@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{SchartlErbeldingDenkHolteretal.1993, author = {Schartl, Manfred and Erbelding-Denk, Claudia and Holter, Sabine and Nanda, Indrajit and Schmid, Michael and Schroder, Johannes H. and Epplen, J{\"o}rg T.}, title = {Reproductive failure of dominant males in the poeciliid fish Limia perugiae determined by DNA fingerprinting}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61643}, year = {1993}, abstract = {Hierarchical structures among male indlviduals in a population are frequently reflected ln differences in aggressive and reproductive behavior and access to the females. In general, sodal dominance requires the Investments, which in turn then may have to be compensated for by high reproductive success. However, this hypothesls has so far only been sufficiently tested in small mating groups (one or two males with one or two females) due to the difficulties of determining paternity by conventional methods. DNA fingerprinting overcomes these problems by offering the possibility to determine genetic relationships and mating patterns within larger groups [Borke, T. (1989) Trends Ecol. Evol. 4, 139-144]. We show here that in the poecUiid fish Limia perugitu, in small matlng groups the dominant male has 8 mating success of 100\%, whereas ln larger groups lts contribution to the offspring unexpectedly drops to zero.}, subject = {Physiologische Chemie}, language = {en} } @article{MeyerMorrisseySchartl1994, author = {Meyer, Axel and Morrissey, Jean M. and Schartl, Manfred}, title = {Recurrent origin of a sexually selected trait in Xiphophorus fishes inferred from a molecular phylogeny}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61569}, year = {1994}, abstract = {DARWIN\(^1\) believed that sexual selection accounts for the evolution of exaggerated male ornaments, such as the sword-like caudal fin extensions of male fishes of the genus Xiphophorus, that appear detrimental to survival. Swordtails continue to feature prominently in empirical work and theories of sexual selection; the pre-existing bias hypothesis has been offered as an explanation for the evolution of swords in these fishes\(^{2,3}\). Based upon a largely morphological phylogeny, this hypothesis suggests that female preference to mate with sworded males arose in ancestrally swordless species, thus pre-dating the origin of the sword itself and directly driving its evolution. Here we present a molecular phylogeny (based on mitochondrial and nuclear DNA sequences) of Xiphophorus which differs from the traditional one: it indicates that the sword originated and was lost repeatedly. Our phylogeny suggests that the ancestor of the genus is more likely to have possessed a sword than not, thus questioning the applicability of the pre-existing bias hypothesis as an explanation for the cvolution of this sexually selected trait.}, 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{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{NandaSchartlEpplenetal.1993, author = {Nanda, Indrajit and Schartl, Manfred and Epplen, J{\"o}rg T. and Feichtinger, Wolfgang and Schmid, Michael}, title = {Primitive sex chromosomes in poeciliid fishes harbor simple repetitive DNA sequences}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61659}, year = {1993}, abstract = {The demonstration ofthe chromosomal mode ofsex determinationvia genetic experiments as well as the absence of heteromorphic sex chromosomes affirm poeciliid fishes as a unique group among vertebrates that are endowed with the mostprimitive form of sex chromosornes. In many different taxa the evolutionary process involved in the differentiation ofadvanced sex chromosomes is outlined through sex specifically organized repetitive sequences. In this investigation hydridization of synthetic probes specific to genomic simple repeat motifs uncovers a sex-specific hybridization pattern in certain viviparaus fishes ofthe family Poeciliidae. The hybridization pattern together with specific staining ofthe constitutive heterochromatin by C-banding reveals heterogamety in males (Poecilia reticulata) as weil as in females (P. sphenops). In P. velifera, however, C-banding alone fails to unravel the heterogametic status. The female specific W-chromosome can be detected by simple repetitive sequence probes. Therefore, the principal significance of heterochromatization as a means of generating differentiated sex chromosomes is evident.}, subject = {Physiologische Chemie}, language = {en} } @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{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{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{GoetzKoesterWinkleretal.1994, author = {G{\"o}tz, Rudolf and K{\"o}ster, Reinhard and Winkler, Christoph and Raulf, Friedrich and Lottspeich, Friedrich and Schartl, Manfred and Thoenen, Hans}, title = {Neurotrophin-6 is a new member of the nerve growth factor family}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61544}, year = {1994}, abstract = {DURING vertebrale development, many neurons depend for survival and differentiation on their target cells\(^{1-3}\). The best documented mediator of such a retrograde trophic action is the neurotrophin nerve growth factor (NGF)\(^1\). NGF and the other known members of tbe neurotrophin family, brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT -3) and neurotrophin-4/5 (NT -4/5) are conserved as distinct genes over large evolutionary distances\(^{4 -6}\). Here we report the cloning of neurotrophin-6 (NT -6), a new member of this family from the teleost fish Xiphophorus. NT -6 distinguishes itself from the other known neurotrophins in that it is not found as a soluble protein in the medium of producing cells. The addition of heparin (but not chondroitin) effects the release of NT -6 from cell surface and extracellular matrix molecules. Recombinant purified NT -6 has a spectrum of actions similar to NGF on chick sympathetic and sensory neurons, albeit with a lower potency. NT -6 is expressed in tbe embryonie valvulla cerebelli; expression persists in some adult tissues. The interaction of NT-6 with heparin-binding molecuJes may modulate its action in the nervous system .}, subject = {Physiologische Chemie}, language = {en} }