-SMC) cells alterations in nucleolar structure and composition were observed. These were detected by electron microscopy and double-label immunofluorescence microscopy using antibodies to proteins representative of the three major components of the nucleolus. The microinjected antibodies produced a progressive loss of the material of the dense fibrillar component (DFC) from the nucleoli which, at 4 h after injection, were transformed into bodies with purely granular component (GC) structure with attached fibrillar centers (FCs). Concomitantly, numerous extranucleolar aggregates appeared in the nucleoplasm which morphologically resembled fragments of the DFC and contained a protein (fibrillarin) diagnostic for this nucleolar structure. These observations indicate that the topological distribution of the material constituting the DFC can be experimentally influenced in interphase cells, apparently by modulating the transcriptional activity of the rRNA genes. These effects are different from nucleolar lesions induced by inhibitory drugs such as actinomycin D-dependent "nucleolar segregation". The structural alterations induced by antibodies to RNA polymerase I resemble, however, the initial events of nucleolar disintegration during mitotic prophase.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40666
ER  - 
TY  - JOUR
A1  - Raulf, F.
A1  - Robertson, S. M.
A1  - Schartl, Manfred
T1  - Evolution of the neuron-specific alternative splicing product of the c-src proto-oncogene
N2  - The observation of a slower migrating form of pp6oc-src in neural tissue of chicken and mouse has recently been shown to be due to an alternative transcript form of tbe c-src gene (Martinez et al.: Science 237:411-415, 1987; Levy et al.: Mol Cell Bio17:4142- 4145, 1987). An insertion of 18 basepairs between exons 3 and 4, presumed to be due to alternative splicing of a mini-exon, gives rise to six amino acid residues not found in the non-neuronal (termed flbroblastic) form of pp60\(^{c-src}\). Wehave addressed the question of the evolutionary origin of the c-src neuronal insert · and its functional signiflcance regarding neural-speciflc expression of the c-src gene. To this end we have investigated whether the c-src gene of a lower verlebrate (the teleost fish Xiphophorus) gives rise to a neural-specific transcript in an analogous manner. We could show that the fish c-src gene does encode for a "fibroblastic" and a "neuronal" form of transcript and that the neuronal transcript does indeed arise by way of alternative splicing of a mini-exon. The miniexon is also 18 basepairs long and we could demoostrate directly that this exon lies within the intron separating exons 3 and 4. For comparative purposes we have examined whether the fish c-yes gene, the member of the src gene family most closely related to c-src, also encodes a neural tissue-specific transcript. No evidence for a second transcript form in brain was obtained. This result suggests that the mini-exon arose within the c-src gene lineage sometime between the srclyes gene duplication event and the divergence of the evolutionary lineage giving rise to the teleost fish. Published genomic sequence of src-related genes in Drosophila and our own results with Hydra demoostrate no intron in these species at the analogous location, consistent with first appearance of this mini-exon sometime between 550 and 400 million years ago.
KW  - Physiologische Chemie
KW  - Xiphophorus
KW  - teleost flsh
KW  - polymerase
KW  - chain reaction
KW  - RT -PCR
KW  - mini-exon
KW  - pp6oc-src
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61796
ER  - 
TY  - JOUR
A1  - Wittbrodt, J.
A1  - Adam, D.
A1  - Malitschek, B.
A1  - Maueler, W.
A1  - Raulf, F.
A1  - Telling, A.
A1  - Robertson, M.
A1  - Schartl, Manfred
T1  - Novel putative receptor tyrosine kinase encoded by the melanoma-inducing Tu locus in Xiphophorus
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61800
ER  - 
TY  - JOUR
A1  - Bernards, R.
A1  - Schackleford, G. M.
A1  - Gerber, M. R.
A1  - Horowitz, J. M.
A1  - Friend, S. H.
A1  - Schartl, Manfred
A1  - Bogenmann, E.
A1  - Rapaport, J. M.
A1  - Mcgee, T.
A1  - Dryja, T. P.
T1  - Structure and expression of the murine retinoblastoma gene and characterization of its encoded protein
N2  - No abstract available
KW  - Physiologische Chemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61819
ER  - 
TY  - JOUR
A1  - Weigel, U.
A1  - Meyer, M.
A1  - Sebald, Walter
T1  - Mutant proteins of human interleukin 2. Renaturation yield, proliferative activity and receptor binding
N2  - No abstract available
KW  - Biochemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62543
ER  - 
TY  - JOUR
A1  - Flügge, U. I.
A1  - Fischer, K.
A1  - Gross, A.
A1  - Sebald, Walter
A1  - Lottspeich, F.
A1  - Eckerskorn, C.
