Mapping of Meiotic Single-Stranded DNA Reveals Double-Strand-Break Hotspots near Centromeres and Telomeres

Hannah G. Blitzblau, George W. Bell, Joseph Rodriguez, Stephen P. Bell, Andreas Hochwagen

Research output: Contribution to journalArticlepeer-review

Abstract

Background: Every chromosome requires at least one crossover to be faithfully segregated during meiosis. At least two levels of regulation govern crossover distribution: where the initiating DNA double-strand breaks (DSBs) occur and whether those DSBs are repaired as crossovers. Results: We mapped meiotic DSBs in budding yeast by identifying sites of DSB-associated single-stranded DNA (ssDNA) accumulation. These analyses revealed substantial DSB activity in pericentrometric regions, in which crossover formation is largely absent. Our data suggest that centromeric suppression of recombination occurs at the level of break repair rather than DSB formation. Additionally, we found an enrichment of DSBs within a ∼100 kb region near the ends of all chromosomes. Introduction of new telomeres was sufficient for inducing large ectopic regions of increased DSB formation, thereby revealing a remarkable long-range effect of telomeres on DSB formation. The concentration of DSBs close to chromosome ends increases the relative DSB density on small chromosomes, providing an interference-independent mechanism that ensures that all chromosomes receive at least one crossover per homolog pair. Conclusions: Together, our results indicate that selective DSB repair accounts for crossover suppression near centromeres and suggest a simple telomere-guided mechanism that ensures sufficient DSB activity on all chromosomes.

Original languageEnglish (US)
Pages (from-to)2003-2012
Number of pages10
JournalCurrent Biology
Volume17
Issue number23
DOIs
StatePublished - Dec 4 2007

Keywords

  • DNA

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology
  • General Agricultural and Biological Sciences

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