@article{HannigOttilieSchartl1991,
  author    = {Hannig, Gerhard and Ottilie, Sabine and Schartl, Manfred},
  title     = {Conservation of structure and expression of the c-yes and fyn genes in lower vertebrates},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86723},
  year      = {1991},
  abstract  = {The src-gene family in mammals and birds consists of 9 closely related protein tyrosine kinases. We have cloned the c-yes and fyn bomologues of the src-family from the teleost fish Xiphophorus helleri. Both genes show a high degree of sequence conservation and exhibit all structural motifs diagnostic for functional src-like protein tyrosine kinases. Sequence comparisons revealed three domains (exon 2, exons 3--6, exons 7-12) which evolve at different rates. Both genes exhibit an identical expression pattern, with preferential expression in neural tissues. No transcripts of c-yes were found in liver wbich is contrary to the situation in higher vertebrales. In malignant melanoma, elevated Ieveis of c-yes andfyn were detected indicating a possible function during secondary steps of tumor progression for src-related tyrosine kinases.},
  subject      = {Konservierung},
  language  = {en}
}
@article{ThiryScheerGoessens1991,
  author    = {Thiry, Marc and Scheer, Ulrich and Goessens, Guy},
  title     = {Localization of nucleolar chromatin by immunocytochemistry and in situ hybridization at the electron microscopic level},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-39289},
  year      = {1991},
  abstract  = {Nucleoli are the morphological expression of the activity of a defined set of chromosomal segments bearing rRNA genes. The topological distribution and composition of the intranucleolar chromatin as well as the definition of nucleolar structures in which enzymes of the rDNA transcription machinery reside have been investigated in mammalian cells by various immunogold labelling approaches at the ultrastructural level. The precise intranucleolar location of rRNA genes has been further specified by electron microscopic in situ hybridization with a non-autoradiographic procedure. Our results indicate that the fibrillar centers are the sole nucleolar structures where rDNA, core histones, RNA polymerase I and DNA to po isomerase I are located together. Taking into account the potential value and limitations of immunoelectron microscopic techniques, we propose that transcription of the rRNA genes takes place within the confines of the fibrillar centers, probably close to the boundary regions to the surrounding dense fibrillar component.},
  language  = {en}
}
@article{SchartlAdam1992,
  author    = {Schartl, Manfred and Adam, Dieter},
  title     = {Molecular cloning, structural characterization, and analysis of transcription of the melanoma oncogene of xiphophorus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61989},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{SchluppParzefallEpplenetal.1992,
  author    = {Schlupp, Ingo and Parzefall, Jakob and Epplen, J{\"o}rg T. and Nanda, Indrajit and Schmid, Michael and Schartl, Manfred},
  title     = {Pseudomale behaviour and spontaneous masculinization in the all-female teleost Poecilia formosa (Teleostei: Poeciliidae)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61688},
  year      = {1992},
  abstract  = {Pseudosexual behaviour is a rare phenomenon associated with unisexuality in vertebrates. In the gynogenetic, all-female teleost Poecilia formosa, rare individuals occur that resemble males of closely related gonochoristic species both in behaviour and external morphology. These masculinized gynogens and normal gynogens are members of the same clone, as demonstrated by DNA-fingerprinting. The behaviour of these masculinized gynogens is described and compared to the behaviour of the gonochoristic species Poecilia mexicana, P. latipinna and their hybrid as weil as androgen-treated individuals of P. formosa. No statistically significant difTerences were found between masculinized gynogens and hormonetreated individuals nor between the gonochoristic P. mexicana and P. latipinna males. Differences exist between gonochoristic and unisexual species. Passihle causes and effects of masculinized gynogens are discussed.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{KruseTonySebald1992,
  author    = {Kruse, N. and Tony, H. P. and Sebald, Walter},
  title     = {Conversion of human interleukin-4 into a high affinity antagonist by a single amino acid replacement},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62469},
  year      = {1992},
  abstract  = {lnterleukin-4 (IL-4) represents a prototypic lymphokine (for a recent review see Paul, 1991). It promotes differentiation of B-cells and the proliferation of T- and B-cell, and other cell types of the lymphoid system. An antagonist of human IL-4 was discovered during the studies presented here after Tyr124 of the recombinant proteinbad been substituted by an aspartic acid residue. This IL-4 variant, Y124D, bound with high affinity to the IL-4 receptor (K\(_D\) = 310 pM), but retained no detectable proliferative activity for T -<:ells and inhibited IL-4-dependent T -cell proliferation competitively (K\(_i\) = 620 pM). The loss of efficacy in variant Y124D was estimated to be > 100-fold on the basis of a weak partial agonist activity for the very sensitive induction of CD23 positive B-cells. The subsitution of Tyr124 by either phenylalanine, histidine, asparagine, Iysine or glycine resulted in partial agonist variants with unaltered receptor binding atTmity and relatively small deficiencies in efficacy. These results demoostrate that high affinity binding and signal generation can be uncoupled efticiently in a Iigand of a receptor betonging to the recently identified hematopoietin receptor family. In addition we show for the first time, that a powerful antagonist acting on the IL-4 receptor system can be derived from the IL-4 protein.},
  subject      = {Biochemie},
  language  = {en}
}
@article{DummerPosseckertNestleetal.1992,
  author    = {Dummer, R. and Posseckert, G. and Nestle, F. and Witzgall, R. and Burger, M. and Becker, J. C. and Sch{\"a}fer, E. and Wiede, J. and Sebald, Walter and Burg, G.},
  title     = {Soluble interleukin-2 receptors inhibit interleukin 2-dependent proliferation and cytotoxicity: explanation for diminished natural killer cell activity in cutaneous T-cell lymphomas in vivo?},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62473},
