Movie 4

Spindle assembly, chromosome alignment and securin proteolysis without anaphase I or PBE in a Cep55-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 securin-GFP reaches a nadir around 8-8.5 h post-GVBD followed by recovery but that neither anaphase I nor PBE occur.