Regulation Mechanisms of Meiotic Recombination Revealed from the Analysis of a Fission Yeast Recombination Hotspot ade6-M26

Metabolic stress-induced long ncRNA transcription governs the formation of meiotic DNA breaks in the fission yeast fbp1 gene

Meiotic recombination is a pivotal process that ensures faithful chromosome segregation and contributes to the generation of genetic diversity in offspring, which is initiated by the formation of double-strand breaks (DSBs). The distribution of meiotic DSBs is not uniform and is clustered at hotspots, which can be affected by environmental conditions. Here, we show that non-coding RNA (ncRNA) transcription creates meiotic DSBs through local chromatin remodeling in the fission yeast fbp1 gene. The fbp1 gene is activated upon glucose starvation stress, in which a cascade of ncRNA-transcription in the fbp1 upstream region converts the chromatin configuration into an open structure, leading to the subsequent binding of transcription factors. We examined the distribution of meiotic DSBs around the fbp1 upstream region in the presence and absence of glucose and observed several new DSBs after chromatin conversion under glucose starvation conditions. Moreover, these DSBs disappeared when cis-elements required for ncRNA transcription were mutated. These results indicate that ncRNA transcription creates meiotic DSBs in response to stress conditions in the fbp1 upstream region. This study addressed part of a long-standing unresolved mechanism underlying meiotic recombination plasticity in response to environmental fluctuation.