@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} } @incollection{AndersSchollSchartl1979, author = {Anders, F. and Scholl, E. and Schartl, Manfred}, title = {Xiphophorus als Modell in der Krebsforschung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72752}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1979}, abstract = {No abstract available.}, subject = {Schwertk{\"a}rpfling}, language = {de} } @article{AdamMauelerSchartl1991, author = {Adam, Dieter and Maueler, Winfried and Schartl, Manfred}, title = {Transcriptional activation of the melanoma inducing Xmrk oncogene in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87584}, year = {1991}, abstract = {The melanoma inducing locus of Xiphophorus encodes a tumorigenic version of a novel putative receptor tyrosine kinase (Xmrk). To elucidate the mechanism of oncogenic activation of Xmrk, we compared the structure and expression of two oncogenic loci with the corresponding proto-oncogene. Only minor structural alterations were found to be specific for the oncogenic Xmrk genes. Marked overexpression of the oncogene transcripts in melanoma, which are approximately 1 kb shorter than the proto-oncogene transcript, correlates with the malignancy of the tumors. The tumor transcripts are derived from an alternative transcription start site that is used only in the oncogenic loci. Thus, oncogenic activation of the melanoma inducing Xmrk gene appears primarily to be due to novel transcriptional control and overexpression.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{SchartlSchartlAnders1982, author = {Schartl, A. and Schartl, Manfred and Anders, F.}, title = {Promotion and regression of neoplasia by testosterone-promoted cell differentiation in Xiphophorus and Girardinus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86684}, year = {1982}, abstract = {No abstract available.}, 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} } @inproceedings{SchartlSchartlAnders1981, author = {Schartl, A. and Schartl, Manfred and Anders, F.}, title = {Phenotypic conversion of malignant melanoma to benign melanoma and vice versa in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86662}, year = {1981}, abstract = {No abstract available.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{SchartlWittbrodtMaeueleretal.1993, author = {Schartl, Manfred and Wittbrodt, J. and M{\"a}ueler, W. and Raulf, F. and Adam, D. and Hannig, G. and Telling, A. and Storch, F. and Andexinger, S. and Robertson, S. M.}, title = {Oncogenes and melanoma formation in Xiphoporus (Teleostei: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87149}, year = {1993}, abstract = {In Xiphophorus melanoma formation has been attributed by classical genetic findings to the overexpression of a cellular oncogene (Tu) due to elimination of the corresponding regulatory gene locus in hybrids. We have attempted to elucidate this phenomenon on the molecular biological level. Studies on the structure and expression of known proto-oncogenes revealed that several of these genes, especially the c-src gene of Xiphophorus, may act as effectors in establishing the neoplastic phenotype of the melanoma cells . However, these genes appear more to participate in secondary steps of tumorigenesis. Another gene, being termed Xmrk, which represents obviously a so far unknown proto-oncogene but with a cons iderably high similarity to the epidermal growth-factorreceptor gene, was mapped to the Tu-containing region of the chromosome. This gene shows features with respect to its structure and expression that seem to justify it to be regarded as a candidate for a gene involved in the primary processes leading to neoplastic transformation of pigment cells in Xiphophorus.}, 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{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} } @incollection{AltschmiedSchartl1994, author = {Altschmied, Joachim and Schartl, Manfred}, title = {Genetics and molecular biology of tumour formation in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69752}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1994}, abstract = {No abstract available.}, subject = {Schwertk{\"a}rpfling}, language = {en} }