Without Swi6, chromosomes lag (top) because centromeres (left) but not chromosome arms (right) fall apart.

Allshire/AAAS

The cohesin complex acts as a glue for sister chromatids, but in some organisms most cohesin is lost from chromosome arms well before anaphase onset. Now, Robin Allshire (MRC Human Genetics Unit, Edinburgh, UK), Jean-Paul Javerzat (CNRS Institut de Biochimie et Génétique Cellulaires, Bordeaux, France), and colleagues show that Swi6, the fission yeast version of heterochromatin protein 1 (HP1), is required for the association of cohesin with centromeres. This provides one explanation for what Swi6 and heterochromatin are doing at the centromere.

“We knew before that mutants in Swi6 lost chromosomes at a high rate and displayed a high frequency of lagging chromosomes on anaphase spindles,” says Allshire. But the explanation for this defect remained unclear. Was Swi6 helping to establish kinetochore structure? Allshire says this remains a possibility,...

The Rockefeller University Press
2001
The Rockefeller University Press
2001
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