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TY - JOUR AU - Bishop, Douglas K. AU - Williamson, Marsha S. AU - Fogel, Seymour AU - Kolodner, Richard D. PY - 1987 DA - 1987/07/01 TI - The role of heteroduplex correction in gene conversion in Saccharomyces cerevisiae JO - Nature SP - 362 EP - 364 VL - 328 IS - 6128 AB - Two different models have been proposed to explain the relative frequencies of the non-mendelian allelic segregations which are detected by tetrad analysis after meiosis in fungi1–7. The first model maintains that 6:2 type tetrads result from correction of heteroduplexes containing mismatched sites and 5:3 type tetrads result from failure to correct mismatched sites. The second model suggests that 6:2 segregations result from the filling-in of double-strand gaps using information obtained from both strands of a homologous duplex. In this model 5:3 type tetrads result if the allele is included in the heteroduplex regions flanking the gap and the resulting mismatched nucleotides are not corrected7. We have studied the correction of heteroduplex plasmid DNA in pms1 mutant strains of Saccharomyces cerevisiae, which are known to exhibit higher frequencies of 5:3 type tetrads and lower frequencies of 6:2 tetrads than wild-type strains. Our results suggest that the pms1 mutation causes a defect in mismatch correction, supporting the hypothesis that meiotic gene conversion in wild-type yeast cells often results from the correction of heteroduplex DNA. SN - 1476-4687 UR - https://doi.org/10.1038/328362a0 DO - 10.1038/328362a0 ID - Bishop1987 ER -