Splitting the chromosome: Cutting the ties that bind sister chromatids

In eukaryotic cells, sister DNA molecules remain physically connected from their production at S phase until their separation during anaphase. This co hesion is essential for the separation of sister chromatids to opposite pol es of the cell at mitosis. It also permits chromosome segregation to take p lace long after duplication has been completed. Recent work has identified a multisubunit complex called cohesin that is essential for connecting sist ers. Proteolytic cleavage of one of cohesin's subunits may trigger sister s eparation at the onset of anaphase,