  year      = {1992},
  abstract  = {No abstract available},
  subject      = {Biochemie},
  language  = {en}
}
@article{HongSchartl1992,
  author    = {Hong, Yunhan and Schartl, Manfred},
  title     = {Structure of the rainbow trout metallothionein A gene},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61679},
  year      = {1992},
  abstract  = {To investigate the regulation of metallothionein-encoding genes in fish, we have isolated and sequenced the rainbow trout metallothionein-A-encoding gene (tMT-A) by polymerase chain reaction. This gene spans about 1.1 kb, consists of three exons and two introns, and has an A+ T-rieb 5' -region which contains a TATAAA signal, and two metal responsive elements (MREs). The transcription start point is centered around an A residue 81 nt upstream of the ATG codon.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{WittbrodtLammersMalitscheketal.1992,
  author    = {Wittbrodt, Joachim and Lammers, Reiner and Malitschek, Barbara and Ullrich, Axel and Schartl, Manfred},
  title     = {Xmrk receptor tyrosine kinase is activated in Xiphophorus malignant melanoma},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61699},
  year      = {1992},
  abstract  = {Xmrk encodes a putative transmembrane glycoprotein of the tyrosine kinase family and is a melanoma-inducing gene in Xiphophorus. We attempted to investigate the biological function of the putative Xmrk receptor by characterizing its signalling properties. Since a potential Iigand for Xmrk has not yet been identified, it has been difficult to analyse the biochemical properlies and biological function of this cell surface protein. In an approach towards such analyses, the Xmrk extracellular domain was replaced by the closely related Iigand-binding domain sequences of the human epidennal growth factor receptor (HER) and the ligand-induced activity of the chimeric HER-Xmrk proteinwas examined. We show that the Xmrk protein is a functional receptor tyrosine kinase, is highly active in malignant melanoma and displays a constitutive autophosphorylation activity possibly due to an activating mutation in its extracellular or transmembrane domain. In the focus formation assay the HER-Xmrk chimera is a potent transfonning protein equivalent to other tyrosine kinase oncoproteins.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{GoetzRaulfSchartl1992,
  author    = {G{\"o}tz, Rudolf and Raulf, Friedrich and Schartl, Manfrad},
  title     = {Brain-derived neurotrophic factor is more highly conserved in structure and function than nerve growth factor during vertebrate evolution},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61703},
  year      = {1992},
  abstract  = {Mammalian nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are members of a protein family with perfectly conserved domains arranged around the cysteine residues thought to stabilize an invariant three-dimensional scaffold in addition to distinct sequence motifs that convey different neuronal functions. To study their structural and functional conservation during evolution, we have compared NGF and BDNF from a lower vertebrate, the teleost fi.sh Xiphophorus, with the mammalian homlogues. Genomic clones encoding fish NGF and BDNF were isolated by cross-hybridization using probes from the cloned mammalian factors. Fish NGF and BDNF were expressed by means of recombinant vaccinia viruses, purified, and their neuronal survival specificities for different classes of neurons were found to mirror those of the mammalian factors. The half-maximal survival concentration for chick sensory neurons was 60 pg/ml for both fish and mammalian purifi.ed recombinant BDNF. However, the activity ofrecombinant fish NGF on both chick sensory and sympathetic neurons was 6 ng,lml, 75-fold lower than that of mouse NGF. The different functional conservation of NGF and BDNF is also reflected in their structures. The DNA-deduced amino acid sequences of processed mature fish NGF and BDNF showed, compared to mouse, 63\% and 90\% identity, respectively, indicating that NGF bad reached an optimized structure later than BDNF. The retrograde extrapolation of these data indicates that NGF and BDNF evolved at strikingly different rates ftom a common ancestral gene about 600 million years ago. By RNA gel blot anaJysis NGF mRNA was detected during late embryonie development; BDNF was present in adult brain.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{NandaSchartlFeichtingeretal.1992,
  author    = {Nanda, Indrajit and Schartl, Manfred and Feichtinger, Wolfgang and Epplen, J{\"o}rg T. and Schmid, Michael},
  title     = {Early stages of sex chromosome differentiation in fish as analysed by simple repetitive DNA sequences},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61715},
  year      = {1992},
  abstract  = {Animal sex chromosome evolution has started on different occasions with a homologous pair of autosomes leading to morphologically differentiated gonosomes. In contrast to other vertebrate classes, among fishes cytologically dernonstrahle sex chromosomes are rare. In reptiles, certain motifs of simple tandemly repeated DNA sequences like (gata)\(_n\)/(gaca)\(_m\) are associated with the constitutive heterochromatin of sex chromosomes. In this study a panel of simple repetitive sequence probes was hybridized to restriction enzyme digested genomic DNA of poeciliid fishes. Apparent male heterogamety previously established by genetic experiments in Poecilia reticulata (guppy) was correlated with male-specific hybridization using the (GACA)\(_4\) probe. The (GATA)\(_4\) oligonucleotide identifies certain male guppies by a Y chromosomal polymorphism in the outbred population. In cantrast none of the genetically defined heterogametic situations in Xiphophorus could be verified consistently using the collection of simple repetitive sequence probes. Only individuals from particular populations produced sex-specific patterns of hybridization with (GATA)\(_4\). Additional poeciliid species (P. sphenops, P. velifera) harbour different sex-specifically organized simple repeat motifs. The observed sex-specific hybridization patterns were substantiated by banding analyses of the karyotypes and by in situ hybridization using the (GACA)\(_4\) probe.},
  subject      = {Physiologische Chemie},
  language  = {en}
}