Movie 3

Spindle assembly, chromosome alignment, securin proteolysis, anaphase I and PBE in a mock-depleted oocyte. Timelapse imaging of an oocyte expressing H2B-RFP (red) and securin-GFP (monochrome) and stained with SiR-tubulin dye (green). Time scale is shown in hh:mm. Note that a bipolar spindle assembles, chromosomes align and anaphase I occurs around 8 h post-GVBD concurrently with which, securin-GFP levels reach a nadir followed very shortly after by PBE, entry into MII and partial recovery of securin-GFP levels.