The efficient repair of double-strand breaks (DSBs) is crucial in maintaining 
genomic integrity. Sister chromatid cohesion is important for not only faithful 
chromosome segregation but also for proper DSB repair. During DSB repair, the 
Smc1-Smc3 cohesin complex is loaded onto chromatin around the DSB to support 
recombination-mediated DSB repair. In this study, we investigated whether Ctf18, 
a factor implicated in the establishment of sister chromatid cohesion, is 
involved in DSB repair in budding yeast. Ctf18 was recruited to HO-endonuclease 
induced DSB sites in an Mre11-dependent manner and to damaged chromatin in G2/M 
phase-arrested cells. The ctf18 mutant cells showed high sensitivity to 
DSB-inducible genotoxic agents and defects in DSB repair, as well as defects in 
damage-induced recombination between sister chromatids and between homologous 
chromosomes. These results suggest that Ctf18 is involved in damage-induced 
homologous recombination.