TY - JOUR A1 - Schartl, Manfred A1 - Schlupp, Ingo A1 - Schartl, Angelika A1 - Meyer, Manfred K. A1 - Nanda, Indrajit A1 - Schmid, Michael A1 - Epplen, Jörg T. A1 - Parzefall, Jakob T1 - 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 N2 - 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 poecilüd 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. KW - Physiologische Chemie KW - DNA fingerprinting KW - androgen-induced masculinization KW - gynogeaesls KW - simple repeat sequences Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61731 ER - TY - JOUR A1 - Schartl, A. A1 - Dimitrijevic, N. A1 - Schartl, Manfred T1 - Evolutionary origin and molecular biology of the melanoma-inducing oncogene of Xiphophorus N2 - No abstract available KW - Physiologische Chemie Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61954 ER - TY - JOUR A1 - Mäueler, Winfried A1 - Schartl, Angelika A1 - Schartl, Manfred T1 - Different expression patterns of oncogenes and proto-oncogenes in hereditary and carcinogen-induced tumors of Xiphophorus N2 - Hereditary melanoma in Xiphophorus hybrids canying the melanoma·induclng Tu-Sd locus is caused by transcriptional activation of the Xmrk gene that resides at the Tu·Sd locus and encodes a novel member of receptor tyrosine kinases (RTK). ln this study, a total of 17 hereditary melanomas from various hybrid genotypes harbouring 7 different Tu alleles were also found to aver-express the correspondlng Xmrlc alleles. The Ievei of over-expression correlated with the degree of malignancy of the melanoma. ln addition, Xsrc expression was high ln many malignant melanomas. Expression pattems and Ieveis of the Xiphophorus EGF-receptor gene (Xerb B), the c-myc (Xmyc), and the PDGF (Xsls) gene(s) were not intriguing. Transcription of the ras gene(s) may be correlated to secondary events of melanoma progression. Expression pattems of Xfms, the Xiphophorus CSF-1 receptor homologue, can be explained by different contents of infiltrating macrophages in the tumors. ln carcinogen-induced tumors includlng one melanoma no significant expression of the Xmrk oncogene could be detected. Xsrc expression, however, was strikingly high. This indicates that activation of oncogenes other than Xmrk ls instrumental in tumorigenesls of neoplasia of non-hereditary origin. KW - Physiologische Chemie Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61592 ER - TY - JOUR A1 - Schartl, A. A1 - Schartl, Manfred A1 - Anders, F. T1 - Promotion and regression of neoplasia by testosterone-promoted cell differentiation in Xiphophorus and Girardinus N2 - No abstract available. KW - Schwertkärpfling KW - Lebendgebärende Zahnkarpfen Y1 - 1982 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86684 ER - TY - CHAP A1 - Schartl, A. A1 - Schartl, Manfred A1 - Anders, F. T1 - Phenotypic conversion of malignant melanoma to benign melanoma and vice versa in Xiphophorus N2 - No abstract available. KW - Schwertkärpfling KW - Krebs Y1 - 1981 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86662 ER - TY - JOUR A1 - Schartl, Angelika A1 - Schartl, Manfred T1 - Genes and cancer: Molecular biology of the melanoma oncogene of Xiphophorus N2 - No abstract available. KW - Schwertkärpfling KW - Krebs Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72670 ER - TY - CHAP A1 - Adam, D. A1 - Schartl, A. A1 - Andexinger, S. A1 - Hölter, S. A1 - Wilde, B. A1 - Schartl, Manfred T1 - Genetic factors in tumour formation: The melanoma-inducing gene of Xiphophorus N2 - No abstract available. KW - Humangenetik KW - Tumor KW - Entstehung Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86388 ER - TY - JOUR A1 - Förnzler, Dorothee A1 - Wittbrodt, Joachim A1 - Schartl, M.anfred T1 - Analysis of an esterase linked to a locus involved in the regulation of the melanoma oncogene and isolation of polymorphic marker sequences in Xiphophorus N2 - 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. KW - Physiologische Chemie KW - Xiphophorus KW - melanoma ; oncogene regulation ; esterase ; molecular marker sequences Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61726 ER - TY - JOUR A1 - Meyer, Manfred K. A1 - Schartl, Manfred T1 - Eine neue Xiphophorus-Art aus Vera Cruz, Mexiko : (Pisces: Poeciliidae) N2 - Xiphophorus andersi n. sp. from the Rio Atoyac, Vera Cruz, Mexico is described: lang head, moderately slender body, large dark black spar at the basis of the anal fin; adult male with short sword-like caudal appendage; rip of ray 5a of gonopodium without a developed claw. Xiphophorus andersi n. sp. differs by the combination of distinct characters from all the other species of the genus known so far. The new species shows features of both the so-called platyfish species group and the so-called swordtail species group. KW - Schwertkärpfling KW - Veracruz Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-87124 ER - TY - JOUR A1 - Meyer, Manfred K. A1 - Schartl, Manfred T1 - Pseudotropheus (Maylandia) hajomaylandi n. sp., a new taxon from Lake Malawi T1 - Pseudotropheus (Maylandia) hajomaylandi n. sp. un nouveau taxon du Lac Malawi N2 - Pseudotropheus hajomaylandi (loc. typ. Isle of Chisumulu, Lake Malawi) is described as a new species. It is compared with Ps. aurora, Ps. greshakei, Ps. livingstonii, Ps. lombardoi, and Ps. zebra. All these taxa, including Ps. hajomaylandi and Ps. heteropictus, are classified in the subgenus Maylandia. KW - Buntbarsche KW - Njassasee Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-70989 ER -