T1  - The triose phosphate-3-phosphoglycerate-phosphate translocator from spinach chloroplasts: nucleotide sequence of a full-length cDNA clone and import of the in vitro synthesized precursor protein into chloroplasts
N2  - No abstract available
KW  - Biochemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62559
ER  - 
TY  - JOUR
A1  - Kreft, Jürgen
A1  - Funke, D.
A1  - Schlesinger, R.
A1  - Lottspeich, F.
A1  - Goebel, Werner
T1  - Purification and characterization of cytolysins from Listeria monocytogenes serovar 4b and Listeria ivanovii
N2  - Several exoproteins from Listeria monocytogenes serovar 4b (NCTC 10527) and Listeria ivanovii (ATCC) 19119, SLCC 2379), respectively, have been purified to homogeneity by thiol-disulfide exchange chromatography and gel filtration. Both strains produce a haemolytic/cytolytic protein of Mr 58 kDa, which has all the properties of a SH-activated cytolysin, the prototype of which is streptolysin 0 (SLO), and this protein has therefore heen termed Iisteriolysin 0 (LLO). In addition a protein of Mr 24 kDa from culture supernatants of L. ivanovii co-purified withLLO. The N-terminal aminoacid sequences of both proteins from L. ivanovii have been determined. By mutagenesis with transposons of Gram-positive origin (Tn916 and TnI545), which have been introduced via conjugation into L. ivanovii, several phenotypic mutants (altered haemolysis on sheep blood agar or lecithinase-negative) were obtained. Results on the properties of these muntants will he presented.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47036
ER  - 
TY  - JOUR
A1  - Kreft, Jürgen
A1  - Haas, Albert
A1  - Goebel, Werner
T1  - Isolation and characterization of genes coding for proteins involved in the cytolysis by Listeria ivanovii
N2  - We established a library of chromosomal DNA of Listeria ivanovii in the pTZ19R plasmid system, using Escherichia coli DH5alpha as the host. One recombinant clone reacted strongly with a polyclonal antiserum raised against the listeriolysin 0 and a second exoprotein (24kDa) of L. ivanovii, which is most probably also involved in cytolytic processes. The recombinant E. coli clone may contain part of the listeriolysin 0 gene of L. ivanovii.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46991
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Bruns, G. A. P.
T1  - A physical map around the WAGR complex on the short arm of chromosome 11
N2  - A long-range restriction map of part of the short arm of ehromosome 11 including the WAGR region has been constructed using pulsed-field gel electrophoresis and a number of infrequently cutting restriction enzymes. A total of 15.4 Mbp has been mapped in detall, extending from proximal 11p14 to the distal part of 11p12. The map localizes 35 different DNA probes and reveals at least nine areas with features eharaeteristle of BTF islands, some of which may be candidates for the different loci underlying the phenotype of the WAGR syndrome. This map will furthermore allow screening of DNA from individuals with WAGR-related phenotypes and from Wilms tumors for associated chromosomal rearrangements.
KW  - Biochemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59246
ER  - 
TY  - JOUR
A1  - Gessler, Manfred
A1  - Thomas, G. H.
A1  - Couillin, P.
A1  - Junien, C.
A1  - McGillivray, B. C.
A1  - Hayden, M.
A1  - Jaschek, G.
A1  - Bruns, G. A.
T1  - A deletion map of the WAGR region on chromosome II
N2  - The WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) region has been assigned to chromosome 11p13 on the basis of overlapping constitutional deletions found in affected individuals. We have utilized 31 DNA probes which map to the WAGR deletion region, together with six reference loci and 13 WAGR-related deletions, to subdivide this area into 16 intervals. Specific intervals have been correlated with phenotypic features, leading to the identification of individual subregions for the aniridia and Wilms tumor loci. Delineation, by specific probes, of multiple intervals above and below the critical region and of five intervals within the overlap area provides a framework map for molecular characterization of WAGR gene loci and of deletion boundary regions.
KW  - Biochemie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-59255
ER  - 
TY  - JOUR
A1  - Kreft, Jürgen
A1  - Funke, Dorothee
A1  - Haas, Albert
A1  - Lottspeich, Friedrich
A1  - Goebel, Werner
T1  - Production, purification and characterization of hemolysins from Listeria ivanovii and Listeria monocytogenes Sv4b.
N2  - In culture supematants of both Listeria ivanovii and Listeria monocytogenes Sv4b, for the first time a hemolysin of molecular weight 58 kDa was identified, which had all the characteristics of an SH-activated cytolysin, and which was therefore identified as Iisteriolysin 0 (LLO). In the case of L. ivanovii a second major supematant protein of molecular weight 24 kDa co-purified with LLO. However, the function of this protein has to be determined. In culture supematants of L. ivanovii a sphingomyelinase and a Iecithinase activity could be detected, both enzymatic activities together contributing to the pronounced hemolysis caused by L. ivanovii. The N-tenninal amino acid sequences of LLO and the 24 kDa from L. ivanovii are shown.
