@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{SchartlDimitrijevicSchartl1994, author = {Schartl, A. and Dimitrijevic, N. and Schartl, Manfred}, title = {Evolutionary origin and molecular biology of the melanoma-inducing oncogene of Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61954}, year = {1994}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{MaeuelerSchartlSchartl1993, author = {M{\"a}ueler, Winfried and Schartl, Angelika and Schartl, Manfred}, title = {Different expression patterns of oncogenes and proto-oncogenes in hereditary and carcinogen-induced tumors of Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61592}, year = {1993}, abstract = {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.}, subject = {Physiologische Chemie}, 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{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{SchartlSchartl1990, author = {Schartl, Angelika and Schartl, Manfred}, title = {Genes and cancer: Molecular biology of the melanoma oncogene of Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72670}, year = {1990}, abstract = {No abstract available.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @incollection{AdamSchartlAndexingeretal.1991, author = {Adam, D. and Schartl, A. and Andexinger, S. and H{\"o}lter, S. and Wilde, B. and Schartl, Manfred}, title = {Genetic factors in tumour formation: The melanoma-inducing gene of Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86388}, publisher = {Universit{\"a}t W{\"u}rzburg}, year = {1991}, abstract = {No abstract available.}, subject = {Humangenetik}, language = {en} } @article{MeyerSchartl1979, author = {Meyer, Manfred K. and Schartl, Manfred}, title = {Eine neue Xiphophorus-Art aus Vera Cruz, Mexiko : (Pisces: Poeciliidae)}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87124}, year = {1979}, abstract = {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.}, subject = {Schwertk{\"a}rpfling}, language = {en} } @article{MeyerSchartl1984, author = {Meyer, Manfred K. and Schartl, Manfred}, title = {Pseudotropheus (Maylandia) hajomaylandi n. sp., a new taxon from Lake Malawi}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-70989}, year = {1984}, abstract = {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.}, subject = {Buntbarsche}, language = {en} } @article{NandaSchoriesSimeonovetal.2022, author = {Nanda, Indrajit and Schories, Susanne and Simeonov, Ivan and Adolfi, Mateus Contar and Du, Kang and Steinlein, Claus and Alsheimer, Manfred and Haaf, Thomas and Schartl, Manfred}, title = {Evolution of the degenerated Y-chromosome of the swamp guppy, Micropoecilia picta}, series = {Cells}, volume = {11}, journal = {Cells}, number = {7}, issn = {2073-4409}, doi = {10.3390/cells11071118}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267242}, year = {2022}, abstract = {The conspicuous colour sexual dimorphism of guppies has made them paradigmatic study objects for sex-linked traits and sex chromosome evolution. Both the X- and Y-chromosomes of the common guppy (Poecilia reticulata) are genetically active and homomorphic, with a large homologous part and a small sex specific region. This feature is considered to emulate the initial stage of sex chromosome evolution. A similar situation has been documented in the related Endler's and Oropuche guppies (P. wingei, P. obscura) indicating a common origin of the Y in this group. A recent molecular study in the swamp guppy (Micropoecilia. picta) reported a low SNP density on the Y, indicating Y-chromosome deterioration. We performed a series of cytological studies on M. picta to show that the Y-chromosome is quite small compared to the X and has accumulated a high content of heterochromatin. Furthermore, the Y-chromosome stands out in displaying CpG clusters around the centromeric region. These cytological findings evidently illustrate that the Y-chromosome in M. picta is indeed highly degenerated. Immunostaining for SYCP3 and MLH1 in pachytene meiocytes revealed that a substantial part of the Y remains associated with the X. A specific MLH1 hotspot site was persistently marked at the distal end of the associated XY structure. These results unveil a landmark of a recombining pseudoautosomal region on the otherwise strongly degenerated Y chromosome of M. picta. Hormone treatments of females revealed that, unexpectedly, no sexually antagonistic color gene is Y-linked in M. picta. All these differences to the Poecilia group of guppies indicate that the trajectories associated with the evolution of sex chromosomes are not in parallel.