Figure 1. γH2AX recruits cohesin to damage sites. Top—experimental data showing the broad region where γH2AX (red) forms; in contrast, repair proteins (here Mre11p, blue) bind in a narrow region. Bottom—nucleosomes containing γH2AX (red) recruit cohesin complexes (green rings), which use the unbroken sister chromatid to “splint” broken ends together, while leaving the ends themselves free for repair. ChIP, chromatin immunoprecipitation; DSB, DNA double-strand break.