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Ectopic Mitotic Recombination in Drosophila Probed with Bacterial β-Galactosidase Gene-Based Reporter Transgenes

Bärtsch, Stephan ; Dücker, Klaus ; Würgler, Friederich E. ; Sengstag, Christian

In: Nucleic Acids Research, 1997, vol. 25, no. 19, p. 3917-3924

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    Title
    • Ectopic Mitotic Recombination in Drosophila Probed with Bacterial β-Galactosidase Gene-Based Reporter Transgenes
    Author
    • Bärtsch, Stephan. Institute of Toxicology, Swiss Federal Institute of Technology and University of Zurich, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
    • Dücker, Klaus. 1nstitute of Zoology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
    • Würgler, Friederich E.. Institute of Toxicology, Swiss Federal Institute of Technology and University of Zurich, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
    • Sengstag, Christian. Institute of Toxicology, Swiss Federal Institute of Technology and University of Zurich, Schorenstrasse 16, 8603 Schwerzenbach, Switzerland
    Document Type
    • Postprint
    Language
    • English
    Published in
    • Nucleic Acids Research, 1997, vol. 25, no. 19, p. 3917-3924. Oxford University Press
    Other Version
    Classification
    • Health
    OAI-PMH Identifier
    • oai:doc.rero.ch:296515
    Summary
    Plasmids were constructed to investigate homologous mitotic recombination in Drosophila cells. Heteroalleles containing truncated but overlapping segments of the bacterial β-galactosidase gene (lacZ) were positioned either on separate plasmids or as direct repeats on the same chromosome. Recombination reconstituted a functional lacZ gene leading to expression of LacZ+ activity detectable by histochemical staining. High extrachromosomal recombination (ECR) frequencies between unlinked heteroalleles were observed upon transient co-transfection into Drosophila melanogaster Schneider line 2 (S2) cells. Stably transfected cells containing the lacZ heteroalleles linked on a chromosome exhibited intra-chromosomal recombination (ICR) frequencies two orders of magnitude lower than ECR frequencies. Recombination was inducible by exposing the cells to ethyl methanesulphonate or mitomycin C. Recombination products were characterized by multiplex PCR analysis and unequal sister chromatid recombination was found as the predominant mechanism reconstituting the lacZ gene. To investigate recombination in vivo imaginal disc cells from transgenic larvae carrying the reporter gene on the X chromosome were isolated and stained for LacZ+ activity. The presence of a few LacZ+ clones indicated that mitotic recombination events occurred at frequencies two orders of magnitude lower than the corresponding event in cultured cells and late during larval development