}, language = {en} } @article{DedukhDaCruzKneitzetal.2022, author = {Dedukh, Dmitrij and Da Cruz, Irene and Kneitz, Susanne and Marta, Anatolie and Ormanns, Jenny and Tichop{\´a}d, Tom{\´a}š and Lu, Yuan and Alsheimer, Manfred and Janko, Karel and Schartl, Manfred}, title = {Achiasmatic meiosis in the unisexual Amazon molly, Poecilia formosa}, series = {Chromosome Research}, volume = {30}, journal = {Chromosome Research}, number = {4}, doi = {10.1007/s10577-022-09708-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-325128}, pages = {443-457}, year = {2022}, abstract = {Unisexual reproduction, which generates clonal offspring, is an alternative strategy to sexual breeding and occurs even in vertebrates. A wide range of non-sexual reproductive modes have been described, and one of the least understood questions is how such pathways emerged and how they mechanistically proceed. The Amazon molly, Poecilia formosa, needs sperm from males of related species to trigger the parthenogenetic development of diploid eggs. However, the mechanism, of how the unreduced female gametes are produced, remains unclear. Cytological analyses revealed that the chromosomes of primary oocytes initiate pachytene but do not proceed to bivalent formation and meiotic crossovers. Comparing ovary transcriptomes of P. formosa and its sexual parental species revealed expression levels of meiosis-specific genes deviating from P. mexicana but not from P. latipinna. Furthermore, several meiosis genes show biased expression towards one of the two alleles from the parental genomes. We infer from our data that in the Amazon molly diploid oocytes are generated by apomixis due to a failure in the synapsis of homologous chromosomes. The fact that this failure is not reflected in the differential expression of known meiosis genes suggests the underlying molecular mechanism may be dysregulation on the protein level or misexpression of a so far unknown meiosis gene, and/or hybrid dysgenesis because of compromised interaction of proteins from diverged genomes.}, language = {en} } @article{JonesFrucianoKelleretal.2016, author = {Jones, Julia C. and Fruciano, Carmelo and Keller, Anja and Schartl, Manfred and Meyer, Axel}, title = {Evolution of the elaborate male intromittent organ of Xiphophorus fishes}, series = {Ecology and Evolution}, volume = {6}, journal = {Ecology and Evolution}, number = {20}, doi = {10.1002/ece3.2396}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164956}, pages = {7207-7220}, year = {2016}, abstract = {Internally fertilizing animals show a remarkable diversity in male genital morphology that is associated with sexual selection, and these traits are thought to be evolving particularly rapidly. Male fish in some internally fertilizing species have "gonopodia," highly modified anal fins that are putatively important for sexual selection. However, our understanding of the evolution of genital diversity remains incomplete. Contrary to the prediction that male genital traits evolve more rapidly than other traits, here we show that gonopodial traits and other nongonopodial traits exhibit similar evolutionary rates of trait change and also follow similar evolutionary models in an iconic genus of poeciliid fish (Xiphophorus spp.). Furthermore, we find that both mating and nonmating natural selection mechanisms are unlikely to be driving the diverse Xiphophorus gonopodial morphology. Putative holdfast features of the male genital organ do not appear to be influenced by water flow, a candidate selective force in aquatic habitats. Additionally, interspecific divergence in gonopodial morphology is not significantly higher between sympatric species, than between allopatric species, suggesting that male genitals have not undergone reproductive character displacement. Slower rates of evolution in gonopodial traits compared with a subset of putatively sexually selected nongenital traits suggest that different selection mechanisms may be acting on the different trait types. Further investigations of this elaborate trait are imperative to determine whether it is ultimately an important driver of speciation.}, language = {en} } @article{BrunetVolffSchartl2016, author = {Brunet, Fr{\´e}d{\´e}ric G. and Volff, Jean-Nicolas and Schartl, Manfred}, title = {Whole Genome Duplications Shaped the Receptor Tyrosine Kinase Repertoire of Jawed Vertebrates}, series = {Genome Biology Evolution}, volume = {8}, journal = {Genome Biology Evolution}, number = {15}, doi = {10.1093/gbe/evw103}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146988}, pages = {1600-1613}, year = {2016}, abstract = {The receptor tyrosine kinase (RTK) gene family, involved primarily in cell growth and differentiation, comprises proteins with a common enzymatic tyrosine kinase intracellular domain adjacent to a transmembrane region. The amino-terminal portion of RTKs is extracellular and made of different domains, the combination of which characterizes each of the 20 RTK subfamilies among mammals. We analyzed a total of 7,376 RTK sequences among 143 vertebrate species to provide here the first comprehensive census of the jawed vertebrate repertoire. We ascertained the 58 genes previously described in the human and mouse genomes and established their phylogenetic relationships. We also identified five additional RTKs amounting to a total of 63 genes in jawed vertebrates. We found that the vertebrate RTK gene family has been shaped by the two successive rounds of whole