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Swi5 acts in meiotic DNA joint molecule formation in Schizosaccharomyces pombe

Chad Ellermeier1, Henning Schmidt, Gerald R Smith

  • 1Fred Hutchinson Research Cancer Center, Seattle, Washington 98109, USA.

Genetics
|October 7, 2004
PubMed

Insights

The Schizosaccharomyces pombe swi5 gene product is crucial for DNA repair and mating-type switching. This study reveals Swi5

Area of Science:

  • Molecular Biology
  • Genetics
  • Cell Biology

Background:

  • Schizosaccharomyces pombe swi5 mutants exhibit defects in mitotic mating-type switching and meiotic DNA double-strand break repair.
  • The precise role of Swi5 in these processes remained largely uncharacterized.

Purpose of the Study:

  • To identify and characterize the function of the swi5 gene in Schizosaccharomyces pombe.
  • To elucidate Swi5's role in DNA repair pathways and meiotic recombination.

Main Methods:

  • Gene identification and characterization of swi5.
  • Construction and analysis of swi5 deletion mutants.
  • Assessment of DNA damage sensitivity, mating-type switching, and meiotic recombination frequencies.

Main Results:

  • The swi5 gene encodes an 85-amino-acid polypeptide with a predicted coiled-coil domain.
  • swi5 deletion mutants showed normal mitotic growth but were hypersensitive to DNA damage and defective in mating-type switching.
  • Meiotic recombination frequencies were reduced ~10-fold, and spore viability was affected in conjunction with other DNA repair proteins.

Conclusions:

  • The Swi5 polypeptide plays a significant role in the branched pathway of joint molecule formation during the repair of meiotic DNA breaks.
  • Swi5 is essential for efficient DNA double-strand break repair and mating-type switching in Schizosaccharomyces pombe.

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