Molecular Genetics and Genomics

, Volume 267, Issue 1, pp 64–70

Most meiotic CAG repeat tract-length alterations in yeast are SPO11 dependent

  •  C. Jankowski
  •  D. Nag
Original Paper

DOI: 10.1007/s00438-001-0635-4

Cite this article as:
Jankowski, C. & Nag, D. Mol Gen Genomics (2002) 267: 64. doi:10.1007/s00438-001-0635-4


The expansion of trinucleotide repeat sequences associated with hereditary neurological diseases is believed from earlier studies to be due to errors in DNA replication. However, more recent studies have indicated that recombination may play a significant role in triplet repeat expansion. CAG repeat tracts have been shown to induce double-strand breaks (DSBs) during meiosis in yeast, and DSB formation is dependent on the meiotic recombination machinery. The rate of meiotic instability is several fold higher than mitotic instability. To determine whether DSB repair is responsible for the high rate of repeat tract-length alterations, the frequencies of meiotic repeat-tract instability were compared in wild-type and spo11 mutant strains. In the spo11 background, the rate of meiotic repeat-tract instability remained at the mitotic level, suggesting that meiotic alterations of CAG repeat tracts in yeast occur by the recombination mechanism. Several of these meiotic tract-length alterations are due to DSB repair involving use of the sister chromatid as a template.

Triplet repeat instability Double-strand break repair Meiotic recombination Yeast 

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  •  C. Jankowski
    • 1
  •  D. Nag
    • 1
  1. 1.Molecular Genetics Program, Axelrod Institute, Wadsworth Center, 120 New Scotland Avenue, Albany, NY 12201-2002, USA
  2. 2.Department of Biomedical Sciences, School of Public Health, State University of New York, Albany, NY 12201, USA

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