(B and E) Chromosome spreads at metaphase and anaphase of meiosis I (6 and 9 hours after GVBD) or meiosis II (left and right panels, respectively), in the presence or absence of STLC (for 2.5 hours) and Reversine (+Rev., for 1 hour) as indicated. Spreads were stained with CREST serum (red) and Hoechst (grey). Single chromosomes are present in anaphase I and single sister chromatids in anaphase II. Scale bar indicates 5 µm in (A and D), and 10 µm in (B, C, E and F). In all panels n indicates the number of oocytes with the shown phenotype and the total number of oocytes analyzed. 