@inproceedings{AndersSchartlBarnekow1984, author = {Anders, Fritz and Schartl, Manfred and Barnekow, Angelika}, title = {Xiphophorus as an in vivo model for studies on oncogenes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86398}, year = {1984}, abstract = {The capacity of Xiphophorus to develop neoplasia can be formally assigned to a "tumor gene" (Tu), which appears to be a normal part of the genome of all individuals. The wild fish have evolved population-specific and cell type-specific systems of regulatory genes (R) for Tu that protect the fish from neoplasia. Hybridization of members of different wild populations in the laborstory followed by treatment of the hybrids with carcinogens led to disintegration of the R systems permitting excessive expression of Tu and thus resulting in neoplasia. Certain hybrids developed neoplasia even spontaneously. Observations on the genuine phenotypic effect of the derepressed Tu in the early embryo indicated an essential normal function of this oncogene in cell differentiation, proliferation and cell-cell communication. Tu appeared to be indispensable in the genome but may also be present in accessory copics. Recently, c-src, the cellular homolog of the Rous sarcoma virus oncogene v-src, was detected in Xiphophorus. The protein product of c-src, pp60c-src, was identified and then examined by its associated kinase activity. This pp60c-src was found in all individuals tested, but, depending on the genotype, its kinase activity was different. The genetic characters of c-src, such as linkage relations, dosage relations, expression, etc., correspond to those of Tu. From a systematic study which showed that pp60c-src was present in all metazoa tested ranging from mammals down to sponges, we concluded that c-src has evolved with the multicellular organization of animals. Neoplasia of animals and humans is a characteristic closely related to this evolution. Our data showed that small aquariurn fish, besides being used successfully because they are time-, space-, and money-saving systems for carcinogenicity testing, are also highly suitable for basic studies on neoplasia at the populational, morphological, developmental, cell biological, and molecular levels.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{SchartlSchmidtAndersetal.1985, author = {Schartl, Manfred and Schmidt, C. R. and Anders, A. and Barnekow, A.}, title = {Elevated expression of the cellular src gene in tumors of differing etiologies in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61889}, year = {1985}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @inproceedings{RiehlSchartlAnders1985, author = {Riehl, R{\"u}diger and Schartl, Manfred and Anders, Fritz}, title = {An ultrastructural study of melanoma in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70978}, year = {1985}, abstract = {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.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @inproceedings{PeterSchartlAndersetal.1985, author = {Peter, R. U. and Schartl, Manfred and Anders, F. and Duncker, H.-R.}, title = {Pigment pattern formation during embryogenesis in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69370}, year = {1985}, abstract = {No abstract available.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{AndersSchartlBarnekowetal.1985, author = {Anders, F. and Schartl, Manfred and Barnekow, A. and Schmidt, C. R. and Luke, W. and Jaenel-Dess, G. and Anders, A.}, title = {The genes that carcinogens act upon}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72704}, year = {1985}, abstract = {No abstract available.}, subject = {Onkogen}, language = {en} } @article{MauelerEigenbrodtSchartl1987, author = {Maueler, W. and Eigenbrodt, E. and Schartl, Manfred}, title = {Intermediary metabolism of normal and tumorous tissue of Xiphophorus (Teleostei: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61855}, year = {1987}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{BarnekowSchartl1987, author = {Barnekow, A. and Schartl, Manfred}, title = {Comparative studies on the src proto-oncogene and its gene product pp60\(^{c-src}\) in normal and neoplastic tissues of lower vertebrates}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61869}, year = {1987}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{BarnekowPaulSchartl1987, author = {Barnekow, A. and Paul, E. and Schartl, Manfred}, title = {Expression of the c-src protooncogene in human skin tumors}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61870}, year = {1987}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlSchroeder1987, author = {Schartl, Manfred and Schr{\"o}der, Johannes Horst}, title = {A new species of the genus Xiphophorus Heckel 1848, endemic to northern Coahuila, Mexico (Pisces: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87117}, year = {1987}, abstract = {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.}, subject = {Schwertkr{\"a}pfling}, language = {en} } @article{FoersterSchartl1987, author = {Foerster, Wolfgang and Schartl, Manfred}, title = {Karyotype and isozyme patterns of five species of Aulonocara REGAN, 1922}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86774}, year = {1987}, abstract = {No abstract available.}, subject = {Aulonocara}, language = {en} } @article{AdamWittbrodtTellingetal.1988, author = {Adam, D. and Wittbrodt, J. and Telling, A. and Schartl, Manfred}, title = {RFLP for an EGF-receptor related gene associated with the melanoma oncogene locus of Xiphophorus maculatus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61822}, year = {1988}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlPeter1988, author = {Schartl, Manfred and Peter, R. U.}, title = {Progressive growth of fish tumors after transplantation into thymus-aplastic (nu/nu) mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61833}, year = {1988}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{Schartl1988, author = {Schartl, Manfred}, title = {A sex chromosomal restriction-fragment-length marker linked to melanoma-determining Tu loci in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61842}, year = {1988}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{MaeuelerRaulfSchartl1988, author = {M{\"a}ueler, Winfried and Raulf, Friedrich and Schartl, Manfred}, title = {Expression of proto-oncogenes in embryonic, adult, and transformed tissue of Xiphophorus (Teleostei: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86233}, year = {1988}, abstract = {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.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{MauelerBarnekowEigenbrodtetal.1988, author = {Maueler, W. and Barnekow, A. and Eigenbrodt, E. and Raulf, F. and Falk, H. F. and Telling, A. and Schartl, Manfred}, title = {Different regulation of oncogene expression in tumor and embryonal cells of Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86240}, year = {1988}, abstract = {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.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @inproceedings{SchartlMaeuelerRaulfetal.1988, author = {Schartl, Manfred and M{\"a}ueler, Winfried and Raulf, Friedrich and Robertson, Scott M.}, title = {Molecular aspects of melanoma formation in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72689}, year = {1988}, abstract = {No abstract available.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{RaulfRobertsonSchartl1989, author = {Raulf, F. and Robertson, S. M. and Schartl, Manfred}, title = {Evolution of the neuron-specific alternative splicing product of the c-src proto-oncogene}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61796}, year = {1989}, abstract = {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 ยท 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.}, subject = {Physiologische Chemie}, language = {en} } @article{WittbrodtAdamMalitscheketal.1989, author = {Wittbrodt, J. and Adam, D. and Malitschek, B. and Maueler, W. and Raulf, F. and Telling, A. and Robertson, M. and Schartl, Manfred}, title = {Novel putative receptor tyrosine kinase encoded by the melanoma-inducing Tu locus in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61800}, year = {1989}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{BernardsSchacklefordGerberetal.1989, author = {Bernards, R. and Schackleford, G. M. and Gerber, M. R. and Horowitz, J. M. and Friend, S. H. and Schartl, Manfred and Bogenmann, E. and Rapaport, J. M. and Mcgee, T. and Dryja, T. P.}, title = {Structure and expression of the murine retinoblastoma gene and characterization of its encoded protein}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61819}, year = {1989}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{RaulfMaeuelerRobertsonetal.1989, author = {Raulf, Friedrich and M{\"a}ueler, Winfried and Robertson, Scott M. and Schartl, Manfred}, title = {Localization of cellular src mRNA during development and in the differentiated bipolar neurons of the adult neural retina in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86703}, year = {1989}, abstract = {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.}, subject = {Schwertk{\"a}rpfling}, language = {en} }