A, Frequency of long-range RMD is increased by an additional DSB downstream of the 3' repeat. Illustrations show the GFP-RMD reporter, with sgRNAs/Cas9 cleavage sites indicated as red arrows (left). The frequency of BIR/SSA in mES cells carrying the RMD-GFP reporter was determined after cleavage of the reporter by the indicated sgRNAs/Cas9 (right). 