Figure 3.

Proposed model for MMBIR. (A) Failure to repair collapsed replication forks by BIR has been shown to induce MMBIR. The 3′ end dissociates from the original donor template (in blue) and can anneal to microhomologous sequences present in the newly replicated ssDNA within the recipient molecule (in red) via a snapback mechanism (B,C) or at any other donor template (in green) (D,E). The 3′ strand extension proceeds with low processivity and involves multiple template switchings before annealing back to the original template (F), resulting in complex genomic rearrangements (G).