Meiotic DNA breaks associated with recombination in S. pombe.

In the fission yeast Schizosaccharomyces pombe, we have detected prominent DNA breaks that appeared shortly after premeiotic DNA replication. These breaks, like meiotic recombination, required the products of the six rec genes tested. Prominent breaks were detected at widely separated sites, about 100-300 kb apart, equivalent to about 50-150 sites per genome or approximately the number of meiotic recombination events. Certain features of these breaks are similar to those in the distantly related yeast Saccharomyces cerevisiae, the only other organism in which meiotic DNA breaks have been reported. Other features, however, appear to be different. These results suggest that, although DNA breaks may be a general feature of meiotic recombination, the breaks in S. pombe may play a role different from those in S. cerevisiae.