Fig. 6. tws618/5 mks1 cells show abnormal anaphases. Orcein stained squashed preparations of mks1(A,D), tws618/5 (B,E) and tws618/5 mks1 (C,F) cells show that tws618/5 is epistatic to mks1 with respect to abnormal anaphase. The proportion of anaphase figures is similar in tws618/5 mks1 and tws618/5 cells (Table 1C). However, mks1 is epistatic to tws618/5 with respect to chromosome condensation.