genome duplications (WGD) called 1R and 2R (1R/2R) that occurred at the base of the vertebrates. In addition, the Vegfr and Ephrin receptor subfamilies were expanded by single gene duplications. In teleost fish, 23 additional RTK genes have been retained after another expansion through the fish-specific third round (3R) of WGD. Several lineage-specific gene losses were observed. For instance, birds have lost three RTKs, and different genes are missing in several fish sublineages. The RTK gene family presents an unusual high gene retention rate from the vertebrate WGDs (58.75\% after 1R/2R, 64.4\% after 3R), resulting in an expansion that might be correlated with the evolution of complexity of vertebrate cellular communication and intracellular signaling.}, language = {en} } @article{MatosSucenaMachadoetal.2011, author = {Matos, Isa and Sucena, {\`E}lio and Machado, Miguel P and Gardner, Rui and In{\´a}cio, {\^A}ngela and Schartl, Manfred and Coelho, Maria M}, title = {Ploidy mosaicism and allele-specific gene expression differences in the allopolyploid \(Squalius\) \(alburnoides\)}, series = {BMC Genetics}, volume = {12}, journal = {BMC Genetics}, number = {101}, doi = {10.1186/1471-2156-12-101}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142879}, pages = {1-10}, year = {2011}, abstract = {Background Squalius alburnoides is an Iberian cyprinid fish resulting from an interspecific hybridisation between Squalius pyrenaicus females (P genome) and males of an unknown Anaecypris hispanica- like species (A genome). S. alburnoides is an allopolyploid hybridogenetic complex, which makes it a likely candidate for ploidy mosaicism occurrence, and is also an interesting model to address questions about gene expression regulation and genomic interactions. Indeed, it was previously suggested that in S. alburnoides triploids (PAA composition) silencing of one of the three alleles (mainly of the P allele) occurs. However, not a whole haplome is inactivated but a more or less random inactivation of alleles varying between individuals and even between organs of the same fish was seen. In this work we intended to correlate expression differences between individuals and/or between organs to the occurrence of mosaicism, evaluating if mosaics could explain previous observations and its impact on the assessment of gene expression patterns. Results To achieve our goal, we developed flow cytometry and cell sorting protocols for this system generating more homogenous cellular and transcriptional samples. With this set-up we detected 10\% ploidy mosaicism within the S. alburnoides complex, and determined the allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin) in cells from liver and kidney of mosaic and non-mosaic individuals coming from different rivers over a wide geographic range. Conclusions Ploidy mosaicism occurs sporadically within the S. alburnoides complex, but in a frequency significantly higher than reported for other organisms. Moreover, we could exclude the influence of this phenomenon on the detection of variable allelic expression profiles of ubiquitously expressed genes (rpl8; gapdh and β-actin) in cells from liver and kidney of triploid individuals. Finally, we determined that the expression patterns previously detected only in a narrow geographic range is not a local restricted phenomenon but is pervasive in rivers where S. pyrenaicus is sympatric with S. alburnoides. We discuss mechanisms that could lead to the formation of mosaic S. alburnoides and hypothesise about a relaxation of the mechanisms that impose a tight control over mitosis and ploidy control in mixoploids."}, language = {en} } @article{KneitzMishraChalopinetal.2016, author = {Kneitz, Susanne and Mishra, Rasmi R. and Chalopin, Domitille and Postlethwait, John and Warren, Wesley C. and Walther, Ronald B. and Schartl, Manfred}, title = {Germ cell and tumor associated piRNAs in the medaka and \(Xiphophorus\) melanoma models}, series = {BMC Genomics}, volume = {17}, journal = {BMC Genomics}, number = {357}, doi = {10.1186/s12864-016-2697-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146028}, year = {2016}, abstract = {Background A growing number of studies report an abnormal expression of Piwi-interacting RNAs (piRNAs) and the piRNA processing enzyme Piwi in many cancers. Whether this finding is an epiphenomenon of the chaotic molecular biology of the fast dividing, neoplastically transformed cells or is functionally relevant to tumorigenesisis is difficult to discern at present. To better understand the role of piRNAs in cancer development small laboratory fish models can make a valuable contribution. However, little is known about piRNAs in somatic and neoplastic tissues of fish. Results To identify piRNA clusters that might be involved in melanoma pathogenesis, we use several transgenic lines of medaka, and platyfish/swordtail hybrids, which develop various types of melanoma. In these tumors Piwi, is expressed at different levels, depending on tumor type. To quantify piRNA