The localization of condensin along chromosome arms is crucial for chromosome segregation in anaphase. Condensin is also enriched at telomeres but how and for what function remains elusive. Here we show that Taz1, the main component of the Shelterin complex that ensures telomeric functions, acts as a positioning device to enrich condensin at telomeres in fission yeast. High condensin occupancy at telomeres is needed for their full disjunction in anaphase. Consistent with a cis-acting process, condensin drives telomere separation independently of the decatenation activity of Topoisomerase II also required for chromosome arm separation. Our results reveal a cis-acting pathway that enriches condensin at telomeres to promote their separation during mitosis.

In fission yeast, Aurora B localizes at telomeres during meiosis I and promotes telomere and chromosome arm separation as observed in mitosis. Oppositely, in meiosis II, Aurora B and condensin appear dispensable for telomere and chromosome arm separation illustrating the critical differences in the control of chromosome segregation between mitosis and meiosis II.