PiggyMac and the NHEJ pathway orchestrate accurate assembly of MAC chromosomes. On the diagrams shown on top of each panel, the IES is drawn in red and its flanking DNA in black. The excisase complex, which includes PiggyMac and putative additional partners, is represented in blue. In bottom panels, different germline chromosomes are displayed in different colors, with IESs in red. (a) If a synaptic complex is formed prior to cleavage, adjacent MAC-destined chromosome fragments are brought together, which might favor their alignment during the repair step, therefore limiting the risk of translocation. (b) In the absence of a synaptic complex, IES excision could lead to catastrophic chromosome breakage and translocation, as described in [68].