Dynamics of separase, securin, and cohesin at anaphase onset. (A) SEP-1::GFP (green) co-expressed with H2B::mCherry (magenta) at the spindle in meiosis I. In prometaphase I, spindle SEP-1::GFP localizes to kinetochore cups around the bivalents (kinetochore). Just before anaphase onset, SEP-1::GFP accumulates on spindle poles, then invades the midbivalent region (yellow caret), where it accumulates when chromosomes move apart. (B) Montage showing rapid SEP-1::mScarlet (green) relocalization to the midbivalent just before the abrupt loss of COH-3::GFP and the poleward movement of chromosomes (magenta, time in seconds relative to t = 0, anaphase onset). (C) Montage showing the dynamics of endogenous IFY-1^WT::GFP (green) co-expressed with chromosome marker H2B::mCherry (magenta) during the metaphase-to-anaphase I transition. IFY-1^WT::GFP signal is significantly reduced by anaphase onset. (D) In the cortex, SEP-1::GFP relocalizes from linear elements (white arrow) to cortical granules labeled with mScarlet::RAB-11.1 (arrowhead) by 30 s after anaphase onset. Scale bars: 2 µm.