@article{ClaussWinklerLohmeyeretal.1990,
  author    = {Clauss, Gerd and Winkler, Christoph and Lohmeyer, J{\"u}rgen and Anders, Fritz and Schartl, Manfred},
  title     = {Oncofetal antigen in Xiphophorus detected by monoclonal antibodies directed against melanoma-associated antigens},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61784},
  year      = {1990},
  abstract  = {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.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{FriedenreichSchartl1990,
  author    = {Friedenreich, Hildegard and Schartl, Manfred},
  title     = {Transient expression directed by homologous and heterologous promoter and enhancer sequences in fish cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61774},
  year      = {1990},
  abstract  = {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.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{DracopoliFeltquateSametal.1990,
  author    = {Dracopoli, Nicholas C. and Feltquate, David M. and Sam, Brigitta and Schartl, Manfred},
  title     = {Taql and Mspl RFLPs are detected by the human 2,3-biphosphoglycerate mutase (BPGM) cDNA},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61763},
  year      = {1990},
  abstract  = {No abstract available},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{Schartl1990,
  author    = {Schartl, Manfred},
  title     = {Homology of melanoma-inducing loci in the genus Xiphophorus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61757},
  year      = {1990},
  abstract  = {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.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{WinklerVielkindSchartl1991,
  author    = {Winkler, Christoph and Vielkind, J{\"u}rgen R. and Schartl, Manfred},
  title     = {Transient expression of foreign DNA during embryonic and larval development of the medaka fish (Oryzias latipes)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61743},
  year      = {1991},
  abstract  = {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.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{SchartlSchluppSchartletal.1991,
  author    = {Schartl, Manfred and Schlupp, Ingo and Schartl, Angelika and Meyer, Manfred K. and Nanda, Indrajit and Schmid, Michael and Epplen, J{\"o}rg T. and Parzefall, Jakob},
  title     = {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},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61731},
  year      = {1991},
  abstract  = {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 poecil{\"u}d 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.},
  subject      = {Physiologische Chemie},
  language  = {en}
}
@article{FoernzlerWittbrodtSchartl1991,
  author    = {F{\"o}rnzler, Dorothee and Wittbrodt, Joachim and Schartl, M.anfred},
  title     = {Analysis of an esterase linked to a locus involved in the regulation of the melanoma oncogene and isolation of polymorphic marker sequences in Xiphophorus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61726},
  year      = {1991},
  abstract  = {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.},
  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}
}
@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{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}
}