Double-strand DNA breaks (DSBs) occur at recombination hotspots during 
Saccharomyces cerevisiae meiosis and are thought to initiate exchange at these 
loci. Analysis of DSB sites in three regions of the yeast genome indicated that 
breaks occur at or near many potential transcription promoters and that DSBs 
initiate most, if not all, meiotic recombination. DSB sites displayed 
deoxyribonuclease I hypersensitivity in chromatin from mitotic and meiotic 
cells, and changes in chromatin structure produced parallel changes in the 
occurrence of DSBs. Thus, features of chromatin structure that are established 
before meiosis play a role in determining where meiotic recombination events 
initiate.