KW  - Biologie
KW  - Hemolysin
KW  - Listeria
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60545
ER  - 
TY  - JOUR
A1  - Gilmore, Michael S.
A1  - Cruz-Rodz, Armando L.
A1  - Leimeister-Wächter, Michaela
A1  - Kreft, Jürgen
A1  - Goebel, Werner
T1  - A Bacillus cereus cytolytic determinant, cereolysin AB, which comprises the phospholipase C and sphingomyelinase genes: nucleotide sequence and genetic linkage
N2  - A cloned cytolytic determinant from the genome of Bacillus cereus GP-4 has been characterized at the molecular Ievel. Nucleotide sequence determination revealed the presence of two open reading frames. 8oth open reading frames were found by deletion and complementation analysis to be necessary for expression of the hemolytic phenotype by Bacillus subtilis and Escherichia coli hosts. The 5' open reading frame was found to be nearly identical to a recently reported phospholipase C gene derived from a mutant B. cereus strain which overexpresses the respective protein, and it conferred a lecithinase-positive phenotype to the B. subtilis host. The 3' open reading frame encoded a sphingomyelinase. The two tandemly encoded activities, phospholipase C and sphingomyelinase, constitute a biologically functional cytolytic determinant of B. cereus termed cereolysin AB.
KW  - Biologie
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60588
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Dabauvalle, Marie-Christine
A1  - Scheer, Ulrich
A1  - Chaly, Nathalie
T1  - Functional role of newly formed pore complexes in postmitotic nuclear reorganization
N2  - Many nuclear proteins are released into the cytoplasm at prometaphase and are transported back into the daughter nuclei at the end of mitosis. To determine the role of this reentry in nuclear remodelling during early interphase, we experimentally manipulated nuclear protein uptake in dividing cells. Recently we and others have shown that signal-dependent, pore complex-mediated uptake of nuclear protein is blocked in living cells on microinjection of the lectin wheat germ agglutinin (WGA), or of antibodies such as PI1 that are directed against WGA-binding pore complex glycoproteins. In the present study, we microinjected mitotic PtKz cells with WGA or antibody PIt and followed nuclear reorganization of the daughter cells by immunofluorescence and electron microscopy. The inhibitory effect on nuclear protein uptake was monitored by co-injection of the karyophilic protein nucleoplasmin. When injected by itself early in mitosis, nucleoplasmin became sequestered into the daughter nuclei as they entered telophase. In contrast, nucleoplasmin was excluded from the daughter nuclei in the presence of WGA or antibody PI1 . Although PtKz cells with blocked nuclear protein uptake completed cytokinesis, their nuclei showed a telophaselike organization characterized by highly condensed chromatin surrounded by a nuclear envelope containing a few pore complexes. These findings suggest that pore complexes become functional as early as telophase, in close coincidence with nuclear envelope reformation. They further indicate that the extensive structural rearrangement of the nucleus during the telophase-G1 transition is dependent on the influx of karyophilic proteins from the cytoplasm through the pore complexes, and is not due solely to chromosome- associated components.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40754
ER  - 
TY  - JOUR
A1  - Weber, Thomas
A1  - Schmidt, Erwin
A1  - Scheer, Ulrich
T1  - Mapping of transcription units on Xenopus laevis lampbrush chromosomes by in situ hybridization with biotin-labeled cDNA probes
N2  - A non-radioactive in situ hybridization method is described for the localization of transcription units of defined genes to lateral loops of Xenopus laevis lampbrush chromosomes. Two Xenopus cONA probes were used encoding the nucleolar protein N038/ B23 and cytokeratin 1(8). Both proteins are known to be synthesized in Xenopus oocytes, and Northern blot analysis revealed the presence of the corresponding mRNAs in different oogenic stages. The probes were enzymatically labeled with biotin-dCTP and hybridized to lampbrush chromosomes. The sites of hybridization were detected either by indirect immunofluorescence microscopy using rabbit antibodies against biotin and fluorescein-conjugated antirabbit IgG or enzymatically using peroxidase-conjugated streptavi din. The probe encoding the nucleolar protein hybridized to two sets of lateral loops on different bivalents, the cytokeratin probe to at least four. Our finding that each probe hybridized to more than one chromosomal locus may reflect the tetraploid nature of the Xenopus laevis genome or results from cross-hybridization to other transcriptionally active members of the N038/ B23-nucleoplasmin or the cytokeratin-Iamin gene families. The method described should facilitate further in situ hybridization studies with appropriate genomic clones in order to map specific DNA sequences to defined loop regions and to come to a better understanding of the relationship between loop organization and gene transcription unit.
