Molecular and General Genetics MGG

, Volume 260, Issue 6, pp 551–558

The Saccharomyces cerevisiae RAD54 gene is important but not essential for natural homothallic mating-type switching

  • J. Schmuckli-Maurer
  • W.-D. Heyer
Original Paper

DOI: 10.1007/s004380050928

Cite this article as:
Schmuckli-Maurer, J. & Heyer, WD. Mol Gen Genet (1999) 260: 551. doi:10.1007/s004380050928


Homothallic Saccharomyces cerevisiae strains switch their mating-type in a specific gene conversion event induced by a DNA double strand break made by the HO endonuclease. The RAD52 group genes control recombinational repair of DNA double strand breaks, and we examined their role in native homothallic mating-type switching. Surprisingly, we found that the Rad54 protein was important but not essential for mating-type switching under natural conditions. As an upper limit, we estimate that 29% of the rad54 spore clones can successfully switch their mating-type. The RAD55 and RAD57 gene products were even less important, but their presence increased the efficiency of the process. In contrast, the RAD51 and RAD52 genes are essential for homothallic mating-type switching. We propose that mating-type switching in RAD54 mutants occurs stochastically with a low probability, possibly reflecting different states of chromosomal structure.

Key wordsRAD54 Saccharomyces cerevisiae Recombination Mating-type DNA repair 

Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • J. Schmuckli-Maurer
    • 1
  • W.-D. Heyer
    • 1
  1. 1.Institute of General Microbiology, Baltzer-Strasse 4 CH-3012 Bern, SwitzerlandCH
  2. 2.Section of Microbiology, One Shields Avenue University of California at Davis Davis, CA 95616, USA e-mail: Tel.: +1-530–7523001, Fax: +1-530-7523011US

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