Conversion-type and restoration-type repair of DNA mismatches formed during meiotic recombination in Saccharomyces cerevisiae

Genetics. 1998 Aug;149(4):1693-705. doi: 10.1093/genetics/149.4.1693.

Abstract

Meiotic recombination in yeast is associated with heteroduplex formation. Heteroduplexes formed between nonidentical DNA strands contain DNA mismatches, and most DNA mismatches in wild-type strains are efficiently corrected. Although some patterns of mismatch correction result in non-Mendelian segregation of the heterozygous marker (gene conversion), one predicted pattern of correction (restoration-type repair) results in normal Mendelian segregation. Using a yeast strain in which a marker leading to a well-repaired mismatch is flanked by markers that lead to poorly repaired mismatches, we present direct evidence for restoration-type repair in yeast. In addition, we find that the frequency of tetrads with conversion-type repair is higher for a marker at the 5' end of the HIS4 gene than for a marker in the middle of the gene. These results suggest that the ratio of conversion-type to restoration-type repair may be important in generating gradients of gene conversion (polarity gradients).

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alcohol Oxidoreductases
  • Alleles
  • Aminohydrolases
  • Crossing Over, Genetic
  • DNA Repair / genetics*
  • DNA, Fungal / genetics
  • DNA, Fungal / metabolism
  • Fungal Proteins / genetics
  • Gene Conversion
  • Genes, Fungal
  • Genetic Markers
  • Genotype
  • Meiosis / genetics*
  • Mutation
  • Nucleic Acid Heteroduplexes / genetics
  • Nucleic Acid Heteroduplexes / metabolism
  • Pyrophosphatases
  • Recombination, Genetic*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins*
  • Transcription Factors / genetics

Substances

  • DNA, Fungal
  • Fungal Proteins
  • Genetic Markers
  • Nucleic Acid Heteroduplexes
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Alcohol Oxidoreductases
  • HIS4 protein, S cerevisiae
  • Aminohydrolases
  • Pyrophosphatases