@article{WinklerWittbrodtLammersetal.1994,
  author    = {Winkler, Christoph and Wittbrodt, Joachim and Lammers, Reiner and Ullrich, Axel and Schartl, Manfred},
  title     = {Ligand-dependent tumor induction in medakafish embryos by a Xmrk receptor tyrosine kinase transgene},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87107},
  year      = {1994},
  abstract  = {Xmrk encodes a subclass 1 receptor tyrosine kinase (RTK) which has been cloned from the melanomainducing locus Tu of the poeciliid fish Xiphophorus. To demonstrate a high oncogenic potential in vivo we transferred the gene into early embryos of the closely related medakafish. Ectopic expression of the Xmrk oncogene under the control of a strong, constitutive promoter (CMVTk) led to the induction of embryonic tumors with high incidence, after short latency periods, and with a specific pattern of affected tissues. We demonstrate ligand-dependent transformation in vivo using a chimeric receptor consisting of the extracellular and transmembrane domains of the human EGF receptor (HER) and the cytoplasmatic domain of Xmrk. Expression of the chimeric receptor alone does not lead to ldnase activation or induction of tumors. Coexpression of the chimera with its corresponding ligand, human transforming growth factor alpha (bTGF(X), however, results in the activation of the chimeric RTK. In injected fish embryos the induction of the neoplastic growth is observed with similar incidence and tissue distribution as in embryos carrying the native Xmrk oncogene suggesting that the ligand as well as factors downstream of tbe RTK are required for tumor formation. In this study we show single-step induction of tumors by ectopic expression of RTKs in vivo substantiating tbe significance of autocrine stimulation in RTK induced tumors in vertebrales.},
  subject      = {Japank{\"a}rpfling},
  language  = {en}
}
@article{WinklerHongWittbrodtetal.1992,
  author    = {Winkler, Christoph and Hong, Yunhan and Wittbrodt, Joachim and Schartl, Manfred},
  title     = {Analysis of heterologous and homologous promoters and enhancers in vitro and in vivo by gene transfer into Japanese medaka (Oryzias latipes) and Xiphophorus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86796},
  year      = {1992},
  abstract  = {Efficient expression systems are required for analysis of gene regulation and function in teleost fish. To develop such systems, a nurober of inducible or constitutive promoter and enhancer sequences of fish or higher vertebrate origin were tested for activity in a variety of fish celllines andin embryos of the Japanese medaka fish (Oryzias latipes) and Xiphophorus. The activity of the different promoterenhancer combinations were quantitated. Considerable differences were found for some constructs if tested in vitro or in vivo. From the data obtained, a set of expression vectors for basic research as weH as for aquaculture purposes were established.},
  subject      = {Schwertk{\"a}rpfling},
  language  = {en}
}