levels, whole piRNA populations of testes and melanomas of different histotypes were sequenced. Because no reference piRNA cluster set for medaka or Xiphophorus was yet available we developed a software pipeline to detect piRNA clusters in our samples and clusters were selected that were enriched in one or more samples. We found several loci to be overexpressed or down-regulated in different melanoma subtypes as compared to hyperpigmented skin. Furthermore, cluster analysis revealed a clear distinction between testes, low-grade and high-grade malignant melanoma in medaka. Conclusions Our data imply that dysregulation of piRNA expression may be associated with development of melanoma. Our results also reinforce the importance of fish as a suitable model system to study the role of piRNAs in tumorigenesis.}, language = {en} } @article{AdolfiHerpinRegensburgeretal.2016, author = {Adolfi, Mateus C. and Herpin, Amaury and Regensburger, Martina and Sacquegno, Jacopo and Waxman, Joshua S. and Schartl, Manfred}, title = {Retinoic acid and meiosis induction in adult versus embryonic gonads of medaka}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, doi = {10.1038/srep34281}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147843}, pages = {34281}, year = {2016}, abstract = {In vertebrates, one of the first recognizable sex differences in embryos is the onset of meiosis, known to be regulated by retinoic acid (RA) in mammals. We investigated in medaka a possible meiotic function of RA during the embryonic sex determination (SD) period and in mature gonads. We found RA mediated transcriptional activation in germ cells of both sexes much earlier than the SD stage, however, no such activity during the critical stages of SD. In adults, expression of the RA metabolizing enzymes indicates sexually dimorphic RA levels. In testis, RA acts directly in Sertoli, Leydig and pre-meiotic germ cells. In ovaries, RA transcriptional activity is highest in meiotic oocytes. Our results show that RA plays an important role in meiosis induction and gametogenesis in adult medaka but contrary to common expectations, not for initiating the first meiosis in female germ cells at the SD stage.}, 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 · 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{SchartlAdam1992, author = {Schartl, Manfred and Adam, Dieter}, title = {Molecular cloning, structural characterization, and analysis of transcription of the melanoma oncogene of xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61989}, year = {1992}, 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{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{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{MenescalSchmidtLiedtkeetal.2012, author = {Menescal, Luciana and Schmidt, Cornelia and Liedtke, Daniel and Schartl, Manfred}, title = {Liver hyperplasia after tamoxifen induction of Myc in a transgenic medaka model}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75316}, year = {2012}, abstract = {Myc is a global transcriptional regulator and one of the most frequently overexpressed oncoproteins in human tumors. It is well established that activation of Myc leads to enhanced cell proliferation but can also lead to increased apoptosis. The use of animal models expressing deregulated levels of Myc has helped to both elucidate its function in normal cells and give insight into how Myc initiates and maintains tumorigenesis. Analyses of the medaka (Oryzias latipes) genome uncovered the unexpected presence of two Myc gene copies in this teleost species. Comparison of these Myc versions to other vertebrate species revealed that one gene, myc17, differs by the loss of some conserved regulatory protein motifs present in all other known Myc genes. To investigate how such differences might affect the basic biological functions of Myc, we generated a tamoxifeninducible in vivo model utilizing a natural, fish-specific Myc gene. Using this model we show that, when activated, Myc17 leads to increased proliferation and to apoptosis in a dose-dependent manner, similar to human Myc. We have also shown that long-term Myc17 activation triggers liver hyperplasia in adult fish, allowing this newly established transgenic medaka model to be used to study the transition from hyperplasia to liver cancer and to identify Myc-induced tumorigenesis modifiers.