Figure 7.

 Independent chromosomal association and dissociation of cohesins and condensins in Xenopus egg extracts. Sperm nuclei were incubated with interphase extracts (lanes 1,5,9), or with interphase extract followed by addition of a half volume of CSF-arrested extract to enter mitosis (lanes 2,6,10). Alternatively, sperm nuclei were incubated with CSF-arrested extracts (lanes 3,7,11), or with CSF-arrested extracts followed by addition of 0.4 mm CaCl₂, which promotes exit from mitosis and entry into interphase (lanes 4,8,12). Chromatin fractions were isolated and analyzed by immunoblotting. Lanes 1–4, control; lanes 5–8, cohesin depletion; lanes 9–12, condensin depletion; lane 13, a control without sperm.