DNA break formation induces Scc2/cohesin-dependent recruitment of condensin to meiotic chromosomes

Meiotic chromosome pairing, recombination, and fertility depends on the conserved loop-axis architecture of meiotic chromosomes. This architecture is modulated by condensin, a structural maintenance of chromosome (SMC) complex that catalyzes chromatin loop formation. Here, we investigated how condensin is recruited to meiotic chromosomes in Saccharomyces cerevisiae. We show that double-strand break (DSB) formation, the initiating event of meiotic recombination, causes condensin redistribution from the nucleolus to DSB hotspots, pericentromeric regions and axis attachment sites. Hotspot association of condensin correlates weakly with break probability but does not depend on local DSB formation, whereas association with axis sites and pericentromeric regions depends on the Scc2-associated pool of cohesin, another SMC complex. Intriguingly, Scc2 distribution also changes in response to DSB formation. As condensin and Scc2-cohesin both catalyze chromatin loop extrusion, their redistribution upon DSB formation implies a profound change in chromatin loop dynamics that may help promote proper chromosome pairing and DNA repair. ChIP-seq analysis of condensin binding dynamics in S. cerevisiae in meiosis. Each bedgraph file is the results from paired Input and ChIP samples.