}, subject = {Biologie}, language = {en} } @article{WagnerFischerThomaetal.2011, author = {Wagner, Toni U. and Fischer, Andreas and Thoma, Eva C. and Schartl, Manfred}, title = {CrossQuery : A Web Tool for Easy Associative Querying of Transcriptome Data}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76088}, year = {2011}, abstract = {Enormous amounts of data are being generated by modern methods such as transcriptome or exome sequencing and microarray profiling. Primary analyses such as quality control, normalization, statistics and mapping are highly complex and need to be performed by specialists. Thereafter, results are handed back to biomedical researchers, who are then confronted with complicated data lists. For rather simple tasks like data filtering, sorting and cross-association there is a need for new tools which can be used by non-specialists. Here, we describe CrossQuery, a web tool that enables straight forward, simple syntax queries to be executed on transcriptome sequencing and microarray datasets. We provide deepsequencing data sets of stem cell lines derived from the model fish Medaka and microarray data of human endothelial cells. In the example datasets provided, mRNA expression levels, gene, transcript and sample identification numbers, GO-terms and gene descriptions can be freely correlated, filtered and sorted. Queries can be saved for later reuse and results can be exported to standard formats that allow copy-and-paste to all widespread data visualization tools such as Microsoft Excel. CrossQuery enables researchers to quickly and freely work with transcriptome and microarray data sets requiring only minimal computer skills. Furthermore, CrossQuery allows growing association of multiple datasets as long as at least one common point of correlated information, such as transcript identification numbers or GO-terms, is shared between samples. For advanced users, the object-oriented plug-in and event-driven code design of both server-side and client-side scripts allow easy addition of new features, data sources and data types.}, subject = {CrossQuery}, language = {en} } @article{MeierjohannHufnagelWendeetal.2010, author = {Meierjohann, Svenja and Hufnagel, Anita and Wende, Elisabeth and Kleinschmidt, Markus A. and Wolf, Katarina and Friedl, Peter and Gaubatz, Stefan and Schartl, Manfred}, title = {MMP13 mediates cell cycle progression in melanocytes and melanoma cells: in vitro studies of migration and proliferation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68335}, year = {2010}, abstract = {Background: Melanoma cells are usually characterized by a strong proliferative potential and efficient invasive migration. Among the multiple molecular changes that are recorded during progression of this disease, aberrant activation of receptor tyrosine kinases (RTK) is often observed. Activation of matrix metalloproteases goes along with RTK activation and usually enhances RTK-driven migration. The purpose of this study was to examine RTKdriven three-dimensional migration of melanocytes and the pro-tumorigenic role of matrix metalloproteases for melanocytes and melanoma cells. Results: Using experimental melanocyte dedifferentiation as a model for early melanomagenesis we show that an activated EGF receptor variant potentiates migration through three-dimensional fibrillar collagen. EGFR stimulation also resulted in a strong induction of matrix metalloproteases in a MAPK-dependent manner. However, neither MAPK nor MMP activity were required for migration, as the cells migrated in an entirely amoeboid mode. Instead, MMPs fulfilled a function in cell cycle regulation, as their inhibition resulted in strong growth inhibition of melanocytes. The same effect was observed in the human melanoma cell line A375 after stimulation with FCS. Using sh- and siRNA techniques, we could show that MMP13 is the protease responsible for this effect. Along with decreased proliferation, knockdown of MMP13 strongly enhanced pigmentation of melanocytes. Conclusions: Our data show for the first time that growth stimuli are mediated via MMP13 in melanocytes and melanoma, suggesting an autocrine MMP13-driven loop. Given that MMP13-specific inhibitors are already developed, these results support the evaluation of these inhibitors in the treatment of melanoma.}, subject = {Medizin}, language = {en} } @article{KraeusslingWagnerSchartl2011, author = {Kraeussling, Michael and Wagner, Toni Ulrich and Schartl, Manfred}, title = {Highly Asynchronous and Asymmetric Cleavage Divisions Accompany Early Transcriptional Activity in Pre-Blastula Medaka Embryos}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68906}, year = {2011}, abstract = {In the initial phase of development of fish embryos, a prominent and critical event is the midblastula transition (MBT). Before MBT cell cycle is rapid, highly synchronous and zygotic gene transcription is turned off. Only during MBT the cell cycle desynchronizes and transcription is activated. Multiple mechanisms, primarily the nucleocytoplasmic ratio, are supposed to control MBT activation. Unexpectedly, we find in the small teleost fish medaka (Oryzias latipes) that at very early stages, well before midblastula, cell division becomes asynchronous and cell volumes diverge. Furthermore, zygotic transcription is extensively activated already after the 64-cell stage. Thus, at least in medaka, the transition from maternal to zygotic transcription is uncoupled from the midblastula stage and not solely controlled by the nucleocytoplasmic ratio.}, subject = {Fische}, 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{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} } @article{SchartlBarnekow1984, author = {Schartl, Manfred and Barnekow, A.