Fig. 8
From: DNA double-strand breaks in telophase lead to coalescence between segregated sister chromatid loci
Model for the effect of DSBs on segregated sister chromatids. Segregated sister chromatids are maintained away from each other in telophase. Two complementary mechanisms aid to this aim. Firstly, an elongated spindle is maintained by the action of kinesin-5 Cin8 on interpolar microtubules (iMTs). Secondly, segregated sister chromatids are in a hypercondensed state54. DSBs locally mobilise the affected chromatin through decondensation, so the histone-poor signal in de novo chromatin bridges, and globally accelerate loci movement. In addition, Cin8 is displaced out of iMTs by partial dephosphorylation, abrogating the spindle forces that keep SPBs far from each other. It is likely that enforced astral MTs also participate in bringing closer the SPBs. All these circumstances make possible for sister loci at chromosome arms to coalesce and repair DSBs through HR with the sister chromatid, even when cells are in telophase
