Evolutionary origin and molecular biology of the melanoma-inducing oncogene of Xiphophorus.
Melanoma formation in platyfish/swordtail hybrids of genus Xiphophorus is due to overexpression of the receptor tyrosine kinase oncogene Xmrk. This gene is the molecular equivalent to the Tu-locus of platyfish formerly identified by Mendelian genetics. The supposed evolutionary origin of the Xmrk oncogene is a nonhomologous recombination event in the 5' region of the corresponding Xmrk protooncogene with an anonymous sequence, D. This event led to a gene duplication of Xmrk, whereby the new copy obtained a novel promoter derived from D. Inactivity of this promoter in parental fish warrants lack of tumorigenicity of the Xmrk oncogene in wild playfish. In hybrids, however, the promoter is active. This leads to the pigment cell transforming overexpression of Xmrk.
Schartl
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Biozentrum, Universität Würzburg, Germany.
Dimitrijevic
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Schartl
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D016475:3T3 Cells; D000818:Animals; D030801:Animals, Genetically Modified; D005075:Biological Evolution; D003532:Cyprinodontiformes / Q000145:classification / Q000235:genetics*; D005260:Female; D005393:Fish Diseases / Q000235:genetics*; D029941:Fish Proteins; D015972:Gene Expression Regulation, Neoplastic; D006824:Hybridization, Genetic; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000662:veterinary*; D008547:Melanophores; D051379:Mice; D008957:Models, Genetic; D009857:Oncogenes; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011499:Protein Processing, Post-Translational; D011519:Proto-Oncogenes; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011995:Recombination, Genetic
D029941:Fish Proteins; D011993:Recombinant Fusion Proteins; D020794:Receptor Protein-Tyrosine Kinases; C077101:Xmrk protein, Xiphophorus