KW  - Cytologie
KW  - Lampbrush chromosomes
KW  - in situ hybridization
KW  - transcription units
KW  - Xenopus oocytes
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40763
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Scheer, Ulrich
A1  - Chaly, Nathalie
T1  - Nucleocytoplasmic sorting of macromolecules following mitosis: fate of nuclear constituents after inhibition of pore complex function
N2  - PtK2 cells in which pore complex-mediated transport is blocked by microinjection early in mitosis of a monoclonal antibody (specific for an Mr 68000 pore complex glycoprotein) or of wheat germ agglutinin (WGA) complete cytokinesis. However, their nuclei remain stably arrested in a telophase-like organization characterized by highly condensed chromatin and the absence of nucleoli, indicating a requirement for pore-mediated transport for the reassembly of interphase nuclei. We have now examined this requirement more closely by monitoring the behavior of individual nuclear macromolecules in microinjected cells using immunofluorescence microscopy and have investigated the effect of microinjecting the antibody or WGA on cellular ultrastructure. The absence of nuclear transport did not affect the sequestration into daughter nuclei of components such as DNA, DNA topoisomerase I and the nucleolar protein fibrillarin that are carried through mitosis on chromosomes. On the other hand, lamins, snRNAs and the p68 pore complex glycoprotein, all cytoplasmic during mitosis, remained largely cytoplasmic in the telophase-arrested cells. Electron microscopy showed the nuclei to be surrounded by a doublelayered membrane with some inserted pore complexes. In addition, however, a variety of membranous structures with associated pore complexes was regularly noted in the cytoplasm, suggesting that chromatin may not be essential for the postmitotic formation of pore complexes. We propose that cellular compartmentalization at telophase is a two-step process. First, a nuclear envelope tightly encloses the condensed chromosomes, excluding non-selectively all macromolecules not associated with the chromosomes. Interphase nuclear organization is then progressively restored by selective pore complex-mediated uptake of nuclear proteins from the cytoplasm.
KW  - Cytologie
KW  - Nucleocytoplasmic transport
KW  - nuclear organization
KW  - nuclear envelope
KW  - nucleologenesis
KW  - mitosis
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40777
ER  - 
TY  - JOUR
A1  - Maschwitz, Ulich
A1  - Fiala, Brigitte
A1  - Lee, Ying Fah
A1  - Chey, Vun Khen
A1  - Tan, Fui Lian
T1  - New and little-known myrmecophytic associations from Bornean rain forests
N2  - The woody climber Millettia niuewenhuisii (Fabaceae) and the shrub Myrmeconauclea strigosa (Rubiaceae) in Sabah, Borneo are associated with ants. The hollow stems of Millettia nieuwenhuisii are regularly inhabited by an aggressive Cladomyrma sp., which keeps pseudococcids inside the stem. On Myrmeconauclea strigosa the ants live in hollow internodal swellings near the end of the branches. In this plant many different ant species use the nesting space in an opportunistic manner.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42957
ER  - 
TY  - JOUR
A1  - Fiala, Brigitte
A1  - Maschwitz, Ulrich
A1  - Pong, Tho, Yow
A1  - Helbig, Andreas J.
T1  - Studies of a South East Asian ant-plant association : protection of Macaranga trees by Crematogaster borneensis
N2  - In the humid tropics of SE Asia there are some 14 myrmecophytic species of the pioneer tree genus Macaranga (Euphorbiaceae). In Peninsular Malaysia a close association exists between the trees and the small, non-stinging myrmicine Crema togas ter borneensis. These ants feed mainly on food bodies provided by the plants and have their colonies inside the hollow intemodes. In a ten months field study we were able to demonstrate for four Macaranga species (M. triloba, M. hypoleuca, M. hosei, M. hulletti) that host plants also benefit considerably from ant-occupation. Ants do not contribute to the nutrient demands of their host plant, they do, however, protect it against herbivores and plant competition. Cleaning behaviour of the ants results in the removal of potential herbivores already in their earliest developmental stages. Strong aggressiveness and a mass recruiting system enable the ants to defend the host plant against many herbivorous insects. This results in a significant decrease in leaf damage due to herbivores on ant-occupied compared to ant-free myrmecophytes as well as compared to non-myrmecophytic Macaranga species. Most important is the ants' defense of the host plant against plant competitors, especially vines, which are abundant in the well-lit pioneer habitats where Macaranga grows. Ants bite off any foreign plant part coming into contact with their host plant. Both ant-free myrmecophytes and non-myrmecophytic Macaranga species had a significantly higher incidence of vine growth than specimens with active ant colonies. This may be a factor of considerable importance allowing Macaranga plants to grow at sites of strongest competition.
KW  - Ant/plant interaction
KW  - Myrmecophytes
KW  - Protection
KW  - Macaranga
KW  - Crematogaster borneensis
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42857
ER  - 
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  -