The single-end invasion: An asymmetric intermediate at the double-strand break to double-holliday junction transition of meiotic recombination

Neil Hunter, Nancy Kleckner

Research output: Contribution to journalArticle

461 Scopus citations


We identify a novel meiotic recombination intermediate, the single-end invasion (SEI), which occurs during the transition from double-strand breaks (DSBs) to double-Holliday junction (dHJs). SEIs are products of strand exchange between one DSB end and its homolog. The structural asymmetry of SEIs indicates that the two ends of a DSB interact with the homolog in temporal succession, via structurally (and thus biochemically) distinct processes. SEIs arise surprisingly late in prophase, concomitant with synaptonemal complex (SC) formation. These and other data imply that SEIs are preceded by nascent DSB-partner intermediates, which then undergo selective differentiation into crossover and noncrossover types, with SC formation and strand exchange as downstream consequences. Late occurrence of strand exchange provides opportunity to reverse recombinational fate even after homologs are coaligned and/or synapsed. This feature can explain crossover suppression between homeologous and structurally heterozygous chromosomes.

Original languageEnglish (US)
Pages (from-to)59-70
Number of pages12
Issue number1
StatePublished - Jul 13 2001
Externally publishedYes


ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology

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