Gene conversion plays the major role in controlling the stability of large tandem repeats in yeast.
The genomic stability of the rDNA tandem array in yeast is tightly controlled to allow sequence homogenization and at the same time prevent deleterious rearrangements. In our study, we show that gene conversion, and not unequal sister chromatid exchange, is the predominant recombination mechanism regulating the expansion and contraction of the rDNA array. Furthermore, we found that RAD52, which is essential for gene conversion, is required for marker duplication stimulated in the absence of the two yeast type I topoisomerases. Our results have implications for the mechanisms regulating genomic stability of repetitive sequence families found in all eukaryotes.
Gangloff
S
S
Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
Zou
H
H
Rothstein
R
R
D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004264:DNA Topoisomerases, Type I / Q000235:genetics / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D005785:Gene Conversion; D005800:Genes, Fungal; D005819:Genetic Markers; D008957:Models, Genetic; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012854:Sister Chromatid Exchange
D017931:DNA Primers; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D005819:Genetic Markers; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; D004264:DNA Topoisomerases, Type I