Crossover invariance determined by partner choice for meiotic DNA break repair.

ABSTRACT: Crossovers between meiotic homologs are crucial for their proper segregation, and crossover number and position are carefully controlled. Crossover homeostasis in budding yeast maintains crossovers at the expense of noncrossovers when double-strand DNA break (DSB) frequency is reduced. The mechanism of maintaining constant crossover levels in other species has been unknown. Here we investigate in fission yeast a different aspect of crossover control--the near invariance of crossover frequency per kb of DNA despite large variations in DSB intensity across the genome. Crossover invariance involves the choice of sister chromatid versus homolog for DSB repair. At strong DSB hotspots, intersister repair outnumbers interhomolog repair approximately 3:1, but our genetic and physical data indicate

SUBMITTER: Hyppa RW 

PROVIDER: S-EPMC2911445 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature