TY - CHAP A1 - Peter, R. U. A1 - Schartl, Manfred A1 - Anders, F. A1 - Duncker, H.-R. T1 - Pigment pattern formation during embryogenesis in Xiphophorus N2 - No abstract available. KW - Schwertkärpfling KW - Embryonalentwicklung KW - Pigmentmuster Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-69370 ER - TY - CHAP A1 - Riehl, Rüdiger A1 - Schartl, Manfred A1 - Anders, Fritz T1 - An ultrastructural study of melanoma in Xiphophorus N2 - Melanotic melanoma (MM) of Xiphophorus (Teleostei: Poeciliidae) was studied by conventional preparations and freeze-etch preparations for electron microscopy. MM of Xiphophorus exhibits tightly packed pigment cells with prominent dendritic processes and interdigitations of their plasma membranes. The most impressive feature of MM cells is the occurrence of Iarge lobulated nuclei with numerous nuclear pores and some nuclear pockets. Abundant spheroidal or ellipsoidal melanosomes (diameter 200-650 nm) and vesicular structures are distributed throughout the cellular dendrites, whereas the perinucJear cytoplasm is free of melanosomes. A further characteristic feature of melanoma cells in fish is the occurrence of melanosome complexes (i.e., "compound melanosomes"). These melanosome complexes consist of a few to numerous melanosomes, which are enveloped by a separate rnembrane. Pinocytotic vesicles couJd be demonstrated with distinct differences in frequency and distribution patterns, indicating differences in the metabolic activities of the cells in the same melanoma. Intercellular junctions are lacking in the MM cells. The conventional TEM technique showed clear advantages in the demonstration of intemal architecture of organelles, whereas FE bad considerable potential in respect to the visualization of membrane surface specializations. KW - Schwertkärpfling KW - Krebs KW - Ultrastruktur Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-70978 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 - 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 - Lindenmaier, W. A1 - Dittmar, K. E. A1 - Hauser, H. A1 - Necker, A. A1 - Sebald, Walter T1 - Isolation of a functional human interleukin 2 gene from a cosmid library by recombination in vivo N2 - A method has been developed that allows the isolation of genomic clones from a cosmid library by homologaus recombination in vivo. This method was used to isolate a human genomic interleukin 2 (IL2) gene. The genomic cosmid library was packaged in vivo into A. phage particles. A recombination-proficient host strain carrying IL2 cDNA sequences in a non-homologaus plasmid vector was infected by the packaged cosmid library. After in vivo packaging and reinfection, recombinants carrying the antibiotic resistance genes of both vectors were selected. From a recombinant cosmid clone the chromosomal IL2 genewas restored. After DNA mediated gene transfer into mouse Ltk- cells human IL2 was expressed constitutively. KW - Biochemie KW - Recombinant DNA KW - DNA mediated gene transfer KW - expression plasmid KW - screening KW - packaging KW - bacteriophage lambda Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62662 ER - TY - JOUR A1 - McCarthy, J. E. A1 - Schairer, H. U. A1 - Sebald, Walter T1 - Translational initiation frequency of atp genes from Escherichia coli: identification of an intercistronic sequence that enhances translation N2 - The c, b and ö subunit genes of the Escherichia coli atp operon were cloned individually in an expression vector between the tac fusion promoter and the galK gene. The relative rates of subunit synthesis directed by the cloned genes were similar in vitro andin vivo and compared favourably with the subunit stoichiometry of the assembled proton-translocating A TP synthase of E. coli in vivo. The rate of synthesis of subunit c was at least six times that of subunit b and 18 times that of subunit ö. Progressive shortening of the long intercistronic sequence lying upstream of the subunit c gene showed that maximal expression of this gene is dependent upon the presence of a sequence stretching > 20 bp upstream of the Shine-Dalgarno site. This sequence thus acts to enhance the rate of translational initiation. The possibility that similar sequences might perform the same function in other operons of E. coli and bacteriophage A is also discussed. Translation of the subunit b cistron is partially coupled to translation of the preceding subunit c cistron. In conclusion, the expression of all the atp operon genes could be adjusted to accommodate the subunit requirements of A TP synthase assembly primarily by means of mechanisms which control the efficiency of translational initiation and re-initiation at the respective cistron start codons. KW - Biochemie KW - E. coli atp operon KW - subunit stoichiometry KW - in vitro and in vivo expression KW - translational initiation Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62657 ER - TY - JOUR A1 - Gabellini, N. A1 - Harnisch, U. A1 - McCarthy, J. E. A1 - Hauska, G. A1 - Sebald, Walter T1 - Cloning and expression of the fbc operon encoding the FeS protein, cytochrome b and cytochrome c\(_1\) from the Rhodopseudomonas sphaeroides b/c\(_1\) complex N2 - The gene for the FeS protein of the Rhodopseudomonas sphaeroides b/c1 complex was identified by means of crosshybridization with a segment of the gene encoding the corresponding FeS protein of Neurospora crassa. Plasmids (pRSF1-14) containing the cross-hybridizing region, covering in total 13.5 kb of chromosomal DNA, were expressed in vitro in a homologous system. One RSF plasmid directed the synthesis of all three main polypeptides of the R. sphaeroides blc1 complex: the FeS protein, cytochrome b and cytochrome c1• The FeS protein and cytochrome c1 were apparently synthesized as precursor fonns. None of the pRSF plasmids directed the synthesis of the 10-kd polypeptide found in b/c1 complex preparations. Partial sequencing of the cloned region was performed. Several sites of strong homology between R. sphaeroides and eukaryotic polypeptides of the b/c1 complex were identified. The genes encode the three b/c1 polypeptides in the order: (5') FeS protein, cytochrome b, cytochrome c1• The three genes are transcribed to give a polycistronic mRNA of 2.9 kb. This transcriptional unit has been designated the jbc operon; its coding capacity corresponds to the size of the polycistronic mRNA assuming that only the genes for the FeS protein (jbcF), cytochrome b (jbcß) and cytochrome c1 (jbcC) are present. This could indicate that these three subunits constitute the minimal catalytic unit of the b/c1 complex from photosynthetic membranes. KW - Biochemie KW - R. sphaeroidesl KW - b/c1 complex KW - gene KW - cloning KW - in vitro expression KW - polycistronic mRNA Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62642 ER - TY - JOUR A1 - Harnisch, U. A1 - Weiss, H. A1 - Sebald, Walter T1 - The primary structure of the iron-sulfur subunit of ubiquinol-cytochrome c reductase from Neurospora, determined by cDNA and gene sequencing N2 - No abstract available KW - Biochemie Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62631 ER - TY - CHAP A1 - Scheer, Ulrich A1 - Dabauvalle, Marie-Christine T1 - Functional organization of the amphibian oocyte nucleus N2 - No abstract available KW - Oogenese Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41178 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 - 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 - 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 -