}, title = {Differential expression of the cellular src gene during vertebrate development}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61893}, year = {1984}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlBarnekow1984, author = {Schartl, Manfred and Barnekow, A.}, title = {Cellular src gene product detected in the freshwater sponge Spongilla lacustris}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61904}, year = {1984}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{RiehlSchartl1984, author = {Riehl, R. and Schartl, Manfred}, title = {A Transmission Electron Microscopical and Freeze-Etch Study of Malignant-Melanoma in Fish}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61916}, year = {1984}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{RiehlSchartlKollinger1984, author = {Riehl, R. and Schartl, Manfred and Kollinger, G.}, title = {Comparative studies on the ultrastructure of malignant melanoma in fish and human by freeze-etching and transmission electron microscopy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61920}, year = {1984}, abstract = {Malignant melanomas (MM) in the fish Xiphophorus and in humans were studied both by transmission electron microscopy (TEM) and freeze-etching (FE). In both fish and human melanomas the cells show interdigitations of the,plasma membranes. The nuclei are large and lobulated and have many nuclear pores. Melanosomes are abundant and melanosome complexes ("compound melanosomes") occur regularly. Pinocytotic vesicles could be demonstrated in fish and human melanomas showing iocal differences in frequency and distribution patterns in the tumor. lntercellular junctions are lacking in MM cells from fish and humans. The FE technique showed considerable advantages in demonstrating membrane-surface peculiarities such as nuclear pores or pinocytotic vesicles. The FE replicas of fish melanomas are like those of humans. These findings may support the hypothesis that melanoma in fish and humans reflect the same biological phenomenon.}, subject = {Physiologische Chemie}, language = {en} } @article{SchartlBarnekowBaueretal.1982, author = {Schartl, Manfred and Barnekow, A. and Bauer, H. and Anders, F.}, title = {Correlations of inheritance and expression between a tumor gene and the cellular homolog of the Rous sarcoma virus-transforming gene in Xiphophorus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61937}, year = {1982}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{BarnekowSchartlAndersetal.1982, author = {Barnekow, A. and Schartl, Manfred and Anders, F. and Bauer, H.}, title = {Identification of a fish protein associated with a kinase activity and related to the Rous sarcoma virus transforming protein}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61946}, year = {1982}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @inproceedings{GotzSchartl1994, author = {Gotz, R. and Schartl, Manfred}, title = {The conservation of neurotrophic factors during vertebrate evolution}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61964}, year = {1994}, abstract = {No abstract available}, subject = {Physiologische Chemie}, language = {en} } @article{LubjuhnSchartlEpplen1994, author = {Lubjuhn, T. and Schartl, Manfred and Epplen, J. T.}, title = {Methodik und Anwendungsgebiete des genetischen Fingerabdruckverfahrens}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61978}, year = {1994}, abstract = {No abstract available}, 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{TeutschbeinHaydnSamansetal.2010, author = {Teutschbein, Janka and Haydn, Johannes M. and Samans, Birgit and Krause, Michael and Eilers, Martin and Schartl, Manfred and Meierjohann, Svenja}, title = {Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67900}, year = {2010}, abstract = {Background: Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the Xiphophorus melanoma model system, a mutated version of the EGF receptor Xmrk (Xiphophorus melanoma receptor kinase) triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation. Methods: Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene FOSL1 was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated. Results: Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (Fosl1), early growth response 1 (Egr1), osteopontin (Opn), insulin-like growth factor binding protein 3 (Igfbp3), dual-specificity phosphatase 4 (Dusp4), and tumor-associated antigen L6 (Taal6). Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that FOSL1, OPN, IGFBP3, DUSP4, and TAAL6 also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of FOSL1 in human melanoma cell lines reduced their proliferation and migration. Conclusion: Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute new possible molecular players in melanoma development. Specifically, a role of FOSL1 in melanomagenic processes is demonstrated. These data are the basis for future detailed analyses of the investigated target genes.