(a) Formation of Rad52 and Rpa1 foci after 80 Gy ionizing radiation in wdr70 þ cells and wdr70D cells. n ¼ 3 biological repeats. Error bars ¼ s.d. (b) Top: schematic representation of the HO-DSB locus: vertical lines: ApoI sites (35 bp and 3 kb from break site). HO ...