Mismatch repair of heteroduplex DNA intermediates of extrachromosomal recombination in mammalian cells

Win Ping Deng, Jac A. Nickoloff

Research output: Contribution to journalArticle

29 Citations (Scopus)


Previous work indicated that extrachromosomal recombination in mammalian cells could be explained by the single-strand annealing (SSA) model. This model predicts that extrachromosomal recombination leads to nonconservative crossover products and that heteroduplex DNA (hDNA) is formed by annealing of complementary single strands. Mismatched bases in hDNA may subsequently be repaired to wild-type or mutant sequences, or they may remain unrepaired and segregate following DNA replication. We describe a system to examine the formation and mismatch repair of hDNA in recombination intermediates. Our results are consistent with extrachromosomal recombination occurring via SSA and producing crossover recombinant products. As predicted by the SSA model, hDNA was present in double-strand break-induced recombination intermediates. By placing either silent or frameshift mutations in the predicted hDNA region, we have shown that mismatches are efficiently repaired prior to DNA replication.

Original languageEnglish
Pages (from-to)400-406
Number of pages7
JournalMolecular and Cellular Biology
Issue number1
Publication statusPublished - 1994
Externally publishedYes


ASJC Scopus subject areas

  • Cell Biology
  • Genetics
  • Molecular Biology

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