}, language = {en} } @article{LaisneyBraaschWalteretal.2010, author = {Laisney, Juliette A. G. C. and Braasch, Ingo and Walter, Ronald B. and Meierjohann, Svenja and Schartl, Manfred}, title = {Lineage-specific co-evolution of the Egf receptor/ligand signaling system}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67922}, year = {2010}, abstract = {Background: The epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand system contributes to many human malignancies. Consistent with such various tasks, the Egfr gene family has expanded during vertebrate evolution as a consequence of several rounds of whole genome duplication. Of particular interest is the effect of the fish-specific whole genome duplication (FSGD) on the ligand-receptor system, as it has supplied this largest group of vertebrates with additional opportunities for sub- and/or neofunctionalization in this signaling system. Results: We identified the predicted components of the Egf receptor-ligand signaling system in teleost fishes (medaka, platyfish, stickleback, pufferfishes and zebrafish). We found two duplicated egfr genes, egfra and egfrb, in all available teleost genomes. Surprisingly only one copy for each of the seven Egfr ligands could be identified in most fishes, with zebrafish hbegf being the only exception. Special focus was put on medaka, for which we more closely investigated all Egf receptors and Egfr ligands. The different expression patterns of egfra, egfrb and their ligands in medaka tissues and embryo stages suggest differences in role and function. Preferential co-expression of different subsets of Egfr ligands corroborates the possible subfunctionalization and specialization of the two receptors in adult tissues. Bioinformatic analyses of the ligand-receptor interface between Egfr and its ligands show a very weak evolutionary conservation within this region. Using in vitro analyses of medaka Egfra, we could show that this receptor is only activated by medaka ligands, but not by human EGF. Altogether, our data suggest a lineage-specific Egfr/Egfr ligand co-evolution. Conclusions: Our data indicate that medaka Egfr signaling occurs via its two copies, Egfra and Egfrb, each of them being preferentially coexpressed with different subsets of Egfr ligands. This fish-specific occurrence of Egf receptor specialization offers unique opportunities to study the functions of different Egf receptor-ligand combinations and their biological outputs in vertebrates. Furthermore, our results strongly support the use of homologous ligands in future studies, as sufficient cross-specificity is very unlikely for this ligand/receptor system.}, subject = {Epidermaler Wachstumsfaktor-Rezeptor}, 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{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{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{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{HongSchartl1993, author = {Hong, Yunhan and Schartl, Manfred}, title = {Sequence of the growth hormone (GH) gene from the silver carp (Hypophthalmichthys molitrix) and evolution of GH genes in vertebrates}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61620}, year = {1993}, abstract = {The silver carp (Hypophthalmichthys molitrix) growth hormone (GH) genewas isolated and sequenced following amplification from genomic DNA by the polymerase chain reaction. The gene spans a region of approx. 2.5 kb nucleotides (nt) and consists of five exons. The sequence predicts a polypeptide of 210 amino acids (aa) including a putative signal peptide of 22 hydrophobic aa residues. The arrangement of exons and introns is identical to the GH genes of common carp, grass carp, and very similar to mammals and birds, but quite different from that for the GH genes of tilapia and salmonids. The silver carp GH gene shares a high homology at the nt and aa Ievels with those of grass carp (95.3\% nt, 99.5\% aa) and of common carp (81\% nt, 95.7\% aa).}, subject = {Physiologische Chemie}, language = {en} } @article{AdamDimitrijevicSchartl1993, author = {Adam, Dieter and Dimitrijevic, Nicola and Schartl, Manfred}, title = {Tumor suppression in Xiphophorus by an accidentally acquired promoter}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-61630}, year = {1993}, abstract = {Melanoma formation in the teleost Xiphophorus is caused by a dominant genetic locus, Tu. This locus includes the Xmrk oncogene, which encodes a receptor tyrosine kinase. Tumor induction is. suppressed in wild-type fish by a tumor suppressor locus, R. Molecular genetic analyses revealed that the Tu locus emerged by nonhomologaus recombination of the Xmrk proto-oncogene with a previously uncharacterized sequence, D. This event generated an additional copy of Xmrk with a new promoter. Suppression of the new Xmrk promoter by R in parental fish and its deregulation in hybrids explain the genetics of melanoma formation in Xiphophorus.}, 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{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} }